state of California
The Resources Agency
Department of
Water Resources
The California
Water Plan
Projected Use and
Available Water
Supplies to 2010
UNfVERSlTY OF CALIFORNIA
DAVIS
AUG 2 7 1984
Bulletin 160-83
December 1983
HYDROLOGIC STUDY AREAS
OF
CALIFORNIA
N C - NORTH COAST
S F - SAN FRANCISCO BAY
C C . CENTRAL COAST
L A - LOS ANGELES
S A - SANTA ANA
SAN OIEGO
SACRAMENTO
SAN JOAQUIN
TULARE LAKE
NORTH LAHONTAN
SOUTH LAHONTAN
COLORADO RIVER
^■■f
\
i
DECEMBER 1982
Department of
Water Resources
Bulletin 160-83
The California
Water Plan
Projected Use and
Available Water
Supplies to 2010
December 1983
Gordon K. Van VIeck
Secretary for Resources
The Resources
Agency
George Deukmejian
Governor
State of
California
David N. Kennedy
Director
Department of
Water Resources
Copies of this bulletin at $5.00 each may be ordered from:
Stote of Colifornio
DEPARTMENT OF WATER RESOURCES
P.O. Box 388
Sacramento, CA 95802
Moke checks payable to:
Department of Water Resources
California residents add 6 percent soles tax.
ON THE COVER: The Colifornio
Water Plan comprises the use, control,
protection, conservation, and
development of California s water
resources. These scenes represent the
central aspect of the plan, the transfer
of surplus water from oreas of origin to
satisfy the needs of agriculture and
cities in water-deficient areas.
FOREWORD
This is the fourth in the 160 series of bulletins that contribute to the updating
of the California Water Plan. It presents information on amounts of water
currently used in the State, projects water uses to 2010, and identifies some of
the alternative sources of supplies or potential shortages associated with those
future uses. It is essentially a technical report, representing some four years of
intensive effort by the Department's land and water use analysts, economists,
and engineers.
Since 1974. when the last report in this series was published, urban and
agricultural uses of water have increased steadily, and increases by both sec-
tors are seen as continuing to grow over the next 30 years. Water conservation
and waste water reclamation can and will help to meet future water needs by
extending the use of presently developed supplies. Efforts to conserve water
are projected to reduce needs by 1.6 million acre-feet in 2010. Use of reclaimed
water is also expected to increase.
Trends indicate that the State's population will be 1 1 million greater in 2010,
thus increasing total urban net water use by about 37 percent. The projected
addition of 700,000 acres of irrigated farmland by 2010 is expected to increase
total agricultural net water use by about 6 percent. Most of the expansion in
acreage will occur in the Central Valley, where use in the Sacramento Valley
will grow by 15 percent and in the San Joaquin River basin, by 10 percent. In
the Tulare Lake basin, where 90 percent of the irrigable land overlying usable
ground water is already developed, water use is projected to increase by only
6 percent.
In all but a few local areas of the State, available water supplies are sufficient
to meet current water needs at the 1980 level of development. However, delays
encountered in constructing needed projects could cause widespread difficul-
ties in the future. A series of drought years could also create difficulty because
the present margin of safety narrows as water needs increase. Ground water
overdraft, especially in the San Joaquin Valley, will continue to worsen until
surplus Sacramento River water can be imported.
Generally speaking, the projections in the report indicate considerably less
population growth for California than did the initial report in this series, pub-
lished in 1966. However, the growth that is taking place and the current projec-
tions for growth over the next 30 years indicate that further development of
water facilities will be necessary to meet the State's urban and agricultural
water needs. Recommended actions for these facilities will be the subject of
other Department reports.
David N. Kennedy
Director
Department of Water Resources
STATE OF CALIFORNIA
George Deukmejian. Governor
THE RESOURCES AGENCY
Gordon K. Van VIeck. Secretary for Resources
DEPARTMENT OF WATER RESOURCES
David N. Kennedy. Director
Alex R. Cunningham Howard H. Eastin Robert E. Whiting
Deputy Director Deputy Director Deputy Director
Salle S. Jantz
Assistant Director
DIVISION OF PLANNING
Arthur C. Gooch Chief
James U. McDaniel Chief. Statewide Planning Branch
This report was prepared by
Warren J. Cole Chief. Coordinated Statewide Planning
Ralph G. Allison Senior Engineer. Water Resources
Donald K. Cole Research Manager II
Albert J. Dolcini Special Editor and Advisor
Guy Fairchild * Supervising Engineer. Water Resources
Travis Latham Research Writer
Rose M. Nonini Staff Services Manager II
Glenn B. Sawyer Supervising Land and Water Use Analyst
With assistance from
Nadeil A. Chan Steven Kasower Richard Soehren
Joseph C. Fitz Steven C. Macaulay James Dee Turner
Adrian H. Griffin Edward A. Pearson Janet Turner
Maria J. Hambright David E. Pelgen Richard J. Wagner
Edward F. Huntley Helen J. Peters James M. Wardlow
Maurice D. Roos
Editorial ana proaucnon services were provioed by
Marjorie C. Bergeron Wora Processing Technician
Earl G. Bingham Research Writer
Marge Hutchinson „ Associate Governmental Program Analyst
Paulyne D. Joe Senior Delineator
David LaBrie Production Coordinator
Wii =~ '^ McKane Supervisor of Drafting Services
Lee r!- Management Services Technician
Li-c5 .<v. Smith Senior Stenographer
Susan M Tatayon Editorial Aid
• Decs 5 =80
District staff who made major contributions
NORTHERN DISTRICT, RED BLUFF
Charles Alenskis * Associate Engineer, Water Resources
Charles L. Ferchaud Associate Land and Water Use Analyst
Robert L. McGill Senior Land and Water Use Analyst
Walter L. Qumcy Research Manager II
CENTRAL DISTRICT, SACRAMENTO
Gurdev S. Chima Assistant Engineer, Water Resources
Richard A. Cocke Associate Land and Water Use Analyst
Sina Darabzand Junior Civil Engineer
Harold H. Higgins Senior Engineer, Water Resources
Raymond F. Hoagland Research Manager II (Economic/Resources)
Yoshio J. Kono Associate Land and Water Use Analyst
Lyndon R. Pommells Research Analyst II
George K. Sato Senior Land and Water Use Analyst
SAN JOAQUIN DISTRICT, FRESNO
Mark W. Cowin Assistant Engineer, Water Resources
Terry L. Eriewine Assistant Engineer, Water Resources
Lloyd Hartwig Associate Engineer, Water Resources
W. Max Hubbart Associate Engineer, Water Resources
Norman A. MacGillivray Associate Land and Water Use Analyst
Stanley E. Sherman Research Manager II
Frederick E. Stumpf Senior Land and Water Use Analyst
Iris M. Yamagata Assistant Engineer, Water Resources
SOUTHERN DISTRICT, LOS ANGELES
Jay Federman Research Manager II
David Inouye Associate Land and Water Use Analyst
Vern Knoop Associate Engineer, Water Resources
Diane Sanchez Water Resources Engineering Associate
John Tenero Associate Land and Water Use Analyst
■ Deceased
State of California
Department of Water Resources
CALIFORNIA WATER COMMISSION
ROY E. DODSON, Chairperson. San Diego
DANIEL M. DOOLEY, Vice Chairperson. Visalia
Stanley M. Barnes Visalia
Thomas K. Beard Stockton
Merrill R. Goodall Claremont
Martin A. Matich San Bernardino
Charlene H. Orszag Sherman Oaks
Alexandra C. Stiliman Areata
Jack G. Thomson Bakersfield
Orville L. Abbott
Executive Officer and Chief Engineer
Tom Y. Fujimoto
Assistant Executive Officer
The California Water Commission serves as a policy advisory body to the Director of Water Resources
on all California water resources matters. The nine-member citizen commission provides a water resources
forum for the people of the State, acts as a liaison between the legislative and executive branches of State
Government, and coordinates Federal, State, and local water resources efforts.
CONTENTS
Page
Foreword iii
Organization, Department of Water Resources iv
Membership, California Water Commission vi
Acknowledgments for Photographs xvi
Metric Conversion Factors 268
CHAPTER I. SUMMARY AND FINDINGS 1
Outlool< in 1983 2
In General 2
On Growth 2
On Water Uses 2
On Present Water Supplies 3
On Future Water Supplies 4
Organization and Scope of Report 4
Planning for Water Resources Development (Chapter II) 5
Water Use and Water Supply in 1980 (Chapter III) 5
Future Water Use— 1980 to 2010 (Chapter IV) 5
Projected Use of Water Supplies to 2010 (Chapter V) 6
Water Management Options (Chapter VI) 6
CHAPTER II. PLANNING FOR WATER RESOURCES DEVELOPMENT 7
Early Planning and Development 7
California Water Rights 10
Development of Ground Water Resources 11
Major Urban Water Development 13
Major Agricultural Water Development 14
The California Water Plan 15
Update of the California Water Plan 16
The 1966 Update 16
The 1970 Update 17
The 1974 Update 17
Water Quality Control Planning 21
Recent Water Supply Developments 21
The Drought of 1976 and 1977 23
Effects of the Drought 24
Lessening of the Drought's Effects 24
The Drought's Outcome 24
Need for and Significance of Water Use Projections 25
CHAPTER III. WATER USE AND WATER SUPPLY IN 1980 27
Agricultural Water Use 27
Land Use 27
Derivation of 1980 Acreage 29
Principal Changes in Irrigated Land and Crop Acreage, 1972-1980 29
Factors Causing Changes in Irrigated Acreage and Crop Patterns 32
Irrigation Water Use 34
Evapotranspiration 34
Evapotranspiration of Applied Water 34
Applied Water 35
Recent Trends in Irrigation Systems 37
CONTENTS (Continued)
CHAPTER III (Continued) Page
Agricultural Water Conservation 38
Urban Water Use 41
Population 41
Migration 41
Natural Increase 43
Inter-County Growth Patterns 43
Urban Per Capita Applied Water 45
Gross Per Capita Use of Agency-Supplied Water 45
Gross Per Capita Use of Self-Supplied Water 45
Factors Responsible for Changes m Per Capita Applied Water 46
Trends in Gross Per Capita Use 48
Water Conservation Efforts 50
Other Water Uses 50
Energy Production 50
Power Plant Cooling 50
Enhanced Oil Recovery 51
Water Quality Control 51
Fish, Wildlife, and Recreation Offstream Water Uses 54
Urban Parks and Landscaped Recreation Areas 54
Other Parks and Recreation Areas 55
Waterfowl Management Areas 55
Fish, Wildlife, Recreation, and Hydropower Instream Water Uses 58
Protection of Instream Water Uses 59
Hydropower Projects 59
Net Water Use 60
Present Sources of Supply 62
Recent Surface Water Projects 75
Local Projects 75
Federal Projects 75
Ground Water 76
Present Knowledge of Ground Water Conditions 76
Dependable Ground Water Supply and Overdraft 76
Ground Water Levels and Pumping Costs 76
Conjunctive Use and Ground Water Management 77
Reclaimed Urban Waste Water 79
Present Waste Water Reclamation 79
Limitations and Constraints 80
Energy Use 81
Current Costs 81
Water Prices 81
Statewide Hydrologic Balance 85
Statewide Hydrologic Balance Network 87
Summaries of Hydrologic Study Areas 91
North Coast Hydrologic Study Area 93
San Francisco Bay Hydrologic Study Area 94
Central Coast Hydrologic Study Area 98
Los Angeles Hydrologic Study Area 101
CONTENTS (Continued)
CHAPTER III (Continued) Page
Santa Ana Hydrologic Study Area 105
San Diego Hydrologic Study Area 109
Sacramento Hydrologic Study Area Ill
San Joaquin Hydrologic Study Area 117
Tulare Lake Hydrologic Study Area 123
North Lahontan Hydrologic Study Area 129
South Lahontan Hydrologic Study Area 131
Colorado River Hydrologic Study Area 133
CHAPTER IV. FUTURE WATER USE— 1980 to 2010 135
Assumptions of Water Supply Availability and Prices 137
Key Assumptions 137
Agricultural Water Use 138
Studies and Considerations for Projecting Irrigated Crop Acreages 141
National Inter-Regional Agricultural Projection Model 141
Factors Affecting Competition from Other Producing Areas of the U.S 141
Study of the Livestock Industry and Its Need For Feed and Forage 142
Central Valley Agricultural Model 143
Other Information and Considerations 143
Projections of Acreages of Irrigated Crops 144
Future Changes in Irrigation Efficiency 150
Agricultural Applied Water and Net Water Use — 1980 and Projected 151
Urban Water Use 153
Population Projections 153
Population Distribution 154
Per Capita Applied Water Projections 154
Projection of Trends (Without Conservation) 154
Results of Per Capita Applied Water Projections (Without Conservation) 156
Impacts of Expected Water Conservation on Per Capita Applied Water 156
Reductions in 2010 Per Capita Use Due to Conservation 159
Urban Applied Water and Net Water Use— 1980 and Projected 160
Fish, Wildlife, Recreation, and Related Water Management Needs 160
Future Use of Fishery Resources 162
Future Use of Wildlife Resources 163
Future Water-Associated Recreation 164
Future Offstream Water Use for Fish, Wildlife and Fresh-Water Recreation 164
Future Protection and Enhancement of Instream Water Uses 165
Water Use for Energy Production 165
Water Use for Power Plant Cooling 165
Enhanced Oil Recovery 167
Summary of Applied Water and Net Water Use 168
Impacts of Water Conservation Assumptions 171
Water Supply Savings from Water Conservation 171
Energy Savings from Water Conservation in the Central Valley 173
CONTENTS (Continued)
Page
CHAPTER V. PROJECTED USE OF WATER SUPPLIES TO 2010 175
S^r-ace Water Supp.es 177
State Water Project Supply 177
SWP Ground Water Storage Program 178
SWP Brackish Water Reclamation Progrann 179
Projected Use of SWP Supply 180
Federal Central Valley Project Supply 180
Projected Use of CVP Supply 182
Impact of Delta Outflow Requirements on Operation of SWP and CVP 183
Other Federal Water Projects 186
Colorado River Water Allocation to California 186
Local Water Supply Projects 187
Ground Water Availability and Use 187
Ground Water Use 189
Reclaimed Waste Water 189
Legal Requirements and Public Acceptance 189
Role of the Department of Water Resources 189
Projected Use of Reclaimed Waste Water 190
Comparison of Water Supply and Projected Use 190
Effects of 1976-1977 Drought Period on Estimates of Dependable Supply 193
Dry-Year Realities 194
Statewide Summary of 1980 and Projected Net Water Use and Water Supplies 195
Hydrologic Study Area Summaries of Net Water Use and Water Supply 197
North Coast Hydrologic Study Area 200
San Francisco Bay Hydrologic Study Area 205
Central Coast Hydrologic Study Area 209
South Coastal Region (Los Angeles. Santa Ana, and San Diego Hydrologic Study Areas) 217
Sacramento Hydrologic Study Area 221
San Joaquin Hydrologic Study Area 226
Tulare Lake Hydrologic Study Area 231
North Lahontan Hydrologic Study Area 236
South Lahontan Hydrologic Study Area 240
Colorado River Hydrologic Study Area 245
CHAPTER VI. OPTIONS FOR THE FUTURE 247
CoDst'Bints on Water Management 247
The Resource Supply Outlook 247
The Total Surface Water Resource 247
The Present Water Supply Situation 248
The Future Water Supply Situation 248
Basic Water Supply-Net Water Use Assumptions 248
Demands on the Central Valley 249
Water Supply Options 250
Surface Water 250
North Coast 250
Sacramento Valley 250
Delta Transfer Facility 250
Colorado River 250
CONTENTS (Continued)
CHAPTER VI (Continued) Page
Ground Water 251
Sacramento Valley 251
San Joaquin Valley 251
South Coastal Region 252
South Bay Area 252
Conjunctive Use 253
Water Reclamation 253
Brackish Agricultural Drainage Water 253
Desalting (Sea-Water Conversion) 253
Weather Modification 254
Vegetation Management 254
Nonstructural Water Supply Options 254
Water Transfers 254
Supply Dependability and Risk 255
Water Conservation 255
Project Costs and Financing 257
Water Project Construction Costs 257
Interest Rates 257
Funding and Financing 258
Water Agency Roles in Water Management 260
Local Agencies 260
State Agencies 260
Federal Agencies 260
GLOSSARY 261
Sidebars
The Sacramento Valley Rice Bonanza 31
Land Usfe Survey Procedures 32
Key Water Use Terms 34
The Alfalfa Story in Northeastern California 35
Industrial Water Use 47
Protection of Fish and Wildlife Resources in the Sacramento-San Joaquin Estuary 52
The Federal Central Valley Project 68
The California State Water Project 71
Ground Water Storage Definitions 77
Pumping Energy Used for California's Water Supplies 83
Descriptions of Components of the Hydrologic Balance for California 88
Potential Impacts of Future Water Prices on Irrigated Agriculture 139
Effects of Alternative Assumptions for Water Supply and Energy Costs 148
CONTENTS (Continued)
Figures
No. Page
1 California's Geography — the Key to Understanding the State's Basic
Water Problems 8
2 Comparison of California Population Projections, Bulletin 160 Series 18
3 Comparison of Total Net Water Use Projections, Bulletin 160 Series 19
4 Comparison of Irrigated Land Projections, Bulletin 160 Series 20
5 Historical Development of Reservoir Capacity in California 22
6 Steps in Determining Present Water Use 26
7 Destination of California Animal and Vegetable Products Exported in 1979 33
8 Farm Income and Production Expenses in California, 1972-1980 34
9 Average Unit Evapotranspiration of Applied Water for Alfalfa at Selected Sites .. 36
10 Annual Population Growth by Components 42
11 California Population by Components of Growth, 1940-1980 43
12 Population Growth by County, 1972-1980 44
13 Percent of Urban Applied Water by Type of Use 45
14 Gross Daily Per Capita Water Use for Selected Communities 46
15 Total New Single and Multi-Family Dwelling Units, 1972-1980 48
16 Historical Gross Per Capita Urban Applied Water for Selected Cities 49
17 Streamflow Diversion Sites with Agreements for Fish Flow Releases 58
18 Number of FERC Notices and Water Rights Applications for Hydroelectric
Projects Since January 1980 59
19 Derivation of Net Water Use 61
20 Effect of improved Irrigation Efficiency on Net Water Use 61
21 Major Storage Reservoirs and Conveyance Facilities 64
22 Major Features of the State Water Project and the Central Valley Project 67
23a CVP Deliveries for the Period, 1951-1980 69
23b Sources of Repayment of Project Costs to End of Repayment Period (2050) 70
24a SWP Deliveries for the Period. 1962-1981 73
24b Sources of Repayment of Project Costs to End of Repayment Period (2035) 73
25 Basins Subject to Critical Conditions of Overdraft or With Special Problems 78
26 Existing Intrastate Water Transfers at 1980 Level of Development 86
27 Hydrologic Balance Network for California— 1980 88
28 North Coast Hydrologic Study Area 92
29 San Francisco Bay Hydrologic Study Area 95
30 Central Coast Hydrologic Study Area 97
31 Los Angeles Hydrologic Study Area 100
32 Santa Ana Hydrologic Study Area 104
33 San Diego Hydrologic Study Area 108
34 Sacramento Hydrologic Study Area 112
35 San Joaquin Hydrologic Study Area 116
36 Tulare Lake Hydrologic Study Area 122
37 North Lahontan Hydrologic Study Area 128
38 South Lahontan Hydrologic Study Area 130
39 Colorado River Hydrologic Study Area 132
40 Studies and Information Used in Projecting Irrigated Crops 140
41 Change in State Total Irrigated Acreage, by Crops. 1980 to 2010 145
42 Change in Agricultural Net Water Use, by HSA. 1980 to 2010 152
CONTENTS (Continued)
No. Figures (Continued) Page
43 Projected Population Increase, by Decades, 1980 to 2010 154
44 Increase in Urban Net Water Use, by HSA, 1980 to 2010 161
45 Participation-Days in Various Water-Associated Recreation Activities, 1980 and
2010 165
46 Change in Total Net Water Use by HSA, 1980 to 2010 171
47 Remaining Developable Surface Water in California 176
48 SWP Projected Water Requirements and Water Supply Sources 178
49 Potential Ground Water Feasibility Study Areas for State Water Project 179
50 Annual Delta Inflow and Its Uses, 1980 184
51 Annual Delta Inflow and Its Uses, 2000 184
52 Monthly Delta Inflow and Its Uses for an Average and a Dry Year 185
53 Allocation of California's Colorado River Water Supply 188
54 Water Year Natural Basin Runoff, October 1, 1976-September 30, 1977 192
55 Cumulative Unimpaired Runoff for Two Year Droughts for Selected Central Val-
ley Supply Sources 193
56 Surface Water Projects — North Coast Hydrologic Study Area 198
57 Water Supply and Use Summary — North Coast Hydrologic Study Area, 1980-
2010 199
58 Surface Water Projects — San Francisco Bay Hydrologic Study Area 202
59 Water Supply and Use Summary — San Francisco Bay Hydrologic Study Area,
1980-2010 203
60 Surface Water Projects— Central Coast Hydrologic Study Area 206
61 Water Supply and Use Summary — Central Coast Hydrologic Study Area, 1980-
2010 207
62 Surface Water Projects — Los Angeles, Santa Ana, and San Diego Hydrologic
Study Areas 212
63 Water Supply and Use Summary — Los Angeles, Santa Ana, and San Diego Hy-
drologic Study Areas, 1980-2010 215
64 Surface Water Projects — Sacramento Hydrologic Study Area 218
65 Water Supply and Use Summary — Sacramento Hydrologic Study Area, 1980-
2010 219
66 Surface Water Projects — San Joaquin Hydrologic Study Area 224
67 Water Supply and Use Summary — San Joaquin Hydrologic Study Area, 1980-
2010 225
68 Surface Water Projects — Tulare Lake Hydrologic Study Area 228
69 Water Supply and Use Summary — Tulare Lake Hydrologic Study Area, 1980-
2010 229
70 Proposed Valley Dram 233
71 Surface Water Projects — North Lahontan Hydrologic Study Area 234
72 Water Supply and Use Summary — North Lahontan Hydrologic Study Area, 1980-
2010 235
73 Surface Water Projects — South Lahontan Hydrologic Study Area 238
74 Water Supply and Use Summary — South Lahontan Hydrologic Study Area, 1980
-2010 239
75 Surface Water Projects — Colorado River Hydrologic Study Area 242
76 Water Supply and Use Summary — Colorado River Hydrologic Study Area, 1980-
2010 243
77 Central Valley Surface Water Supply 249
78 Present Use of Dependable Supply 251
79 Water Supply Capability — State Water Project with 1982 Facilities 256
CONTENTS (Continued)
Figures (Continued)
No. Page
80 Historical and Projected Costs of Water Supply Facilities (1980 Dollars) 258
81 Historical Federal Reclamation and Flood Control Appropriations in California .... 259
82 Projected Federal Water Project Appropriation Requirements in California 259
Tables
1 Comparison of Irrigated Crop Acreage and Land Area by Hydrologic Study
Area, 1972 and 1980 29
2 Area Used to Produce California Crops Exported to Foreign Countries, 1974 to
1980 33
3 Estimated Crop Acreage Irrigated by Major Types of Irrigation Systems by
Hydrologic Study Area, 1980 37
4 California's Population Growth by Hydrologic Study Area, 1972 and 1980 41
5 Typical Net Delta Outflow Requirements for Various Types of Water Years 54
6 Recreation of Selected Water Projects with Over 500,000 Visitor-Days Annually .. 56
7 Participation in Whitewater Boating and Fishing on
North Coast Wild and Scenic Rivers 57
8 Recreation on Selected Northern California Streams 57
9 Statistics for Surface Water Supply Reservoirs Shown on Figure 21 63
10 Statistics for Aqueducts Shown on Figure 21 66
11 Ground Water Storage Capacity by Region, 1980 76
12 Disposition of Treated Urban Waste Water by Hydrologic Study Area, 1980 79
13 Reported Intentional Use of Reclaimed Water by Hydrologic Study Area, 1979 .... 80
14 Average Urban and Agricultural Retail Water Prices by County 82
15 Examples of Pumping Energy Used for Water Supply 83
16 Total Applied Water and Net Water Use by Hydrologic Study Area, 1980 84
17 Changes in Net Water Use by Region, 1972 to 1980 84
18 Dependable Water Supplies. 1980 Level of Development, by Hydrologic Study
Area 84
19 Net Water Use and Water Supply Summary, by Hydrologic Study Area, 1980 85
20 Comparison of Locally Developed and Imported Net Water Supplies, 1980 87
21 Net Water Use and Water Supply, North Coast Hydrologic Study Area, 1980 93
22 Net Water Use and Water Supply, San Francisco Bay Hydrologic Study Area,
1980 96
23 Net Water Use and Water Supply, Central Coast Hydrologic Study Area, 1980 .... 98
24 Net Water Use and Water Supply, Los Angeles Hydrologic Study Area, 1980 101
25 Net Water Use and Water Supply, Santa Ana Hydrologic Study Area, 1980 105
26 Net Water Use and Water Supply, San Diego Hydrologic Study Area, 1980 109
27 Net Water Use and Water Supply, Sacramento Hydrologic Study Area, 1980 Ill
28 Net Water Use and Water Supply, San Joaquin Hydrologic Study Area, 1980 117
29 Net Water Use and Water Supply, Tulare Lake Hydrologic Study Area, 1980 124
30 Net Water Use and Water Supply, North Lahontan Hydrologic Study Area, 1980 129
31 Net Water Use and Water Supply, South Lahontan Hydrologic Study Area, 1980 131
32 Net Water Use and Water Supply, Colorado River Hydrologic Study Area, 1980.. 133
33 1975 Water Costs as a Percentage of Total Crop Production Costs for Selected
Regions 139
34 Comparison of^lrrigated Crop Acreage and Land Area, by Hydrologic Study
Area, 1980 and 2010 144
35 Irrigated Crop Acreage and Land Area, by Hydrologic Study Area, by Decades
to 2010 147
CONTENTS (Continued)
Tables (Continued)
No. Page
36 Examples of Weighted Average Irrigation Efficiencies, by Crop, 1980 and 2010 .... 151
37 Agricultural Applied Water and Net Water Use, by Hydrologic Study Area, by
Decades to 2010 152
38 California Population by Hydrologic Study Area, by Decades to 2010 154
39 Projected Change in Weighted Average Per Capita Applied Water Without
Conservation, Statewide and by Hydrologic Study Area. 1980 to 2010 156
40 Effects of Water Conservation on Weighted Average Per Capita Applied Water
in 2010, Statewide and by Hydrologic Study Area 159
41 Urban Applied Water and Net Water Use, by Hydrologic Study Area, by
Decades to 2010 160
42 Angling License Sales m California, 1950 to 1980 162
43 Estimated Angler Participation in California by Type of Fishing, 1980 and 1990 .... 162
44 Hunting License Sales in California, 1950 to 1980 164
45 Selected Water-Associated Recreation Activities in California, 1980 and 2000 164
46 Water Use for Wildlife Management Areas by Hydrologic Study Area, by
Decades to 2010 166
47 Water Use in Nonurban Public Parks, by Hydrologic Study Area, by Decades to
2010 166
48 Water Use for Power Plant Cooling, by Hydrologic Study Area, by Decades to
2010 167
49 Water Use for Enhanced Oil Recovery, by Hydrologic Study Area, by Decades
to 2010 167
50 Total Applied Water and Net Water Use by Hydrologic Study Area, 1980 169
51 Total Applied Water and Net Water Use by Hydrologic Study Area, 1990 169
52 Total Applied Water and Net Water Use by Hydrologic Study Area, 2000 170
53 Total Applied Water and Net Water Use by Hydrologic Study Area, 2010 170
54 Annual Applied Water Reduction and Related Water Supply Savings in 2010 Re-
sulting from Water Conservation, by Hydrologic Study Area 172
55 Federal Water Supply Projects in California Other Than the Central Valley
Project 186
56 Projected Incremental Increase in Use of Reclaimed Waste Water by Major
Urban Areas, by Decades to 2010 190
57 Present and Projected Use of Reclaimed Waste Water by Hydrologic Study
Area, by Decades to 2010 191
58 Projected Statewide Use of Water Supplies, by Decades to 2010 195
59 Summary of Present and Projected Net Water Use and Water Supply
by Hydrologic Study Area, by Decades to 2010 196
60 Water Supply and Use Summary — Los Angeles Hydrologic Study Area, 1980-
2010 213
61 Water Supply and Use Summary— Santa Ana Hydrologic Study Area, 1980-2010 213
62 Water Supply and Use Summary— San Diego Hydrologic Study Area, 1980-2010 214
63 Present (1980) and Projected Future Net Water Uses Dependent on Central
Valley Water Resources 250
Plates
1 Surface Water Projects in California f In pocket at inside
2 Irrigated and Urban Lands | back cover
ACKNOWLEDGMENTS FOR PHOTOGRAPHS
Page Source
Pac,
7
California State Library
153
11
Department of Water Resources (DWR)
155
Negative 4546-17
158
12
DWR 830-25 (left), 1032-69 (right)
159
13
DWR 6139-1
161
14
DWR 3896-26
163
15
DWR 3896-25
166
21
DWR 3385-18
168
28
National Aeronautics and Space Adnninistra-
177
tion
181
30
DWR 6112-33
182
41
DWR 6112-39
183
50
DWR 4947-126
187
53
National Aeronautics and Space Administra-
191
tion
194
55
DWR 4521-6
200
56
California Department of Fish and Game
204
75
DWR 6139-77
208
118
DWR 6139-76
216
125
DWR 6139-91
220
134
DWR 6139-58
222
136
DWR 6139-92
226
141
U.S. Soil Conservation Service
230
142
DWR 6139-94 (upper). 6139-95 (lower)
232
143
DWR 6139-78
236
146
DWR 6139-96
240
147
DWR 6139-79
244
150
DWR 6139-74
252
? Source
DWR 6139-54
DWR 6139-12 (left). 4515-6 (right)
DWR 4947-21
DWR 6139-23
DWR 3811-1
DWR 6139-97
U.S. Soil Conservation Service
U.S. Soil Conservation Service
DWR 4142-3
U.S. Bureau of Reclamation
Western Aerial Photos, Redwood City. Calif.
DWR 5435-26
U.S. Bureau of Reclamation
DWR 4497-41
DWR 5233-28
DWR 6139-82
DWR 6112-22
DWR 6139-81
Los Angeles Times
DWR 6112-19
DWR 6139-73
DWR 6139-80
DWR 6139-7
DWR 6139-98
DWR 6139-4
DWR 3645-28
U.S. Soil Conservation Service
The Metropolitan Water District of Southern
California
CHAPTER I
SUMMARY AND FINDINGS
Since publishing The California Water Plan (Bulle-
tin 3) in 1957, the Department of Water Resources
has issued a series of reports that update certain
elements of the plan. This report (Bulletin 160-83) is
the fourth in that series. It describes in detail the
current water use and supply situation (1980); pre-
sents an up-to-date appraisal of statewide water uses
for various beneficial purposes throughout the State
in 1990, 2000, and 2010; and identifies potential
sources of water supplies to satisfy those uses. It also
describes key events and accomplishments in water
planning and development of the State's water re-
sources.
The Bulletin 160 series is designed to present the
overall outlook for water supply needs throughout
the State and to assess the availability of water sup-
plies to satisfy these needs. The series presents basic
information for those who are interested in water
matters in California and provides a framework for
water managers and the Legislature in making water
management decisions. Rather than serving as a
blueprint for specific water management actions,
these reports emphasize the relationship between
water supplies and expected changes in the agricul-
tural, urban, instream, and other beneficial uses of
the resource.
While the basic scope of these reports has re-
mained essentially unchanged, each has had some
distinguishing characteristic reflecting attitudes and
emphasis at the time of its publication. Bulletin 160-66
emphasized implementation of the California Water
Plan. Bulletin 160-70 modified the outlook of earlier
reports by recognizing a slowdown in the State's
population growth and reflected this with a state-
ment that the need for additional water facilities for
the State Water Project could be delayed beyond the
date previously projected. Bulletin 160-74 departed
from the earlier practice of developing a single fore-
cast of future water use by presenting four different
scenarios as to future conditions and events that af-
fect water use.
This update compares water use and water sup-
plies and provides additional information on the plan-
ning process conducted by the Department. As such,
it is more of a "user's manual" than previous editions
have been. As part of this process, agricultural mod-
els were developed and applied for the first time.
Although much remains to be done to improve the
models, they were especially helpful in assessing the
general economic effects of increasing water and
energy costs. The report quantifies the effect of ur-
ban and agricultural water conservation measures
and the potential for water reclamation as a means
of reducing water needs. Finally, a number of non-
structural options for making more effective use of
water supplies, particularly in times of shortage, are
proposed for further consideration.
The more important findings, set forth below, sum-
marize concisely the information of significance for
which supporting data and other information are pre-
sented in detail in the ensuing chapters. Most of the
findings and conclusions presented in this report are
summarized by Hydrologic Study Area (HSA). The
12 HSAs, which cover all of California, are shown in
the map on the inside front cover of this report.
THE BULLETIN 160 SERIES
Bulletin 160-66
Implementation of the California
Water Plan
March 1966
Bulletin 160-70
Water for California
The California Water Plan
Outlook in 1970
December 1970
Bulletin 160-74
The California Water Plan
Outlook in 1974
November 1974
Outlook
In General —
• While available water supplies are generally
sufficient to meet current water needs, they
include significant ground water overdraft.
Delays encountered in developing additional
surface water supplies m a tinnely manner will
result in future shortages or increased ground
water overdraft until needed projects can be
built.
. Service areas of the State Water Project will
face increased risk of severe deficiencies in
drier years until adequate supplemental sup-
plies are provided. Moreover, without a Delta
transfer facility, substantial releases from
storage will be required for protection of the
Delta and even then will not completely re-
store the fishery.
• In the San Joaquin Valley, continued expan-
sion of irrigated agriculture must rely on in-
creased use of ground water supplies until
additional surface water supplies can be im-
ported.
• Although water conservation and water rec-
lamation will help to delay the need for addi-
tional surface water development in some
areas, they are by no means sufficient to sat-
isfy the water needs projected to occur dur-
ing the next 30 years.
• Laws, administrative actions, environmental
concerns, public opinion, cost considera-
tions, and other developments of the past
two decades have limited new surface water
development. As a result, increased attention
has been given to nonstructural solutions to
water problems.
• Population increase and related economic
growth — factors over which there is probably
the least influence or control — will have the
most significant impact on projected in-
creases in water use.
• Continued urban and agricultural growth and
greater attention to instream flows will inten-
sify the competition for California's water re-
sources, necessitating even more prudent
management.
• While the quality of surface water throughout
the State is generally satisfactory, contamina-
tion is threatening ground water in some
areas and poses health problems.
• Agricultural problems from insufficient drain-
age of brackish water in the San Joaquin Val-
ley will progressively worsen, if no increase m
remedial actions occurs.
in 1983
On Growth —
• California's population is expected to in-
crease from 23.8 million in 1980 to 34.4 million
in 2010. This amounts to an average annual
increase of 340,000, compared to 380,000 an-
nually between 1970 and 1980.
• Projected natural increase in population ac-
counts for more than half, or 5.8 million per-
sons, out of the projected growth of 10.6
million between 1980 and 2010. The total
growth assumes a birth rate of 2.1 children
per woman of childbearing age and an aver-
age annual net in-migration of 150,000.
• The South Coastal region — comprising the
Los Angeles, Santa Ana, and San Diego Hy-
drologic Study Areas — are projected to ac-
count for 50 percent of total statewide
population growth over the next 30 years.
• Irrigated land acreage is projected to in-
crease from 9.5 million acres in 1980 to 10.2
million acres by 2010. This increase, about
700,000 acres (equal to about 7 percent of the
1980 level), represents a significant slow-
down from historical trends, and is, in fact,
about the same as that which occurred in the
preceding eight years. Most of the increase
will occur in the Central Valley, with the Sac-
ramento HSA increasing the most (15 per-
cent), followed by the San Joaquin HSA (10
percent) and the Tulare Lake HSA (6 per-
cent).
• Increases in production cost will continue the
trend toward higher value crops, such as cot-
ton, truck crops, and grapes, with a decline in
grain and pasture. It appears that California
can retain or even improve its competitive
marketing position for certain crops because
other competing areas in the United States
are facing serious water problems.
• Public participation in fresh-water recreation
and in fish and wildlife activities is expected
to intensify because of growth of population
and greater per capita participation in water-
related leisure pursuits.
On Water Uses —
• Statewide, net water use is projected to in-
crease from 33.8 million acre-feet in 1980 to
37.3 million acre-feet by 2010. Of this increase,
urban use accounts for 1.8 million acre-feet (a
37-percent increase over 1980). This com-
pares to an increase of 1.7 million acre-feet (a
6-percent increase over 1980) for agriculture.
Total net water use is projected to increase at
an average annual rate of 120,000 acre-feet
over the next 30 years (1980-2010). This is
markedly less than the average annual rate of
increase of about 550,000 acre-feet for the
previous 30 years (1950-1980).
The greatest need for additional water sup-
plies exists m the San Joaquin, Tulare Lake,
and South Coastal region HSAs. The latter
two areas are the principal importers of sup-
plies from the State Water Project.
Sixty percent of the increase in net urban wa-
ter use is expected to occur in the coastal
metropolitan areas of the San Francisco Bay,
Central Coast, Los Angeles, Santa Ana, and
San Diego HSAs. About 45 percent or 860,000
acre-feet of this use will take place in the
latter three areas, which together make up
the South Coastal region.
The Central Valley (the Sacramento, San Joa-
quin, and Tulare Lake HSAs) will experience
the major increase in agricultural net water
use. The San Francisco Bay and South
Coastal region HSAs are projected to have
decreases in agricultural net water use.
• The principal increase in annual net water
use by 2010 is 700,000 acre-feet in the Tulare
Lake HSA. This is a 9-percent increase over
the 1980 level. If the State Water Project is
unable to meet its contract commitments,
there will be a shortage of as much as 660,-
000 acre-feet of dependable surface water
supply annually, 90 percent of which could
be offset by additional overdraft. In that
case, total overdraft may be as much as 2.4
million acre-feet annually by 2010.
• The projected increase in annual net water
use of 480,000 acre-feet by 2010 in the San
Joaquin HSA (an 8-percent increase) can
be satisfied by use of available dependable
surface water supplies of 330,000 acre-feet
and increased ground water overdraft of
150,000 acre-feet annually by 2010.
• The projected increase in annual net water
use of 460,000 acre-feet in the Sacramento
HSA (a 7-percent increase) can be satis-
fied by water supplies available within that
area.
in the Colorado River HSA, increased irriga-
tion efficiency and water conserved by re-
ducing the amount of water lost as outflow to
the Salton Sea could allow increased agricul-
tural production. It may be possible to trans-
fer the conserved water to the South Coastal
region.
• Net water use associated with public wildlife
management areas, nonurban public parks,
and energy production is forecast to increase
annually from 710,000 acre-feet in 1980 to
900,000 acre-feet in 2010, for a 30-percent or
190,000-acre-foot increase. Statewide de-
mand for instream flows was not evaluated
separately.
• Overall, higher costs of energy, labor, and
other production elements are expected to
increas.e irrigation efficiencies, thereby re-
ducing applied water in 2010 by about 3.5 mil-
lion acre-feet, a greater reduction than would
otherwise have been projected. The corre-
sponding reduction in the need for additional
water supplies, however, is only 645,000 acre-
feet because of reuse of excess applied wa-
ter.
• Reduction in additional water supply needs
due to expected urban water conservation
measures is projected to amount to 70 per-
cent of resultant reductions in applied water
in 2010 (950,000 acre-feet out of 1.4 million
acre-feet).
• Increased irrigation efficiency could save
considerable energy. Annual savings of 400
million kilowatthours are forecast in the Cen-
tral Valley for 2010.
On Present Water Supplies —
• California's present water needs are being
met by existing State, federal, and local
projects, and, in some areas, especially the
San Joaquin Valley, by overdrafting ground
water supplies. More water is available from
the existing projects than is being used now,
and this reserve could be used to satisfy in-
creasing needs for a number of years, or al-
leviate existing overdraft, if ncessary
conveyance facilities were constructed in a
timely manner. One such facility is the Mid-
Valley Canal, which would convey water to
the San Joaquin and Tulare Lake HSAs.
• Supplemental water needs currently average
1 .8 million acre-feet per year. These needs are
being met primarily through ground water
overdraft. The major overdrafted areas are
situated in the San Joaquin, Tulare Lake, and
Central Coast HSAs.
• Total overdraft of ground water basins has
decreased in the past eight years by about
80,000 acre-feet per year, primarily because of
new water brought into the western San Joa-
quin Valley by the State Water Project and
the San Luis Division of the Central Valley
Project, thus replacing to some extent previ-
ous ground water use. Remaining overdrafts
are not considered permanent sources of wa-
ter supply.
• Intentionally reclaimed waste water fur-
nished about 250,000 acre-feet of usable wa-
ter supply in 1980, most of which was used for
irrigation of crops and landscaping. An addi-
tional 610,000 acre-feet of waste water was
indirectly reclaimed, returned to the surface
and ground water supply, and reused.
• The following major surface water supply
projects have been built since 1974:
. Hidden Dam on the Fresno River, Buchanan
Dam on the Chowchilla River, and New Me-
lones Dam on the Stanislaus River, construct-
ed by the U. S. Army Corps of Engineers and
integrated into the Central Valley Project.
Warm Springs Dam on Dry Creek, a tributary
of the Russian River, scheduled for comple-
tion by the Corps in 1984, will provide water
for Sonoma and Marin Counties.
Indian Valley Dam on the North Fork Cache
Creek, built by the Yolo County Flood Control
and Water Conservation District to provide
water for irrigation in Yolo County.
• Soulajule Dam, built and operated by the Ma-
rin Municipal Water district for municipal wa-
ter supply.
On Future Water Supplies —
• Only about 5.5 million acre-feet, out of a total
remaining undeveloped statewide surface
water resource of 47.9 million acre-feet, ap-
pears to be potentially developable, consider-
ing current uses; wild and scenic river
designations: and geologic, economic, and
other constraints. Of this potential source, 4.6
million acre-feet, or 84 percent, occurs within
the Sacramento Valley.
Upstream depletions will reduce the present
yield of the existing State Water Project
facilities from 2.3 million acre-feet annually to
about 1.7 million acre-feet by 2010. These up-
stream depletions may be offset by savings
from conservation, water reclamation, addi-
tional pumping capacity at the Delta, con-
struction of the Cottonwood Creek Project,
and greater use of underground storage
capacity in conjunction with surplus surface
supplies. The resulting yield is about 1.5 mil-
lion acre-feet less than projected require-
ments. Because of voter rejection of
Proposition 9, certain additions to the State
Water Project have been eliminated from
consideration. Several alternatives exist to
eventually make up this deficit, and planning
is under way to select the best projects and
schedules.
With currently developed supplies, the State
Water Project can satisfy its service area
needs m average and wet years during the
1980s. Beyond that period, the projected de-
creases m yield, coupled with continued
growth in requirements, increase the risk of
more severe and frequent shortages.
Total ground water in storage in California
amounts to more than 850 million acre-feet. In
most areas where shortages in surface sup-
plies are projected, ground water is available
within economic pumping lifts and can be
used as a supplemental supply until surface
supplies become available.
Organization and Scope of Report
Each chapter in this report is intended to consider
a particular aspect of long-range water planning.
While future water needs and the availability of wa-
ter to meet those needs is the central focus of the
report, these aspects must be viewed in the context
of legislation and events influencing water manage-
ment. Consequently, the reader will find background
information in the first part of the report, including
those significant events and planning considerations
that not only influence water management decisions
but also affect projections of future water needs. The
report concludes with a general summation of the
water situation facing California and a recognition of
some matters that are not fully reflected in this report
but that are likely to influence water management in
the future.
Earlier editions of the Bulletin 160 series were
based on similar areas, for the most part, but there
are some significant differences. Specifically, com-
pared to Bulletin 160-74, the western boundary
between the San Joaquin and Tulare Lake HSAs has
been shifted northward somewhat: the Delta-Central
Sierra HSA has been eliminated and the area split
between the Sacramento and San Joaquin HSAs: the
Russian River drainage area has been transferred
from the San Francisco HSA to the North Coast HSA:
and the South Coast HSA has been divided into three
parts, namely, the Los Angeles, Santa Ana. and San
Diego HSAs.
This restructuring of areas has come about as a
result of a cooperative effort by the Department of
Water Resources, the State Water Resources Con-
trol Board, and the U. S. Geological Survey to estab-
lish boundaries each agency could use for data and
study summaries, thereby providing for more effi-
cient exchange of information.
Planning for Water Resources Development
(Chapter II)
The publication of the Bulletin 160 series of reports
has extended over a sufficient number of years to
permit development of a "track record." Chapter II
looks at that record. It contains charts showing popu-
lation, irrigated land, and net water use over several
decades. Of particular interest is the comparison of
the 1980 "actuals" with some of the earlier trend line
projections for that year. On the record, the Depart-
ment has not consistently erred, overall, on either the
high or low side. The tendency has been to overesti-
mate population growth and underestimate agricul-
tural development. There are, however, exceptions
to even this generalization. The 1980 census showed
that California grew more rapidly in the last decade
than was anticipated during the 1970s. In some areas,
in fact, the 1980 population proved to be larger than
that projected for 1990.
Chapter II also presents a brief history of water
planning and development in California and de-
scribes the conditions that have made such work
necessary, including geographic and climatic fac-
tors. Not only are the most agriculturally productive
areas of the State climatically arid or semi-arid, but
most of the urban growth has occurred outside the
"water-rich" areas of the State. Consequently, both
agricultural and urban growth have created enor-
mous pressure to develop and transport the re-
source. That pressure, however, is not necessarily
compatible with other water uses, and therein lies
the basis for the continuing debate regarding ways to
best manage water supplies.
The chapter also includes a description of the se-
vere drought of 1976 and 1977 and the ways in which
California coped with its effects.
Water Use and Water Supply in 1980
(Chapter III)
Probably the most complete presentation of the
Department's involvement in water planning yet ap-
pearing in the Bulletin 160 series is presented in
Chapter III, which is an information base for water
use and water supply in 1980. Both procedural and
factual, it contains present (1980) data on those fac-
tors affecting water use projections. Significant in-
formation is presented which is intended as a
take-off point for the projections described in Chap-
ters IV and V.
Chapter III describes the Department's land use
surveys and satellite surveillance programs. From
these programs, the Department can determine how
much irrigated crop acreage there is by type and
where it is located. Likewise, on-ground measure-
ments and surveys provide necessary water use in-
formation. These data are basic to long-range water
planning. Chapter III also explains net water use and
its relationship to applied water, evapotranspiration,
and the potential for water savings. It also contains
a brief discussion of irrigation systems and other fac-
tors affecting water conservation. Rice and alfalfa
are big water users and, as noted in the report, have
a story of their own.
Chapter III includes a discussion of fish and wildlife
resources in the State, including the effects of water
development on these resources. A summary of wa-
ter supplies presented in the last half of the chapter
identifies the more significant dams (and reservoirs)
and conveyance facilities within the State. The
ground water situation is discussed and its manage-
ment in conjunction with surface water supplies is
considered. Energy use and water cost data are also
presented. These latter two considerations have re-
ceived considerable attention since the oil embargo
of 1972 and the general increase m the cost of build-
ing new water facilities. Their inclusion in this report
reflects the Department's recognition of their in-
creased importance in assessing water use, and both
were included as specific variables in the models
used to assist in the projection of agricultural water
use presented in Chapter IV.
An understanding of the State's water problems
and management options requires a knowledge of
the hydrologic balance — the relationship between
water use and water supplies. "The Hydrologic Bal-
ance Network for California, 1980," Figure 27, depicts
the statewide water network, tracing the uses of wa-
ter supplies from their source. From this overview,
the last portion of the chapter discusses and shows
in some detail the sources and disbursement of wa-
ter for each of the Hydrologic Study Areas in Califor-
nia.
Future Water Use— 1980 to 2010 (Chapter IV)
The outlook for future water use in California is
presented in Chapter IV. When combined with the
water supply considerations presented in Chapter V,
it forms the basis for taking specific actions to allevi-
ate any shortfall between developed supplies and
future use. Chapter IV also provides a basis for deter-
mining the effectiveness of any particular measure,
or combination of measures, to meet water supply
deficiencies.
Chapter IV is an extension of the planning consid-
erations, data sources, and methodologies described
in Chapter III. All the thought and work associated
with Chapter IV are designed to produce one key
finding; total net water use. The thought process and
considerations which lie behind that finding are pre-
sented in some detail. The assumptions behind the
agricultural water use projections, for example, con-
cern the derivation of irrigated acreage, appropriate
rates of evapotranspiration of water by each crop
type, and projections of irrigation efficiency. On the
urban side, birth rates and net nnigration assunnptions
are presented as a basis for the population projec-
tions. Factors affecting per capita water use are pre-
sented, including water conservation measures. The
chapter also presents net water uses associated with
power plant cooling, enhanced oil recovery, recrea-
tion, and wildlife habitat.
At least two aspects of the projections appearing
in this report distinguish it from previous reports in
the Bulletin 160 series. The first is an explicit attempt
to account for water savings resulting from conserva-
tion. The reader will find a fairly complete discussion
of water conservation measures and actions and
their impact on the need for water supplies.
A second aspect includes the use of economic
models to assist in the projection of agricultural wa-
ter use. Upon the recommendation of an economic
advisory group, the Department began work on this
task in 1979. The principal results of this effort includ-
ed an analysis of California's feed and forage indus-
try, using a linear programming model, and a similar
but larger model for all major crops grown in the
Central Valley. These models allowed the Depart-
ment to evaluate directly the impact of water costs
on agricultural acreage, particularly the often-raised
issue of agriculture's future in relation to increasing
water costs.
In summary. Chapter IV represents the Depart-
ment's best forecast of future water use levels for the
State as a whole, as well as by regions within the
State. The major variables affecting those projec-
tions are presented. The findings in this chapter,
combined with the water supply considerations pre-
sented in Chapter V, establish a basis for assessing
water management options and their urgency.
Projected Use of Water Supplies to 2010
(Chapter V)
As the title suggests. Chapter V emphasizes water
supplies. It assesses the ways and means of meeting
future water needs. Conservation is reflected in the
estimates of net water use presented in Chapter IV.
The need for additional water supplies discussed in
this chapter is measured against the reduced level of
use created by conservation.
Chapter V contains two major sections: { 1 ) a gen-
eral or statewide treatment of water supplies and (2)
regional discussions that compare supplies with uses
by decade from 1980 to 2010. In the first section, one
of the most telling displays shows the remaining
developable surface water m California, as limited by
current priorities for use and other constraints. In
addition, water supplies, as they relate to the State
Water Project and the Central Valley Project, are
discussed m some detail. The reader may find the
comparison of water supplies and requirements on
the SWP particularly relevant. The SWP is looked to
as a supply for most of the additional urban water
requirements. Without additional supplies, the ability
of the existing facilities to meet contractual commit-
ments decreases because of growth in both the im-
port and the upstream areas. The latter, referred to
as areas of origin, have first call on the resource.
To round out the statewide discussion of water
supplies. Chapter V identifies major existing and po-
tential local projects, waste water reclamation pos-
sibilities, and ground water availability and use. As
noted previously, cost considerations have taken on
added importance, particularly as they relate to
ground water and the cost of pumping. Agriculture,
especially, is sensitive to significant increases in the
cost of obtaining ground water.
Chapter V concludes with a series of Hydrologic
Study Area summaries and. in that respect, is an ex-
tension of the last half of Chapter III. Insights into
those key conditions affecting water management
decisions in each area are highlighted, as are the
issues and management problems expected to exist
in coming decades.
Options for the Future (Chapter VI)
Finally. Chapter VI draws from earlier chapters,
particularly Chapters IV and V, and discusses some
of the options available to meet indicated water
needs over the next 30 years. The chapter presents
a concise summary of the present water supply situa-
tion, statewide and by region. This is followed by a
discussion of potential water supply sources, includ-
ing surface and ground water, conjunctive use pos-
sibilities, water reclamation, water transfers, and
other nonstructural water management options.
Chapter VI concludes with a discussion of some of
the factors that will ultim.ately decide which solutions
receive greatest emphasis and the respective roles of
agencies responsible for their implementation.
CHAPTER II
PLANNING FOR WATER RESOURCES DEVELOPMENT
Water resources planning and development in Cal-
ifornia has a long and often complex history that
dates back to the late 18th century. This chapter re-
views the more notable events that have occurred,
with emphasis on the California Water Plan and the
modifications it has undergone. It presents the his-
torical growth in water storage facilities and com-
pares the projections of population and water use
(prepared for planning in anticipation of future wa-
ter needs) published in the 1966, 1970, and 1974 up-
dates of the California Water Plan. An understanding
of California's geography and climate is basic to a
discussion of water in California. The maps and text
in Figure 1 review California's geography and climate
and their profound impact on water problems.
Early Planning and Development
The earliest instances of the development of Cali-
fornia's water resources occurred at the Spanish mis-
sions in the last three decades of the 18th century.
Already familiar with the arid conditions in Baja Cali-
fornia, the Franciscan fathers tended to establish
their mission settlements in Alta California where wa-
ter for irrigation was most readily available. Although
some cultivation by Indians had taken place along
the Colorado River, the history of irrigated agricul-
ture in California really began with the mission gar-
dens and fields fed by streams that were dammed
and diverted through canals. The missions were
forced out of operation under Mexican rule in the
1830s, and many of them eventually fell to rums, but
their irrigation works set an example for the incom-
ing American and European settlers who were not
accustomed to California's long, rainless summers.
After the mission era ended, little was done to
develop water until the mid-19th century when Cali-
fornia erupted with the frenzy of the gold rush. The
miners that thronged by the tens of thousands over
the foothills of the Sierra Nevada soon discovered
that water was the most effective instrument for un-
locking the riches they sought. They built reservoirs
and widespread networks of ditches and flumes to
divert water from streams at higher elevations and
sluice the gold-bearing deposits. These were Califor-
nia's first major hydraulic engineering works. By the
mid-1860s, more than 4,000 miles of mining canals
and ditches were in operation.
Flumes built during Cali-
fornia's gold rush brought
water to the miners'
sluice boxes at placer
mining sites.
MEAN ANNUAL PRECIPITATION
E « apo tr antp V • lion
JfMAMJJ ASONO
Months
EL CENTRO
MEAN ANNUAL UNIMPAIRED RUNOFF
:«..!
VAF
10
*•'
% OF
TOTAL
■ WC
2B.6
■ 35
300 :
40.4
: SF
1.$
Z
000
2.3
cc
2.5
3
100
3.S
LA
0.6
0
700
0,9
SA
0.3
0
400
0.4
■ SO !
OJ
0
400
0.4
; 50 i
2?.4
27
600 :
31.6
■ 5j ■
1.9
9
700 :
11.2
T>
3.3
4
100
4-7
1.8
2
200
2.5
bl.
1.3
1
600
1.8
' CR ;
0.2
0
200
OJ
'ij^l
TOJB
i 87
300 :
100.0
MAF •
Hllllsn ■er*-t««i
106«.?
Mini
an cub
Ic m*lt«a
\
(
FIGURE 1— CALIFORNIA'S
GEOGRAPHY— THE KEY
California is a land of contrasts. Both the highest and the
lowest elevations m the contiguous 48 states are situated
in California's 100 million acres. The climate ranges from
desert to alpine, with average annual precipitation that
varies from less than 2 inches to more than 100 inches.
California's variation in precipitation is shown on the map
at upper left.
California has warm, dry summers and cool, wet winters.
Nearly all the rain and snow occurs in the five winter
months — November through March — with practically
none during the summer growing season. Fortunately, con-
siderable precipitation occurs as snow at the higher eleva-
tions, sustaining the flow of many streams into early
summer (see bar graph on map at lower left). The fre-
quency precipitation is highly variable from year to year,
including dry periods that have persisted from one to sev-
eral years. A recent reminder of this fact occurred in 1976
and 1977. the driest two consecutive years ever recorded
in California. The longest drought since flow measure-
ments began persisted from 1928 to 1934. However, studies
of tree rings conducted by the University of Arizona indi-
cate that California and the western United States have
experienced even longer and more severe dry periods.
Those studies also indicate that, in the last 200 years, dry
periods occurred from 1760 and 1820 and again from about
1860 to 1880. While tree ring studies provide only a general
indication of trend, evidence suggests that both of these
periods had less annual rainfall than fell during the 1928-
1934 drought upon which California's largest water
projects are based. Thus, our developed water supplies
may not be as dependable as presently believed.
Average yearly statewide precipitation amounts to 193
million acre-feet. Under natural conditions (that is, exclud-
ing the effects of human activities), about 65 percent of
this amount is taken up through evaporation and transpira-
tion by trees, plants, and other native vegetation. The re-
mainder, 71 million acre-feet, makes up the long-term
average annual statewide runoff. Annual runoff has
ranged, however, from as little as 15 million acre-feet in
1976-77 to more than 135 million acre-feet in 1982-83. Cali-
fornia's mean annual unimpaired runoff by region is depict-
ed on map at lower left.
The water supply situation is further complicated by the
uneven pattern of precipitation. About 70 percent of the
State's total precipitation — both ram and snow — occurs in
the northern third of the State. However, the use of water
is just the reverse — more than 80 percent occurs in the
southern two-thirds of the State. Total streamflow is abun-
dant, but It IS poorly distributed in place and time to meet
needs. Most of the population lives near the coast m large
cities that are remote from adequate natural water sup-
plies. A large part of the highly productive agricultural de-
velopments are located in arid and semiarid regions where
U A M
Uonth*
MEAN ANNUAL UNIMPArRED RUNOFF
TO UNDERSTANDING THE STATE'S
BASIC WATER PROBLEMS
the natural water supply is insufficient to meet irrigation
needs. (See bar graphs on map at upper left, for example.)
The naturally uneven distribution of water within the State,
arising from its regional climatic differences, and the unev-
en distribution of water throughout the year, has required
extensive engineering works to regulate and convey the
water to areas where the need has developed. More than
1,200 reservoirs have been built over the years by private
effort and public agencies at all levels. Their aim has been
to regulate wintertime and wet-year runoff and conserve
the supply for use when the natural streamflow is insuffi-
cient. While the overall water picture in California is made
up of many complex and interrelated problems, the redis-
tribution of water from areas of surplus to areas of defi-
ciency continues to provide the greatest challenge.
California also has an abundance of ground water under-
lying Its alluvial valleys, although in some areas, particularly
in the southern San Joaquin Valley, the supply is being
depleted by pumping in excess of natural replenishment.
Statewide total ground water in storage is about 860 mil-
lion acre-feet, of which a substantial portion may not be
readily usable. Average annual natural replenishment is
about 5.8 million acre-feet. Overall, ground water in Califor-
nia is being overdrafted at a rate of about 1.8 million acre-
feet annually.
The climate of California favors the growth of most food
and fiber crops, including certain crops not grown com-
mercially anywhere else in the nation. Because rainfall for
most of California is generally inadequate during the grow-
ing season, most crops must be irrigated. Today, 85 per-
cent— 28 million acre-feet — of the developed water
supplies is used for irrigation of crops. The amount of irri-
gated land and major crop types are identified on map at
upper right.
Forty percent of the water used for irrigation in the State
is applied in the Tulare Lake and Colorado River Hydrolog-
ic Study Areas. With an average yearly rainfall of less than
10 inches, irrigation water is the lifeblood of farming in
these areas.
The Imperial and Coachella Valleys have high-priority
rights to water from the Colorado River. Irrigation develop-
ment in the Tulare Lake Hydrologic Study Area is sustained
through an abundant natural and imported water supply
and by overdrafting of the ground water basins.
The mild climate of much of Southern California makes
the area an appealing place to live, although climate is only
one of many reasons for living there. Over half the State's
population lives in the south coastal area, as shown on map
at lower right. Local water supplies are fully developed,
and about 60 percent of the area's needs must be met by
importing water.
IRRIGATED LANDS IN 1980
(In lo'oo'a)
,..
ACRE*
M*
TOTAL
NC
316
1»
3
•r
a«
7B
1
cc
4S»
lae
S
LA
1 10
47
>
SA
i4g
no
7
SO
SB
40
1
9B
20TS
• 3B
37
SJ
;o«i
634
93
Tl
328?
133B
3S
NL
13B
56
«
SL
B3
33
'
cn
SOO
0440
243
38?0
too
\
ALFALFA a PASTURE
FIELD
OnCHAFlO S VINEVAfiD
TRUCK
COTTON
nicE
1980 POPULATION
; r—^ I ^^ *— '
\_,^-X K
V ^«-"V'■J!.V'■~--i
HSA
1.000.000
PEOPLE
% OF
TOTAL
0 4
1.9
4.9
■"O.S
1.0
4,/
7,9
33.3
3.0
12.6
2.0
a. 6
1.6
6.9
1,0
4.1
),?
6.0
0.1
0.3
0,3
I.J
0.3
23.?
1,3
100.0
\.
^
X
\.
\
'-V
Then, as the returns from the gold fields began to
decline, some of the miners, as well as other new-
comers to California, turned to farming. Water for
irrigation took on increasing importance. In the
northern and central parts of the State, irrigation
practices were relatively simple. Individual settlers
often dug ditches to convey water from streams to
nearby fields. Artesian ground water was also plenti-
ful in many valley and coastal plains in those years.
In the southern part of California, however, some-
what drier conditions prevailed. Early irrigators
learned to recognize the value of storage reservoirs,
and several important dams had been completed or
were under construction by the 1880s.
Until about 1900, water development m California
was generally undertaken by individuals and private
companies. Farmers formed groups to excavate irri-
gation ditches, and, during the 1870s and 1880s, de-
velopment companies and cooperatives built
irrigation works in San Joaquin Valley and Southern
California. As the State grew and the need for water
increased, private initiative was later supplemented
by public endeavor. Community enterprises, irriga-
tion districts, public utilities, and municipal projects
of steadily increasing size and complexity arose. The
Wright Irrigation District Act of 1887 and legislative
changes to the Act in 1909 and 1911 gave strong
impetus to the spread of irrigated agriculture. In au-
thorizing the formation of local public irrigation dis-
tricts, the original law declared the use of water for
irrigation of district lands to be a public use and em-
powered districts to take over private irrigation en-
terprises and to acquire water. The earliest districts
date from the 1880s. By 1930 more than 100 irrigation
districts were in operation in California.
The cities of Los Angeles and San Francisco were
early leaders in planning and developing projects to
import water from other areas of the state. Later,
regional organizations such as The Metropolitan Wa-
ter District of Southern California and the East Bay
Municipal Utility District developed large-scale im-
port facilities.
Local plans for the use of water were conceived
and executed without the benefit of a statewide
framework to provide guidance and coordination. Al-
though proposals for large regional water use
schemes date from an 1874 federal investigation, the
first statewide plan for development of California's
water resources was set forth in 1920 by Colonel
Robert B. Marshall, chief hydrographer for the U.S.
Geological Survey. Marshall's proposal, which was
privately published, was based on a comprehensive
water plan for the entire Central Valley, by then a
well-established agricultural region. Among other
things, the Marshall plan called for a storage reser-
voir on the Sacramento River at the northern end of
the Sacramento Valley and a pair of aqueducts, one
to transport the stored water down the eastern side
of the valley and one down the western side. The
plan also included provision for conveying water to
Los Angeles. Marshall's ambitious proposal captured
much public attention, but its far-reaching concepts
were viewed with disfavor by some government
agencies and engineers.
Despite this, growing interest in the idea of a state-
wide plan for the orderly management of water,
along with the interest aroused by the Marshall plan,
led the Legislature in 1921 to direct the State Engi-
neer to make a comprehensive statewide investiga-
tion of California's water resources. The study
culminated in the publication of the Report to the
Legislature of 1931 on State Water Plan, which out-
lined a coordinated plan for conserving, developing,
and using the State's water. This was the first govern-
mental proposal for transferring surplus water from
Northern California to the southern part of the Cen-
tral Valley. The plan was approved and adopted by
the Legislature and designated as the State Water
Plan.
Other reports that followed dealt in more detail
with plans to develop water in the Sacramento and
San Joaquin Valleys. Although many years were to
pass before such broad plans were acted upon, these
studies would ultimately form the basis for the Cen-
tral Valley Project, built by the federal government,
and the State Water Project.
The State filed water rights applications for poten-
tial dams and reservoirs in 1927. These reserved fil-
ings have been maintained m force by legislative
acts, and supplemental applications have been made
in subsequent years.
California Water Rights
The climate and the historical development of the
State and its water resources have caused a complex
body of water rights law to evolve. Competition
among water users has emphasized the right to se-
cure and use surface water. California does not now
administer rights to ground water, except in in-
stances where judicial decisions have required the
implementation of intensive management.
California's surface water rights fall into two major
categories; riparian and appropriative. Riparian
rights go only with land adjacent to a watercourse or
body of water. Holders of riparian rights have the
right to use the natural flow of a stream, but they
cannot store water.
In California most land is not situated adjacent to
a body of water. The concept of the appropriative
right was developed to allow for the water needs of
such lands when other sources were not naturally
available. An appropriative water right allows water
users to transport water to any place of use, some-
times several hundred miles away, and to store water
on either a short- or long-term basis.
10
Riparian rights come under the control of the
courts only when there is a legal dispute among com-
peting water users, or when an action has been filed
against the users on the basis of waste or unreasona-
ble use. Appropriators, on the other hand, secure a
specified flow or quantity under their right. Before
1872, appropriators secured their water rights by
merely taking and using the water. Between 1872 and
1914, a permissive procedure was provided that also
allowed the initiation of a right by posting a notice at
the point of diversion and filing a copy of the notice
with the county recorder. These appropriative rights
are limited both as to amount and season by the
actual beneficial use of the water, notwithstanding
the amount and season named in the original notice
or as initially diverted.
After 1914, the State assumed administration of
further appropriations of water and established a
permit system that is now under the jurisdiction of
the State Water Resources Control Board (SWRCB) .
Over the years, SWRCB has imposed numerous con-
ditions in permits, based on public interest and prior
right considerations. The key to the appropriative
doctrine is the concept of priority: first in time, first
in right. Riparian rights have equal priority and ordi-
narily are senior to all appropriative rights.
The filings for pre-1914 appropriative rights specify
a rate or quantity of water, the point of diversion, the
use to be made of the water, and the place of use.
Permits for post-1914 appropriative rights specify the
same four items. Any change in use, place of use, or
point of diversion must comply with the prohibition
against injury to other users. SWRCB has jurisdiction
over all permit holders and must go through an ad-
ministrative review process before permit conditions
can be changed. Within these constraints, the user
can divert the water and put it to any use, as long as
the use is reasonable and not wasteful. When a per-
mittee has completed appropriation within the time
specified by SWRCB, a license is issued confirming
the right to use the water.
Development of Ground Water
Resources
The existence of ground water beneath much of
California's land surface gave early-day farmers and
ranchers the option of settling almost anywhere they
wished. The widespread availability of enough un-
derground water lying close to the surface meant
that a family could supply itself and its livestock sim-
ply by digging a well or developing a spring. As
pumping became practicable, it opened the way to
even more water, ultimately leading to the State's
flourishing agricultural industry. Ground water devel-
opment in California has helped establish vigorous
urban and agricultural economies that have been
able to meet the costs of developing and importing
surface water supplies, often from distant regions of
Water is pumped from the Sacramento River for use on adja-
cent land, in accordance with water right law.
11
the State. Ground water today supplies 39 percent of
the applied water used in California.
The water they drew from wells and springs for
domestic use greatly benefited the health of early
California settlers. Before the days of water treat-
ment facilities, polluted surface water was a major
health problem. Where people took their water from
streams and used them to carry off most of their
wastes, the contaminated water transported disease
organisms to other water users downstream. The use
of ground water, which is often improved m quality
by percolation through the soil and the granular
media of aquifers, minimizes the transfer of water-
borne diseases.
As California grew, wells were often the most eco-
nomical means of obtaining good quality water for
domestic and municipal uses in communities under-
Windmills were used widely in the early days,
pumping ground water principally for domestic and
livestock needs.
Few artesian wells exist today in California, but
they were common in many locations 100 years
ago.
12
lain by ground water basins. Ground water was fre-
quently used in preference to surface water, even
when a surface supply was available and could be
treated and distributed. Ranchiers found it more con-
venient to water their stock at the site with water
obtained from springs and windmill-driven pumped
wells.
Artesian wells were often used for irrigation in the
early development of agriculture in California. These
were an abundant source of water in the Central
Valley and in many other valleys where underground
pressure was sufficient to cause ground water to rise
in wells to the surface and flow freely. Advances in
well drilling techniques and equipment by the turn of
the century enabled drillers to reach deep enough to
penetrate these confined artesian aquifers.
In the early 1900s. development of the centrifugal
pump, powered by gasoline engines or electric mo-
tors, allowed large quantities of water to be drawn
from wells. Centrifugal pumps operating in pits 20 or
more feet deep were fairly numerous through the
early 1950s, and some remain in operation in Califor-
nia today.
Development of the deep well turbine pump and
the wider distribution of electrical power to agricul-
tural areas in the 1920s led to extensive use of ground
water for irrigation, even where water had to be
Today most ground water is extracted by deep well
turbine pumps from depths of 100 feet or more.
pumped from depths of several hundred feet. The
application of ground water enabled farmers to irri-
gate large areas of land with relatively small capital
outlay. Deep well turbine pumps also provided de-
pendable supplies of municipal and industrial water
for cities having good-sized populations, whose sur-
face water sources dwindled in summer when
streamflows declined or disappeared.
Major Urban Water Development
The cities of San Francisco and Los Angeles were
the prime movers in development and transport of
water from distant sources for the use of urban resi-
dents. While the efforts of each city to increase its
supply of water differed greatly in many respects,
their goals were similar: to serve the future needs of
the additional population each city expected to ac-
quire. Both of these metropolitan areas grew rapidly
throughout the latter half of the 1800s, and municipal
leaders foresaw the time when the numbers of
people would outstrip the available water.
San Francisco studied many possible sources of
additional water for some 20 years and. by the turn
of the century, finally settled upon the Tuolumne Riv-
er, which flowed through the Hetch Hetchy Valley,
part of Yosemite National Park in the Sierra Nevada.
Hetch Hetchy was selected because it could store an
ample supply of high-quality water and because the
elevation was great enough to provide the drop
needed to generate electrical power for San Fran-
cisco.
In the years preceding authorization of the project.
the proposal to flood the Hetch Hetchy Valley
aroused a great deal of controversy. It was vigorously
opposed by John Muir. founder of the Sierra Club,
and by many other conservationists. Competing wa-
ter interests in the San Joaquin Valley also fought the
city's plans on the grounds that they had prior rights
to the water of the Tuolumne River. Because Hetch
Hetchy Valley lay in federal reserved lands, the opin-
ion of the Secretary of the Interior weighed heavily
in the situation. For some years, the proposal was
alternately accepted and rejected by successive Inte-
rior Secretaries, depending on the political position
of each. Congressional legislation authorizing the
Hetch Hetchy project was finally enacted in 1913.
Construction of the Hetch Hetchy Aqueduct be-
gan in 1914. and the first water to the city was deliv-
ered in 1934. The intervening years were marked by
continuing disputes with a consortium of private util-
ity companies over the question of the future sale of
water and power from the project and by the need
for repeated infusions of money to keep the work
going. The Hetch Hetchy project cost S100 million,
which was $30 million more than the builders original-
ly calculated, but its benefits over the years have
been substantial. San Francisco gains revenue from
13
the sale of more than half Its water supply to other
cities in the Bay area and also from the sale of power
the project generates.
Faced with the same problem as San Francisco —
an upswing in population — Los Angeles also under-
took its first venture in long-distance water develop-
ment early in this century. The Los Angeles
Aqueduct, which carries enough water to meet
about 80 percent of the city's needs, extends about
340 miles from the Owens Valley in Inyo County
southward to Los Angeles. The project is also a. pow-
er-producer, supplying a significant amount of elec-
tricity for Los Angeles.
Although not without its problems, construction of
the Los Angeles project was initially relatively free of
the kind of controversy that slowed the construction
of the Hetch Hetchy development. First conceived
about 1905, the Los Angeles Aqueduct was started in
1909 and completed four years later when Owens
Valley water began arriving in Los Angeles. This was
a situation in which local irrigation water was pur-
chased (land and associated water rights) and trans-
ported from the drainage basin for urban use.
The 1920s were marked by strong local opposition
to the project. Owens Valley ranchers, angered by
the acquisition of the valley's land and water and the
city's action to prevent certain upstream diversions,
blew up the aqueduct in 1924 and again m 1927, at
which time Los Angeles sent armed guards to pro-
tect the project. The valley's violent resistance ended
shortly afterward, although the controversy has con-
tinued to the present. In 1940, the system was extend-
ed farther north to Mono Lake, and, in 1970, a second
aqueduct from Owens Valley was built along a simi-
lar route.
Only a few years after the completion of the first
Los Angeles Aqueduct, the city was considering
other means of expanding its sources of water and
power. In 1920, Los Angeles went on record as favor-
ing the construction of engineering works (as a fed-
eral project) to regulate the erratic flows of the
Colorado River and thus make the river a reliable
resource for all users. Approval of the federal Boul-
der Canyon Project Act in 1928 paved the way for
development of the Colorado River, including con-
struction by the federal government of Boulder Dam
(later Hoover Dam), completed in 1936. Regulation
of the river ensured a dependable supply of water for
the Los Angeles area. Construction of the Colorado
River Aqueduct was undertaken by a consortium of
Southern California communities, joined as The Met-
ropolitan Water District of Southern California. The
240-mile-long facility was completed in 1940, and
deliveries commenced the following year.
Major Agricultural Water
Development
Before World War II, irrigated agriculture in Cali-
fornia relied largely on development by irrigation dis-
tricts of local surface water supplies and pumping of
ground water. The area under irrigation reached 4
million acres by 1930, concentrated chiefly in the
Central and Imperial Valleys, and the South Coast
area. The need for supplemental sources of water to
halt falling ground water tables in the San Joaquin
Valley portion of the Central Valley gave impetus to
a comprehensive program of water importation.
Water transported by the Los Angeles Aqueduct moves
through an inverted siphon across Jawbone Canyon, about
100 miles from the terminus of the system.
14
The federal Reclamation Law of 1902 made possi-
ble the use of federal funds for large-scale, inexpen-
sive development of irrigation for agriculture m the
western states. One of the first projects built under
the 1902 Reclamation Act and the first such built in
California, was the Orland Pr'oject, located on the
west side of the Sacramento Valley west of Chico
and Orland. Construction of the project began in
1903 and was completed by 1928. The project con-
sists of East Park and Stony Gorge Dams, several
smaller diversion dams, and a distribution and drain-
age system. In 1954 the U. S. Bureau of Reclamation
transferred operation of project facilities to the Or-
land Unit Water Users Association.
The Imperial Valley is located in southeastern Cali-
fornia near the border common to California and Ari-
zona and the international boundary with Mexico.
Development of irrigated agriculture was begun by
the California Development Company, which was
formed in 1896 to irrigate the valley with water from
the Colorado River. The company constructed an
unlined canal from the Colorado River to the Imperial
Valley. In 1905. the bank of the Colorado River gave
way and the river flowed into the Salton Sink for
almost two years, creating the present-day Salton
Sea. Flood-related costs caused the company to go
into receivership, and in 1916 its Colorado River wa-
ter rights were acquired by the newly formed Impe-
rial Irrigation District. The district initially sold and
distributed water but later took a more active role in
water and power development. The Boulder Canyon
Project Act of 1928. which authorized construction of
Hoover Dam, also authorized construction of the All-
American Canal by the federal government, and,
with the initial delivery of water through the All-
American Canal in 1940, the Imperial Valley became
a major agricultural region in California.
In 1933, California voters approved a $170-million
bond measure to finance the start of work proposed
in the 1931 State Water Plan, but the State's plans
were thwarted when the market for bonds evaporat-
ed m the nationwide depression in the 1930s. As a
result, the major work of water development in
Northern California at that time fell to the federal
government. The Central Valley Project, constructed
by the U. S. Bureau of Reclamation, extends from
near Mt. Shasta on the north to the southern end of
the San Joaquin Valley. The multipurpose project's
numerous dams, reservoirs, and canals, which were
intended principally to develop water for irrigation,
also help control floods; generate electric energy:
improve river navigation; supply domestic and indus-
trial water: protect water quality, and fish and wildlife
habitat; and provide settings for recreation. Con-
struction of the first unit of the CVP began in 1937;
work on additional units continues today.
The California Water Plan
Immediately after World War II, attention at the
State level turned to updating planning studies done
in the late 1920s and early 1930s. In 1947, at the direc-
tion of the State Legislature, the Division of Water
Resources (predecessor of the Department of Water
Resources) began the Statewide Water Resources
Investigation. This investigation consisted of three
phases:
After leaving the Colorado River, the All-American Canal
crosses an expanse of desert to reach the Imperial Valley.
15
• Identification of the water resources of California,'
• Deternnmation of present and potential "ultimate"
water requirements, and
• Planning for the orderly development of the State's
water resources to meet its potential ultimate re-
quirements.
The first phase of the investigation was a state-
wide inventory of sources, quantities, and character-
istics of water in California. The results were
presented in 1951 in Water Resources of California,
Bulletin 1.^ a concise compilation of data on precipi-
tation, runoff, flood frequencies, and water quality
throughout the State.
Estimates of present and ultimate water require-
ments, published in 1955 in Water Utilization and Re-
quirements of California, Bulletin 2.' made up the
second phase of the study. The report presented the
statewide water use in 1950 for all consumptive pur-
poses and forecast ultimate water requirements.
The final phase of the investigation involved a
statewide plan, published in 1957 in The California
Water Plan. Bulletin 3.^ This report described a com-
prehensive master plan to guide and coordinate the
planning and construction of facilities required to
control, conserve, protect, and distribute the water
of California to meet present and future beneficial
needs throughout the State.
The plan identified watersheds where current sur-
plus supplies existed and areas where deficiencies
were forecast, identified existing and potential water
problems, and suggested methods for distributing
the State's water for beneficial use in all areas. Desig-
nated as the initial unit of the plan was the State
Water Project (then called the Feather River
Project), which was recommended for immediate
construction. The plan also recognized watershed
management, sea-water conversion, waste water
reclamation, and weather modification as possible
means of supplementing California's water supply.
The plan demonstrated that available water, includ-
ing rights to Colorado River water, was adequate for
full development of agricultural and urban areas of
the State, and that physical accomplishment of these
objectives was possible within prevailing water man-
agement policies. The total net water requirement in
1950 was about 21 million acre-feet and was forecast
to increase ultimately^ to over 51 million acre-feet.
' The concept of the California Water Plan as an "ultimate" plan is based
generally on the developmental capability of the land. As explained in
Bulletin 3, the concept "pertains to conditions after an unspecified but
long period of years in the future when land use and water supply
development are at maximum and essentially stabilized."
'Bulletins 1 and 2 cited here were published by the (then) State Water
Resources Board: Bulletin 3 was published by the Department of Water
Resources.
The California Water Plan was intended to provide
a flexible framework into which future specific
projects could be integrated. It was also understood
that the plan would be modified and improved as
more detailed information became available and as
changes were dictated by shifts m public policy and
other unforeseeable events. Bulletin 3 concluded the
Statewide Water Resources Investigation. However,
intensive studies by the Department of Water Re-
sources were continued to (1) identify plans and
programs to meet local and statewide water needs,
(2) analyze their economic justification and financial
feasibility, and (3) determine their priority of im-
plementation. This work continues today. Subse-
quent periodic updates are discussed later in this
chapter.
The projections presented in Bulletin 3 were based
on California's rapid expansion in population, indus-
try, and agriculture during and immediately following
World War II. In 1940. California had a population of
about 7 million; by 1950 the population was about 10.5
million, and. by 1955. it had increased to more than 13
million. This growth, and similar growth in industry
and agriculture, dramatically increased the need for
water.
Update of the California Water Plan
The 1957 California Water Plan was the first com-
prehensive master plan for statewide water develop-
ment. Since 1950, the base year for the study, urban
and agricultural use has been changing continuously
as population has grown and agriculture has expand-
ed. Moreover, public values regarding water have
changed substantially over recent years, and the plan
has needed periodic revision to accommodate all
these changes.
Statewide planning studies to update the Califor-
nia Water Plan have continued since 1961. The stud-
ies have incorporated economic considerations into
projections of future water needs (as contrasted to
"ultimate requirements" in Bulletin 2) and have
analyzed the staging of additional water supply de-
velopments, together with other water management
options, to meet the projected water needs. Results
of the studies have been presented in the Bulletin 160
series of reports. The present report is the fourth
major update of the plan. The three previous reports
and the significance of changes to which they re-
sponded are discussed in the following sections.
The 1966 Update
In 1966, the Department of Water Resources pub-
lished Implementation of the California Water Plan.
' Ultimate requirements were based on full development of all land defined
as irrigable. 16.2 million acres, and an estimated urban acreage of 3.6
million acres.
16
Bulletin 160-66. the first of the 160 series of bulletins.
That report assessed the changes that had occurred
in the years since the California Water Plan was first
published. The base year for the 1966 report was
1960.
The State's population had grown from about 10.5
million in 1950 to about 16 million m 1960, an increase
of almost 45 percent. California was fast becoming
the most populous state m the nation. Based on this
rate ofgrowth. Bulletin 160-66 projected that there
would be more than 35 million people by 1990, and 54
million by 2020 (Figure 2) . Total net water use m 1960
was about 23 million acre-feet. This was projected to
increase to over 31 million acre-feet in 1990 and about
38 million acre-feet in 2020 (Figure 3).
California's growth rate was matched by a stepped
up pace in water development. In 1960, California
voters approved financing of the State Water
Project, a major project identified in the California
Water Plan as a means of transferring surplus water
to areas of need. By 1966, California was in the midst
of an accelerated water development era. Much of
the State Water Project was under construction, and
the U. S. Bureau of Reclamation (USBR), the U. S.
Army Corps of Engineers (USCE), and local agen-
cies were intensifying their water resource planning
and construction activities.
Projections made in Bulletin 160-66 indicated much
higher population growth than later occurred;
however, the continued growth in irrigated agricul-
ture that took place between 1966 and 1982 was not
anticipated at that time (Figure 4) . Concern was not-
ed regarding flood control needs, but the report
recognized that nonstructural approaches, such as
flood plain management, must occur. Increasing
growth of power demands and some of its implica-
tions were discussed. Needs for water-related recre-
ation, the relationship of fish and wildlife to water
development, and water quality control were also
discussed as water management policy concerns.
The 1970 Update
The California Water Plan was updated a second
time with publication in 1970 of Water for California:
The California Water Plan: Outlook in 1970, Bulletin
160-70. The base year for that report was 1967.
By 1967, three million more people were living in
California than in 1960, bringing the total to 19 million.
This increase represented an average annual growth
of about 430,000, a drop from the average annual
growth of 500,000 from 1950 to 1960. The slowdown
was caused by reductions in both births and immigra-
tion. This trend was used to revise population projec-
tions to 29 million for 1990 and 45 million for 2020,
with a corresponding reduction in estimated future
urban water use (Figure 2). Estimates of irrigated
acreage were also reduced (Figure 4), but, with the
availability of more accurate information on the con-
sumptive use of crops and the extent of water reuse,
estimates showed a likely overall increase in net wa-
ter use. Net water use was projected to be more than
34 million acre-feet for 1990 and about 40 million acre-
feet for 2020 (Figure 3) . With the projects then under
construction or authorized, the report concluded
that sufficient water supplies would be available to
meet most of the 1990 requirements.
The 1970 report also expressed concern about
flood control, water-related recreation, and water re-
quirements for energy production, and, for the first
time, noted the need for ". . . more attention to the
emerging environmental problems associated with
water conservation projects and the evolvement of
definite public policies on such problems." Specific
environmental issues identified in the report includ-
ed the need to classify California's rivers, protect and
enhance fisheries and wildlife habitat, and maintain
acceptable water quality. In addition, the relation-
ship of water and land development was recognized
in a major section of the report devoted to a discus-
sion of alternative land use policies and population
dispersal. The report concluded that, although total
statewide water demands would be unchanged, new
population centers would require altered patterns of
water transportation facilities.
Probably the most significant conclusion stated in
Bulletin 160-70 was that the projected slower popula-
tion growth, together with additional water supplies
being developed or authorized, would provide a
breathing spell that would allow more time ". . . to
consider alternative sources of water supply and de-
velop policies for the maximum protection of the
environment." The report specifically recognized the
need for a comprehensive policy framework that
would provide a clearer view of water resource de-
velopment, but concluded that: "Until such policy is
articulated by the State, the Department must con-
tinue Its philosophy and policy of ensuring that the
water needs of the people are satisfied. . . ." The
trend toward increasing environmental awareness
was noted for both the national and State levels, in
addition to legislative action in response to this new
direction.
The 1974 Update
When the third update. The California Water Plan:
Outlook in 1974, Bulletin 160-74, was published in
1974, It reported that, by 1972 (the base year for that
report), the population had reached about 21 million,
indicating a continuing slowdown in the rate of
growth. Population projections were again revised
downward to about 27 million for 1990 and about 37
million for 2020. While projected urban water use
was lower than earlier estimates, projected irrigated
agricultural acreage and water use were greater. The
net result was that the total projected net water use
17
LU
_J
Q.
O
lU
O.
u.
o
(0
z
o
Figure 2. COMPARISON OF CALIFORNIA POPULATION PROJECTIONS
BULLETIN 160 SERIES
ii
1940
1960
1980
2000
2020
YEARS
18
Figure 3. COMPARISON OF TOTAL NET WATER USE PROJECTIONS
BULLETIN 160 SERIES
40
30
I
o
<
0)
= 20
10
0
1960 1967 1972
-W\ost
reasonablejutu^^.
_L
1980
1990
2000
2010
2020
YEARS
19
Figure 4.
COMPARISON OF IRRIGATED LAND PROJECTIONS
BULLETIN 160 SERIES
CO
111
cr
o
<
O
w
z
o
20
for 1990 rose to about 37 million acre-feet, and pro-
jected net use for 2020 rennained about 40 million
acre-feet, the same amount shown in Bulletin 160-70
(Figure 3).
Bulletin 160-74 concluded that the status of avail-
able supplies, compared to the (then) present use,
was favorable. This conclusion was based on the
premise that the Auburn, New Melones, and Warm
Springs Reservoirs and the Peripheral Canal would
be operational by 1980. The report was less conclu-
sive about the extent to which supplies would satisfy
future water needs, considering the increase in-re-
quirements for stream water quality and the setting
aside by the California Legislature of wild and scenic
rivers, primarily in the North Coast area of California.
(Both factors are discussed later in this report.)
The bulletin includes a chapter devoted to a dis-
cussion of key water policy issues, including cooling
water for electric energy production, water deficien-
cies (risk), water exchanges, public interest in agri-
cultural drainage (San Joaquin Dram), water use
efficiency (water conservation), economic effi-
ciency (water transfers), and waste water reclama-
tion. (Some of the still-relevant issues are considered
in Chapter VI of this report, Bulletin 160-83.)
Water Quality Control Planning
Water quality control is the responsibility of the
State Water Resources Control Board (SWRCB).
California's Clean Water Bond Act of 1970 provided
funds to develop a water quality control plan, or Ba-
sin Plan, for each of the 16 water quality planning
basins in the State. With the adoption of the Federal
Water Pollution Control Act Amendments of 1972
(Public Law 92-500), each state was also required to
submit to the Environmental Protection Agency
(EPA) similar water quality control plans. Basin Plans
covering all 16 California basins were prepared by
SWRCB staff, adopted by the various California Re-
gional Water Quality Control Boards, approved by
SWRCB in 1975, and approved (some conditionally)
by EPA soon thereafter.
From the perspective of impacts to California's
water supplies, perhaps the most important of the
basin plans is that for the Sacramento-San Joaquin
Delta. The 1975 Basin Plan provided for protection of
the Delta's varied beneficial uses of water through a
set of water quality objectives, which were similar to
requirements in Decision 1379 of SWRCB, a decision
pertaining to water rights for the State Water Project
and the federal Central Valley Project.
In August 1978, SWRCB adopted the Water Qual-
ity Control Plan for the Sacramento-San Joaquin Del-
ta and the Suisun Marsh (the Delta Plan) and the
corresponding water rights Decision 1485, which su-
perseded Decision 1379. Both documents amend wa-
ter quality standards related to salinity control and
protection of fish and wildlife in the San Francisco
Bay-Delta estuary. Standards are based generally on
the degree of protection that municipal, industrial,
agricultural, and fish and wildlife uses would other-
wise have experienced, had the State Water Project
(SWP) and Central Valley Project (CVP) not been
built. The new standards require that the SWP and
CVP make operational decisions to maintain Delta
salinity and to meet Delta fresh-water outflow within
specified limits. These revised standards are in addi-
tion to nonsalinity standards in the 1975 Basin Plan,
which remain in effect.
Federal law (Public Law 92-500) requires that all
water quality basin plans receive a triennial review.
Since 1975, SWRCB and the nine regional water qual-
ity control boards have made numerous amend-
ments to the plans as needed. Such periodic
updating occurs outside the formal triennial review.
The status of water quality problem areas is dis-
cussed at length m other publications, especially in
SWRCB's most recent biennial report, \A/ater Qual-
ity/Water Rights. W78-80 Report.
Recent Water Supply Developments
Although several significant projects were built
before 1950, most of California's present reservoir
capacity has been developed since the early 1950s.
The historical development of reservoir capacity in
California, by decade, is shown in Figure 5.
Tulloch Reservoir in Calaveras County, o local facility built in the 1950s.
21
Figure 5. HISTORICAL DEVELOPMENT OF RESERVOIR
CAPACITY IN CALIFORNIA
(Reservoirs of more than 75,000 acre-feet)
/=7
C
j-
I I FEDERAL
□ STATE
I I LOCAL
ZL
CZ7
PRE-1940
Total Capacity
(Million Ac- Ft.)
1960-69
r T.2
1970-79
7.0
Development during the 1950s was a mix of federal
and local projects, including Donnells, Beardsley.
and Tulloch Reservoirs on the Stanislaus River; Cher-
ry Valley Reservoir on Cherry Creek; Lake Piru on
Piru Creek; and Nacimiento Reservoir on the Naci-
miento River — all local projects; and Casitas Lake on
Coyote Creek, Folsom Reservoir on the American
River, Lake Isabella on the Kern River, and Lake Berry-
essa on Putah Creek — all federal projects.
The decade of the 1960s was an era of State Water
Project development, and Lake Oroville on the
Feather River was completed by the Department of
Water Resources m 1968. Other projects completed
in the 1960s include Camanche Reservoir on the Mo-
kelumne River, the Upper American River Project,
New Exchequer Reservoir on the Merced River, and
San Antonio Reservoir on the San Antonio River — all
local projects; New Hogan Reservoir on the Cala-
veras River, Clair Engle Lake (Trinity Dam) and as-
sociated transport facilities on the Trinity River, and
Terminus Reservoir on the Kaweah River — all federal
projects; and the offstream San Luis Reservoir on the
western side of the San Joaquin Valley near Los
Banos. a joint State-federal project. About one-third
of California's current reservoir capacity was added
during this decade. (A list of major reservoirs ap-
pears in Chapter III.)
With the 1970s came a slowdown in development,
although significant new capacity was added by lo-
cal public districts and the State and federal govern-
ments. Major projects completed through 1979
include New Bullards Bar Reservoir on the Yuba Riv-
er, the Indian Valley Project on Cache Creek, and
New Don Pedro Reservoir on the Tuolumne River —
all local projects; Buchanan Reservoir on the Chow-
chilla River, Hidden Reservoir on the Fresno River,
New Melones Reservoir on the Stanislaus River, and
Stampede Reservoir on Little Truckee River — all fed-
eral projects; and four State Water Project terminal
reservoirs in Southern California; Pyramid, Castaic,
Silverwood, and Perris.
Foundation and other preparatory work for con-
struction of Auburn Dam, a CVP feature authorized
by Congress in 1965, was halted by the concerns for
safety raised by the Oroville earthquake of 1975. This
event led to a major seismic safety study, as a result
of which the dam's design was changed in 1980 from
a concrete arch to a concrete gravity structure. Be-
cause construction cost estimates now exceed the
22
original authorization, full reauthorization is neces-
sary before work on the dam can be resumed.
Not all the reservoir capacity identified in Figure 5
translates into water supply yield. Large amounts of
storage reserved for flood control produce little or no
yield, and storage projects operated primarily for hy-
droelectric power generation develop less yield un-
less downstream re-regulatory storage is available.
Variations in stream hydrology also affect yield. A
few major reservoirs were developed for long-term
carryover storage (water stored for use over several
dry years), which means that storage capacity is sev-
eral times the firm annual yield. Examples of such
facilities are Shasta, Oroville, Berryessa, and New
Melones. Most of the post-1950 yield is associated
with new reservoirs. During the 1960s and 1970s,
some development occurred at those sites that were
already developed, and several "new" dams were
built that inundated older reservoirs (for example.
New Melones, New Bullards Bar, and New Don Pe-
dro).
Almost one-third of California's developed surface
water supplies is associated with the federal Central
Valley Project and the State Water Project. Both
projects have spanned decades of development and
serve water over a wide geographic area. The CVP
serves primarily agricultural uses in the Central Val-
ley, while the SWP delivers water to agricultural, mu-
nicipal, and industrial users in the San Francisco Bay
area, the Central Valley, and Southern California."
Construction of the CVP began in the 1930s, and its
builder, the U.S. Bureau of Reclamation, continues to
plan for additional elements of the project. The SWP,
authorized by the electorate in 1960 and built by the
Department of Water Resources, has been under
construction since the early 1960s. The CVP has de-.
veloped under a program that determines water sup-
ply needs, constructs facilities, and subsequently
negotiates water supply contracts. The SWP has
been developed quite differently. The Department
contracted for the planned maximum yield of SWP
facilities before the facilities were constructed. Wa-
ter service contracts provide for delivering increas-
ing amounts of water to contractors over time, with
staged construction of facilities to make additional
water available on a schedule in accordance with the
increasing contractual demand.
Ground water has continued to supply a major por-
tion of the total water applied. In 1955. ground water
supplied an estimated 12 million acre-feet of the 28.9
million acre-feet used. In 1965, ground water was es-
timated to furnish about 16 million acre-feet of the
33.6 million acre-feet used. By 1972, this level of use
had dropped slightly to 15 million acre-feet, and it has
remained about the same since then.
When the land overlying a ground water basin is
fully urbanized or fully devoted to irrigated agricul-
ture, the water needs of such an area usually exceed
the amount of water that replenishes the basin. If this
situation continues for some years, the basin is de-
scribed as being in a state of overdraft. The water
table falls, pumping costs increase, wells must be
deepened, and poor quality water sometimes enters
the wells. These effects, along with the wish for a
dependable water supply, often prompt water users
to seek a supplemental supply.
Continuing heavy reliance on ground water in Cali-
fornia has caused severe overdraft to occur in por-
tions of basins in Southern California, along the
Central Coast area, and in the San Joaquin Valley.
Most of the overdraft in Southern California has been
overcome during the last half-century by importing
additional water and by adjudicating or by manage-
ment of the ground water basins by local water agen-
cies. Imported water supplies have lessened but not
eliminated ground water overdraft in the San Joa-
quin Valley. The effect of the imports has been offset
by the continuing growth of irrigated agriculture.
Ground water overdraft has continued to increase in
the Central Coast area. Overdrafts in the coastal por-
tions of the area have, in some cases, caused sea
water to intrude into coastal basins.
The Drought of 1976 and 1977
Although California has experienced other periods
in which precipitation was unusually light, the
drought years, 1976 and 1977. proved to be the driest
two-year period in the State in 125 years of weather
record-keeping.^ Considered individually, 1976 was
the fourth driest water year of record, and 1977 was
the driest.
While drought losses for the two years totaled
more than $2.5 billion, for the most part the State
came through the period remarkably well, largely be-
cause of the way in which both individuals and water
service agencies adjusted to often-difficult condi-
tions. Once convinced of the seriousness of the situa-
tion, the public responded whole-heartedly.
Likewise, water agencies worked together, where
possible, to pool their supplies.
For many water agencies, the drought was a valua-
ble learning experience. For example, after the quan-
tities of runoff in 1976 were known, some immediate
questions were raised. How dry is 1977 going to be?
What about 1978? How much risk should be taken?
The answers were not readily forthcoming. The art
and science of long-range weather forecasting were
not (and are not now) sufficiently developed to be
relied upon. Many farmers wanted full water deliver-
' More detailed information on the history and features of the CVP and the
SWP IS shown in Chapter III.
'In California, hydrologic data are recorded by 12-month water years that
begin on October 1. However, for ease of expression, in this report the
recent drought years are identified as 1976 (for 1975-76) and 1977 (for
1976-77).
23
ies in 1976 and were willing to take the chance that
1977 rainfall would be nearly normal. For urban water
purveyors, rationing plans had to be devised and put
into action. In metered areas, revenues from water
sales declined, while operating costs remained es-
sentially the same, creating financial problems for
water agencies. When water rates were raised, users
complained about paying more for less water. Over-
all, however, the public responded very positively to
requests to conserve water, and. in fact, as the
drought worsened, even exceeded conservation
goals in many instances.
Effects of the Drought
Probably those hardest hit economically were the
businesses that depend primarily on precipitation to
continue operating — ranches and recreation facili-
ties, particularly ski resorts. Cattle ranchers sold their
herds sooner than planned or bought expensive feed
to make up for the lack of grass for grazing. Some ski
resorts did not reopen in 1977. after a very poor 1976
snowfall season. Reservoir recreation areas were
also severely affected, with many facilities made
unusable by greatly lowered reservoir levels. Recrea-
tion in the national forests and state parks was cur-
tailed by water shortages in campgrounds and
extreme fire hazard conditions. The forests suffered
heavy indirect losses from increased insect damage
and disease occasioned by stress from lack of mois-
ture.
Many cities and communities had to resort to such
emergency measures as temporary importation of
water from other regions of the State, drilling of new
wells, mandatory conservation, and. in the most
severely limited areas, rationing to meet basic essen-
tial water needs. Lowered reservoir levels and re-
duced streamflows cut greatly into hydroelectric
energy production. In 1977. statewide hydroelectric
generation was only 38 percent of normal output.
The deficit in Northern and Central California was
made up. at much higher cost, by additional fossil-
fueled generation and purchases from Southern Cali-
fornia utilities.
Lessening of the Drought's Effects
ivia Or Teoer3i icQiSictiO'"' vVa5 DaSseo iH 19// tnat
provided funds to assist California's drought victims,
making loans and grants available to augment, use.
and conserve water for irrigation; to improve com-
munity water systems; to purchase and transport wa-
ter; and to promote water conservation.
At the end of the second drought year, most sur-
face reservoirs had fallen to or below normal mini-
mum operating levels. Fortunately. Lake Mead and
Lake Powell on the Colorado River were nearly full,
which permitted The Metropolitan Water District of
Southern California (MWD) to use surplus Colorado
River flows in place of State Water Project water.
MWD agreed to reduce its demands on the project
by up to 400.000 acre-feet, thereby making water
available to agricultural users in the San Joaquin Val-
ley and to urban users in the San Francisco Bay area.
One such specially arranged transfer was designed
to relieve water-short Marin County, where supply
additions had been rejected in an attempt to control
growth. This transfer involved pumping an emer-
gency supply from the Sacramento-San Joaquin Del-
ta by way of the facilities of the State Water Project,
the city of Hayward. the San Francisco Water De-
partment, and the East Bay Municipal Utility District,
and, finally, through a temporary pipeline laid on the
deck of the Richmond-San Rafael Bridge.
Perhaps the most significant factor in minimizing
losses during this period was the immense ground
water reservoir that underlies the Central Valley of
California. Overall, water users who had access to
ground water felt the drought's effects the least. Al-
though some farmland that was customarily irrigated
had to lie fallow, total reductions of producing acre-
ages were held to a minimum because this vast un-
derground resource was available. Some farmers
were able to shift to crops that use less water and
practiced less double-cropping than usual. These ac-
tions saved water, but they also tended to reduce
farm income. Agricultural production costs in-
creased because farmers were using ground water in
place of cheaper but generally unavailable surface
water. It was costly for them to drill or deepen thou-
sands of wells and pump water from increasing
depths. In the two drought years, ground water
pumping was increased by 3.0 million acre-feet in the
San Joaquin Valley alone and. in the State as a whole,
by 4.5 million acre-feet.
The Drought's Outcome
In retrospect, the 1976-1977 drought reinforced
views of certain aspects of water management and
provided a new perspective on others. Certainly it
demonstrated the importance of preserving ground
water as a viable source of water and operating it as
a long-term supply — to be used but not to be so dep-
leted that it cannot serve as an economic resource.
The drought also demonstrated that urban users
were able to reduce water use more readily and with
fewer adverse effects than could agricultural users.
This fact suggests that the present policy of requiring
agriculture to take the first and largest deficiencies
should probably be re-evaluated. The drought also
forced implementation, to some degree, of several
options that are discussed in Chapter VI of this re-
port, primarily water transfers and changes in. water
project operating criteria.
24
Further information on the drought and its
effects are presented in the Department's
May 1978 report, The 1976-1977 California
Drought — A Review, and in preceding re-
ports issued during 1976 and 1977. For im-
plications of future dry periods or
droughts, see especially the concluding
section, "The Lessons Learned," in the
May 1978 report.
Need for and Significance of Water
Use Projections
The basic purpose of projecting a level of future
conditions is to facilitate informed decisions about
that future by those affected by it. The projections in
this series of reports, like most projections, were, and
are, not intended to be accurate portrayals of future
reality nor self-fulfilling prophecies. Rather, they are
attempts to present the potential future conse-
quences implied by the choices that Californians
made or were making at those points in time. They
also forewarn of the need to make decisions, if
trends continue, or to modify past decisions, if trends
change direction.
Past projections of land and water use, made in the
Bulletin 160 reports, have demonstrated the effect of
extrapolating past and current trends into the future.
They have included population and the factors in-
fluencing the growth of population and irrigated
agriculture. The projections have been intended to
provide reasonable lead time for decisions and ac-
tions necessary to implement the most effective
means of satisfying water needs. At the same time,
they provide a basis to:
• Evaluate the factors that make up the trends.
• Determine the long-range effect of current land
use and water management decisions.
• Judge whether current water management poli-
cies will fulfill their purpose.
• Develop and promulgate new policies and pro-
grams.
Trends vary in directions, however, and events that
cannot be foreseen today subject such projections,
correspondingly, to increasing change with the pas-
sage of time. Accordingly, the estimates of the future
presented in this report represent only the magni-
tudes or conditions foreseen at the present time.
Periodic revision in light of additional information
and experience will continue to be necessary, and
revisions may be either upward or downward.
Some perspective may be gained by reviewing
briefly the Department's experiences in making pro-
jections in the Bulletin 160 series. For example. Bulle-
tin 160-66 based population projections on the high
growth rate experienced during the preceding 20
years. However, population growth rates declined
during the late 1960s, which caused the Department
to adjust its forecasts downward in Bulletin 160-70. A
further drop in growth during the early 1970s resulted
in a further flattening of the future trend line in Bulle-
tin 160-74. The most recent population trends have
resulted in a future trend line slightly higher than in
Bulletin 160-74, but lower than that in Bulletin 160-70.
These projections are shown in Figure 3.
Historic and projected net water requirements for
all consumptive purposes shown in Figure 4 reveal
that the Department's projections have tended to be
conservative. The relatively large increase from Bul-
letin 160-66 to Bulletin 160-70 does, however, reflect
the inclusion of more accurate information on con-
sumptive water use of crops and the extent of reuse
that resulted in projecting greater net water use.
Projections of irrigated land have demonstrated
similar variability. Figure 5 shows projections of irri-
gated land for updates of the California Water Plan
published in 1966, 1970, and 1974. The Department
has tended to underestimate the rate of such devel-
opment. Several factors may be responsible for this,
including a lack of complete understanding (even in
academic circles) of the full complexity and flexibili-
ty of the agricultural system in California. Time and
again, the industry has demonstrated its ability, both
collectively and on the part of the individual farm
operator, to react in a positive way to continually
changing market and economic conditions. This abil-
ity is probably due in part to the favorable climate
that gives the farmer a wide choice of crops to raise
and, at least until recent times, in part to the ready
availability of relatively low-cost water.
The comparisons in this section have been pre-
pared to point up the significance of the differences
that have occurred between what we thought might
happen, had trends continued, and what actually did
happen or what we now think might happen. The
future which Californians will eventually inhabit will
be largely, though not completely, a matter of
choices made in the present. The projections and
other information on water use presented later in this
report have been prepared in the hope that they will
stimulate critical review and discussion by Californi-
ans of those choices.
25
Figure 6. STEPS IN DETERMINING PRESENT WATER USE
AGRICULTURAL WATER USE OTHER WATER USES
URBAN WATER USE
SURVEY IN FIELD OF
IRRIGATED CROP
ACREAGES
ESTIMATE ETAW* AND
APPLIED WATER FOR FISH,
WILDLIFE. RECREATION.
AND ENERGY PRODUCTION
DETERMINE THE RATE
OF ETAW^OF EACH
CROP
ESTIMATE IRRIGATION
EFFICIENCIES BASED
ON PRESENT IRRIGATION
PRACTICES
CALCULATE APPLIED
WATER RATE FOR EACH
CROP
I
CALCULATE AGRICULTURAL
ETAW*AND APPLIED WATER
BY STUDY AREA
1
ESTIMATE POPULATION
t
SURVEY SAMPLE OF
URBAN WATER DELIVERIES
BY SERVICE AGENCIES
SURVEY SAMPLE OFSELF
PRODUCED INDUSTRIAL
WATER SUPPLIES
CALCULATE REPRESEN-
TATIVE PER CAPITA
WATER USE FOR EACH
URBAN AREA
CALCULATE TOTAL URBAN
ETAW* AND APPLIED WATER
BY STUDY AREA
I
CALCULATE HYDROLOGIC BALANCE,
INCLUDING WATER REUSE. TOTAL
ETAW*. IRRECOVERABLE LOSSES.
AND OUTFLOW
I
NET WATER USE
* EVAPOTRANSPIRATION OF APPLIED WATER (see section
"Irrigation Water Use Factors," later in this chapter.)
26
CHAPTER III
WATER USE AND WATER SUPPLY IN 1980
This chapter discusses urban, agricultural, and
other water uses representative of the 1980 level of
development in California. These uses are related to
water supplies that could reasonably be expected to
have been available in 1980 ' under assumed average
hydrologic conditions. The discussion covers the fol-
lowing points;
• Factors that influence water use.
• Methods of estimating amounts of water use.
• Changing trends in water use.
• Identification of present water supplies.
• Interrelationships among sources of water and
uses of water.
• Summaries by Hydrologic Study Areas of (1)
present applied water, (2) net water use, and (3)
related water supplies.
• Changes in water supplies and uses since 1972, the
base year for the preceding report in this series.
Bulletin 160-74.
Steps for estimating how much water is used for
crop irrigation and urban purposes are identified in
Figure 6.
The section, "Statewide Hydrologic Balance," in-
cludes summary tables that provide information on
applied water, net water use, water supplies, and a
balance of net water use and net water supply.
Agricultural Water Use
California's irrigated agriculture, with more than
200 commercial crops in production, continues to
change — in acreages of the various crops, areas
where the crops are grown, methods of irrigation,
and quantities of irrigation water applied. Of these
various changes, the most difficult to determine is
total water applied.
California's vast acreages of irrigated lands, nu-
merous water supply sources, and intricate farm irri-
gation and reuse systems make it impractical to
attempt direct measurement of the amount of water
used for irrigation, nor are there requirements to re-
port water use, as in some other states. It is, there-
fore, necessary to use an indirect procedure for
calculating this water use. The location and acreage
of the various crops grown in an area are determined
by land use surveys. Unit water values (that is, acre-
feet per acre) are then derived for each crop in the
study area. These data provide the basis for calculat-
ing the amount of irrigation water application and
evapotranspiration of water for each study area and
the State as a whole.
Land Use
The Department has made periodic detailed land
use surveys to monitor changes in agricultural crops
and urban development throughout the State over
the past 30 years. Summary crop acreage informa-
tion for large areas is generally obtainable from other
sources, such as the California Crop and Livestock
Reporting Service and the County Agricultural Com-
missioner's Annual Crop Reports. However, there is
no information on the crop locations; this is needed
to relate calculated water use to available water sup-
plies. Accordingly, the Department began land use
surveys m 1948 and has periodically updated and ex-
panded them since then.
Accordingly, it is an artificial 1980. It compares calculated (not measured)
use to water supply, as it would have been if 1980 fiad been an average
or "normal" water year in all locations in the State. For example, in
above-normal water years, more water is available, while less water is
needed. The reverse occurs in drier years
NOTE; References to Hydrologic Study
Areas in the tables in this report
are indicated by the following ab-
breviations;
NC— North Coast HSA
SF — San Francisco Bay HSA
CC— Central Coast HSA
LA— Los Angeles HSA
SA— Santa Ana HSA
SD— San Diego HSA
SB — Sacramento HSA
SJ — San Joaquin HSA
TL— Tulare Lake HSA
NL— North Lahontan HSA
SL— South Lahontan HSA
CR— Colorado River HSA
27
This Landsot satellite scene covers the area from Mt. Shasta on the south (lower left) to southern Oregon on the north.
Irrigated lands appear as red areas. The circular red shapes at center are fields being irrigated by large center-pivot irri-
gation systems, which hove become popular in northeastern California.
28
To assess statewide water use and needs for the
Bulletin 160 series of reports, the data acquired by
land use surveys conducted over a period of years
are adjusted to reflect statewide conditions for a
single year — in this case. 1980. Connparisons with the
1972 level of development show that nnany important
changes have taken place in both total irrigated acre-
age and the proportions of individual crops.
Deriva tion of 1980 A creage. The 1980 irrigated
crop acreages shown in Table 1 were determined by
adjusting the Department's land use survey data col-
lected statewide over the last seven or eight years.
This adjustment wasbased on the amount of change
between years of survey and 1980, as indicated in
reports of the County Agricultural Commissioner and
the Crop and Livestock Reporting Service. Informa-
tion obtained from the Agricultural Commissioners
and Farm Advisors was also used in determining the
number of acres that are double-cropped m each
county.
Principal Changes in Irrigated Land and Crop
Acreage, 1972-1980. As shown m Table 1, irrigated
land area in California increased from 8.779,000 aces
in 1972 to 9,490,000 acres in 1980, an increase of
711,000 acres. Double-cropping increased by 167.000
acres, providing a total increase of 878,000 acres of
irrigated crops over the eight-year period.
One reason for this large growth was the increased
irrigation of 435,000 acres of gram (oats, barley,
wheat, and gram-hay). Much of that increase has
been gained by converting previously dry-farmed
(nonirrigated) barley land to irrigated wheat, mainly
in the Sacramento and San Joaquin Hydrologic
Study Areas (HSAs) where rainfall is sufficient to
provide acceptable yields of barley but not of wheat.
By contrast, in these same areas, irrigated wheat will
normally out-produce irrigated barley. Although
wheat is a relatively low user of water, the large acre-
ages involved make this change significant in terms
of total water use.
The Sacramento HSA showed the greatest in-
crease in irrigated area (about 350,000 acres), due
principally to the increase of 180,000 acres of nee and
320,000 acres of gram. Next in significance was the
300,000-acre expansion in irrigated land in the Tulare
Lake HSA, where a 500,000-acre increase in cotton
took place, the largest change in specific crop acre-
age in any HSA. Some of the cotton was planted on
newly developed land, but most of it was planted to
replace such crops as alfalfa, corn. milo. and wheat.
On a statewide basis, one of the most significant
changes affecting water use was a 250.000-acre re-
duction in alfalfa and a 300.000-acre reduction in pas-
ture. These crops are both high water users. The
effects of these and other changes in water use are
summarized later in this chapter.
TABLE 1
COMPARISON OF IRRIGATED CROP ACREAGE AND LAND AREA
BY HYDROLOGIC STUDY AREA
1972 and 1980
(In 1,000s of acres)
Crop
NC
SF
CC
LA
SA
SD
SB
SJ
TL
NL
SL
CR
TOTAL
9
(15)
10
(24)
44
(64)
66
(61)
54
(64)
61
(41)
286
(294)
341
(318)
445
(371)
-
2
(3)
34
(34)
1,362
(1.279)
Grapes
28
(10)
27
(11)
54
(20)
2
13
(14)
3
(2)
7
(4)
176
(148)
363
(330)
—
(1)
10
(8)
683
(648)
Vegetables
18
(20)
15
(16)
286
(236)
51
(57)
21
(28)
18
(27)
140
(109)
146
(209)
153
(122)
2
119
(95)
969
(919)
Cotton
—
_
—
_
—
197
(119)
1.239
(715)
109
(49)
1,546
(883)
Rice
—
—
—
491
(313)
41
(31)
13
(6)
545
(349)
Grain
80
(73)
5
9
(4)
2
(3)
26
(35)
13
(7)
399
(79)
276
(99)
600
(605)
12
(8)
7
(2)
157
(135)
1.485
(1,050)
Other fields
3
(6)
4
(1)
61
(65)
8
(12)
15
(20)
5
(3)
389
(366)
484
(416)
285
(380)
1
2
(4)
61
(177)
1.318
(1,460)
Alfalfa
51
(46)
1
(1)
51
(38)
2
(2)
11
(14)
1
(4)
105
(149)
181
(286)
319
(423)
34
(22)
45
(57)
185
(192)
986
(1.234)
125
(102)
4
(12)
26
(32)
3
(4)
13
(20)
4
(14)
369
(436)
301
(422)
67
(130)
101
(106)
20
(11)
18
(29)
1.041
(1.334)
TOTAL CROP ACflES
314
(290)
66
(66)
531
(449)
134
(139)
163
(195)
106
(98)
2.176
(1,749)
2,142
(2.048)
3.384
(3.081)
148
(135)
78
(78)
693
(719)
9.924
(9.046)
DOUBLE CROP
—
2
(2)
72
(40)
16
(19)
6
(10)
5
(10)
92
(19)
80
(19)
72
(65)
89
(83)
434
(267)
TOTAL LAND AREA
314
(290)
64
(63)
459
(409)
118
(120)
147
(185)
100
(88)
2.084
(1,730)
2.062
(2.029)
3,312
(3.016)
148
(135)
78
(78)
604
(636)
9,490
(8.779)
Values for 1972 are shown in parentheses.
29
.'* ■V«*-X'' - ■ -T<
Rice fields stretch across the Sacramento Valley.
30
THE SACRAMENTO VALLEY RICE BONANZA
Genetic breakthroughs, improved irrigation and fertiliza-
tion technology, and development of new and larger markets
have brought about burgeoning Sacramento Valley rice acre-
age. As a result of intensive plant breeding, farmers can select
a rice variety that fits a particular farming operation and still
meets exacting market demands. Farmers can pick a variety
of rice with o short or medium groin and a medium or long
growing season and couple these characteristics with short,
medium, or toll plant stature. The application of special soil
amendments, such as zinc, and the use of more than 200
pounds of nitrogen fertilizer per acre have propelled valley-
wide average yields to more than 6,000 pounds per acre, with
some rice paddies producing more than 10,000 pounds per
acre under ideal conditions.
A decade ago, the rice industry was plagued by a large
annual "carryover"; that is, rice that had to be stored for long
periods because of slow market demand. Statewide plantings
were about 300,000 acres. During the 1970s, plantings fluc-
tuated from year to year, but the overall trend was strongly
upward, with rice acreages reaching 550,000 acres by 1980.
This up-trend in numbers of acres was also accompanied by
on up-trend in yield per acre.
Seventy-three percent of the California rice produced in
1980 was exported to other countries. Of the remaining 27
percent, 10 percent went to Puerto Rico, Hawaii, and Guam;
9 percent went to domestic use; and 8 percent was used for
seed and other farm uses, carryover storage, and government
purchases.
Rice farming today is a science. The application of preci-
sion land leveling has aided in maintaining desired water
levels in rice paddies. The use of large quantities of nitrogen,
along with careful weed and insect control by herbicides and
Insecticides, has been largely responsible for the phenomenal
increase in yield. Development of short-stature rice has great-
ly reduced the amount of straw left in rice fields after harvest-
ing. A long-standing practice has been to burn the straw to
control pathogens that over-winter there. Air pollution from
the burning has long been a problem in parts of the valley.
Short-stature rice reduces the amount of straw, which, in turn,
reduces by about 50 percent the particulate matter produced
by burning it. For more than a decade, the industry has been
seeking uses for rice straw that would moke its collection
economically feasible and thereby moke burning unneces-
sary. Little success has yet been achieved.
Traditionally, rice farmers have irrigated rice by opening
the heodgote in early May, allowing the water to flow
through the rice poddy and spill into drains at the end of the
field. Applied water of 9 or 10 acre-feet per acre or even
more were common. Today it has been demonstrated that,
where soils are sufficiently slow in allowing water to perco-
late, rice can be grown with 6 acre-feet per acre or less of
applied water. Atmospheric losses by evaporation and tran-
spiration are about 3.5 acre-feet per ocre, and the bolance
(2.5 acre-feet per acre) is divided between deep percolation
and runoff to surface drains. Nearly all this remainder, of
course, is recaptured locally later by pumping from the ground
water or from drains. Because about 85 percent of Califor-
nia's rice acreage is grown in the Sacramento Valley up-
stream from the Delta, relatively little water in the system is
actually wasted because runoff is available for reuse either
down-slope or downstream and would finally serve the bene-
ficial use of Delta outflow.
While irrigation efficiency on a single farm may be only 50
to 60 percent, overall basin efficiency may approach 80 per-
cent because of the reuse or recycling of water.
Even though California must compete with other nations or
other parts of this country that also grow rice, the ability to
grow a wide variety of types of rice tailored to fit the de-
mands of a foreign or domestic market gives California grow-
ers an advantage. Land suitability and water supply studies
indicate that the Sacramento Valley could devote more than
one million acres to the production of rice.
Rice production is not without Its problems. A source of
Inexpensive water Is essential. Moreover, rice culture Is ener-
gy-intensive. Large tractors are required to till the heavy clay
soil and harvest the crop, sometimes when the land Is wet or
boggy. Numerous aerial operations are required for planting
and applying fertilizer and pesticides, and the harvested rice
must be dried, conveyed, and stared. Other problems are air
pollution from rice straw burning and public concern over the
potential contamination of downstream water supplies by
accidental release of herbicides and Insecticides In drainage
water.
31
Additional discussion of irrigated land and crop
acreage changes is presented m the section, "Sum-
maries of Hydrologic Study Areas," m this chapter.
Factors Causing Changes in Irrigated Acre-
age and Crop Patterns. Agriculture m California,
as well as m the rest of the nation, is influenced by
certain basic forces, as shown below.
Foreign trade
Government Policy
Crop supports-marketing
orders
Tax laws
Water pricing
Market Forces
Form Income
Prices received production
costs
Management and tech-
nological change
Resource Availability
and Costs
Some of these factors influence long-term produc-
tion trends, while others influence year-to-year deci-
sions. Taken as a group, their overall effect during
the past decade has been expansionary, as reflected
in the previously mentioned increase of 71 1.000 acres
of irrigated land in California between 1972 and 1980.
Probably the most significant factors have been
foreign trade, coupled with large amounts of readily
available and affordable ground water supplies. In
general, trade agreements with European Common
Market countries have had a positive influence. In
addition, population growth and increasing real in-
comes have spurred market development in the Pa-
cific Basin, including the People's Republic of China,
Japan, South Korea, Taiwan, and Hong Kong. The
significance of this region may be seen in Figure 7,
which shows that 70 percent of animal and vegetable
products exported to other countries from California
in 1979 were shipped to Asian nations.
In 1980, about 30 percent of California's total irri-
gated area was planted to crops that were subse-
quently exported. This is shown in Table 2, which
shows irrigated acreage required to produce the
crops exported. In 1974, exports amounted to 20 per-
cent of total irrigated area. The increase in export
production totaled over a million acres, demonstrat-
ing a major shift in the relative importance of foreign
markets.
The top five agricultural exports from California in
1980 were, in descending order of value, cotton, al-
monds, rice, wheat, and grapes. The increase in cot-
ton acreage was brought about by worldwide
demand and by the rise in the price of synthetic fi-
bers that increased oil prices caused. The opening of
trade with China also provided a new market for
California cotton. Lint cotton led the exports of Cali-
fornia farm products at $1.1 billion in 1980 and repre-
sented 28 percent of the total value of all California
farm products exported. The major countries import-
ing U.S. cotton were China. Japan. South Korea, Tai-
wan, and Hong Kong. Almonds, the second leading
crop exported from California, represented $430 mil-
lion, followed by nee at $318 million, wheat at $283
million, and grapes (fresh, raisin, and crushed/wine)
at $230 million.
LAND USE SURVEY PROCEDURES
Land use surveys begin with taking vertical aerial photo-
graphs. The 35-millimetre transparencies show about one
square mile of land at a scale of approximately 1:62,500.
They are projected onto o screen, boundaries of fields are
interpreted, and, to the extent possible, crops are identified.
This information is delineated on U.S. Geological Survey
1:24,000 scale 7/2 minute quadrangle maps, which are then
taken into the field for positive crop identification for each
parcel and the acreage of each crop type by counties, hy-
drologic areas, irrigation districts, and other areas is then
determined. At present, the areas of significant water use ore
resurveyed, on the overage, about once every seven years;
that is, each year, each of the Department of Water Re-
sources' four District Offices surveys about one-seventh of its
area of significant water use. Other areas in which urban or
ogricultural water use is low are surveyed only once every 15
years or so.
The Department has been working for more than five years
with the Notional Aeronautics and Space Administration
(NASA) , the Space Sciences Laboratory of the University of
California (UC) at Berkeley, and the Geography Department
at UC Santo Barbara in developing technologies to use Land-
sot satellite imagery to assist these surveys. In 1979, some of
these techniques were tested in a statewide survey of irrigat-
ed acreage. The exercise demonstrated the technique to be
a cost-effective and valuable tool for deriving interim esti-
mates of irrigated acreage between regularly scheduled,
more detailed surveys. Identification of specific crops from
satellite imagery is much more complex than simply determin-
ing total irrigated acreage because California produces some
200 commercially grown crops. The Statistical Reporting
Services of the U. S. Department of Agriculture (Washington,
D.C. office), the California Crop and Livestock Reporting
Service, the California Department of Food and Agriculture,
NASA, UC Berkeley's Space Sciences Laboratory, and the
Department of Water Resources have agreed to cooperate in
further research and development of satellite imagery-related
techniques for crop acreage determination.
32
Figure 7. DESTINATION OF CALIFORNIA
ANIMAL AND VEGETABLE PRODUCTS
EXPORTED IN 1979
(In percent of dollar value)
At present, the cost of borrowing money is a princi-
pal concern for farmers. However, such was not the
case during most of the period since 1972. Farmers
were assisted by low-interest loans from the federal
government and tax shelters for significant portions
of farm income.
The foregoing factors, combined with the effect of
changes in prices received and production costs, are
probably best reflected by net farm income. Since
1972, the increase in farm production costs exceeded
the increase in receipts in three of the intervening
years. However, the overall trend has been increased
receipts over costs. The most severe drop occurred
during the 1976-1977 drought, but this was followed
by a quick recovery in 1978. In 1979, net farm income
exceeded three billion dollars for the first time.
Recent trends in gross farm income, production
expenses, and net farm income are depicted in
Figure 8.
TABLE 2
AREA USED TO PRODUCE CALIFORNIA CROPS EXPORTED TO FOREIGN COUNTRIES '
1974 to 1980
(In 1,000s of acres)
Crop
19/4
1975
1976
1978
1979
1980
Cotton Lint
Wheat
Rice
Almonds
Oranges
Dry Beans
Alfalfa Hay
Grapes
Walnuts
Lemons
Prunes
Lettuce
Peacties
Tomatoes
TOTALS FOR;
Above Crops .
All Crops
693
570
252
113
43
16
46
59
36
16
22
11
5
8
620
801
168
156
45
11
22
91
42
10
36
11
6
10
840
611
163
144
55
25
44
75
48
20
25
11
7
11
1,890
2,000
2.029
2,100
2,079
2.200
1,178
465
255
170
45
80
44
99
47
16
31
11
7
2,456
2,600
1,373
668
235
264
34
68
42
86
36
17
24
9
9
14
2.879
3.000
1,433
784
314
192
95
85
63
58
56
16
23
8
7
10
3.144
3.200
' Estimated from statewide average yields. Data for 1974-1976 on fiscal year basis No
data available for 1977
Sources: Annual reports of California Department of Food and Agriculture. California
Crop and Livestock Reporting Service. Exports of Agricultural Commodities
Produced in California, Sacramento.
33
Figure 8. FARM INCOME AND
PRODUCTION EXPENSES IN CALIFORNIA
1972-1980
1972
1980
y Includes cash receipts, government payments,
value of home consumption, gross rental value
of farm dwellings, and income from recreation,
machine hire, and custom work.
2/ Preliminary
Source: "California Outlook: Agriculture 1981"
Bank of America, May 29, 198 1
KEY WATER USE TERMS
APPLIED WATER for urban, agricultural, recreotion-
al, wildlife, and other uses is defined as the quantity of woter
delivered to the intake to a city's water system and the farm
headgate, the omount of water diverted from a streom or
pumped, in the case of self-developed supplies, and, for
wildlife, the amount of water supplied to a marsh or other
wetland, either directly or by incidentol drainage flows. Be-
cause of the large amount of reuse that occurs, the term falls
short in describing the amount of water supply needed for
water-related purposes over a wide areo. For this, the follow-
ing expression is employed.
NET WATER USE is a term devised to represent the
relationship between applied water and the water supply
needed for a specific area. It is the measure of the quantity
of water that must be developed in or delivered to a service
area. The Department of Water Resources defines net water
use OS the sum of the evapotranspiration of applied water
required in on areo, the irrecoverable losses from the water
distribution system, and the outflow leaving the area. (For a
full discussion of the term, see the section, "Net Water Use,"
later in this chapter.)
EVAPOTRANSPIRATION OF APPLIED WA-
TER (ETAW) is the portion of the evapotranspiration of
a specific crop or landscape vegetation supplied by irrigation
water. It is computed by subtracting from total evapotranspi-
ration the water supplied to the crop or vegetation by precipi-
tation, including that amount stored in the soil.
EVAPOTRANSPIRATION (ET) is the water taken
into the plant, transpired by the foliage, and evaporated from
the surrounding soil.
irrigation Water Use
Ti^'ee kev terms, evapotranspiration. evapotran-
spiration of applied water, and applied water, are
used in describing irrigation water use. A fourth inn-
portant ternn, net water use, is used to relate irriga-
tion water use to water supply.
Evapotranspiration. Values for crop evapotran-
spiration (ET) were developed by the Department of
Water Resources and other agencies through ap-
plied research conducted at many sites throughout
the State.^ The results of this woric reflect the varia-
tions in climate and growing conditions prevailing
from region to region within California. These differ-
ences have great significance in evaluating water use
by agriculture. Crop evapotranspiration is a function
of time and length of growing season, temperature,
humidity, wind, and other factors.
Evapotranspiration of Applied Water. The
portion of :ota. ET tnat is suophed by irrigation is
called evapotranspiration of applied water (ETAW).
The part of the total precipitation used by a crop
' Crop evapotranspiration data gathered in cooperation with other agencies
are summarized in Vegetative Water Use in California. 1974. Bulletin
113-3. Department of Water Resources. April 1975.
\ 34
(through evapotranspiration) is called effective
precipitation. It includes the portion of precipitation
that falls during the nongrowing (winter) season and
IS stored in the soil within the plant root zone and is
thus available to the crop during the following grow-
ing season, thereby reducing irrigation needs.
With wide differences in ET and effective precipi-
tation that occur throughout California, ETAW for
any one crop varies greatly. As Figure 9 illustrates, for
alfalfa, ETAW varies from 1.0 acre-foot per acre at
Eureka to 6.6 acre-feet per acre in Coachella Valley
in Riverside County. ETAW is affected considerably
by annual variations in precipitation, and deficiencies
in stored soil moisture must be supplemented by in-
creased irrigation.
The effectiveness of precipitation depends on two
factors: the specific time the rain occurs and the
quantity needed to replenish soil moisture losses.
Severe problems arose in 1976 and 1977 because rain-
fall failed to fully make up for soil moisture lost during
the previous years and because of the lack of late
precipitation to satisfy spring season growing needs
of such shallow-rooted crops as wheat and barley.
Where possible, these deficiencies were met with
supplementary irrigation to complete the crop grow-
ing cycle.
Days of strong, dry winds greatly increase the rate
of evapotranspiration and are another factor affect-
ing ETAW. Such winds blew in the Sacramento Val-
ley during the spring of 1976, compounding the
effects of inadequate rainfall. To compensate, sig-
nificantly more irrigation was necessary than would
have been needed in a more normal springtime.
Applied Water. Although the ET rate for each
crop IS relatively constant within a region, irrigation
efficiencies range considerably; therefore, the
amount of water applied varies considerably. (Irriga-
tion efficiency is computed by dividing ETAW by
AW.) Applied water data are assembled by making
on-site measurements and acquiring data from other
agencies and individuals who also measure water
applications. In many cases, however, no measured
data are available; therefore, estimates are obtained
from knowledgeable individuals. The amount of wa-
ter applied varies, depending upon such factors as
crop ETAW, climate, soil texture and depth, land
slope, cost of water, cost of labor, water table
depths, leaching requirements, type of irrigation sys-
tem, and method of operating the irrigation system.
Usually some water is applied in excess of ET and
leaching requirements (water needed to flush harm-
ful quantities of salt from the surface and the root
zone), even in the most carefully managed irrigation
system. This is because of:
• The relatively high cost of making precise applica-
tions compared to the benefits (which are related
to water price).
THE ALFALFA STORY IN NORTHEASTERN CALIFORNIA
Substantial increases in alfalfa acreage have been record-
ed in northeastern California over the past ten years. For the
most part, these increases have occurred because plantings
in the Central Valley have declined. Cotton in the San Joa-
quin Valley is the key to the situation. The demand for cotton
has been so great that much of the good-quality row crop
land in the San Joaquin Valley has been planted to high-
income-producing cotton. Total acreage of lower-income-pro-
ducing alfalfa, which also competes for the higher quality
land, has diminished markedly. This has caused a shift in
acreage within California and increased the demand for alfal-
fa from neighboring Nevada, Oregon, and Arizona.
Consequently, areas such as Surprise Valley, Butte Valley,
and the upper Pit River basin in Northern California are
currently in the midst of an alfalfa boom. These mountainous
areas have always been noted for their premium quality hay
(high in total digestible nutrients), but they have had to
compete directly with the lower quality, but higher yield,
harvests in Central Valley areas. Higher-yielding alfalfa varie-
ties and better irrigation techniques have combined to meet
increased market demands. New center-pivot and wheel-line
sprinkler systems have proliferated, many of these delivering
new water supplies from ground water.
Land use surveys during the summers of 1979 and 1980
indicate that more than 80 large center-pivot sprinkler sys-
tems— most covering 160 acres, with some to 640 acres — are
now operating in the northeastern area. More are planned in
the immediate future, particularly around Goose Lake in the
North Fork Pit River area. For more popular, however, are the
standard wheel-mounted sprinkler systems that are estimated
conservatively to outnumber center pivots twentyfold. Some
of the advantages of sprinkler systems, particularly those
designed for low pressure (around 20 pounds per square
inch), are relatively low costs of maintenance, labor and
energy; capability of applying water evenly; and elimination
of land leveling, a particularly important factor on shallow
soils. Sprinkler systems can also be used to irrigate undulating
or steep land parcels.
Since nearly all the existing surface water in these moun-
tain valleys is already in use, farmers have turned to drilling
wells or converting meadow pasture served from ditch sys-
tems to higher-return alfalfa hay. The following tabulation
gives some insight into the direction alfalfa plantings have
taken in northeastern California.
In 1,000s of acres
Area 1970
Surprise Valley 11.9
Upper Pit River 13.4
Butte Valley 9.4
Total 34.7
1980 Chartge
+ 4.4
-1-16.0
-h8.3
+ 28.7
35
Figure 9. AVERAGE UNIT EVAPOTRANSPIRATION OF APPLIED WATER
FOR ALFALFA AT SELECTED SITES (Feet)
NC -
NORTH COAST
SF -
SAN FRANCISCO
CC -
CENTRAL COAST
LA -
LOS ANGELES
SA -
SANTA ANA
SD -
SAN DIEGO
SB -
SACRAMENTO
SJ -
SAN JOAQUIN
TL -
TULARE LAKE
NL -
NORTH LAHONTAN
SL -
SOUTH LAHONTAN
CR -
COLORADO RIVER
%A-^
Hydrologic Study
Area Boundary
36
• The risk of miscalculation when trying to provide
only enough for ETAW (which could cause under-
irrigation and reduce crop production in the event
of unexpected high winds or temperature).
• Factors inherent in the design and performance of
the various irrigation systems, including the inabili-
ty to account for all variations in soil characteris-
tics throughout a field.
Water applied in amounts that exceed the rate of
ET IS not necessarily lost, however, but may be avail-
able for reuse later through percolation to usable
ground water or by return flow, which may provide
a water supply to down-slope users. This is discussed
in more detail in the section, "Net Water Use," later
in this chapter.
Recent Trends in Irrigation Systems. Almost
80 percent of California's cropland is irrigated by sur-
face (flood) irrigation systems, such as border, basin,
or furrow systems (Table 3). Sprinklers and drip sys-
tems have been increasing in popularity, however,
because they have characteristics not found in sur-
face methods. This does not mean that surface irriga-
tion is necessarily inefficient by comparison; rather,
sprinkler and drip systems usually require less labor
and attention to operate at a high level of efficiency.
The problem of paying for converting existing sys-
tems to newer, more efficient systems has been a
deterrent. Improvements in surface irrigation meth-
ods have created a potential for increasing water use
efficiency, while retaining the advantage of relatively
lower installation cost and energy requirements.
These improvements include precision land leveling
with laser-controlled equipment and systems for
recovering and recycling irrigation water after it has
been used (pump-back systems).
Highlights of some of the surface, sprinkler, drip,
and subsurface systems and their uses are given be-
low. The acreages irrigated by each type of system
are given in Table 3.
• Surface Systems
Surface irrigation is used on the major portion of
irrigated land — 7,800,000 acres — and involves two
general types of operation: complete flooding
(wild flood, border, and basin) and partial flooding
(furrow) of the soil surface. The border strip sys-
tem, the principal complete flooding method, con-
sists of wide, bordered channels in which the
water flows across the field from the water supply
ditch to the end of the field in a relatively thin
sheet.
For the level basin system, an area is completely
surrounded by a dike and the entire amount of
water is applied quickly to the area and slowly
absorbed by the soil. Very high irrigation efficien-
cies with relatively uniform applications can be
achieved by this method. Laser-controlled land lev-
eling, which smoothes the ground surface with a
precision of less than a one-inch variation in 40
acres, can reduce the quantity of water that must
be applied.
With furrow irrigation, small channels convey the
water over the soil surface in narrow, parallel
streams. After it has infiltrated the soil, the water
TABLE 3
ESTIMATED CROP ACREAGE IRRIGATED BY MAJOR TYPES OF IRRIGATION SYSTEMS
BY HYDROLOGIC STUDY AREA
1980
(In 1,000s of acres)
1980
Irngated
Crop
Acreage
Surface Systems
Sut>-
surface
System
Sprinkler Systems
HSA
Wild
Flood
Border
Basin
Furrow
TOTAL
Solid
Set
Hand
Move
fvlectianical
Move
TOTAL
Drip
Systems
NO
310
70
530
130
150
110
2.180
2,140
3,380
150
80
690
9.920
25
100
5
100
30
260
135
5
26
10
750
860
1.000
15
410
3210
5
410
76
180
25
35
730
5
310
65
16
5
520
980
1.460
5
5
240
3,600
166
6
340
65
25
5
1.780
1,920
2.630
145
35
685
7.800
—
85
40
125
25
40
55
10
50
70
66
80
396
10
10
110
35
85
20
170
36
530
30
1.036
110
5
16
70
36
60
6
15
306
145
55
180
45
85
70
310
135
660
5
46
1.735
SF
10
CO
10
1_A
20
SA
40
SD
35
SB
5
SJ -
TL .. .
45
90
1^:::::::..;...::::.: :: :....
SL
_
OR
5
TOTAL
260
PERCENT
100
3
33
7
36
79
1
4
10
3
17
3
No data shown for less than 3.000 acres.
Estimates based upon information provided by the U C Cooperative Extension Service,
In the case of dual irrigation systems (for example, where sprinklers are used tor
leaching before planting and a furrow system is used for regular irrigation), only the
principal irrigation system is indicated.
37
moves laterally as well as downward to wet the
plant root zone.
To achieve high efficiency with both furrow and
border strip systems, care must be taken to stop
the flow of water soon enough to minimize the
amount that runs off the field or collects at its end.
Moreover, the length of the run and the gradient
are extremely important in controlling the water to
attain percolation into the soil as evenly as possible
at both ends of the field. Soil texture and structure
are important considerations in designing an effi-
cient furrow or border strip system. In recent
times, water recovery (pump-back) systems have
gained popularity because they permit the opera-
tor to capture and re-apply excess irrigation flows
that run off the field from furrow or border strip
systems.
Wild flooding is the least extensive and most primi-
tive of the surface irrigation systems. It consists of
random spilling of water over the edge of a ditch,
with the water flowing over the natural contours of
the land. Its only significant use occurs in mountain
meadow areas, principally in Northern California.
Sprinkler Systems
There are three types of sprinkler systems; hand-
moved pipeline (or hose line), permanently in-
stalled (solid-set) systems, and mechanically
moved systems.
Wheel-mounted pipelines moved by machine have
been used for years throughout the State. Center-
pivot sprinkler systems that rotate about a central
point (the source of water for the system) have
been used only on a limited basis in the Central
Valley, but to a much greater extent in the
northeastern part of the State. These systems are
designed to automatically irrigate a large circular
area of a quarter-section or more. Corner swing
arms may be added to irrigate field corners that are
not otherwise reached in a circular pattern. Of
more promise for increased use in the flat Central
Valley floor is the recently developed automated
linear-move sprinkler system, which moves in a
straight line across the field. New designs use com-
puter-controlled tractor units, flexible water supply
lines that automatically couple and uncouple to a
series of valves spaced along a buried mam supply
line, and low-pressure sprinkler heads. This system
is totally self-contained and is powered by a fuel-
efficient diesel generator.
Drip Systems
Drip irrigation is now used on about 260,000 acres
of irrigated land, and it has been increasing in pop-
ularity. Unlike other methods that apply large
amounts of water periodically, drip irrigation sys-
tems use small amounts of water flowing more or
less continuously. The steady flow of drops or drib-
bles IS accomplished by plastic emitters, or a per-
forated tube, fed with water that has been
carefully filtered to prevent the minute orifices
from clogging. Drip systems moisten less ground
surface area than do sprinkler or surface systems,
thereby reducing the amount of water evaporated
from bare soil. Although drip systems can be oper-
ated at very high efficiencies, the rate of ETAW
remains about the same, except for some signifi-
cant reduction in evaporation from the soil where
young trees or grape vines are being grown.
Drip systems are costly to install; however, the use
of this system has increased, often where other
methods are unsuitable or where water costs are
high. An example of both conditions exists in San
Diego County where avocados are cultivated on
steep, rocky slopes with very expensive water. If
other methods of irrigation were used there, runoff
and soil erosion would be excessive. Another im-
portant area of use is the southern San Joaquin
Valley where young trees and vineyards are irrigat-
ed by this method. Even where water costs are not
high, drip irrigation is of interest to farmers be-
cause it offers opportunities to save on labor.
Subsurface System
This is a unique system used only in a very limited
area. In much of the Sacramento-San Joaquin Del-
ta, the water level in the channels is considerably
higher than the ground surface of the islands. To
keep the islands from being inundated, deep drain
ditches carry water to pumps that dispose of it into
the river channel. To irrigate a crop, the pumps are
shut off, which allows the water to rise in the soil.
The pumps are then restarted to draw this water
below the level of the root zone of the plants.
Agricultural Water Conservation. As used in
this report, any increase in on-farm irrigation effi-
ciency is considered water conservation. Whether
such action results m a saving of basic water supply
depends on the hydrologic characteristics of a par-
ticular situation. (This is discussed in detail under
"Net Water Use" later in this chapter.) Agricultural
water conservation has benefits other than water
savings, however. These may include reduced ener-
gy use. increased flows in certain reaches of rivers,
less need for fertilizer, fewer weed control problems,
and, in some instances, increased crop yields.
38
IRRIGATION METHODS (1) Linear-move sprinklers. (2) Hand-moved pipeline sprinklers. (3) Hand-moved side-roll sprinklers. (4) Subsurface
irrigation. (5) Basin irrigation. (6) Drip irrigation by perforated tube. (7) Wild flooding. (8) Center-pivot.
39
IRRIGATION METHODS (9) Gated pipe furrow system. (10) Drip irrigation by plastic emitters. (11) Border irrigation. (12 Laser-con-
trolled land leveling. (13) Solid-set sprinklers. (14) Mechanically moved side-roll sprinklers. (15) Pump-bock system. (16) Siphon tube
furrow system.
40
Urban Water Use
This section describes how urban water use is de-
termined and the historic trends in the factors in-
fluencing urban water use.
Estimates of urban water use are based upon esti-
mates of the area's population and representative
values for the per capita rate of water use. These
values are based on a sampling of water service
agencies' records of deliveries, the number of con-
nections served, and estimates of the number of per-
sons per connection. Sample data from individuals
who develop their own water supplies are also in-
cluded. As with agricultural applied water, a portion
of urban applied water is evapotranspired, principal-
ly by landscape vegetation.
Population
California continues to be the most populous state
in the nation, with 23,773,000 people reported in the
1980 census (Table 4). From 1972 to 1980. the State's
population grew by more than 3 million, a 15-percent
increase, or 1.8 percent per year. The Santa Ana Hy-
drologic Study Area (HSA) added the greatest num-
ber—610,000 people.
Migration. From 1972 to 1980, immigration ac-
counted for 60 percent of California's growth (Fig-
ures 10 and 11). Half these people came from the
industrialized states of New York, Illinois, Ohio, New
Jersey, and Pennsylvania. Two-thirds of the immi-
grants settled in the metropolitan areas of Los Ange-
les, San Diego, and south San Francisco Bay. It is also
suspected that an additional significant number of
undocumented immigrants from Mexico and various
countries in Asia were not counted in the 1980 cen-
sus.
Employment opportunities have been the mam
force behind this migration influx. While the nation
A developing area in Sacramento typifies the urban expan-
sion that occurred in California between 1972 and 1980.
was experiencing employment growth of 3 percent
in the nonagricultural sectors, California experienced
a 4-percent employment growth (more than 30 per-
cent greater than the nation as a whole). The result
was that half the immigrants came to California ei-
ther for a job transfer, to take a new job, or to look
for work.
TABLE 4
CALIFORNIA'S POPULATION GROWTH
BY HYDROLOGIC STUDY AREA
1972 and 1980
Population
Increase
HSA
1972
1980
Persons
Percent
NC
363.000
4.475.000
833,000
7,398.000
2.364.000
1,529.000
1.311.000
805,000
989,000
44,000
245,000
237.000
20.593.000
459,000
4.790.000
1.005.000
7,927.000
2.974.000
2.068,000
1,674.000
1.014.000
1.178,000
61,000
303,000
320,000
23.773,000
96.000
315,000
172,000
529,000
610.000
539.000
363.000
209.000
189,000
17,000
58,000
83,000
3.180.000
26
SF
7
CC
21
LA
7
SA
26
SD
35
SB
28
SJ
26
TL
19
NL
39
SL
24
CR
35
STATE TOTAL
15
41
Figure 10. ANNUAL POPULATION GROWTH BY COMPONENTS
700-
600-
500
®
a.
o
o
a.
•jr 400-
co
c
(0
CO
300
200
100
1940 1945 1950 1955 1960 1965 1970 1975 1980
Years
42
Figure 11. CALIFORNIA POPULATION BY COMPONENTS OF GROWTH
1940 - 1980
1975
Other forces contributing to California's growth
from migration have been the greater number of re-
tirees, who are often free to resettle where they wish;
greater freedom of movement of families due to the
decrease in the birth rates; the increase in the num-
ber of women in the labor force; climate; and the
desire to be near relatives.
Natural Increase. The remaining 40 percent of
California's growth from 1972 to 1980 came from
natural increase — births minus deaths. While both
the birth rates and death rates have been declining,
the numbers of births and deaths have been increas-
ing. The greater number of deaths is attributed to the
increase m the number of elderly people. The rise in
births results from two factors:
• Women born during the post-World War II "baby
boom" who have now reached childbearing years.
• Women in the labor force who delayed marriage
and childbearing now deciding to start their fami-
lies.
Inter-County Growth Patterns. For the first
time since 1850, when California became a state.
population in the 50 counties north of the Tehachapi
Mountains, which separate the Central Valley from
Southern California, grew between 1972 and 1980 at
a greater percentage rate than did the eight counties
south of the Tehachapis. Since 1970, the northern
counties have grown almost 19 percent, and the
southern counties by 17 percent.
Migrants to California tend to move first into the
metropolitan areas of Los Angeles and San Fran-
cisco: but, within a few years, many move to the less
congested surrounding counties. Perhaps one-quar-
ter to one-third of the growth in non-metropolitan
counties can be attributed to this resettlement to
outer suburban areas. The population in counties
with commuting ties to the metropolitan areas grew
more than population in the more remote counties
(Figure 12). The mam forces behind the growth in
non-metropolitan counties have been:
• The search for less expensive housing.
• The increase in employment opportunities result-
ing from recent decentralization of employment
centers.
• The attraction of coastal, lake, and hill counties.
43
Figure 12. POPULATION GROWTH BY COUNTY
1972-1980
100,000 OR MORE
POPULATION INCREASE
55.000 - 99,999
27.500 - 54.999
27,499 OR LESS
POPULATION INCREASE
\
\
\
\
>o^=^
44
The 1980 population was based on the census,
which tabulated population by county and county
subdivisions. The Department then allocated these
figures to the appropriate HSA and detailed study
areas.
Urban Per Capita Applied Water
The gross per capita urban applied water value is
a factor selected to represent total average urban
applied water per permanent resident. This value in-
cludes residential, industrial, commercial, and gov-
ernmental use. On a statewide basis, 61 percent of
the applied water is residential, 16 percent is com-
mercial, 16 percent is industrial, and 7 percent is gov-
ernmental (Figure 13).
The gross per capita applied water value is ex-
pressed as gallons per capita daily or acre-feet per
capita annually. These values are derived from sam-
ple data, principally from two sources: water agen-
cies that serve a large number of customers and
individual entities that develop their own supply. To
calculate urban applied water for a particular geo-
graphic area, per capita applied water values derived
from data for communities within, or most similar to,
the area in question are selected and multiplied by
the area's population. Important community charac-
teristics considered are climate, type of housing,
housing density, age, industrial activity, and general
economic level.
Figure 13. PERCENT OF URBAN
APPLIED WATER BY TYPE OF USE
San Francisco, Los Angeles
Santa Ana and San Diego HSA'S
GOVERNMENT
SIDENTIA
INDUSTRIA
16%
Gross Per Capita Use of Agency-Supplied Wa-
ter. Gross per capita use of agency-supplied water
IS computed by dividing the total quantity of water
supplied to the conveyance system of a water serv-
ice agency by the number of permanent residents
living within the agency's service area. Industrial and
commercial water uses are included in the average
per capita applied water value derived by this com-
putation method. Large deliveries for industrial or
transient recreational purposes will result in higher
per capita values. The quantity of water supplied to
the conveyance system differs from "water deliv-
ered" (a term used to denote the quantity delivered
to the users' connections) in that it includes all losses
between the point of introduction into the system
and the users' connections.
In gathering data from water suppliers, a sampling
procedure is employed whereby information on wa-
ter supplied, number of connections, and population
served is obtained from most large water agencies,
as well as representative smaller water agencies,
throughout the State. The single-unit value that
represents average use for a particular study area is
computed by weighting the unit gallons per capita
daily (gpcd), calculated for each of the suppliers
sampled in the area, by the population served by
each supplier. When little or no sample data are avail-
able for an area (which sometimes is the case for
relatively small study areas), values are derived by
weighting those obtained from samples of similar
areas.
This procedure is not a rigid statistical sampling
process because water suppliers are not randomly
selected. This is because of the great variation in
record-keeping practices by water agencies, a factor
that can add greatly to the cost of collecting, aug-
menting, and processing data from some agencies.
Rather than limiting data to a specified preselected
sample, all readily obtainable data of acceptable
quality are used in the calculations.
California does not require the reporting of water
use data to a central State agency, as do many other
states, and it becomes necessary to locate individual
data sources and obtain and verify these records.
Special atttention is given to verifying the "popula-
tion served" estimate, which is often just a rough
estimate by the agency. The Department of Water
Resources periodically updates gross per capita ap-
plied water estimates on the basis of data from about
175 water service agencies throughout the State. Es-
timates for selected communities are shown in Fig-
ure 14. They range from 553 gpcd in Palm Springs in
the Colorado River HSA to 85 gpcd at Pacifica, a
largely residential community on the coast south of
San Francisco.
Gross Per Capita Use of Self-Supplied Water
Periodic surveys of manufacturing water use are con-
ducted to determine quantities of self-supplied wa-
ter. The local water agency supplies water to most of
45
Figure 14. GROSS DAILY PER CAPITA
WATER USE FOR SELECTED COMMUNITIES
(Agency Supplied Water- 1980)
1
"1
BLYTHE
PALM SPRINGS AND VICINITY
RIVERSIDE
SAN DIEGC
3
LOS ANGELES
1
BEVERLY HILLS
SANTA BARBARA
PASO ROBLES
BAKERSFIELD
FRESNO
SACRAMENTO
SALINAS
SAN JOSE
PACIFICA
SAN FRAN
1
CISCO
EAST BAY CITIES
CORNING
REDDING
EUREKA
I
I
0 100 200 300 400 500
GALLONS PER CAPITA PER DAY
600
the smaller manufacturing facilities situated in cities;
however, larger users located both inside and out-
side urban areas have tended to develop their own
ground water supplies or to divert from local streams
as a less costly alternative to purchasing it from a
public agency. The surveys are directed principally at
water-intensive manufacturing plants, such as can-
neries, refineries, and pulp and paper mills.
A sampling procedure is used in which readily
available data on water use are gathered and aver-
aged by each specific type of industry. In this proc-
ess, each industry value obtained is weighted
according to the number of persons employed. Unit
employee use (expressed in gallons per employee
working day), averaged from replies from a particu-
lar county or study area, is assumed to be typical of
all industry of that type in the area. The quality of the
computed unit-employee-use data depends on the
level of response for each industry type. Where data
from certain industry types are deficient or missing
for a particular service area, statewide averages are
substituted. The sample data for each type of indus-
try in an area are then expanded to represent total
use of each type by multiplying the unit employee
use by the total number of employees in that indus-
try. Some of the findings of the most recent survey
m 1979 are presented in the sidebar, "Industrial Wa-
ter Use."
Water self-supplied by all types of industry in an
area is divided by the area's total resident population
and added to the per capita value based on agency-
supplied water to obtain the total gross per capita
applied water value.
Factors Responsible for Changes in Per Capi-
ta Applied Water. Many different factors may in-
fluence urban water use, and the effect will vary
widely among service areas, depending on local
situations. These factors are:
• Housing Density: Increasing density of residen-
tial development is generally associated with a de-
creasing rate of per capita residential applied
water. This results from the reduced amount of
landscaped area per capita where lot sizes are
small and/or multi-family housing has been devel-
oped.
Single-family construction decreased from about
90 percent of all new housing starts m the mid-
1950s to just over 50 percent by the late 1960s.
During this same period, multi-family apartment
construction increased from less than 10 percent
to over 40 percent of all new housing starts. By
1972, multi-family units had increased to 55 per-
cent. However, in recent years, as interest rates
climbed, finding financing for the larger, multi-fam-
ily unit projects has been more difficult, which has
caused this type of construction to drop to 44 per-
cent of new housing starts (1980) . Numbers of sin-
J/ Water supplied by public water purveyors-additional
water may be supplied by Indivduals and industries
for their own use.
46
INDUSTRIAL WATER USE
The Department o< Water Resources conducted a survey of
1979 industrial applied water by lorgewater-use manufactur-
ing plants throughout California, updating information last
obtained for 1970. The results of the survey have been pub-
lished in Water Use By Manufacturing Industries in California,
1979 (Bulletin 124-3, May 1982) . Highlights of the survey of
1979 water use are:
• About 3,000 plants responded, accounting for about 55
percent of the total fresh-water intake by manufacturing
industries in California.
• Total water use, based on expansion of sample returns,
was about 920,000 acre-feet.
• Some 33,000 manufacturing plants with five or more em-
ployees operate in California.
• About 58 percent of the fresh-water supply was reported
to have been purchased from water service agencies, and
the remaining 42 percent was self-produced, principally
from wells located at plant sites.
• Water recycling has increased about 20 percent over the
last ten years.
• Los Angeles remains first among the State's 58 counties,
with a total annual fresh-water use of 272,000 acre-feet
(and first in total number of manufacturing plants) . Contra
Costa County is second, with an annual use of 89,000
acre-feet.
• Plants with high water requirements are often located near
bays, estuaries, or on the coast where large quantities of
brackish or saline water are available for cooling. Most of
these plants are situated in Contra Costa County. Others
are located in Los Angeles, Monterey, Alameda, and San
Mateo Counties.
Brackish water composed 37 percent of the total water
intake reported by the manufacturing industry.
Although most plants require water only for employees'
sanitation and drinking needs, process water use is now the
major fresh-water application in manufacturing, followed
closely by cooling water.
The food processing industry, the major industrial user of
fresh water, uses an estimated 224,000 acre-feet of fresh
water annually.
Second in level of use is petroleum refining, which uses
150,000 acre-feet, followed, in declining order, by lumber
and wood products; paper and allied products; chemicals;
stone, clay and glass; and primary metals.
The use of water varies considerably among plants. The
discharge-intake ratios vary from slightly more than 0.25
to more than 0.94 for those industries that replied to the
questionnaire.
Total manufacturing water use in 1979 was about 918,000
acre-feet. This is slightly less than the 1970 level, although
the number of industrial plants increased by some 4,000.
The rates of water use by the various major industries have
changed somewhat, with most industries now using less
water.
The industrial sector uses about 18 percent of the State's
total urban applied fresh water.
gle-family units have exceeded multi-family units
since 1973 (Figure 15).
Water-Using Appliances: Following World
War II, average per capita residential water use
began a steady climb, as automatic clothes wash-
ers, automatic dishwashers, garbage disposals,
and other water-using appliances were introduced
and widely purchased by the public. The use of
major water-using appliances may have ap-
proached a saturation level in many communities
by now.
Persons-per-Household: During the 1970s, the
population increased 18 percent, but the number
of households increased 31 percent. Much of this
increase in households can be attributed to the
growth in numbers of single-person households
arising from higher divorce rates, longer life ex-
pectancy, and the postwar "baby-boom" genera-
tion's early departure from home and delayed
marriage.
There were 2.9 persons per household in 1970; this
figure has now dropped to 2.6. The impact of this
change is to increase per capita applied water be-
cause some household water uses are somewhat
independent of the number of household resi-
dents. Landscape irrigation is an example.
l\/letering: Metering of water to customers has a
pronounced effect on residential water use. Stud-
ies have indicated that conversion from a flat rate
to metered billing may reduce water use by as
much as 50 percent initially; although this level of
reduction commonly is not permanent, use will
normally continue to be significantly less than
before metering began. Most of the major urban
areas of California are already metered; statewide,
more than 90 percent of delivered water is me-
tered. The San Francisco Bay, Los Angeles, and
San Diego metropolitan areas are almost com-
pletely metered; but only about 10 to 15 percent of
the Central Valley and upland communities meas-
ure water delivered to customers.
Water Costs: Escalation of materials and labor
costs, extension of service to more distant areas,
and, in some cases, necessary development of
remote and costly supply sources have contribut-
ed to increasing real water costs. Present condi-
tions indicate a continuing general trend toward
higher costs of water service. With rising water
47
Figure 15. TOTAL NEW SINGLE AND MULTI-FAMILY DWELLING UNITS
1972-1980
1972
1973
1974
1975
1976
YEAR
1977
1978
1979
1980
prices, the customer is becoming more aware of
the relationship between amount of use and water
cost. An additional impact occurs where sewer
service costs are billed on the basis of water used.
This IS discussed further in Chapter IV.
Climate: Statewide, an average of about 47 per-
cent of residential applied water is used for land-
scape irrigation. The influence of changes in
climatological conditions on applied water varies
widely, depending on the amount of supplemental
irrigation normally required for landscape plant
growth and the magnitude and occurrence of cli-
matological extremes.
An examination of historic data suggests that an-
nual variations in rainfall exert the greatest influ-
ence on annual fluctuations in residential water
use in California. In some communities, per capita
applied water has typically varied inversely with
annual variations in precipitation, with landscape
irrigation requiring more water in long, dry periods
and less in prolonged wet periods. Variations in the
growing season rainfall pattern have caused resi-
dential use to vary by 25 percent or more. Howev-
er, in areas where average annual precipitation is
less than five inches, water use is only slightly af-
fected by variances in rainfall distribution and
amounts.
The patterns of per capita applied water in the
several California urban areas shown in Figure 16
illustrate the fundamental divergence in rates of
use between inland valley cities and coastal cities,
due mainly to differences in climate. High summer
temperatures in Redding, Sacramento, and Fresno
require much heavier watering to sustain land-
scapes.
• Urban Redevelopment: In some cases, exten-
sive urban redevelopment has had a significant lo-
cal impact on the amount and nature of water use.
Usually It reduces use as residences are replaced
by commercial, governmental, or light industrial
development.
Trends in Gross Per Capita Use
The overall trend in per capita applied water for
many cities and regions appears to have been down-
ward or tended to level off over the past decade.
48
Figure 16. HISTORICAL GROSS PER CAPITA
URBAN APPLIED WATER FOR SELECTED CITIES
400
300
CO
I-
o
a.
« 200
o
Q.
CO
c
o
"5
(D
100
J I L
EAST BAY j|tUD
h^^'
O*^'
.eLES,
J L
J L
\
1960
1965
1970
1975
1980
Years
49
Water-using oppliances such as this au-
tomatic dishwasher have contributed to
the increase in per capita water use.
although interpretation of the trend line has been
somewhat complicated by the 1976 and 1977 drought
(Figure 16). During the drought, many communities
experienced mandatory or voluntary water rationing.
Since 1977, per capita applied water appears to be
returning to about the level of use that prevailed just
prior to the drought.
Between 1960 and 1980 (excluding 1976 and 1977),
calculated trend lines for the communities included
in Figure 16 show an overall increase, except in the
city of Fresno. However, more years of data beyond
the 1976-1977 drought are needed to determine the
direction of the long-term trend and the impact of
water conservation.
Water Conservation Efforts. In the past few
years, water conservation — that is, increased effi-
ciency of use — has become an important considera-
tion in the management of public water and
sewerage utilities. The traditional approach to
managing utilities was to enlarge the delivery system
continually and seek new sources of water as popula-
tion growth increased use: however, in recent years,
water utilities serving growth areas have begun to
see water conservation as a way to reduce the im-
mediate need to develop new supplies. In the past,
high levels of consumption tended to reduce unit
costs for the water utility because of the economies
of scale in larger pipelines and more reservoirs and
treatment plants. Many water utilities, however, have
reached the limit of their less expensive sources of
water and must turn to more costly sources of water
as use increases. In an attempt to avoid as much of
these high costs for as long as possible, many utilities
have taken measures to encourage their customers
to use less water. These conservation efforts have
evidently had an effect on per capita applied water
rates in these areas.
Other Water Uses
While irrigated agriculture and urban water use
make up the major water uses, there are other impor-
tant beneficial uses of water. They are discussed in
this section.
Energy Production
Water use by oil refineries and supplemental small
thermal electric generation plants are included in the
estimates of total urban water use. Since all the wa-
ter IS returned later to the stream, use of water by
hydroelectric generation plants is included under the
"Instream Water Use" section later in this chapter.
On the other hand, substantial quantities of cooling
water for major inland thermal electric generation
plants and water for enhanced oil recovery is con-
sumed, and very little of it is available for reuse.
Power Plant Cooling. Steam electric power
plants require high-quality water for steam genera-
tion, most of which is recycled continuously and only
a small part of which is lost in the process. The high-
quality make-up water for steam generation is fre-
quently obtained initially by distillation to remove all
constituents that might cause scaling or corrosion of
the boiler, or in any way affect the steam generation
equipment. Much larger quantities of cooling water
are required to recondense the steam for reuse. The
50
cooling water is either passed through the plant and
returned to its source (once-through cooling) or re-
cycled through a cooling tower.
The thermal electric plants located on the coast of
California or at its bays and estuanes take advantage
of the large volume of cold water available from the
ocean for the once-through cooling process. Inland
power plants, such as Sacramento Municipal Utility
District's Rancho Seco nuclear power plant, use
evaporative cooling towers and recycle fresh cooling
water until the concentration of total dissolved solids
approaches specific waste water discharge quality
limits set by the Regional Water Quality Control
Board. These limits are designated to protect the
quality of the body of water receiving the discharged
water.
About 79 percent of the present statewide steam
electric generation plant capacity uses once-through
ocean-water cooling. Plants aggregating 19 percent
of such capacity use cooling towers. Present use of
fresh water for cooling is 42,000 acre-feet per year.
Existing geothermal plants also employ cooling tow-
ers, but they are not included here because their
cooling water requirements are met with geothermal
steam that has been condensed back to water.
The potential for once-through ocean-water cool-
ing for new electric generating facilities in California
has steadily diminished over the last decade. Under
the California Coastal Act of 1976, the California
Coastal Commission has designated much of the
coastline as unsuitable for siting new power plants.
When federal lands, urban development, and topo-
graphic constraints are considered, only 3 percent of
the coastline remains for consideration as potential
power plant sites; however, even before the coastal
protection movement began, seismic, population
safety, and air quality considerations limited coastal
siting. The U.S. Environmental Protection Agency's
restrictive approach to controlling thermal dis-
charges has further discouraged the use of once-
through ocean-water cooling. Forecasts of electrical
energy use by the California Energy Commission are
now more conservative, so fewer new power plants
will be required to meet future energy needs.
Geothermal electric generation is emerging as an
important energy source in California. Two types of
geothermal resources — vapor-dominated (dry
steam) and liquid-dominated (hot water) systems
with temperatures above 150°C — are considered
economically feasible for commercial electric gener-
ation. The vapor-dominated resource has undergone
the greatest development. Current production in Cal-
ifornia at the Geysers in Sonoma County is 908 mega-
watts, with an additional 326 megawatts under
construction. At the Geysers, condensed steam is
used in the cooling towers and is sufficient to meet
cooling water needs. At present, there are only two
liquid-dominated geothermal electric generation
plants in California. These are 10- and 1 1.2-megawatt
demonstration projects located in the Colorado Riv-
er Hydrologic Study Area (HSA) . Together they use
a total of 3,000 acre-feet per year.
Enhanced Oil Recovery. A large amount of Cal-
ifornia's oil reserves are extractable only through the
use of enhanced oil recovery (EOR). Enhanced oil
recovery includes waterflooding and thermal stimu-
lation that forces or improves the flow of oil to pro-
duction wells. In California, EOR has been used to
extend the life of old oil fields and facilitate extrac-
tion of California's heavy oils.
Waterflooding is a process in which water is inject-
ed into an oil reservoir to increase the pressure and
force oil to flow toward the production wells. The
Wilmington field in the Los Angeles HSA is the site
of one of the largest waterflooding projects in the
world. Its yield from waterflood operations has been
more than 20 million barrels of oil per year in recent
years.
Thermal stimulation, the injection of steam, has
also been used for a relatively long time in California,
primarily because the more viscous oils flow more
readily when heated. The major area for thermal
stimulation is the Tulare Lake HSA, where close to 90
million barrels of oil were produced by that method
in 1980.
Water uses in HSAs in which onshore oil recovery
occurred in 1980 are listed in the following table.
Water Uses for
Enhanced Oil Recovery in California
1980
In 1,000s of acre-feet
Fresh Other
HSA Water Water' Total
Tulare Lake 7 56 63
Los Angeles 2 93 95
Central Coast 7 8 15
Santa Ana 1 26 27
' Production water (water produced along with the oil), sea water, and treated waste
water.
Water Quality Control
Actions by the State Water Resources Control
Board (SWRCB) in water quality control and related
water rights matters have had significant impacts on
water use and water supply in the past few years.
Recent water quality control efforts by SWRCB
have been notably effective in protecting overall wa-
ter quality in streams. Improved stream conditions
have resulted largely from State and federal laws
requiring clean-up of discharges from waste water
treatment plants and industries. Municipal waste wa-
ter treatment plants are eligible for State and federal
assistance in complying with strict standards, and
some $4 billion in State, federal, and local funds have
51
PROTECTION OF FISH AND WILDLIFE RESOURCES IN THE
SACRAMENTO-SAN JOAQUIN ESTUARY
The Sacramento-San Joaquin Del»a, the Suisun Marsh, and
San Pablo and San Francisco Boys provide vital habitat for
a variety of fish and wildlife. The most significant sport fish
ore anadromous species — striped bass, chinook salmon, stur-
geon, American shad, and steelhead rainbow trout. All these
fish spawn in fresh woter and spend most of their lives in the
lower bays of the estuary or in the ocean. The Delta is an
important nursery area for most of these fish. Of the several
resident fish that also depend on the Delta, white catfish ore
a particularly important sport fish.
The Suisun Marsh is a vital wintering area for waterfowl
of the Pacific Flyway. Many small mammals and more than
200 species of shore and song birds also inhabit the estuarine
marsh habitat. Two endangered species, the California clap-
per rail and the salt-marsh harvest mouse, and the rare Cali-
fornia block roil are indigenous to the marsh.
The Delta and the fish and wildlife it supports contribute
significantly to the orea's economy. Central Valley rivers sup-
ply about 75 percent of California's commercial chinook
salmon catch in ocean waters and contribute to both the
ocean and inland sport fishery. The overage annual commer-
cial catch is about 550,000 fish, which represents an annual
return to the industry of about SI 3.4 million at 1981 prices.
The salmon sport fishery was projected to be worth $1.3
million annually in 1970 (1965 dollars). It is undoubtedly
worth far more than that today, although no current estimates
exist.
Striped bass hove long been one of California's top-rank-
ing sportfish. Significant fisheries also exist for American
shod, sturgeon, steelheod, and several resident fish, including
lorgemouth bass and catfish.
The kinds of fish caught in the Delta ore very different from
those that might hove been caught historically. Native spe-
cies, such as salmon, steelhead, and sturgeon, have been
supplemented by such introduced species as striped bass,
American shod, and catfish.
Historically, annual runoff from the estuary's watershed
varied more widely than it does today. Spring flows were
always high, even in dry years, and summer flows were low.
In August, for instance, there was almost no outflow from the
Delta and salt water intruded farther into the system than it
does now. Releases from SWP and CVP reservoirs now ensure
outflow and control of salt-water intrusion.
Fish and wildlife studies over the last 20 years have identi-
fied major impacts associated with the altered flow regimes
described above and the way in which the Central Valley
Project and State Water Project are operated in the Delta.
In 1977 the State Water Resources Control Board adopted
Decision 1485, pertaining to Delta water rights for the CVP
and SWP, which set stringent water quality standards for the
Delta and for part of the estuary surrounding the Suisun
Marsh. These standards were arrived at after consideration
of testimony from local. State, and federal agencies, as well
as private conservation groups and individuals. Nearly 15
years of intensive research, a large part of which was fi-
nanced by the major water development agencies, provided
important information. As a result of D-1485, the Department
of Water Resources is currently constructing a multi-million-
dollor system of water control structures. These ore designed
to redistribute water from the Sacramento River in a manner
that will provide the managed wetlands in the Suisun Marsh
with water meeting the D-1485 stondords. This system, com-
bined with improved marsh management practices, is intend-
ed to protect the marsh habitat.
52
The Sacramento-San Joaquin Delta, looking west. The wider
waterway at center is the Sacramento River, as it meets the
San Joaquin River near Antioch. Just above center, the chan-
nel narrows as it passes between the Montezuma Hills (right)
and the foothills of Mt, Diablo (left). The waterway then
opens into Suisun Boy before passing through the Corquinez
Straits and San Francisco Bay and finally enters the Pacific
Ocean through the fog-shrouded Golden Gate.
53
been spent since 1972 on the clean-up program. Cali-
fornia's industries have also spent large sums of
money in reducing discharge of pollutants. Where
required by local environmental conditions,
municipalities and industries have successfully met
more stringent advanced waste water treatment re-
quirements. Additional clean-up measures to control
acidic and metallic drainage from abandoned mines
and special requirements at high erosion sites and
elsewhere have also contributed to improved stream
water quality.
In 1978. SWRCB adopted water right Decision
1485, defining water quality standards to protect the
Sacramento-San Joaquin Delta and Suisun Marsh.
The standards are also included in the Water Quality
Control Plan for these areas. The standards are tai-
lored to the hydrology of the area, with less stringent
standards m drier years than in wetter years. D-1485
standards are very complicated. Relationships
between Delta water quality and Delta outflow have
been developed through three decades of prior
investigations by the Department to estimate the
magnitude of outflow required to satisfy those stand-
ards. Applying these relationships to the historic hy-
drologic sequence of Central Valley runoff indicates
that minimum annual Delta outflow required by
D-1485 will range from 3 million to 6 million acre-feet
and will average about 5.1 million acre-feet per year.
Present average annual Delta inflow is 21.2 million
acre-feet per year. For an average water year. 24
percent (5.1 million acre-feet per year) is required as
Delta outflow to meet the water quality standards,
and another 8 percent (1.6 million acre-feet) is used
consumptively within the Delta. Existing storage and
export capability of the State Water Project and the
Central Valley Project diverts 29 percent (about 6.2
million acre-feet), of which 5.8 million acre-feet is
classified as firm yield. The remaining 39 percent (8.3
million acre-feet) flows into the San Francisco Bay as
additional outflow.
The Department notified the SWRCB in 1982 that
the Suisun Marsh facilities will not be completed by
the October 1, 1984, deadline provided in Decision
TABLE 5
TYPICAL NET DELTA OUTFLOW
REQUIREMENTS^
FOR VARIOUS TYPES OF WATER YEARS
(In acre-feet)
Water Year
Net Delta Outflow
Wet
5.800.000
Above normal
5.200.000
Below normal
4.900.000
Dryf
3.100.000
Critical
2.800.000
' Approximate requirements under 1960 level of development, in accordance vnth water
rights Decision 1485.
1485. The current estimate of the earliest possible
completion date is October 1987. However, it is
proposed to construct the facilities in stages, as an
alternative to completing construction by 1987. This
will allow the Department to test their performance
against model predictions before beginning the next
facility. The U.S. Bureau of Reclamation will build its
portion as funds and authorization are obtained. The
Montezuma Slough control structure will be the first
unit of the overall facilities to be built, as originally
planned.
Decision 1400 of the State Water Resources Con-
trol Board pertaining to water rights for Auburn Dam
has had no impact to date on water use and water
supply because it would apply only after the dam had
been built. Because it controls flows only in the lower
American River. Decision 1400 would have little over-
all impact on water supply, in any case. Decision
1422, pertaining to New Melones Dam, has also had
limited impact on water supply because it has re-
stricted storage in New Melones Reservoir only from
1979; high inflows during the wet years of 1982 and
1983 negated the storage restrictions. SWRCB has
since ruled that New Melones may be filled for pow-
er and water because the U.S. Bureau of Reclama-
tion is actively seeking to sign water contracts.
During this period, nonstored water has been avail-
able for use downstream in the Delta. The practical
impacts of D-1422 appear to rest with future court
decisions. D-1422 allows storage to satisfy prior
rights, water quality flows, and fishery flows, in addi-
tion to the federal provision for flood control storage.
Water under prior rights in an amount up to 654.000
acre-feet per year is diverted at Goodwin Dam 15
miles below New Melones. The fishery below Good-
win Dam is provided for by releases of up to 98,000
acre-feet per year. The Department of Fish and Game
is authorized to test lower flows in below-normal wa-
ter years. The release schedule is not definite at
present; it is subject to studies to be conducted by
the Department of Fish and Game.
Fish, Wildlife, and Recreation Offstream
Water Uses
Offstream uses of water for fish, wildlife, and recre-
ation take place outside natural stream channels and
riparian habitat, such as along canals and drainage
ditches. Water used by vegetation (evapotranspira-
tion) that provides wildlife habitat in and near canals
and drainage facilities is not available for other uses.
Water conservation often includes measures to
reduce runoff from farm fields and to prevent seep-
age from conveyance systems that support this vege-
tation. The effects of such conservation practices on
wildlife habitat should be evaluated before they are
implemented.
Urban Parks and Landscaped Recreation
Areas. Water used to irrigate lawns and other land-
54
The irrigated lawn at the entrance to An-
gel Island State Park is an example of
water use in nonurbon public porks.
scape vegetation at park and recreation areas may
constitute a nnajor local use. Evapotranspiration at
these facilities may amount to several acre-feet per
acre of landscaping each year. Water use for these
purposes is included in the urban water use esti-
mates in this report.
Other Parks and Recreation Areas. Most re-
gional. State, or national park and recreation areas
emphasize natural environmental systems and there-
fore have little landscaping to be irrigated. Water use
in such areas is often primarily domestic use by visi-
tors and employees. Planning studies of the Depart-
ment of Water Resources assume 20 to 40 gallons per
person per day for such use. Part of this water is
available for reuse, either directly or after reclama-
tion.
Waterfowl Management Areas. Both the Cali-
fornia Department of Fish and Game and the U. S.
Fish and Wildlife Service manage waterfowl re-
source areas in California. The federal system totals
230.000 acres in 21 major areas, while the State pro-
vides 70,000 acres in 12 major areas for waterfowl
management. Some part of these lands is planted to
feed crops, and the remainder, in most cases, is
marshland.
Wetlands, including marshes, once totaled 5 mil-
lion acres in California, with 4 million acres in the
Central Valley alone. Most of these lands have been
reclaimed and converted to other uses. Today only
about 250,000 acres of these original wetlands remain
in the Central Valley. These wetlands and adjacent
croplands provide an important part of winter habitat
for 12 million waterfowl annually. The wetlands also
provide permanent and seasonal homes for other
birds, and for amphibians, reptiles, and mammals.
Survival of rare and endangered species such as the
American peregrine falcon, bald eagle, California yel-
low-billed cuckoo, and giant garter snake depends on
these wetlands. Wetlands may also improve water
quality, recharge ground water, and detain flood-
flows.
At one time, all wetlands were sustained by sea-
sonal or perennial streamflows. In the Central Valley
and the Delta, nearly all major wetlands are now
managed for maximum wildlife benefits with water
applied directly or incidentally as agricultural return
flows.
Some lands other than wetlands are irrigated and
crops are grown that will provide habitat for water-
fowl, mainly during fall and winter when Pacific Fly-
way waterfowl are occupying the southern areas of
their range. This practice provides alternative food
sources, thereby reducing crop depredation by
waterfowl on nearby farmlands. Part of the land is
used for managed hunting programs. The evapotran-
spiration of water on major Central Valley wetlands
and other waterfowl areas amounts to about 900,000
acre-feet annually. About 250,000 acre-feet occurs in
the designated public waterfowl management areas.
The remainder is supported by losses from water
conveyance systems, agricultural return flows, and
other incidental water sources. Some of this water is
otherwise unusable brackish irrigation return flows.
55
J-
y
^^^m
im
Wetlands are essential to the vast waterfowl population that
migrates through central California along the Pacific Flyway.
TABLE 6
RECREATION AT SELECTED WATER PROJECTS WITH OVER 500,000 VISITOR-DAYS ANNUALLY
(In 1,000s of visitor-days)
U.S. Bureau
of Reclamation
Visitor-
days
1380
U.S. Corps of
Engineers
Visitor-
days
1980
State Water
Protect
Visitor-
days
1980
Local Projects with
Recreation Grants
Visitor-
days
1977
Cachuma
918
1.000
615
1.300
800
891
1.527
7,051
2.392
9,443
Lake Mendocino
2.650
714
682
933
1.489
6.468
1.834
8.302
Lake Oroville Complex
Castaic
811
1.054
670
1.186
3.621
2.079
5.700
San Antonio
Lopez
Subtotal
27 Other Projects
TOTAL
513
Foisom
Pine Flat
500
Natoma
Kaweah
Success
Isabella
Subtotal
Shasta
Whiskeytown
Subtotal
9 Other Facilities
Casitas
Subtotal
1013
13 Ott\er Resewoirs
3826
TOTAL
TOTAL
TOTAL
4839
Source: Data furnished by agencies responsible for project operation-
56
TABLE 7
PARTICIPATION IN WHITEWATER BOATING AND FISHING
ON NORTH COAST WILD AND SCENIC RIVERS
Whitewater
Boating
(recreation-days)
Fishing (angler-days)
River Segment
Juvenile
Salmon Steelhead Steelhead
Smith (entire)
1,000-3,000
10,000-25,000
0
100-500
0
500-1,000
5,000-10,000
0
0
500-1,000
5,000-10.000
1,000-2,000
1.000-2,000
100-500
1,000-2.000
25,000-57,000
11 500 16 600 16000
Klamath
Iron Gate to mouth
47 000 69 000 90 000
Salmon
Mam
0 0 0
North Fork
1 200 1 200 30 000
Wooley Creek
0 0 0
Scott
200 1000 14 000
Trinity
Main
16000 13000 36000
North Fork
New River
0 0 Trinity River
Included with Trinity River
5 000 12 500 30 000
South Fork
Eel
Mam
2 700 15 000 40 000
Middle Fork
200 1 700 3 500
North Fork
0 0 4000
Van Duzen
700 3 000 3 000
TOTAL
84 500 133 000 266 500
Source: U.S. Department of the Interior. Heritage Conservation and Recreation Service,
Final Environmental Impact Statement. Proposed Designation of Five California
Rivers in the National Wild and Scenic Rivers System. Volume 1. December
1980.
TABLE 8
RECREATION ON SELECTED NORTHERN CALIFORNIA STREAMS
Stream
Boating
Boating- (non-
Fishing Swimming Molomed motorized) Picnicking Camping
Riding '
Sight-
seeing
Other''
TOTAL
SURVEY PERIOD: MEMORIAL DAY AND LABOR DAY, 1978'
(In user-hours)
South Fofl( American Rivec, Coioma and Lotus 16,000 82,000 — 93.000 53.000 199.000 6.000 7,000 134.000
Cache Creek. Bear Creek Confluence to Guinda 2.000 32.000 — 44.000 20,000 15.000 1,000 2.000 16.000
SURVEY PERIOD: MEMORIAL DAY AND LABOR DAY, 1977'
(In user-hours)
North Fork Feather River. Belden Dam to State Route
70
Putah Creek, Monticello Dam to Pleasant Valley Road
Tuolumne River in Modesto
SURVEY PERIOD: JANUARY-DECEMBER, 1980*
(In user-hours)
Sacramento River, Keswick to Courtland 1.890,000 437.000 548.000 259.000 288.000 249.000 40.000 16.000
Lower American River .
SURVEY PERIOD: MARCH 1978-MARCH 1979*
(In visitor-days)
380.000 380.000 56.000 400.000 204.000
— 296.000 532.000
Middle Fork Feather River..
SURVEY PERIOD: OCTOBER 1979-SEPTEMBER 1980'
(In visitor-days)
18.000 11,000 — 1.000 2.000 23.000
11,000
41,000
39,000
590,000
312.000
13.000
9.000
—
1,000
1,000
38,000
1,000
3.000
22.000
88.000
58.000
20.000
—
5,000
14.000
3,000
1,000
4,000
21.000
126,000
6.000
45.000
—
—
25,000
2.000
1,000
4,000
36,000
19,000
1.073.000 4,800,000*
1.628,000 4,000,000
146.000
' "Riding" includes horses, bicycles, motorcycles, and off-road vehicles,
^ "Other" includes relaxing, photography, nature study, golf, games, jogging, and walk-
ing.
* Source; DWR Technical Information Report "River Recreation Activity Survey Data of
Selected Northern California Streams During 1977 and 1978". February 1979-
• Source DWR Northern District Report (Review Draft), "Sacramento River Recreation
Survey", December 1981-
* The total Sacramento River use count of 4,800.000 recreation hours translates
to 2.000,000 visitor-days
"Source: Sacramento County. Department of Parks and Recreation, interview,
'Source: U.S. Forest Service. Plumas National Forest-
57
Figure 17. STREAMFLOW DIVERSION
SITES WITH AGREEMENTS FOR FISH
FLOW RELEASES
• •.•.•\
•^ ^
\
\
/
/
• • '^ • •
•••• .
o •• \
\
\
\
Legend
• Single Diversion
O Group of 20
D Group of 40
r
r
Many privately owned holdings are managed en-
tirely or in part to attract waterfowl during the fall
and winter hunting season. These areas — collectively
known as duck clubs — comprise an estimated
417,000 acres of land in California. In addition to pro-
viding a great deal of waterfowl hunting for their
owners or members, these clubs provide a significant
amount of critically needed waterfowl wintering
habitat and feed. The Department of Fish and Game
considers them a strong, positive force m manage-
ment of the resource.
The public waterfowl management areas and pri-
vate duck clubs are similar in their general manage-
ment and water use. They are usually planted, at least
in part, to a crop requiring irrigation that will have
value as food for ducks and geese. For the private
duck club land, the evapotranspiration associated
with this crop is included in the estimates of agricul-
tural water use in this report. Sometimes the duck
clubs can include the production of a cash crop or
livestock grazing in their operations. In the fall, at a
time planned to coincide with the arrival of the mi-
grating birds, much of the available non-wetted land
IS flooded to increase its attractiveness to the birds.
Due to the time of year, evapotranspiration losses
are assumed to be minimal.
Fish, Wildlife, Recreation, and Hydropower
Instream Water Uses
Instream water uses relate directly to natural
stream channels and their associated riparian vegeta-
tion. The major uses in this category are fish, wildlife,
recreation, and hydroelectric energy generation. Wa-
ter is required to support such uses, but, with the
exception of riparian habitat, these uses do not sig-
nificantly deplete streamflow. They may, however,
compete with other potential uses that require diver-
sion from the stream. The water that riparian vegeta-
tion takes up through evapotranspiration represents
a streamflow depletion that is accounted for in the
determination of water supply; therefore, this use is
not included in the water use tabulations in this re-
port.
Water is of such fundamental importance to fish,
wildlife, and recreation that these resources and ac-
tivities are found in almost all water environments.
Water flowing in streams bordered by vegetation
creates one of the most attractive and productive
settings for fish, wildlife, and recreation. When water
is impounded in reservoirs, it also attracts numerous
users of these resources. In fact, some of California's
major producers of water recreation benefits are its
large water supply reservoirs.
Water conveyance facilities are also attractive to
recreationists and can provide habitat for fish and
wildlife. No large aqueduct system in California is
without a fishing access program, and several aque-
duct rights-of-way have been improved to provide
safe routes for bicycle nding and hiking.
'^^W*
58
Protection of Instream Water Uses. The State
Constitution and the State Water Code both recog-
nize that fish, wildlife, and recreation are beneficial
uses of water. The Water Code specifies that these
uses be considered before issuing water right per-
mits or making water quality control and other ad-
ministrative decisions that could adversely affect
fish, wildlife, and recreation. The State Fish and
Game Code declares that protection and conserva-
tion of fish and wildlife resources are of utmost pub-
lic interest, and recognizes the importance of
commercial and sport uses, as well as esthetic, scien-
tific, and educational uses.
State and Federal Wild and Scenic Rivers Acts
have been enacted to control development and pro-
tect instream uses and other environmental uses.
The rivers covered under these acts are depicted on
Plate 1.
Water of adequate quality that is released in suffi-
cient quantity and at the proper time is critically im-
portant to streamflow for fish, wildlife, and riparian
vegetation. Until recently, the importance of main-
taining adequate streamflows and water quality for
fish and wildlife was often not given sufficient recog-
nition. Even when these factors were considered, the
effort sometimes failed because of inadequate
knowledge of the ecosystem. The Department of
Fish and Game has negotiated streamflow agree-
ments throughout the State. Most have been north of
Bakersfield in the Sierra Nevada and the Coast
Range (Figure 17). The agreements reflect the water
that has been specifically allocated by the State Wa-
ter Resources Control Board and the Federal Energy
Regulatory Commission to instream and offstream
water needs, as determined by both agencies at the
time the permit terms are established. The stream-
flow allocations have often proved to be less than the
amount necessary to maintain fish life at preproject
levels. This is particularly true for permits issued
before 1960, which were established when less
weight was given to instream uses and less was
known about instream requirements. However, in
some cases, hatcheries are provided to mitigate the
loss of habitat.
Hydropower Projects. Since 1980, there has
been a rush to file for development of small hydro-
power generation facilities throughout the country,
particularly in California. This activity is motivated
largely by changes in federal law that require electric
utilities to purchase power from small power produc-
ers at rates equal to the cost of the most expensive
power the utility produces or obtains from other
sources (avoided cost). In California, this purchase
rate is based primarily on the cost of burning import-
ed oil to generate electricity; thus the potential rate
of return for small hydropower investors is great. In
addition, recent changes in federal tax laws encour-
age investment in small hydropower facilities. Most
of the proposed projects in California are small
Figure 18. NUMBER OF FERC NOTICES
AND WATER RIGHTS APPLICATIONS
FOR HYDROELECTRIC PROJECTS
SINCE JANUARY 1980
600
500-
400-
<
o
300-
<
_j
3
O
200-
100-
0 -
il II II II
1982
facilities with a capacity of 5 megawatts or less.
Small hydropower proposals come in the form of
applications for State water rights permits and Fed-
eral Energy Regulatory Commission (FERC) permits.
These applications increased dramatically in 1981.
Figure 18 shows the frequency of filing for both per-
mits since January 1980. The large number of applica-
tions submitted for these projects (generally five
megawatts or less) also spawned considerable inter-
est in examining their potential environmental im-
59
pacts. The Department of Fish and Ganne and others
have expressed concern regarding cumulative im-
pacts of construction and operation that would be
caused by many small hydropower projects — par-
ticularly impairment of flows in sections of streams,
changes in stream hydrology caused by changes in
the time and duration of flow, and sharp reductions
in flows needed to flush and otherwise maintain grav-
els. Proposals for projects on river systems that sup-
port anadromous fisheries have raised the most
questions.
Net Water Use
Both the derivation of net water use and the dis-
tinction between net water use and applied water
are important in evaluating various aspects of water
use. To understand the impact of applied water for
the various uses discussed in the preceding sections
on existing water supplies, the substantial amount of
reuse and depletions that take place in most situa-
tions must be considered. This is important not only
in comprehending how present needs are being sat-
isfied, but also the impact that increasing the effi-
ciency of water use (water conservation) may have
on the amount of water supply needed.
The basic water supply information available for
analysis is expressed in terms of streamflow. stream
diversion, yield of surface water reservoirs, ground
water pumping, and ground water levels. The expres-
sion of water use that most directly relates to these
data elements has been termed "net water use." The
purpose of computing net water use is to determine
the amount of water supply needed in an area to
support ail uses in that area — residential, agricultural,
industrial, and others. Net water use in an area is the
sum of the water depletions within the area, plus
outflow from the area. Water depletions include
crop ETAW (evapotranspiration of applied water),
evapotranspiration and evaporation of water as-
sociated with the water supply and drainage sys-
tems, and other irrecoverable losses, including water
percolating to unusable ground water.
The quantity of outflow from an area is a function
of the water distribution system and on-farm irriga-
tion practices in the area. Except where the outflow
goes into a salt sink (such as the ocean), it usually
constitutes a part of the water supply to downstream
users. Tightening of water distribution system opera-
tions and increased on-farm irrigation efficiency may
reduce outflow and total net water use for the area;
however, in many notable cases in California, this
does not reduce the total quantity of net water sup-
ply needed because equivalent quantities from other
sources are required to replace the reduced outflow
that no longer supplies downstream users. However,
energy savings, water quality improvements, and in-
stream flow increases may occur. Generally speak-
ing, net water use is less than total applied water by
the amount of excess applied water that is reused
within the area. This is demonstrated m Figures 19
and 20.
In Figure 19. total applied water is the sum of the
water (157 units) applied to Farms "A" and "B". to
the wildlife area, and that which is delivered to the
city. The total amount of water reused (57 units)
consists of (1) surface return flows (45 units) from
Farm "A", the wildlife area, and the city; and (2) the
pumping of water that has percolated to ground wa-
ter (12 units) from Farm "A" and the city. The result-
ant net water use in this example is 100 units (157
units of total applied waterless 57 units of total water
reused). The 10 units of outflow from the service
area will be part of a prime water supply to a down-
stream user.
An effect of agricultural water conservation (in-
creased on-farm irrigation efficiency) can be ob-
served by comparing Figures 19 and 20. In Figure 19,
the irrigation efficiency of Farm "A" is 61 percent
and of Farm "B" is 69 percent, if, through conserva-
tion efforts, both farms were to increase their irriga-
tion efficiencies to 75 percent, then the results would
be as shown in Figure 20. Farms "A" and "B" would
apply 73 and 29 units of water, respectively, for a total
of 102 units (down from the 122 total units they ap-
plied in Figure 19). The 97 units of water diverted
from the river (net water supply) is in balance with
the 97 units of the net water use. This compares to
the 100 units of diversion and the 100 units of net use
shown in Figure 19. Net depletion of river flow down-
stream from the return flow site would be the same
in both examples, 90 units. A major benefit would be
the additional 3 units of water in the river between
the diversion and return flow sites. To keep the max-
imum amount of water in the river for instream bene-
fits (without reducing offstream benefits), the return
flow from Farm "B" would be only the water required
to leach salts from the soil.
These examples also demonstrate that reductions
in quantities of on-farm applied water may increase
farm irrigation efficiency, but they do not necessarily
save any water, viewed from a service area or hy-
drologic area standpoint. All that might differ is the
routing of water through or around a given service
area. However, in some cases, a portion of the return
flow moves into a saline dram or percolates to salty
or otherwise unusable ground water basins, thus
eliminating or greatly reducing opportunities for
reuse.
Although greatly simplified, the foregoing discus-
sion illustrates situations typical of most Hydrologic
Study Areas and their subunits in California. One sig-
nificant item has been omitted from the examples —
irrecoverable losses from the water distribution sys-
tem. These consist of losses experienced in bringing
60
Figure 19. DERIVATION OF
NET WATER USE
Figure 20. EFFECT OF IMPROVED
IRRIGATION EFFICIENCY ON
NET WATER USE
50p UNITS
(<<^^
^UNITS
DIVERSION TO SERVICE
r-^ AREA 100 UNITS
I EVAPOTHANSPIRATION I 1
OF APPLIED WATER | '
r
Applied Water
90 Units
/ FARM 'A' _,
Iff .Ell. 5 |4 X 100.61%'
90
DEEP PERCOLATION
10 UNITS
EVAPOTRANSPIRATION
OF APPLIED WATER
3 UNITS
Applied Water 10 Units
RETURN FLOW
2 5 UNITS
EVAPOTRANSPIRATION
OF APPLIED WATER
10 UNITS
WILDLIFE AREA
iDEEP PERCOLATION
UNITS
EVAPOTRANSPIRATION
OF APPLIED WATER
22 UNITS
TREATED
RETURN FLOW
I 5 UNITS
GROUND WATER
PUMPAGE
12 UNITS
Applied Water
5 + 15+ 12 = 32 Units
FARM "B"
Irr.EII.- II X 100»69%
OUTFLOW FROM
SERVICE AREA
10 UNITS
Reuseable in Downstream Service Area
NET WATER USE
Farm *A'
Wildhle Area
Cilv
Farm "B*
- 90 Units
- 25 Unit!
- 10 Units
• 32 Units
Total Applied
- 157 Units
Minus reuse
- 57 Units
Within Service Area
Service Area
Net Water Use
500 UNITS
DIVERSION TO SERVICE
97 UNITS
EVAPOTR
OF APP
55 UNITS
lANSPIRATION I 1 ''' '"^'^ -
LIED WATER I I
BYPASS
/
/Applied Water
' 73 Units
FARM 'A"
Irr.EII. I ^ X 100.75X
DEEP PERCOLATION
10 UNITS
EVAPOTRANSPIRATION
OF APPLIED WATER
3 UNITS
Applied Water 10 Units
RETURN FLOW
8 UNITS
EVAPOTRANSPIRATION
OF APPLIED WATER
10 UNITS
WILDLIFE AREA
EVAPOTRANSPIRATION
OF APPLIED WATER
22 UNITS
TREATED
RETURN FLOW
5 UNITS
GROUND WATER
PUMPAGE
"" \ 12 UNITS
Applied Water *
5+12+ 12 = 29 Units
FARM 'B'
OUTFLOW FROM
SERVICE AREA
7 UNITS
Reuseable In Downstream Service Area
NET WATER USE
Farm 'A'
- 73 Units
Wildllte Area
- 22 Units
City
- 10 Units
Farm *B'
- 29 Units
Total Applied
134 Units
Minus reuse
- 37 Units
Within Service Area
Service Area
Net Water Use
97 Units
61
the water to the point of use and losses within the
area by evaporation from water surfaces and evapo-
transpiration by natural vegetation growing along
ditch banks and fringes of fields. These losses add to
net water use for the area. Part of the total irrecover-
able losses from the distribution system is composed
of losses experienced in conveying water from one
study area to another. In the tables in this report that
present agricultural, urban, and other net water use,
these additional losses are identified as "conveyance
losses."
The handling of waste water reclamation repre-
sents a modification of procedures generally em-
ployed in computing other types of reuse. In the
examples in Figures 19 and 20. treated waste water
was considered as reuse of a return flow (incidental
reclamation) that was used by Farm "B". However,
deliberately reclaimed municipal and industrial
waste water for a specific purpose would be consid-
ered as a new supply, rather than reuse. For example,
if Farm "B" had a contract with the city for the 5 units
of reclaimed water, this water would be counted as
a new supply and the 5 units of reclaimed water
would be added to the 100 units of net water supply,
giving a total of 105 units. The 5 units would also be
subtracted from the total reuse of 57 units (Figure
19). leaving instead 52 units of reuse.
Net water use in an area is normally somewhat less
than total applied water; however, where convey-
ance losses are relatively large and reuse is small, net
water use can exceed applied water. The Colorado
River HSA is one such example. Conveyance losses
from the All-Amencan Canal occur before the water
in transit reaches the service areas in the Imperial
and Coachella Valleys and these are lost to the sys-
tem: reuse of irrigation water in this region is limited
because excess applied water either percolates to
saline ground water or runs off into drainage ditches,
carrying highly saline water from subsurface drain-
age systems. In this region, applied water in 1980 was
3,650,000 acre-feet, including the reuse of 90,000 acre-
feet. Conveyance losses were 540,000 acre-feet. This
resulted in a net water use of 4,100,000 acre-feet.
Net water use by Hydrologic Study Areas is shown
in tables in the "Statewide Hydrologic Balance" sec-
tion of this chapter.
Present Sources of Supply
In an average water year, aoout 75 percent of Cali-
fornia's present net water use is met from regulated
surface water supplies and direct diversion from
streams. An extensive network of local. State, and
federal storage reservoirs provides a significant de-
gree of regulation on most streams in the Central
Valley and those coastal regions that have been high-
ly developed. At present, there are 450 reservoirs in
California having a storage capacity of 1,000 acre-
feet or greater. The sources and amounts of surface
and ground water being used at the current (1980)
level of development are identified on a statewide
basis and by HSAs under "Statewide Hydrologic Bal-
ance" later in this chapter. Major surface water sup-
ply and conveyance facilities are shown in Figure 21
and listed in Tables 9 and 10.
Generally speaking, water supplies are available
for present needs in all areas of the State, except in
periods of drought. In some local areas, a full irriga-
tion supply is not available in years of below-normal
rainfall. Some foothill and coastal communities also
experience shortages during these periods. Howev-
er, present needs in some areas are being met by
overdrafting the ground water reservoirs. The aver-
age rate of overdrafting of ground water supplies
under 1980 conditions of development is 1.8 million
acre-feet per year. This rate has been as high as 2.2
million acre-feet (1972), but, with the use of SWP
surplus supplies, when available, the rate has been
reduced.
IDENTIFICATION OF OWNERS OF
RESERVOIRS AND AQUEDUCTS
LISTED IN TABLES 9 & 10
DWR
California Department of Water
Resources
EBMUD
East Bay Municipal Utility District
HSVID
Hot Springs Valley Irrigation District
KCWA
Kern County Water Agency
LADWP
Los Angeles Department of Water and
Power
MCFCWCD
Monterey County Flood Control and
Water Conservation District
MID
Merced Irrigation District
MWD
Metropolitan Water Distict of Southern
California
OID-SSJID
Oakdale Irrigation District — South San
Joaquin Irrigation District
OWID
Oroville-Wyandotte Irrigation District
PCWA
Placer County Water Agency
PGandE
Pacific Gas and Electric Company
SCE
Southern California Edison
SCVWD
Santa Clara Valley Water District
SD
City of San Diego
SF
City and County of San Francisco
SMUD
Sacramento Municipal Utility District
SSWD
South Sutter Water Distnct
TID-MID
Turlock Irrigation District — Modesto
Irrigation District
USCE
U. S. Army Corps of Engineers
USER
U. S. Bureau of Reclamation
UWCD
United Water Conservation District
VID
Vista Irrigation District
YCFCWCD
Yolo County Flood Control and Water
Conservation District
YCWA
Yuba County Water Agency
62
TABLE 9
STATISTICS FOR SURFACE WATER SUPPLY RESERVOIRS SHOWN
ON FIGURE 21'
Reservoir (Dam)
Clear Lake
Tahoe
Clear Lake
Huntington Lake
Big Sage
Pillsbury
Hetch Hetchy
Henshaw
Calaveras
Shaver
Almanor
Bucks
Pardee
Salt Springs
Havasu (Parker)
Mathews
Crowley ,
San Vicente ,
Shasta ,
Millerton (Fnant)
Anderson
Isabella
Cachuma
Edison
Pine Flat
Piru
Folsom
Lloyd
Beardsley
Nacimiento
Berryessa
Twitchell
Wishon
Casitas
Little Grass Valley ...
Success
Clair Engie (Trinity)
Kaweah (Terminus).,
Black Butte
Camp Far West
Union Valley
Camanche
Whiskeytown
HSA
NC
NL
SB
SJ
SB
NC
SJ
SD
SF
SJ
SB
SB
SJ
SJ
CR
SA
SL
SD
SB
SJ
SF
TL
cc
SJ
TL
LA
SB
SJ
SJ
cc
SB
CC
TL
LA
SB
TL
NC
TL
SB
SB
SB
SJ
SB
Area
Acres
24,800
122,000
43,000
1,440
5,270
2,000
1,960
6,000
1,450
2,180
28,260
1,830
2,130
920
20,400
2,750
5,280
1,070
29,500
4,900
980
11,400
3,090
1.890
5,970
1,240
11,450
1,760
650
5,370
20,700
3,670
1,000
2,720
1,430
2,400
16,400
1,940
4,560
2.680
2,869
7,700
3,200
Capacity
Acre-feet
527,000
745,000
420.000'
89.000
77,000
94,000
360,000
204,000
100,000
135.000
442,000'
103.000
210,000
139.000
648,000
182,000
184,000
90,000
4,552,000
520,000
91,000
570,000
205,000
125,000
1,000,000
100,000
1.010,000
268.000
98,000
350,000
1,600,000
240,000
128,000
254,000
93,000
82,000
2,448,000
150,000
160,000
103,000
271,000
431,000
241,000
Owner ^
USBR
USBR
YCFCWCD
SCE
HSVID
PGandE
SF
VID
SF
SCE
PGandE
PGandE
EBMUD
PGandE
USBR
MWD
LADWP
SD
USBR
USBR
SCVWD
USCE
USBR
SCE
USCE
UWCD
USBR
SF
OID-SSJID
MCFCWCD
USBR
USBR
PGandE
USBR
OWID
USCE
USBR
USCE
USCE
SSWD
SMUD
EBMUD
USBR
Year
Completed
1910
1913
1914
1917
1921
1921
1923
1923
1925
1927
1927
1928
1929
1931
1938
1938
1941
1943
1945
1947
1950
1953
1953
1954
1954
1955
1956
1956
1957
1957
1957
1958
1958
1959
1961
1961
1962
1962
1963
1963
1963
1963
1963
75.000 acre-feet or larger.
Above natural outlet
See separate list of identification of owners
Under Construction.
(TABLE 9 continues on Page 66)
63
/
\
o /
.-"t
\
\
Alturas
\
\
/^
f-'
\
\
\
/
/
Cl§ii EfH Lttt
-1*
\
^.x
Redding
Litllt erastVtlHf fitl
Eureka
»«<(»sj 2:-'"»""'
V/orA
P^Ui/M Vkl/t/ f!«
£?■
/Sun
/>es mSearasle/ Res
£!!■ P.-'l 'tl ^
,.,,.,. s S^ .,.,
San Francisco
Hilksltr Cmtl
tocimitmit ffes-
FIGURE 21. MAJOR STORAGE RESERVOIRS
64
Legend
LOCAL PROJECTS
STATE WATER PROJECT
FEDERAL PROJECTS
Xx-^.
DASHED LINES DELINEATE AUTHORIZED
FACILITIES NOT VET CONSTRUCTED
NEVADA
iopei Res
'achiitna Res
Sa"^^ R'^f
AND CONVEYANCE FACILITIES
EDITION OF 1982
65
TABLE 9— Continued
STATISTICS FOR SURFACE WATER SUPPLY RESERVOIRS SHOWN
ON FIGURE 21 '
Reservoir (Dam)
Loon Lake
French Meadows
San Antonio
Hell Hole
Davis (Grizzly Valley)
San Luis
McClure (New Exchequer) .
Oroville
New Bullards Bar
Stampede
Mojave
New Don Pedro
Silverwood (Cedar Springs)
Castaic
Perns
Pyramid
Indian Valley
Buchanan
Hidden
New Melones
Auburn
Sonoma (Warm Springs)
Dutch Gulch
Tehama
HSA
Area
Acres
Capacity
Acre-feet
Owner '
Year
Completed
SB
SB
CC
SB
SB
SJ
SJ
SB
SB
NL
SL
SJ
SL
LA
SA
LA
SB
SJ
SJ
SJ
SB
NC
SB
SB
1.450
1.420
5.720
1.250
4.000
12.700
7,130
15,800
4.810
3,440
1,980
12,960
980
2,240
2,320
1.360
4.000
1.780
1.570
12.500
10.400
3.600
11.200
10.200
77,000
134.000
348.000
208.000
84.000
2.039,000
1,026.000
3.538,000
970.000
225,000
90,000
2.030.000
75.000
324,000
131,000
171,000
300.000
150.000
90,000
2.400.000
2.326,000
381,000
900,000
700,000
SMUD
PCWA
MCFCWCD
PCWA
DWR
DWR-USBR
MID
DWR
YCWA
USCE
USCE
TID-MID
DWR
DWR
DWR
DWR
YCFCWCD
USCE
USCE
USCE
USBR
USCE
USCE
USCE
1963
1965
1965
1966
1966
1967
1967
1968
1970
1970
1971
1971
1971
1973
1973
1973
1976
1979
1979
1979
uc-
U.C.
Authorized
Authorized
' 75.000 acre-feet or larger
Above natural outlet
See separate list of identification of owners.
* Under Construction.
TABLE 10
STATISTICS FOR AQUEDUCTS SHOWN ON FIGURE 21
Name
Capacity''
Cubic
feet
per
second
Length
Miles
Owner'
Initial
Year
of
Operation
Los Angeles
Mokelumne River
Hetch Hetchy
All American
Contra Costa
Colorado River
Friant-Kern
Coachella
San Diego No. 1
Delta-Mendota
Madera
Putah South
Santa Rosa-Sonoma
San Diego No. 2
Corning
Petaluma
Tehama-Colusa
South Bay
North Bay
California
Folsom South
Cross Valley
710
590
460
15.100
350
1.600
4.000
2.500
200
4.600
1.000
960
62
1.000
500
16
2.530
360
46
13.100
3.500
740
244
90
152
80
48
242
152
123
71
116
36
35
31
93
21
26
113
43
26
444
27
20
LAPWP
EBMUD
SF
USBR
USBR
MWD
USBR
USBR
SD
USBR
USBR
USBR
SCWA
SD
USBR
SCWA
USBR
DWR
DWR
DWR
USBR
KCWA
1913
1929
1934
1938
1940
1941
1944
1947
1947
1951
1952
1957
1959
1960
1960
1961
1961'
1965
1968'
1972'
1973'
1975
' A number of major irrigation canals in tfie Central Valley, some as large as tfiose sfiown. could not be included on tfie figure because
of tf^e tack of space.
Initial reach only for most irrigation canals. Interim tacililieS-
See separate list of identification of owners. To Southern California.
Tehama and Glenn Counties. Reaches 1 and 2.
66
Figure 22. MAJOR FEATURES OF THE STATE WATER PROJECT
AND THE CENTRAL VALLEY PROJECT
»
«
c
o
«
>
L egend
— — Stat« Water Project
—— Central Valley Project
~~ Joint Use Facilities
PH Powerplant
PP Pumping Plant
PG Pump-generating Plant
Authorized aqueducts are stiown as dashed lines
Cimlrn Co.s'Ki C>
San Francisco(*\\
South Bay Aqueduct-
\
LAKE DEL VALLE'
I
Santa Ctani Canal
Hollister Cunduii
sai/luis res.-
Joint Use
MILURTOM LAKe
Fn'ont K,H'
Pleasant VaUi^v Canal
/ 9 %
o° (^^ V Bakersfield
)bispo ioo 11
°0 13 14
San Luis
N
12
16 '"O" 15
PYRAMID LAKE^
17A)
CASTAIC LAKE
Los Angeles*
18
\
4000
3000
2000
1000
SWP Aqueduct Profile
Key
1 EDWARD HYATT PG
2 THERMALITO PG
3 H 0 BANKS DELTA PP
4 SOUTH BAY PP
5 DEL VALLE PP
6 SAN LUIS PG
7 DOS AMIGOS PP
8 LAS PERILLAS PP
9 BADGER HILL PP
10 BUENA VISTA PP
*y. ^i o^
11 WHEELER RIDGE PP
12 WIND GAP PP
13 EOMONSTON PP
14 OSO PP
15 ALAMO PH
16 WILLIAM E WARNE PH
17 CASTAIC PH
18 PEARBLOSSOM PP
19 DEVIL CANYON PH
SILVERWOOD LAKE
^19
\
(7 LAKe FERRIS
/
\
15
16^
»13
17
■^10
012
'11
67
The Federal Central Valley Project
The Central Valley Project (CVP) was conceived as a
plan to correct the problems of natural maldistribution of
water supply and needs in the great Central Valley of Cali-
fornia. It was apparent as early as the 1920s that the natural
water supply of the southern San Joaquin Valley was
inadequate to meet the needs of this fertile area.
Planning and Implementation
In 1921, the State Legislature authorized the State's wa-
ter officials, then in the Department of Public Works, to
conduct a statewide water resources investigation. The
Department made several reports to the State Legislature
during the next 10 years, and in 1931 submitted a report on
the "State Water Plan," The plan provided for a transfer of
surplus water from the northern to the southern portion of
the Central Valley and served as the basis for the present
federal Central Valley Project.
In 1933, the Legislature passed the State Central Valley
Project Act to implement the CVP, the initial feature of the
State Water Plan. In addition to water storage and convey-
ance features, the act included a provision for public con-
struction of both generating plants and transmission lines.
As a result of a referendum campaign, the proposal was
then placed before the voters of the State m a special
election held in December 1933, and the act authorizing the
CVP obtained statewide approval by a narrow majority.
State funds to begin construction could not be obtained,
however, because the nationwide economic depression
made the revenue bonds unmarketable. Consequently, ar-
rangements were made for federal authorization and fi-
nancing, first administratively, and later under the Rivers
and Harbor Act of 1937. Congress authorized the project
for construction by the U.S. Bureau of Reclamation
(USSR) to improve navigation, regulate the flows of the
San Joaquin and Sacramento Rivers, control floods, store
water, reclaim arid and semiarid lands, and generate elec-
tric energy.
The authorizing act declared that the dams and reser-
voirs "shall be used first for river regulation, navigation and
flood control; second for irrigation and domestic uses; and
third for power." Salinity control in the Delta was not spe-
cifically listed as a project purpose; development of facili-
ties and water supplies for recreation, fish, and wildlife
have been included in subsequent reauthorizations of the
CVP.
Principal Features and Operation
USBR operates the CVP principally to transport water
from the Sacramento, Trinity, American, and San Joaquin
River Basins to the water-deficient areas of the Sacra-
mento and San Joaquin Valleys. The key water supply fea-
ture IS Shasta Reservoir on the Sacramento River. Water
stored here is first used to generate power — as at most
CVP reservoirs — and then flows south in the natural chan-
nel of the Sacramento River toward the Delta. Diversions
from the Trinity Division (Clair Engle Lake) also flow in the
Sacramento River to the Delta. Water stored by the Friant
Division IS transported to the Tulare Lake Basin by the
Friant-Kern Canal and to the San Joaquin Basin by the
Madera Canal.
At Red Bluff, a diversion dam diverts water from the
Sacramento River to the Corning Canal and the Tehama-
Colusa Canal to irrigate lands in Tehama. Glenn, and Co-
lusa Counties, and northern Yolo County. In addition, nu-
merous CVP water users divert their supply directly from
the Sacramento River.
American River water is stored in Folsom Lake for use in
the Folsom-South service area and for release to the Delta.
Below Folsom Dam, Nimbus Dam acts as an afterbay,
reregulating the releases for power, and directs water into
the Folsom-South Canal to provide cooling water for Ran-
cho Seco power plant. Completion of the canal to provide
water to San Joaquin County has been deferred, pending
resolution of problems concerning Auburn Dam and the
lower American River.
South of Sacramento, the Delta Cross Channel facilitates
the flow of water from the Sacramento River across the
Delta to the Rock Slough Intake of the Contra Costa Canal
and to the export pumps near Tracy, while improving the
quality of irrigation supplies m the central Delta.
From Rock Slough in the southern Delta, the CVP sup-
plies water to the Contra Costa Canal, the first unit of the
CVP to become operational (1940). This canal extends
west 48 miles to the vicinity of Martinez, providing water
for municipal, industrial, and irrigation uses.
The Tracy Pumping Plant lifts as much as 4,600 cubic feet
per second 197 feet into the Delta-Mendota Canal, which
delivers water to the lower San Joaquin Valley as far as 1 17
miles south, terminating at the San Joaquin River at the
Mendota Pool. There it replaces a portion of the natural
flows of the San Joaquin River that are stored by Friant
Dam (Millerton Lake) in the Sierra Nevada foothills
northeast of Fresno. Water from Millerton Lake is distribut-
ed north and south, respectively, through the Madera and
Fnant-Kern Canals.
About 60 miles south of the Delta, between the Delta and
the Mendota Pool, is the federal-State, joint-use San Luis
Dam and Reservoir, an offstream storage facility of the
CVP and the SWP. Water diverted from the Delta by both
the Delta-Mendota Canal (CVP) and the California Aque-
duct (SWP) IS pumped into San Luis Reservoir during the
winter and early spring for release to service areas during
the summer and fall.
The most recent addition to the CVP (1979) is New Me-
lones Dam and Reservoir on the Stanislaus River. Contro-
versy surrounding this project has resulted in two
statewide initiatives. Proposition 17 m 1974 and Proposi-
tion 13 in 1982, along with several legal actions. The project
was constructed by the Corps of Engineers and has been
turned over to USBR for operation.
New Melones Reservoir provides additional flood con-
trol protection and releases for downstream fishery pur-
poses, water quality control, downstream water rights,
power generation, recreation, and a water supply for irriga-
tion and municipal and industrial uses. In March 1983, the
State Water Resources Control Board lifted the restric-
tions it had previously placed on the filling of New Melones
Reservoir, permitting the full storage of water for power
generation and consumptive use.
The Bureau of Reclamation is well advanced in pursuing
water service contracts for interim and firm water supplies
with the Tuolumne Regional Water District, the Central
San Joaquin Water Conservation District, and the Stock-
ton-East Water District. It is expected that the water serv-
68
ice contracts wi
of 1983.
have been approved and executed m fal
The San Felipe Division of the CVP is presently under
construction. By pumped diversions from San Luis
Reservoir via the Pacheco tunnel, service will be provided
to parts of the Santa Clara Valley and Santa Clara and San
Benito Counties, and possibly later to Santa Cruz and Mon-
terey Counties.
Social, Environmental, and Economic Impacts
The development and growth of the Central Valley
Project has stimulated economic and social growth
throughout California's Central Valley — especially in the
San Joaquin Valley. Communities have developed in some
of the new farming areas. Several San Joaquin Valley coun-
ties are among the top counties in the nation in value of
farm products — due to farming operations made possible
by CVP and other water supplies.
In 1982, nearly 2.7 million acres of farmland in the Central
Valley received irrigation water service from the CVP. This
service contributed to the production of approximately
$3 billion in gross crop receipts at the farm, which in turn
stimulated an estimated S3-$4 billion in additional econom-
ic activity elsewhere in California and the nation.
Californians spend millions of "recreation days" each
year enjoying the boating, fishing, swimming, picnicking,
and other outdoor recreation opportunities afforded by
CVP facilities. While many of these environmental benefits
represent improvement over previous opportunities, not all
CVP environmental impacts have been beneficial. Effects
unrecognized at the time of planning and construction
have harmed fish and wildlife. Red Bluff Diversion Dam has
been implicated m a variety of negative impacts on anadro-
mous fish in the upper Sacramento River. The Tehama-
Colusa Canal Fish Facilties were constructed as mitigation
for the dam. The fish facilities slightly exceed the original
mitigation requirements, but there are additional problems
that were not anticipated when the dam was built. Pres-
ently, USBR is funding two separate programs to develop
and implement solutions to the fish problems at the dam
and fish facilities. The unfenced, concrete-lined Tehama-
Colusa Canal is also a hazard to wildlife, claiming as many
as 300 deer per year by drowning as they attempt to cross
the canal. Friant Dam was completed in June 1944, without
mitigation provisions for salmon. Since then, salmon runs
on the San Joaquin River have been depressed.
Trinity Dam blocks anadromous salmon and steelhead
from reaching the upper part of the Trinity River. The Trin-
ity Hatchery was built to offset the loss of habitat upstream
from the dam. A minimum flow release was agreed upon,
but the release proved inadequate to prevent degradation
of the downstream habitat. USBR was the lead agency for
a multi-agency investigation of fish problems in the Trinity
River, and a multi-year study of a variety of solutions, in-
cluding increased streamflow releases, has been
proposed.
Financing and Repayment
Financing of the CVP facilities has its roots in federal
reclamation laws and policies. Under existing laws and
current policies, capital and operation and maintenance
costs are allocated to and repaid by those who benefit
from the project. Costs allocated to flood control and navi-
gation are considered to benefit the nation and are repaid
from the federal treasury. Costs allocated to recreation,
fish, and wildlife enhancement are borne by both federal
and nonfederal interests. Costs allocated to the municipal
and industrial water supply and commercial power pur-
poses are repaid with interest by the municipal and indus-
trial and power contractors. Costs allocated to irrigation
are repaid without interest by the CVP irrigation contrac-
tors, with provisions for financial assistance from other
water and power beneficiaries whenever the cost of irriga-
tion water service exceeds the irrigator's repayment abili-
ty-
CVP water and power users are scheduled to repay
about 85 percent of the authorized project costs, inasmuch
as the water and power customers will realize the largest
portion of the project benefits. The State of California will
contribute an amount equal to about 3 percent of the au-
thorized capital cost as payment of its share of the cost of
the joint federal-State San Luis facilities. Local entities will
repay an amount equal to less than 1 percent of the total
project cost as their share of local recreation, fish, and
wildlife enhancement. The remaining 11 percent will be
repaid by the federal government as its contribution to-
ward flood control, navigation, and nonreimbursable recre-
ation, fish, and wildlife.
Figure 23a. CVP DELIVERIES ^
FOR THE PERIOD 1951-1980
4-
Jty For reimbursement
UJ
u.
' 3
c
U
<
CO
:; 2-
1-
J]
0
1951 1955
— n —
1960
— n —
1965
— n —
1970
I I
1975 1980
69
YEARS
CENTRAL VALLEY PROJECT FEATURES
Reservoir (Dam)
Shasta Lake
Clair Engle Lake (Trinity) .
Lewiston Lake
Whiskeytown Lake
Spring Creek Debris
Keswick
Red Bluff Diversion
Black Butte '
Jenkinson Lake (Sly Park)
Folsom Lake
Lake Natonna (Nimbus)
Contra Loma
San Luis^
O'Neill (San Luis Forebay)
Los Banos'
Little Panoche'
Millerton Lake (Friant)
New Melones
Sugar Pine
Capacity
Acre-
feet
4.552,000
2.448,000
14,600
241,000
5,900
23,800
3,900
160,000
41,000
1,010,000
8,800
2,100
2,038,800
56,400
34,600
5,600
520,500
2,400,000
7,000
Surface
Area
Acres
Purpose '
29,740
16.535
800
3,220
87
640
530
4,560
650
11,450
540
81
12,700
2,250
470
188
4,900
12.500
142
W, P, F, R
W, P, R
W, P
W, P, R
D
P. S
W
W, F, R
W. R
W, P, F, R
P. S
R, S
S, R, P
S
D
D
W,
W,
F. R
F, R
W. R
Year
Compieted
1945
1962
1963
1963
1963
1950
1964
1963
1955
1956
1955
1967
1967
1967
1965
1966
1942
1979
1982
Capacity
Length
Aqueduct
Cubic
feet
per
second
Miies
Year
Compieted
Corning
500
3.500
350
4.600
13,100
1.000
4.000
2.530
21
27
48
116
101
36
151
113
1959
Folsom South .
1973'
Contra Costa ^
1948
Delta-Mendota
1951
San Luis '
1967
Madera
1952
Friant-Kern
1944
Tehama-Colusa
1961
Figure 23b SOURCES OF REPAYMENT
OF PROJECT COSTS TO END OF
REPAYMENT PERIOD (2050)
' Operated by the Corps of Engineers
'Operated by El Dorado Irrigation District
^ Joint use with State Water Project, operated by State of California
* Only first 27 miles complete out of a total of about 68 miles
'Operated by Contra Costa County Water District
'W— Water supply. P— Power. F — Flood control. R — Recreation, D — Debris control.
S — Reregulatory storage.
Area
irrigated
Year
Acres
1968 . .. .
1 464 100
1969
1.530.200
1970
1 542 000
1971
1 624 200
1972
1733 400
1973
1.933,900
1974
2,040,500
1975
1,932 700
1976
1 958 100
1977
1814 100
Federal government t
(flood control, navigation)
Other, such as
Stale share of
San Luis facilities
Recreation, Fisheries
and Wildlife
Source; US. Department of the Interior. Water and Power Resources Service. Project
Data. 1981
70
The California State Water Project *
Planning for the State Water Project (SWP), originally
called the Feather River Project, began after World War II,
During the latter part of the 1940s, the State Division of
Water Resources conducted two programs. One concen-
trated on collecting basic data and developing a statewide
water plan — the California Water Plan. The other consid-
ered a specific project as the initial State-constructed por-
tion of the plan. The first complete report on the project,
published in 1951, proposed a multiple-purpose dam and
reservoir on the Feather River near Oroville, with a power
plant, an afterbay dam and power plant, a Delta cross chan-
nel, an electric power transmission system, an aqueduct to
transport water from the Delta to Santa Clara and Alameda
Counties, and an aqueduct to transport water from the
Delta to the San Joaquin Valley and Southern California.
Some of the factors that influenced the State to become
directly involved in water development were:
• Rapid population growth in Southern California was ex-
pected to exceed the capacity of available water sup-
plies, and additional water could be obtained only in
Northern California.
• Federal water development agencies were primarily
concerned with providing irrigation supplies (USBR, un-
der the federal Reclamation Act) or flood control (U,S.
Army Corps of Engineers), They were not authorized to
construct major inter-basin water supply projects to
meet municipal and industrial needs. Therefore, the
State was the more appropriate agency.
• A number of State and local water agencies were dissat-
isfied with federal policies affecting construction and
operation of the federal CVP, the project originally con-
ceived and planned by the State, It was believed that the
irrigation and power policies of the CVP should be di-
rected by the State so that the project could be more
responsive to California's social and economic issues,
• San Joaquin Valley farmers believed the 160-acre limita-
tion on use of CVP water was inappropriate because the
water was being used as a supplement by large farms
that were already established through the use of ground
water and local surface water supplies,
• Private utilities wanted to prevent further expansion of
low-cost, subsidized public power generation and trans-
mission.
The project was authorized by the Legislature in 1951
under the State Central Valley Project Act, It was designat-
ed "The Feather River and Sacramento-San Joaquin Delta
Diversion Project." Operating under authorization of the
State Central Valley Project Act of 1933, the Water Project
Authority, through the Division of Water Resources, con-
tinued investigations, surveys, and studies, including the
preparation of plans and specifications for construction of
the authorized works.
In 1955, after approval of its plans by the Water Project
Authority, the Division submitted another report to the
Legislature on the proposed project. This report stated
that the project had engineering and financial feasibility
and recommended that the Legislature appropriate funds
■ For a more complete discussion, see; Department of Water Resources,
California State Water Project. Bulletin 200, Vol. I. "History, Planning,
and Early Progress," November 1974.
to Start construction The report also recommended add-
ing San Luis Reservoir on the west side of the San Joaquin
Valley for offstream storage of Delta surplus flows.
To further the development of the State's water re-
sources program, the Legislature, in 1956, established the
Department of Water Resources, and nearly all the func-
tions and authorities of the Water Project Authority, the
State Water Resources Board, and the Division of Water
Resources of the Department of Public Works were trans-
ferred to the new department. Appropriation of water and
the determination of water rights were vested in a new
State Water Rights Board (now the State Water Resources
Control Board).
Construction funds for the SWP were first made avail-
able to the Department in 1957, when the Legislature,
reacting to the widespread flooding that occurred during
December 1955 and January and February, 1956, appro-
priated over $25 million in State tidelands oil revenues to
begin highway and railroad relocation around the Oroville
reservoir site. Year-to-year funds were appropriated
through 1960 to permit continuation of the Oroville reloca-
tions and to permit the start of construction of the South
Bay and California Aqueducts in 1959.
An assured source of project funds was established
when the Legislature enacted the California Water Re-
sources Development Bond Act (Burns-Porter Act) in 1959
and California voters approved it in November 1960 by a
margin of 173,944 out of a total of 5.8 million votes cast.
Popular support in Southern California delivered this nar-
row victory. Butte County, site of the proposed Oroville
Dam, and Yuba County were the only two counties north
of Fresno to vote for the bond act. These results represent-
ed a reversal of the votes cast in the 1933 referendum on
the State CVP Act when Southern California voted against
the issue and Northern California supported it.
The 1959 bond act authorized issuance of $1.75 billion in
general obligation bonds, backed by the State's full faith
and credit, and appropriated all moneys in and accruals to
the California Water Fund for construction of the SWP.
The Burns-Porter Act authorized certain facilities, includ-
ing:
• A multiple-purpose dam and reservoir at Oroville, and
five upstream reservoirs in Plumas County,
• An aqueduct system, including North Bay, Soutn Bay,
San Joaquin Valley-Southern California, and coastal
aqueducts: and an offstream storage reservoir near Los
Banos.
• Facilities in the Sacramento-San Joaquin Delta for water
conservation, water supply in the Delta, transfer of water
across the Delta, flood and salinity control, and related
functions,
• Additional unspecified facilities in the Sacramento and
certain north coastal watersheds for local needs and to
augment water supplies in the Delta, as necessary.
• Local projects provided for under the Davis-Grunsky Act
for which State loans and grants are authorized.
The State entered into contracts with 31 water agen-
cies "" to deliver an ultimate 4,23 million acre-feet of water
' Because two contracting agencies have since merged, there are now 30
water service contractors. The total SWP water service obligations are
unchanged.
71
annually to service areas in northern, central, and southern
parts of California. The facilities now constructed can
deliver about 2.3 million acre-feet of water per year on a
dependable basis and up to 3 million acre-feet m a wet
year. Additional facilities will be required to meet full con-
tract entitlements and to compensate for future depletion
of Delta surplus flows. Present excess supplies are sold as
"surplus water for irrigation and ground water recharge."
Principal Features and Operation
The Initial facilities of the SWP are shown on the accom-
panying map. The project begins with three small reser-
voirs on Feather River tributaries in Plumas County — Lake
Davis and Frenchman and Antelope Lakes — which are de-
voted primarily to recreation. Farther downstream, water
released from the mam storage facility. Lake Oroville. flows
through power generating facilities, thence down the
Feather River and the Sacramento River, and into the net-
work of channels in the Sacramento-San Joaquin Delta.
The North Bay Aqueduct, scheduled for completion
before 1990, will deliver water to Napa and Solano Coun-
ties. Interim facilities serve Napa County with water from
the Solano Project of the U.S. Bureau of Reclamation.
At the southern edge of the Delta are the Clifton Court
Forebay, the John E. Skinner Fish Protective Facilities, and
the Harvey 0. Banks Delta Pumping Plant.
At the pumping plant, water is lifted 244 feet into the
California Aqueduct.' The South Bay Aqueduct branches
at this point and delivers water as far west as San Jose. The
California Aqueduct conveys water south to the San Joa-
quin Valley and Southern California. Surplus winter and
spring flows from the Delta are stored in San Luis Reser-
voir, a joint federal-State facility, for use later in the year.
An aqueduct planned to serve areas in San Luis Obispo and
Santa Barbara Counties has been delayed and the area's
entitlement was reduced as the result of action by Santa
Barbara County.
Environmental Impacts
Operation of the SWP has both a positive and a negative
effect on the environment. Fish species characteristic of
the Bay-Delta system have declined because of the transfer
of SWP and CVP water across the Delta. These diversions
have resulted m reverse flows in some waterways that in-
terfere with migrating salmon. Loss of fish fry and food
organisms occurs in the Harvey 0. Banks Delta Pumping
Plant.
On the other hand, salmon runs in the Feather River are
greater now than before Oroville Dam was built. Releases
are controlled to produce better water temperature condi-
tions and improved habitat, especially during subnormal
periods of runoff. A substantial striped bass fishery has
become established in the California Aqueduct and in
Southern California reser\/oirs, providing fishing opportuni-
ties where few existed before. Streamflow releases from
Antelope Reservoir have improved the fishery potential m
many miles of Last Chance Creek.
'The aqueduct was renamed the Governor Edmund G. Brown California
Aqueduct in December 1982.
Economic Impacts
The SWP not only has had an immediate economic im-
pact upon the surrounding region during construction, but
also has long-term effects upon regional and State econo-
mies.
In some areas, the impact has substantially affected the
entire growth pattern and economy of a region. For exam-
ple, within Kern County (the primary county in the San
Joaquin service area), about 90 percent of the SWP deliv-
eries are used for agriculture. SWP supplies comprised
about 25 percent of the county's overall water supplies in
1980. In 1980, Kern was the State's third leading agricultural
county, with gross farm receipts of more than $1.27 billion.
Cotton, the leading crop, accounts for almost half the
county's harvested acreage. Grapes rank second in agricul-
tural value, followed by almonds.
In addition to the direct value of crops, economic activity
IS also stimulated in those secondary industries supplying
the agricultural producers with products and services, as
well as in the food processing industries.
Water supplies can also have an economic impact upon
urban areas, although the effect is much more complex
and more difficult to quantify than for agricultural regions.
SWP deliveries to the Southern California. Central Coast,
South Bay, and North Bay service areas are necessary for
economic growth. However, other factors — such as em-
ployment opportunities, resource availability, climate,
housing markets, community lifestyles, and local growth
management policies — also influence growth. The relative
significance of water compared to these other factors is
difficult to assess.
Financing and Repayment
Capital cost financing for the SWP is obtained from sev-
eral sources. Major sources are general obligation bond
proceeds, the California Water Fund (tideland oil reve-
nues), revenue bond proceeds, and miscellaneous re-
ceipts.
The basic concept for repayment for the State Water
Project (SWP) IS that the costs are to be allocated to and
repaid by those who benefit from the project. Major
beneficiaries of the SWP are the now 30 agencies that have
long-term water service contracts with the State. Under
the terms of their contracts, these agencies will repay all
reimbursable costs of the project that are allocated to wa-
ter supply (about 96 percent of total project costs, under
current allocations) . Those who receive the direct benefits
repay the entire principal and interest cost of the general
obligation bond issue, plus all other construction and oper-
ation costs of the project.
The water users — the major beneficiaries — are paying
the largest part of the costs. State funds repay cost of the
broad benefits for all Californians — the costs allocated to
recreation and fish and wildlife enhancement (about 3 per-
cent of costs). Costs of providing flood control at Lake
Oroville and Lake Del Valle (about 1 percent of the costs)
are not repaid (nonreimbursable) by SWP contractors;
they are repaid by the federal government.
72
Figure 24a. SWP DELIVERIES^
FOR THE PERIOD
1962-1981
4 -
UJ
UJ
u.
I
UJ
cc
o
<
o
a>
z
o
2 -
STATE DELIVERIES
^ OTHER WATER
(Mostly 'surplus')
□ ENTITLEMENT WATER
1/ No surplus -mostly
MWD exchange Fp
4
1965
1970
YEARS
Figure 24b. SOURCES OF REPAYMENT
OF PROJECT COSTS TO END
OF REPAYMENT PERIOD
(2035)
M
1975 1980
Recreation,
Fisheries
and Wildlife
Other, such as rentals, sale
of excess property and
lands, interest earnings, etc.
Federal Government, Flood Control
73
STATE WATER PROJECT FEATURES
Reservoir (Dam)
Frenchman Lake
Antelope Lake
Lake Davis
Lake Oroville
Thernnalito Diversion Pool
Thermalito Forebay
Thermalito Afterbay
Clifton Court Forebay
Bethany
Lake Del Valle
San Luis'
O'Neill Forebay
Los Banos
Little Panoche
Silverwood Lake
Lake Perns
Quail Lake
Pyramid Lake
Elderberry Forebay
Castaic Lake ,
Castaic Lagoon
Surface
Capacity
Area
First
Acre-
Year of
feet
Acres
Purpose '
Operation
55,500
1.580
R, W
1961
22,600
931
R
1964
84,400
4.026
R, W
1966
3.537,600
15.805
W, P, F, R
1968
13,300
323
P
1967
11,800
630
P. R
1967
57,000
4 302
S. R
1967
28,700
2 109
S
1969
4,800
161
S. R
1961
77,100
1,060
S, R
1968
2,038.800
12,700
S, R, P
1967
56,400
2.700
S
1967
34,600
623
D
1965
13,200
354
D
1966
75,000
976
S, R
1971
131,500
2.318
S, R
1973
5.000
223
S
171,200
1.297
S. P
1973
28,200
460
S. R
1974
323,700
2.235
S. P. R. W
1973
5,700
196
R
1972
Capacity
Lengtfi
Aqueduct
Cubic
feet
per
second
f^iles
North Bay
46
360
13,100
3.130
450
25'
South Bay
43
California (mam line)
444
California (branches)
West Branch
32
Coastal Branch
96'
W — Water supply, F — Flood control. D — Debris control. P — Power, R — Recreation,
S — Reregulatory storage.
Joint use with Central Valley Project, operated by State of California
Total of connpleted and proposed length.
74
Recent Surface Water Projects
Several major water storage and distribution facili-
ties have been completed by federal. State, and local
agencies since publication of Bulletin 160-74 in 1974.
In addition, another major reservoir project. Warm
Springs Dam, is nearing completion, and construc-
tion has been suspended on another (Auburn Dam),
pending redesign and reauthorization.
Local Projects. Projects completed by local
agencies were Indian Valley Dam on North Fork
Cache Creek in Lake County, Soulajule Dam on a
tributary to Walker Creek in Marin County, and the
Cross Valley Canal in Kern County.
The Indian Valley project was constructed by Yolo
County Flood Control and Water Conservation Dis-
trict to provide supplemental water supplies to east-
ern Yolo County, an area of ground water overdraft.
It will augment the district's surface supplies avail-
able from Clear Lake.
Soulajule Dam was constructed by the Marin Mu-
nicipal Water District to provide about 5,000 acre-
feet more water per year to the district's service area
in eastern Mann County. Water is pumped from the
10,560-ac re-foot capacity reservoir through a pipeline
to Nicasio Reservoir (see Plate 1 for location). From
there it enters the district's delivery system.
The Cross Valley Canal was constructed to facili-
tate exchanges of Central Valley Project water to
nine agencies in three counties in the Tulare Lake
HSA. 1 he water is made available to the agencies
through an exchange agreement between the agen-
cies and the Arvin-Edison Water Storage District
(WSD). CVP water carried in the Cross Valley Canal
IS pumped from the Delta and conveyed to the head
of the canal near Tupman via the California Aque-
duct. The water is then conveyed through the canal
to Arvin-Edison WSD. An equal amount of water is
thereby made available to CVP's Cross Valley Canal
contractors from Arvin-Edison WSD's Friant-Kern
Canal contractual entitlement.
Federal Projects. The U.S. Army Corps of Engi-
neers completed Hidden Dam on the Fresno River
and Buchanan Dam on the Chowchilla River and is
nearing completion of Warm Springs Dam on Dry
Creek, a tributary of the Russian River. All three reser-
voirs provide flood control, water supply, recreation
areas for public use, and habitat for fish and wildlife.
The Hidden and Buchanan projects have been incor-
porated into the CVP. The Corps of Engineers also
completed New Melones Dam on the Stanislaus Riv-
er in 1979 and has turned it over to the U.S. Bureau
of Reclamation for operation as part of the CVP.
USBR IS currently negotiating for the sale of project
yield to water users in San Joaquin, Stanislaus, Tuol-
umne, and Calaveras Counties, which make up the
designated service area. This project has been in-
volved in considerable controversy.
USBR completed construction of Sugar Pine Dam
and pipeline, a feature of the Auburn-Folsom South
Wafer pumped from natural
underground reserves is a vital
source for irrigated agricul-
ture.
75
Unit of the CVP, The project (shown on Plate 1) will
provide supplemental water supplies for the service
area of the Foresthill Divide Public Utility District,
Ground Water
Hydrologically, the ground water supply consists
of the average annual natural and artificial recharge,
deep percolation of excess applied surface water,
and extraction fronn long-term ground water storage
(overdraft).
Present Knowledge of Ground Water Condi-
tions. Current statistics on ground water recharge,
storage capacity, empty storage capacity, and water
in storage are not readily available for the entire
State because there is no statewide requirement for
reporting ground water extraction, use, or artificial
recharge. The Department of Water Resources
makes detailed studies of a few of California's 394
ground water basins each year, and determines cur-
rent yield, water-in-storage, and storage capacity. In
1975 the Department published California's Ground
Water (Bulletin 118), which presented the informa-
tion available at that time. It was not complete for all
basins, however, and some information was consid-
erably out of date. .
As should be expected, the most information ex-
ists for the most heavily used basins. There is sub-
stantial knowledge of many of the developed
Southern California basins and most of the San Joa-
quin Valley basins. Moderate information is available
on other basins in the South Coastal region, the west-
ern areas of the Colorado River and South Lahontan
HSAs, and Central Valley areas near the Delta. Lim-
ited information is available on ground water basins
in the Sacramento Valley and the Coastal Range val-
leys, the northeast basins, and some desert basins.
Only superficial information is available on the re-
maining basins, predominantly situated in desert
areas. Moreover, little is understood of the potential
yield in fractured-rock ground water areas, which are
an important source of water for some agricultural
and residential development m the Sierra Nevada
foothills and other foothill and mountain areas. Fresh
ground water is known or suspected to exist offshore
in more than 10 coastal areas, but specific data are
lacking, except for Monterey Bay and the area off the
coast of Ventura County. General information on wa-
ter in storage and total storage capacity by major
regions of the State is summarized in Table 11.
Dependable Ground Water Supply and Over-
draft. Ground water supply is presented in this re-
port by HSA, rather than by specific ground water
basin. Dependable ground water supply is defined as
average natural recharge, together with intentional
artificial recharge with local surface water. Deep per-
colation of excess applied water, intentional re-
TABLE 11
GROUND WATER STORAGE CAPACITY
BY REGION
1980
(In 1,000s of acre-feet)
Region
Water in
Storage
Empty
Storage
Capacity
Total
Storage
Capacity
4.000
18.000
95.000
540.000
100.000
100,000
857.000
1.000
2.000
5.000
38.000
57.000
58.000
161.000
5.000
(North Coast and San Francisco Bay
HSAs)
20.000
100,000
(Los Angeles, Santa Ana, and San Diego
HSAs)
Cpntral Vallev
578,000
(Sacramento. San Joaquin, and Tulare
Lake HSAs)
157,000
(North Lahontan and South Lahontan
HSAs)
Colorado River HSA
158,000
TOTAL
1,018,000
charge with imported water supplies, and seepage
from water conveyance systems are also compo-
nents of ground water recharge. However, they are
not counted as part of dependable ground water sup-
ply because doing so would, in effect, constitute
double counting and would overstate the basic sup-
ply available to meet net water use.
Overdraft of a ground water basin occurs when the
amount of water pumped exceeds the amount of
recharge water from all sources over a long period of
time. In Ground Water Basins in California (Bulletin
118-80, January 1980), the Department of Water Re-
sources defines a basin as subject to critical condi-
tions of overdraft when continuation of present
water management practices would probably result
in significant overdraft-related environmental, social,
or economic impacts. The Department's report iden-
tified 40 basins in California known to be in overdraft,
with 11 of them in "critical" conditions of overdraft
(Figure 25). Basins not indicated on the figure may
also be in overdraft, but they have not been studied.
The hydrologic balances by HSA appearing at the
end of this chapter reveal the present status of the
ground water supply; that is, those HSAs in which
overdraft occurs and those in which pumping and
recharge approach a balance. Such balances, as
summarized, may be misleading where more than
one ground water basin is included in one HSA or
where more than one HSA overlies a single ground
water basin. For example, in an HSA, one ground
water basin may be in hydrologic balance, while an-
other may be in a condition of overdraft.
Ground Water Levels and Pumping Costs.
The water level in basins north of the city of Sacra-
mento IS less than 100 feet below the surface in all but
isolated areas in late summer. Coastal basins general-
76
ly have relatively high water levels, but sea-water in-
trusion can occur where inland ground water levels
have been drawn below sea level, such as in Ventura
County. Basins in Southern California generally have
water levels less than 200 feet below ground surface.
Water levels have been declining in overdraft
areas for a long tinne, but this decline is not economi-
cally significant in most areas, although in parts of
the San Joaquin Valley, the resultant subsidence has
damaged wells and conveyance systems, and water
may have to be lifted as much as 800 feet in some
wells. In most of the valley, where ground water is
used, pumping lifts are less than 400 feet, with much
of the area having lifts of less than 200 feet.
The 1980 cost of pumping ground water in Califor-
nia, including capital cost and maintenance, ranges
generally from about $10.00 per acre-foot in shallow
water depth areas to about $40.00 per acre-foot in
areas with lifts of 400 feet, such as portions of Kern
County. Energy use varies with the size and condition
of the pump and motor and the height of the pump-
ing lift — all factors that affect the cost of pumped
ground water.
Conjunctive Use and Ground Water
Management
Ground water management develops locally in
stages. Early indications of falling water levels are
usually followed by some artificial recharge of the
ground water basin with excess surface water in wet
years or wet periods of the year. The next step, con-
junctive use, is taken when water levels continue to
drop. This procedure involves artificial recharge in
wet times and installation of joint delivery systems so
that surface water can be used directly when avail-
able, and ground water can be pumped when surface
water is not available. The co-delivery systems can
function on individual farms or as part of a water
agency's facilities. Much of the east side of the San
Joaquin Valley operates in this manner.
Coordination of surface storage with conjunctive
use is one step closer to full ground water manage-
ment. Storm runoff is captured in surface water
reservoirs and released to ground water at an appro-
priate recharge rate. Empty space is retained in the
reservoirs to capture the runoff from the next storm.
Local surface water is managed this way in the Santa
Clara Valley south of San Francisco Bay.
Ground water management, as defined in Bulletin
118-80, includes planned use of the ground water ba-
sin yield, storage space, transmission capability, and
water in storage. It includes:
• Protection of natural recharge and use of artificial
recharge.
• Planned variation in amount and location of pump-
ing over time.
• Use of ground water storage conjunctively with
surface water from local and imported sources.
• Protection and planned maintenance of ground
water quality.
The term planned, appearing throughout the
ground water management definition, implies a local
commitment to some regulation of pumping and zon-
ing of recharge areas. This full ground water manage-
ment concept is approached by the Santa Clara
Valley Water District m Santa Clara County and the
Orange County Water District without adjudication,
and by most adjudicated basins. The unadjudicated
basins rely on a combination of imported water and
pump taxes to regulate pumping.
GROUND WATER STORAGE
DEFINITIONS
Five different kinds of ground water storage ore recog-
nized: total storage capacity, water in storage, available
storage capacity, regulatory storage capacity, and usable
storage capacity.
Total storage capacity of a ground water basin is the total
volume of space between soil particles that could be occupied
by ground water. It is computed as the product of the average
depth of the basin material, the area of the basin, and the
average specific yield* of basin materials, usually expressed
in acre-feet. Some limit of upper and lower elevation is usu-
ally given to define total storage capacity. A reasonable
upper limit is 20 to 50 feet below the ground surface.
Water in storage is the portion of total storage capacity
that is presently full of water. Available storage capacity is
the remaining portion, which is empty and available for the
storage of water. The annual variations in ground water re-
charge necessitate regulatory storage capacity to sustain a
uniform annual yield.
Some of the storage capacity may also serve to regulate
local recharge. When the available storage capacity is larger
than is needed to regulate recharge, additional water from
other sources may be stored in that basin without the risk of
spill to surface water flows.
Usable storage capacity^ storage capacity that is capable
of yielding water to wells economically and of being readily
recharged (filled). Two decades ago, when many of the
estimates of usable storage capacity were made, the econom-
ical limit in many inland areas was considered to be a depth
of 200 feet, and, in other inland areas, it was the base of the
fresh water in a ground water basin. For coastal basins, the
maximum economical limit of usable storage capacity was
considered to be sea level. Some of those earlier assumptions
are now no longer valid, and the data that are available are
very conservative.
' Specific yield is the amount of water by volume released from a
volume of saturated material under the force of gravity. It is
expressed as a ratio or percentage.
77
Figure 25. BASINS SUBJECT TO CRITICAL CONDITIONS OF
OVERDRAFT OR WITH SPECIAL PROBLEMS
BASINS SUBJECT TO CRITICAL CONDITIONS OF OVERDRAFT
PAJARO BASIN
jy
2- CUYAMA VAUEY BASIN
3. VENTURA COUNTY BASIN
A JOAQUIN COUNTY BASIN
*■ EASTERN SAN __ _
5- CHOWCHILLA BASIN
6- MADERA BASIN
T- KINGS BASIN
8- KAWEAH BASIN
9- TULARE LAKE BASIN
'O- TULE BASIN
■•I- KERN COUNTY BASIN
BASINS WITH SPECIAL PROBLEMS
■4- suRPRise VALur basw
*• LOIVG VALLEY BASIN
\C- SIERKA VALLEY BASIN
O. OWENS VALLEY BASIN
: s
_.-~,^ . . . ,. > ^^^ WATER BEARING MATERIALS
jy' As defined in Bulletin I I 8-80, a basin is
subject to critical conditions of overdraft
when continuation of present water management
practices would probably result in significant
adverse overdraft — related environmental, social,
or economic impacts
78
Reclaimed Urban Waste Water
Waste water reclamation is the reuse of treated
urban waste water for beneficial purposes. Biological
treatment is involved and, in some cases, desalting
may also be needed. Some key considerations, such
as dissolved mineral levels, health concerns, costs,
and institutional conflicts, have strongly affected pol-
icy decisions by local agencies in pursuing waste
water reclamation.
There are two terms used to designate waste wa-
ter reclamation: intentional and incidental. Reclama-
tion of waste water that would otherwise be
discharged to salt sinks (such as the ocean or saline
estuaries) or reclamation of water so degraded that
it cannot be discharged to fresh water, would be
intentional and would create a "new" water supply.
On the other hand, some of the urban water used in
California is returned to the fresh water cycle after it
has been treated. This is termed incidental reclama-
tion because additional use made of this water is
only incidental to waste water treatment and dis-
posal.
Up to 50 percent of an urban supply is used for
landscaping and is transpired or evaporated or per-
colates into the ground. The remainder is collected
and conveyed to waste treatment plants. Not all the
collected waste water can be reclaimed, however.
Twenty to 30 percent is needed to carry off concen-
trated wastes. Accordingly, only 20 to 30 percent of
the original supply may be available for reclamation.
Mineral quality of fresh-water supplies is important
in evaluating reclamation. A single cycle of water use
in an urban area normally adds about 300 milligrams
of salts per litre of water. The recommended upper
limit for salts in municipal supplies is 500 milligrams
per litre (mg/L), but up to 1,000 mg/L is acceptable.
A large share of the urban water supply in the coastal
area of Southern California is derived from the Colo-
rado River and has a salt content of around 750 mg/L.
A single use would concentrate the salt sufficiently
to exceed the acceptable limit, and reclaimed water
would have to be desalted or blended with less saline
water. Water delivered by the SWP to Southern Cali-
fornia has a monthly average of only 100 to 440 mg/L.
With an increasingly greater share of the water used
in Southern California supplied by the SWP, mineral
concentrations in the resulting waste water will be
reduced.
Presen t Waste Wa ter Reclama tion. T h e h i g h-
er levels of waste water treatment, motivated largely
by public health, esthetic, and ecological concerns,
have resulted m more complete treatment of wastes
before they are discharged. This treatment makes
the waste flows more suitable for reclamation and
reuse and lowers the incremental cost of reclama-
tion. The competitive position of waste water recla-
mation IS thereby enhanced in comparison with
alternative water supply sources. Increasing de-
mands on the limited water supplies in some areas
have also encouraged waste water reclamation.
Almost 3.4 million acre-feet of urban waste water
was treated in 1980 in California. The disposition of
this treated water (Table 12) shows that 2.4 million
acre-feet of treated waste effluent produced was dis-
charged into salt sinks. As shown, statewide total
TABLE 12
DISPOSITION OF TREATED URBAN WASTE WATER
BY HYDROLOGIC STUDY AREA
1980
(In 1,000s of acre-feet)
Waste Water Reclaimed
Waste
Water
Discharged
to Salt
Sin/cs
Total'
Waste
Water
Produced
Percent
Waste
Water
Reclaimed
HSA
Intentional
Incidental
Total
NC
9
10
9
59
29
9
17
21
67
5
9
3
247
3
3
11
17
74
292
141
41
6
14
10
612
12
13
20
76
103
9
309
162
108
11
23
13
859
62
568
93
1,003
383
275
8
44
2,436
74
584
113
1.079
486
284
329
176
126
11
46
58
3,366
16
SF
2
CC
18
LA
7
SA
21
SD
3
SB
94
SJ
92
TL
86
NL
100
SL
50
CR
24
TOTAL . .
26
This total also includes evaporation from waste water flows
79
reclamation (the sum of the intentional and inciden-
tal reclamation) is 26 percent of the total treated
urban waste water produced. However, a very large
percentage of total waste water production in the
inland Hydrologic Study Areas is reused — about 100
percent m those HSAs that do not discharge waste
water to salt sinks. Thus, most waste water discharge
in these inland areas is reused, even though only
small quantities of waste water are intentionally re-
claimed.
At present, intentionally reclaimed water is used
chiefly for crop irrigation, industrial purposes, munic-
ipal irrigation, wildlife habitat, and ground water re-
charge. The major use of water resulting from
intentional reclamation of urban wastes in 1979, as
reported by municipal, federal, and private agencies,
IS for irrigation— 137,600 acre-feet out of a total of
197,600 acre-feet — as shown in Table 13. Crop irriga-
tion IS the largest single use — 106,900 acre-feet or 54
percent of the total. Almost 84,000 acre-feet is used
in the three small HSAs in the South Coastal region.
Agricultural uses include irrigation of (1) pasture;
(2) fodder, fiber, and seed crops; (3) crops that are
grown well above the ground, and out of the reach
of the water, such as fruits, nuts, and grapes; and (4)
other crops that are processed so that pathogenic
organisms are destroyed before human consump-
tion.
Use of intentionally reclaimed water to recharge
ground water basins — 23,900 acre-feet in 1979 — not
only provides storage but also some natural treat-
ment as it percolates to an underground domestic
supply. Use can also include injection into the
ground m coastal areas to form a sea-water intrusion
barrier.
Industrial uses of reclaimed water — 4,600 acre-feet
in 1979 — include cooling water, process wash water,
boiler feed water, quenching spray water, fire protec-
tion, and secondary product recovery. These are car-
ried out chiefly at metallurgical manufacturing and
fabrication plants, electric power generation plants,
oil refineries and petrochemical plants, and mines
and quarries.
The use of reclaimed water for municipal irrigation
and recreational pursuits includes (1) irrigation of
parks, freeway landscapes, golf courses, and athletic
fields; (2) creation of scenic and ornamental lakes
and ponds; (3) maintenance of recreational lakes for
picnicking, boating, and swimming; (4) irrigation of
landscapes in commercial and industrial develop-
ments; and (5) maintenance of marshes and ponds
for wildlife habitat and fish.
Limitations and Constraints. At this time, sig-
nificant health concerns greatly limit urban use of
reclaimed water. These concerns arise because of
stable organic compounds and viruses that may re-
main in some municipal waste water after treatment.
Development and use of a wide range of organic
compounds for industrial, commercial, agricultural,
and household uses have influenced the quality of
some water supplies. Many of the complex com-
pounds are stable; that is, they persist for a long time
and they do not break down into simpler nontoxic
forms. The long-term effect of ingesting even minute
amounts of some stable organic compounds is un-
certain; therefore, efforts are made to avoid the use
of water containing these compounds where that
use may be detrimental to public health.
TABLE 13
REPORTED INTENTIONAL USE OF RECLAIMED WATER
BY HYDROLOGIC STUDY AREA
1979
(In acre-feet)
Industrial
Irrigation
Other Uses
HSA
Power
Plant
Cooling
Other
Crops
Landscape
Golf
Course
Orna-
mental
Lakes
Ground
Water
Recharge
Recre-
ation
Wild-
life
Habitat
Unclass-
ified
TOTAL
NO
200
800
300
400
1.600
400
900
4.400
8.000
6.500
8,800
1.700
3.70O
100
14.200
20,300
34.600
5,400
2.000
1.700
106.900
1.200
200
11.400
200
100
300
13.400
200
13.600
2,000
800
700
17.300
900
1,100
2.000
12.800
10.400
700
23.900
200
200
100
3,700
200
4,000
600
2,100
100
6,300
14,500
1,700
9,400
SF
10.400
cc
9.100
LA
45.800
SA
29.000
SO
9.100
SB
17,100
SJ
20,600
TL
34.500
NL
5.600
SL
3.700
OR
3.300
TOTAL
200
25.300
197.600
Data in this table are based on responses to a 1980 survev of California waste water
treatment plants by the Department of Water Resources. The table is not a complete
accounting of intentional use.
80
Health officials reject direct distribution of re-
claimed water for human consumption. They also
have severely restricted the use of reclaimed water
to recharge ground water basins drawn on for human
use because of the possible effects of stable organic
compounds and heavy metals. Because ground wa-
ter migrates slowly and does not intermix well, re-
claimed water introduced into a ground water basin
would move away from the area of entry in a body
and might not dissipate for many years.
Distribution of fresh-water supplies and treatment
and disposal of municipal waste water are usually
handled by different agencies with different objec-
tives. Because of this, institutional constraints on
marketing the reclaimed water have tended to inhibit
its reclamation and reuse. Water supply agencies
generally build a new pipeline to take the reclaimed
water from the waste water treatment plant to the
areas of use. In marketing this water, these agencies
may be burdened with the costs of maintaining dual
water distribution systems, one for fresh water and
one for reclaimed water. In addition, the price of
reclaimed water is often established through
negotiation, and the ultimate users may pay less for
it then they do for fresh water. This occurs because
they also have the added expense of operating dual
water systems and controlling water use to meet
public health criteria.
Energy Use. Since a water reclamation project
provides water to a local area, less energy may be
consumed to operate it than to import water to the
area from a distant source. In Southern California, for
instance, water reclamation projects use from 200 to
2,200 kilowatthours per acre-foot (kWh/ac-ft), while
about 2,900 kWh/ac-ft is required to transport SWP
water from the Delta. The actual energy required
must be determined on a case-by-case basis and de-
pends on the amount of treatment the waste water
needs and the pumping lift required for distribution
and storage of the water (reclamation plants are usu-
ally situated at elevations below that of the place of
use).
Current Costs. Because of the unique nature of
each water reclamation project, costs must also be
determined case by case. An economical project
should produce water at a cost that does not exceed
the cost of project alternatives, presently $200-350
per acre-foot in most areas of the State.
Water Prices
More than 2,500 agencies in California are engaged
in selling water: over 500 independent special dis-
tricts, 257 municipal waterworks, about 400 private
companies regulated by the State Public Utilities
Commission, and about 1,200 mutual water compa-
nies. Together these represent more than 30 legally
distinct types of entities. Each water purveyor distrib-
utes water within a pricing framework based on its
own policies, costs, objectives, and institutional con-
straints. As a result, a great number of water pricing
systems currently are in use in California. Water
prices vary from less than $1.00 to nearly $200 per
acre-foot for some agricultural water and from less
than $40 to more than $400 per acre-foot for urban
water. Water often passes through one or more
wholesalers and a retailer before it reaches the ulti-
mate consumer.
Policies of water purveyors are important factors
in pricing. For example, the policy of the State Water
Project is to require full repayment by the users of all
costs associated with delivery of the allocated water,
and the SWP water contracts require that this be
done. In keeping with federal reclamation policy, the
irrigation water charges by the Central Valley Project
do not include repayment of interest on construction
costs of the project.
Because of the large number of water purveyors
and the wide range in pricing structures, it is difficult
to develop and present an overall picture of water
pricing. Based on available data, a weighted average
water rate and the range of water rates for both
urban and agricultural water is shown by county in
Table 14. It also includes costs for self-produced wa-
ter for the agricultural sector. (Self-produced water
is either pumped from wells or diverted directly from
a stream.) Examination of the table reveals that (1)
agricultural water is priced highest in the South
Coastal region HSAs and lowest in the Sacramento
HSA portion of the Central Valley: and (2) urban
water is generally priced higher than agricultural wa-
ter. This IS partly because urban supply systems are
more complex and involve greater costs for local
facilities for system regulation, treatment plants, dis-
tribution systems, water meters, and system opera-
tion, including meter reading and customer billing. In
addition, in some cases, the water rate includes a
charge for waste water treatment.
TABLE 14
AVERAGE URBAN AND AGRICULTURAL RETAIL WATER PRICES
BY COUNTY
(In dollars per acre-foot)
County
Alameda ..
Alpine
Amador ....
Butte
Calaveras..
Colusa ,
Contra Costa
Del Norte
El Dorado
Fresno
Glenn
Humboldt
Imperial ....
Inyo
Kern
Kings
Lake
Lassen
Los Angeles .
Madera
Mann
Mariposa
Mendocino .
Merced
Modoc
Mono
Monterey..
Napa
Nevada
Orange
Placer
Plumas
Riverside
Sacramento..
San Benito ..
San Bernardino ...
San Diego
San Francisco
San Joaquin ,
San Luis Obispo
San Mateo
Santa Barbara..
Santa Clara
Santa Cruz
Shasta
Sierra
Siskiyou
Solano
Sonoma
Stanislaus
Urban
Prices '
Range
265
260
230
130
210
110
245
230
220
65
140
195
175
110
175
140
170
190
210
105
340
210
170
65
155
130
195
310
145
195
160
220
190
65
175
150
265
200
180
305
285
315
235
265
145
110
165
200
245
221-369
261
88-403
94-320
210
99-149
197-261
205-324
169-261
61-80
70-22
173-289
147-192
0-225
148-193
137-149
165
189
108-273
82-117
283-394
211
16&-175
61-78
156
128
165-260
305-318
126-194
147-236
127-188
220
156-248
40-81
152-208
139-166
223-346
200
96-303
247-323
164-344
195-401
169-278
264-281
109-200
85-118
150-188
153-351
225-288
54-173
Agricultural
Prices^
N/A
N/A
N/A
5.00
N/A
2.90
5.30
N/A
N/A
14.90
4.20
N/A
7.50
12.60
31.00
20.50
15.90
6.30
36.50
11.50
N/A
N/A
N/A
9,40
10.50
14.70
38.00
N/A
8.60
63.00
7.20
2.80
12.00
5.50
18.90
36.00
145.00
N/A
6.90
32.00
N/A
45.00
21.00
N/A
500
N/A
5.20
6,70
N/A
3.20
Range
N/A
N/A
N/A
1,00-12.00
N/A
1.00-12,00
2.00-9.00
N/A
N/A
100-65.00
1.00-12,00
N/A
7,50
10,00-37.60
6.60-78.00
2-70-37.20
3.00-19.00
4.0O-10.00
30.00-86.00
3,70-18.60
N/A
N/A
N/A
4.00-21.00
5,5044.00
3.00-25.70
19,80-55,00
N/A
8.0O-20.00
40.00-75.00
2.00-24.00
1.00-16,00
3.40-133,00
1. 00-20.00
1.50-19.80
12,00-52,00
40.00-192,00
N.'A
1,50-16-00
28,50-35.00
N/A
25.30-109,00
11,00-30,00
N/A
2,90-10,00
N/A
2,00-10.00
2.0O-20-0O
N/A
0.65-6.90
82
TABLE 14 — Continued
AVERAGE URBAN AND AGRICULTURAL RETAIL WATER PRICES
BY COUNTY
(In dollars per acre-foot)
County
Urban
Prices '
Range
Agricultural
Prices'
Range
Sutter
145
135
330
130
280
240
70
110
133-181
132-145
277^25
108-137
279
206-283
56-97
100-120
4.10
7.60
N/A
14.00
N/A
31.50
6.60
5.80
1.00-6.50
Tehama
2.70-11.37
Trinity .
N/A
Tulare
3.40-23.30
Tuolumne
N/A
Ventura
14.00-78.00
Yolo
1.00-20.00
Yuba
0.75-14.00
' The average urban water prices shown m this table are approximate weighted averages based on a recent DWR survey of 107
cities and service areas The figures represent the 1980 or 1981 cost per acre-foot of water for a fannily using three-fourths
acre-toot of water each year.
^The average agricultural water prices are approximate weighted averages based on a recent DWR survey of 161 water districts
and other water sources The price figures include per-acre assessments and represent 1979, 1980. or 1981 They represent the
rates farmers pay for irrigation district water, and the estimated costs of self-produced water, such as ground water and direct
diversion of river water
N/A = Not available
PUMPING ENERGY USED FOR CALIFORNIA'S WATER SUPPLIES
A significant amount of electricity is used by pumps to
produce, transport, and distribute water to homes, businesses,
factories, and farms. In turn, many utility districts and water
agencies produce hydroelectric energy when they store and
deliver water, even though pumping may be required as part
of the system.
Examples of the energy required to provide water supplies
throughout California are shown in Table 15. There are some
significant omissions; the table does not include information
on some major producers of water, such as the Los Angeles
Department of Water and Power; the East Bay Municipal
Utility District; the San Francisco Water Department; the Im-
perial, Modesto, and Turlock Irrigation Districts; and the Coa-
chella Valley Water District. The systems of these water
agencies generate more electricity than they consume since
they are basically aqueducts and canals that are gravity-flow
systems. Table 15 is based on 1.75 kilowatthours per acre-
foot (kWh/oc-ft) per foot of lift. For the energy-using sys-
tems shown in the table, kilowatthours per acre-foot range
from 25 for diversion from a stream in the Central Valley to
about 3,000 kWh/ac-ft for SWP supplies in Southern Califor-
nia. The information in this table is given to provide a repre-
sentation of energy used in furnishing water supplies. The
data are not sufficient to summarize on the basis of regional
or statewide averages.
A few conclusions can be drawn from the information In
Table 15. Areas with expensive water (see Table 14) also
have water with relatively high kWh/ac-ft ratios. An acre-
foot of imported water generally uses more electricity than an
acre-foot of local surface water.
TABLE 15
EXAMPLES OF PUMPING ENERGY USED FOR WATER SUPPLY
Region
Southern California
Metropolitan Water District
Orange County
Chino Basin, West San Bernardino County
San Francisco Bay
South Bay Aqueduct
Entire Bay Area
Central Valley
Central Valley Area
Lost Hills WSD, Kern County
Wheeler Ridge-Mancopa WSD. Kern County
Butte County
Sacramento County
Fresno County
Kern County
Salinas Valley
Salinas River Valley Area
Water
Source
Colorado River
Aqueduct
SWP
Ground water
Ground water
SWP
Ground water
CVP
River diversion
SWP
SWP
Ground water
Ground water
Ground water
Ground water
Ground water
Year
1980
1980
1975
1981
1979
1975
1972
1981
1980
1980
1979
1979
1979
1979
1975
Average
kWh Per
Acre-Foot
2.050
2.950
175
630
840
155
360
25
550
1,100
90
210
180
440
100
83
TABLE 16
TOTAL APPLIED WATER AND NET WATER USE
BY HYDROLOGIC STUDY AREA
1980
(In 1,000s of acre-feet)
NC
SF
CC
^
SA
SD
SB
SJ
TL
NL
SL
CR
rOTAL
APPLIED WATER
Aoriculture
821
153
260
1
0
1J36
714
151
215
1
1.081
121
967
100
2
6
1.196
121
967
94
2
6
14
1.204
1.189
231
2
7
1.429
902
188
2
7
1.099
348
1.654
7
1
7
2.017
276
1.534
7
1
7
81
1.906
412
734
2
9
1.151
320
586
2
9
45
962
228
389
5
2
624
198
389
5
2
40
634
9.223
570
167
3
9.963
6.682
493
157
I
129
7.464
7.474
403
86
10
15
7.988
5.892
249
64
10
15
111
6.341
11.424
425
45
7
10
11.911
7.781
236
31
7
10
123
8.188
442
23
10
1
476
387
23
10
1
421
493
95
3
9
2
602
338
60
3
9
2
7
419
3.460
118
17
3
3
3.601
3434
102
'\
3
543
4.102
35.636
Urban
5.762
Wildlife -
700
Recreation _
Energy Production _
TOTAL
43
59
42.199
NET WATER USE
27.045
Urban
4.978
Wildlife -
603
43
59
Conveyance Losses....-
TOTAL
1.093
33.821
TABLE 17
CHANGES IN NET WATER USE
BY REGION
1972 to 1980
(In 1,000s of acre-feet)
Regions
North Coast
(North Coast and San Francisco Bay HSAs)
Central Coast HSA
South Coast
(Los Angeles. Santa Ana. and San Diego HSAs)
Central Valley
(Sacramento. San Joaquin, and Tulare Lake HSAs)
North Lahontan HSA
Southeastern Desert
(South Lahontan and Colorado River HSAs)
TOTAL
f972
1980
Amount
of Change
Percent
Change
2.210
950
3.080
20.000
43C
4.350
31.020
2.230
1.100
3.500
22.000
420
4,520
33.820
+70
+ 150
+420
+2.000
-10
+ 170
+2.810
+3
+ 16
+ 14
+ 10
-2
+4
+9
TABLE 18
DEPENDABLE WATER SUPPLIES, 1980 LEVEL OF DEVELOPMENT
BY HYDROLOGIC STUDY AREA
(In 1,000s of acre-feet)
MC
SF
CC
LA
SA
SD
SB
SJ
TL
NL
Si
CR
TOTAL
PRESENT USE OF DEPENDABLE
SUPPLY
Local Surface
388
2
243
458
9
1.060
9
1.089
ra
454
211
81
56
157 =
10
1.197
138
1.335
39
768
54
9
870
17
887
29
752
483
20
481
59
1.824
164
1.988
93
290
402
138
29
952
203
1.155
37
290
77
221
9
634
46
680
7886
9
1.798
2.422
259
17
7.371
535
7.906
3.065
972
1.838
55
8
21
5.949
191
6.140
2.199
551
Z736
243
1.536'
67
7.332
56
7.388
312
11
88
5
416
17
433
44
178
85
9
316
33
349
4
68
3.970
30
3
4.075
4
4.079
9J74
Imports by Locals
1.806
5.839
CVP
issn
Other Federal „ _ -
5.115
SWP ».. .
2.656
247
Subtotal
3Z016
RESERVE SURFACE WATER
SUPPLY
1.413
TOTAL DEVELOPED WATER
SUPPLY
33.429
' Not including overdraft.
'Includes SWP surplus water deliveries.
84
Statewide Hydrologic Balance
The relationship between water use and water
supplies in California is determined through analysis
of the hydrologic balance. The major components of
the balances for each HSA are summarized in tables
appearing later in this chapter that show applied wa-
ter, net water use, and developed water supplies in
1980. The full complexity of a statewide hydrologic
balance is illustrated at the end of this section.
A summary of applied water in 1980 (Table 16)
indicates the quantities of water delivered to the
point of use, such as municipal system, factory, or
farm headgate. The summary of net water use in
1980, also shown, indicates the water supplies actual-
ly needed to support this level of development. Net
water use is considerably less than applied water,
primarily because of the extensive reuse that takes
place. Net water use is the amount of water required
to meet the evapotranspiration of applied water and
the irrecoverable distribution system losses, as well
as the outflow from the area.
Between 1972 and 1980, a substantial increase in
net water use occurred — 2.8 million acre-feet — most-
ly in the Central Valley. Net water use in 1972, as
presented in Bulletin 160-74, is compared in Table 17
by regions (HSAs or combinations of HSAs), with
the current estimate of net water use for 1980 (also
shown in Table 16). In the Central Valley, the in-
crease was 2 million acre-feet, a 10-percent increase
from 1972 to 1980. This increase was mostly in sup-
port of irrigated agriculture. The other region of sub-
stantial increase was in the South Coastal region,
where there was additional net water use of 420,000
acre-feet, mostly for urban purposes.
Statewide, the total annual long-term dependable
developed water supply is 33,429,000 acre-feet, of
which 32,016,000 acre-feet is currently used. This
leaves 1,413,000 acre-feet as a reserve developed sur-
face water supply.
The dependable water supplies used to meet the
net water uses are summarized in Table 18. The re-
serve surface water supply indicated in the table
represents the portion of developed water supply
from specific water projects where the use by the
service areas for those projects has not yet reached
the full capability of the water supply. In general, the
reserve surface water supplies indicated are commit-
ted to the designated service areas and are not avail-
able to meet needs of other areas, even temporarily,
because of a lack of conveyance systems and of insti-
tutional arrangements to make the water available.
The statewide summary of net water use. present
use of dependable water supplies, ground water
overdraft, and reserve supply is presented in Table
19. The Sacramento HSA has the largest net use of
dependable water supply and the largest reserve
supply, 7.4 million acre-feet and 535,000 acre-feet, re-
spectively. The Tulare Lake HSA has the second larg-
est use of dependable supply: but, with the largest
net water use, 8.2 million acre-feet, it also has the
largest overdraft.
Statewide ground water overdraft is estimated at
1.8 million acre-feet annually. Table 19 indicates that
ground water overdraft occurs in some HSAs where
reserve supplies are present. The most notable exam-
ple of this is the San Joaquin HSA because, as in-
dicated above, local areas where the ground water
overdraft occurs do not have access to the reserve
supplies.
One of the major water problems in California is
the lack of natural surface water supplies in the areas
where the most development using water has taken
place. The extensive conveyance systems necessary
to move the water to the area of use are shown on
Plate 1 and are generalized in Figure 26, together with
the substantial quantities of water transferred. More
than 18 million of California's 23.8 million people live
in the coastal metropolitan areas of San Francisco
Bay and the South Coastal region (1980). This popu-
lation is supported substantially by imported water
supplies. Large imports of water are also required to
sustain the current level of irrigated agriculture in the
San Joaquin Valley.
TABLE 19
NET WATER USE AND WATER SUPPLY SUMMARY
BY HYDROLOGIC STUDY AREA
1980
(In 1,000s of acre-feet)
NC
SF
CC
LA
SA
SO
SB
SJ
TL
NL
SL
CR
TOTAL
Net Water Use
Present Use of Dependable Supply
Ground Water Overdraft
Shortage '
Reserve Surface Water Supply
' Shortage in urban water supply,
' Includes SWP surplus water deliveries.
1.081
1,080
1.204
1.197'
7
138
870
224
6
17
1.906
1.824
82
164
962
952
10
203
634
634
46
7,464
7.371
86
8
535
6.341
6.949
391
1
191
8.188
7,332 '
856
56
421
416
5
419
316
103
33
4.102
4.075
27
33.821
32.016
1.790
15
1.413
85
Figure 26. EXISTING INTRASTATE WATER TRANSFERS
AT 1980 LEVEL OF DEVELOPMENT
ACRE-FEET PER YEAR
1 South Bay Aqueduct 150 000
2 Contra Costa Canal 81.000
3 Mokelumne Aqueduct 210.000
4, Hetch Hetctiy Aqueduct 240.000
The four regions that import significant amounts of
water and now have, or previously have had, substan-
tial ground water overdraft are shown in Table 20. In
all these regions, the imported supplies have been
developed to offset overdraft conditions and meet
anticipated future needs. In the South Coastal re-
gion, ground water basins are now mostly managed.
Many of them have been adjudicated, and overdraft
has been largely eliminated. However, the area im-
ports 62 percent of its net water supply, as does the
San Francisco Bay HSA. The Tulare Lake HSA has
the largest ground water overdraft — about 850,000
acre-feet per year — and imports 36 percent of its net
water supply. Most of the net water use in the South
Coastal region and the San Francisco Bay HSA is for
urban purposes, while in the Tulare Lake HSA, it is
primarily for irrigated agriculture.
TABLE 20
COMPARISON OF LOCALLY DEVELOPED
AND IMPORTED NET WATER SUPPLIES
1980
(In percent)
Location
Water Supply
Developed
within the
Area
Water Supply
Imported
San Francisco Bay HSA
38
38
76
64'
62
South Coast Region (Los Angeles, Santa
Ana and San Diego HSAs)
62
24
Tulare Lake HSA
36
' CVP water delivered through Friant-Kern Canal was considered as a water supply
developed within the area.
STATEWIDE HYDROLOGIC BALANCE NETWORK
California's natural water supplies are derived
from an average annual statewide precipitation of
193 million acre-feet. This amount translates to an
average depth of nearly 2 feet, varying from nearly
zero to more than 100 inches across the State. About
60 percent of this precipitation is consumed through
evaporation and transpiration by trees, brush, and
other vegetation. Most of the remainder comprises
the State's average annual runoff, 71 million acre-
feet. Of this, more than 4 million acre-feet percolates
from stream channels to ground water basins. This
amount is about 80 percent of the total prime supply
to ground water in California. Most of this 80 percent
is naturally recharged to ground water. The rest is
local surface supplies that are recharged by artificial
means. The remaining 20 percent is derived from
precipitation percolating directly to the ground wa-
ter through the soil. Average annual precipitation
and runoff by Hydrologic Study Areas are shown in
the series of maps appearing in "Summaries of Hy-
drologic Study Areas" in this chapter.
The overall balance between water use and the
water resources of California is shown in Figure 27.
The amounts shown represent average hydrologic
conditions, current water development, and 1980 lev-
el of water use in relation to:
• Natural water resources of California, both surface
and ground water.
• Interstate imports and exports.
• Developed water supplies.
• Surface water and ground water.
• Applied water.
• Consumptive use of precipitation and developed
water supplies.
• Reuse of water.
• Final outflows to the ocean and other salt sinks.
87
Figure 27. HYDROLOGIC BALANCE NETWORK FOR CALIFORNIA 1980
IN MILLION ACRE-FEET
I
i I
QROUNO
w*
cn
C-'IME SUfPL
8 B
• NI,MCl*L RtCHAHGE 1 1 1
MbP PERCOL
•fpiieo *AT
»T10N
Of
..EBOIXFT
> B
. ..Nvf .*NCt
5.ES1
• 0£ _0J
\
J*
DESCRIPTIONS OF
COMPONENTS OF THE
HYDROLOGIC BALANCE
NETWORK FOR
CALIFORNIA
(Figure 27)
Sequence on Chart Is
Top to Bottom and
Left to Right
1. Colorado River — Representative 1980 level of use
of water diverted from the Colorado River by The Metropoli-
tan Water District of Southern California, Imperial Irrigation
District, Coachella Valley Water District, Palo Verde Irriga-
tion District, the Yuma Project, and others under California's
entitlement to use of Colorado River water.
2. Inflow from Oregon— Klamath River inflow from
Oregon.
3. Precipitation — Long-term average annual precipi-
tation falling in California.
4. Runoff — The portion of long-term overage annual
precipitation which runs off the land and makes up the natural
flow in rivers and streams.
5. Effect of Land Use Changes — The portion of
average annual precipitation that would have been used by
natural vegetation but now contributes to runoff. This is a
result of roads, paved areas, building roofs, land drainage
systems, fields developed for irrigation, and other changes in
land use.
6. Ground Water Prime Supply — The long-term
average annual percolation to the major ground water basins
from precipitation falling on the land and from flows in rivers
and streams. Also includes recharge from local sources that
has been enhanced by construction of spreading grounds and
other structural devices. Recharge of imported and reclaimed
water is not included.
88
7. Evaporation and Evapotranspiration from
Forest, Rangeland, Unirrigated Agriculture, Na-
tive Vegetation, and Other Lands — The statewide
evaporation of precipitation from land surfaces and the
evapotranspiration of precipitation by nonrrrigated trees,
brush, dry-farmed crops, gross, and other plonts.
8. Total Streamflow — The long-term overage annual
natural streamflow and the increase in streamflow due to land
use changes.
9. Ground Water in Storage — The estimated total
fresh water stored in the major ground water basins within the
Stote.
10. Evaporation from Lakes and Reser-
voirs— The overage annual surface evaporation from natu-
ral lakes and constructed surface water storage reservoirs.
11. Agriculturally Effective Evapotranspira-
tion on Irrigated Lands — Average annual precipitation
used by crops planted in developed irrigated land areas.
12. Central Valley and State Water Projects,
Water Stored for Salinity Repulsion — Represents
releose of carryover storage (port of the firm yield) of these
two projects to supplement natural flows to meet outflow
requirements for protection of beneficial uses in the Sacra-
mento-San Joaquin River Delta.
13. Local (In State) Imports — The average annual
inter-watershed transfers of water supply within the State.
14. Local Development — The average annual sur-
face water supplies of individuals and from local water
ogency water projects. It includes direct deliveries of water
from streomflows, as well as local water storage facilities. It
excludes artificial recharge of local water to ground water
basins (port of ground water prime supply).
15. Central Valley Project — The sum of estimated
deliveries, conveyance losses, and available reserves in 1980
from the Central Valley Project.
16 Other Federal — The sum of estimated deliveries
and available reserves in 1980 from federal projects other
than the Central Valley Project.
17. State Water Project — The sum of estimated
deliveries, conveyance losses, and available reserves from the
existing facilities of the State Water Project.
18. Artificial Recharge of Imported Sup-
plies— The average annual contribution from imported wa-
ter supplies and planned waste water reclamation projects.
Does not include recharge of local supplies to ground water
recharge by specific recharge project.
19. Conveyance Losses — The overage loss from ma-
jor water supply conveyance systems to evaporation, seep-
age from unlined canals, and evapotranspiration by
vegetation in and near canals.
20. Developed Water Supply — The total developed
water supply, including surface water supplies, ground water
pumped, imports from the Colorado River, and planned and
incidental waste water reclamation.
21. Ground Water — A summary of the sources of
ground water as part of the developed water supply.
22. Agricultural Return Flows to Developed
Water Supply — Represents surface return flows from irri-
gated agriculture to stream channels that ore available for
use outside the local service area.
23. From Conveyance Losses — That portion of
conveyance losses that seeps into ground water supplies.
24. Reclaimed Waste Water — The planned renova-
tion of waste water for specific beneficial purposes and the
incidental reuse of treated woste water flows that return to
streomflows and ground water basins.
25. To Ground Water — That portion of the convey-
ance losses attributable to seepage from canals that becomes
avoiloble as ground water. (This is the same water as that
shown in 23 above.)
26. Urban Waste Water Produced — Represents
the flow from urban waste water treatment plants.
27. Evapotranspiration of Applied Water — The
applied water consumptively used through evaporation and
transpiration by agricultural crops, urban areas, wildfowl
management areas, parks and other recreation oreos, and
energy production.
28. Water Use (Applied) — Represents the applied
water for irrigated agriculture, urban areas, wildfowl man-
agement areas, nonurbon parks and recreation areas, and
energy production.
29. Evaporation and Evapotranspiration of Ap-
plied Water, Precipitation, and Conveyance
Losses — The total of all evaporation and evapotranspira-
tion under overage natural conditions and 1980 level of ap-
plied water.
30. Deep Percolation of Applied Water — Repre-
sents that portion of applied water for agriculture and urban
purposes that percolates to the ground woter, including the
water used for leaching accumulated salts from the root zone.
31. To Evaporation and Evapotranspiration —
That portion of the urbon waste water produced that evapo-
rotes from evaporation and percolation ponds.
32. Reuse Within Service Area — Represents reuse
of irrigation systems toilwoter and return flows to local distri-
bution systems and streams within o unit geographic study
area; in this case, does not include reuse of excess applied
water that percolates to ground water.
33. Incidental Evapotranspiration of Agricul-
tural Return Flows — Represents the evapotranspiration
by weeds and other vegetation in fringes of fields and in and
near the agricultural drains and sump areas.
34. Agricultural Surface Return Flows — Repre-
sents the flows from applied irrigation water and some returns
of conveyance losses that return to the developed surface
water supply, are discharged to salt sinks, or are consumed
by riparian plants.
35. From Urban Waste Water Produced — The
portion of urban waste water that is lost to evaporation.
89
36. Reserve Supply — Developed but presently unused
surface water supply available to certoin portions of a Hy-
droiogic Study Area to meet planned future water needs;
usually the supply is not available to other areas needing
additional woter because of a lack of physical facilities
ond/or institutional arrangements.
The reserves include the sum of the reserves in each Plan-
ning Subarea (PSA) from:
• Local development and imports
. SWP
. CVP
• Other federol development.
Not all the total of these reserves is usable because some
of it is reduced by conveyance losses and some of it consists
of return flows that become port of the downstream reserve
supply for a PSA. In addition, some of the reserve supply
identified for a PSA may also be included in the amount
identified for one or more other PSAs.
37. Agricultural Flows to Salt Sinks — Agricul-
tural return flows that go to evaporation ponds, saline water
bodies such as the Salton Sea or the ocean, or to saline
ground water.
38. Discharged to Saline Water — Represents that
portion of treated urban waste water discharged to saline
surface and ground water bodies.
39. Salinity Repulsion — Fresh water outflow from the
Sacramento-San Joaquin Delta to protect the beneficial uses
within the Delta from the incursion of saline water.
40. Wild and Scenic Rivers — Average annual natu-
ral flows from the designated North Coast State and Federal
Wild and Scenic Rivers systems.
41. Remaining Runoff — Represents the remaining
natural runoff under average annual hydrologic conditions.
42. Outflows to Nevada — The average annual natu-
ral outflow to the State of Nevada.
90
SUMMARIES OF HYDROLOGIC STUDY AREAS
This section summarizes water-related information for the 12 Hydrologic
Study Areas. Tables in this section present data on net water use and water
supply. Irrigated and urban areas are depicted on the HSA maps, which also
include tabulations of average precipitation, average natural runoff, irrigated
land area, and population. Discussion sections include comments and high-
lights pertaining to population, water supply, and irrigated agriculture (signifi-
cant changes in crops, irrigated land, and irrigation methods). Tabulations
showing detailed hydrologic balances are included for the Los Angeles, Santa
Ana, and San Diego HSAs (the South Coastal region) and the Sacramento, San
Joaquin, and Tulare Lake HSAs (the Central Valley).
91
AVERAGE ANNUAL PRECIPITATION - 51,940.000 acre-feet
Figure 28.
NORTH COAST HYDROLOGIC STUDY AREA
NORTH COAST HYDROLOGIC STUDY AREA
Population
The Russian River portion of this area — the Santa
Rosa area of Sonoma County, in particular — is under-
going the rapid growth that is characteristic of the
San Francisco Bay metropolitan area. To preserve its
agricultural industry, Sonoma County has passed an
ordinance that bans the subdivision of farmlands into
parcels of less than 20 acres.
Irrigated Agriculture
Irrigated lands m the North Coast HSA increased
by 24,000 acres from 1972 to 1980. Changes included
18,000 acres of irrigated vineyards, both new and es-
tablished, to which dual systems were added for frost
protection (overhead spray) and irrigation (drip de-
vices). Orchards, which have been replaced with
vineyards, showed a decrease of 6,000 acres, while
most other categories of crops showed a slight in-
crease. Most of the newly irrigated land is supplied
by ground water.
Russian River
The Russian River drainage basin in Mendocino
and Sonoma Counties is noted for its orchards and
varietal wine grape vineyards, a significant portion of
which have been historically dry-farmed. The crop-
ping pattern in this region has changed greatly since
1972, with urban encroachment and the replacement
of many prune orchards by grape vineyards. In 1972,
about 24,000 acres were planted to orchards; by 1980,
orchards had declined to about 15,500 acres. In con-
trast, vineyards increased from about 33,000 acres in
1972 to about 36,700 acres in 1980. Also, irrigated
vineyards, including those equipped with sprinklers
primarily for frost protection, increased from 21,800
acres in 1972 to 27,400 acres in 1980. About 60 percent
of the sprinkler-equipped acreages are actually irri-
gated during the summer; the remainder receive
frost-control watering only. Most of the new vine-
yards planted in recent years are equipped with per-
manently set sprinkler systems, and some also have
drip irrigation.
It is not uncommon in this region to see orchards
under stress conditions because of insufficient soil
moisture. Moisture stress severely reduces crop
yield in some cases.
Remaining Areas
Irrigated acreage in the major agricultural areas
draining into the Klamath River increased from 26,000
to 41,600 acres between 1969 and 1979. All the in-
crease can be attributed to the development of
ground water for irrigation, principally within Red
Rock Valley and Butte Valley ground water basins.
Red Rock Valley, an area with no irrigation m 1959,
had 5,340 acres under irrigation in 1979. Irrigated
agriculture within the Butte Valley ground water ba-
sin increased about 10,300 acres between 1969 and
1979. Alfalfa and grain are the irrigated crops that
have shown the most substantial increases.
The long-standing method of wild flooding is still
practiced in many counties of the Sierra Nevada and
TABLE 21
NET WATER USE AND WATER SUPPLY
NORTH COAST HYDftCLOGIC STUDY AREA— 1980
(In 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urban
151
714
216
1.081
Local surface water
368
Irrigated agriculture
Major local imports
Ground water
2
243
Central Valley Project
Energy production
Other federal projects
State Water Project
Waste water reclamation
Use of dependable water supply.....
Reserve supply
TOTAL DEVELOPED WATER
458
Wildlife and recreation
9
Conveyance losses
1080
TOTAL
9
1089
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use Met by
Ground Water Overdraft
Urban Shortage
1.081
1.080
-
1
93
the Cascade Range, including Siskiyou County. Typi-
cally, the system functions by diverting a stream into
a ditch constructed to a slight grade that conveys
water on a sloping contour along a hillside, eventual-
ly running above irrigable fields. Water is diverted
from the ditch by flash boards, sand sacks, or other
devices at intervals and allowed to flow onto and
cover most of the field below. Although the system
is a somewhat inefficient means of applying water, it
IS popular because it is inexpensive to establish and
operate: also, it operates entirely by gravity. After the
field IS irrigated, excess water re-enters the local
stream system and is again available for use on low-
er-lying fields. This results, however, in a greater re-
duction in streamflow between the point of diversion
and the point of return to the stream than would
occur in a more efficient system. Irrigated pasture is
generally the only crop in this HSA irrigated in this
manner.
SAN FRANCISCO BAY HYDROLOGIC STUDY AREA
Population
San Francisco County, the only county in Califor-
nia to lose population between 1970 and 1980, and
San Jose, the fastest growing major city in the na-
tion, are both in the San Francisco Bay HSA. Most of
the growth that took place in the South Bay area was
due to natural increase, rather than migration.
However, growth in the South Bay is now being
slowed by a scarcity of affordable housing. A survey
by the Association of Bay Area Governments shows
a decrease in housing densities in the suburbs since
the change in property tax law in 1978 because coun-
ties have adopted fiscal zoning to require larger lots
with higher values and thus increase their tax base.
Completion of the Bay Area Rapid Transit in the early
1970s stimulated growth in the eastern counties of
Solano and Contra Costa where more affordable
housing existed. San Francisco Bay HSA's employ-
ment IS heavily directed toward the aerospace and
electronics industries. Santa Clara County ranks sec-
ond in the State in numbers of people employed in
the aerospace industry. The county is also the home
of the electronics industry, which originated at Stan-
ford University m the 1920s.
Irrigated Agriculture
The San Francisco Bay HSA, even with the pres-
sure of urbanization, underwent a 1,000-acre net in-
crease in irrigated area between 1972 and 1980.
Irrigated vineyards increased by 16,000 acres. Among
these were established, traditionally dry-farmed vine-
yards where irrigation had been added. Some of the
new vineyards (as well as urban expansion) dis-
placed irrigated orchards, which declined by 14,000
acres. Pasture declined by 8,000 acres and vegeta-
bles, by 1,000 acres. All other crops showed a slight
increase. Most of the new irrigation relies on ground
water.
South Bay Area
About 9,000 acres of irrigated crops remain in
Santa Clara County. Water supplies are obtained by
pumping ground water, which is recharged with
about 35,000 acre-feet of State Water Project (SWP)
water. About 3,000 acre-feet of recharged ground
water is used for agricultural crop production. Inten-
sive cultural practices maintain high irrigation effici-
encies in the county — about 80 percent.
About 8,000 acres of irrigated crops are grown in
the Livermore Valley (Zone 7 of the Alameda County
Flood Control and Water Conservation District) . Cur-
rently, the average irrigation efficiency is about 70
percent, and it is likely to increase further because of
higher costs of energy for pumping ground water.
The excess irrigation water enters the ground water
basin underlying the Livermore Valley. About 2,000
acre-feet of irrigation water is obtained from the
SWP and the remainder is ground water.
In the Alameda County Water District near Fre-
mont and Newark, ground water is the source of all
irrigation water. Major crops are cauliflower, lettuce,
nursery stock, and flowers. The present irrigation ef-
ficiency (80 percent or greater in many cases)
should continue about the same m the future.
The climate of the coastal area of San Mateo
County is suitable for such specialty crops as Brus-
sels sprouts, artichokes, and flowers. An inadequate
supply of irrigation water is one of the main factors
that restrains farming in this area. Underground wa-
ter storage is limited; therefore, most of the water is
obtained by pumping directly from creeks or by col-
lecting winter runoff in small reservoirs for later use.
Frequent coastal fogs help reduce the irrigation re-
quirements m the area. Current irrigation efficiency
is high, about 80 percent.
94
AVERAGE ANNUAL PRECIPITATION - 5,830,000 acre-feet
AVERAGE ANNUAL RUNOFF - 1,290,000 acre-feet
IRRIGATED LAND - 64.000 acres
POPULATION - 4,790,000
i
SAN FRANCISQO
MlLtS
Legend
W
iv, ■ IRRIGATED LAND
URBAN LAND
Figure 29.
SAN FRANCISCO BAY HYDROLOGIC STUDY AREA
95
TABLE 22
NET WATER USE AND WATER SUPPLY
SAN FRANCISCO BAY HYDROLOGIC STUDY AREA— 1980
(In 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urban
Irrigated agriculture
Energy production....
Wildlife and recreation..
Conveyance losses
TOTAL
967
121
6
96
1.204
Local surface water
f^ajor local imports
Ground water
Central Valley Project
Other federal projects
State Water Project
Waste water reclamation
Use of dependable water supply.
Reserve supply
TOTAL DEVELOPED WATER
228
454
211
81
56
157'
10
1.197
138
1.335
WATER BALANCE
Net Water Use
Use of Deper)dable
Water Supply
Use Met by
Ground Water Overdraft
Urban Shortage
1,204
1.197
' Includes SWP surplus water deliveries.
North Bay Area
Vineyards are expanding into previously uncul-
tivated hilly areas on the western and eastern fringes
of the Napa Valley. They are irrigated mostly with
drip systems, interspersed with sprinklers. Some
growers use sprinklers for frost control only. Because
water is in short supply in the Napa Valley, many
growers maintain reservoirs to provide enough water
to combat frost. The Napa River has been under a
trial distribution program of the State Water Re-
sources Control Board since 1973 to allocate river
flows during the frost-risk season (March 15 to May
15).
In Napa County, about 95 percent of the irrigated
crop acreage is vineyards. Irrigation efficiency is cur-
rently about 80 percent, with widespread use of
sprinklers and drip systems. Sources of water are
equally divided between surface and ground water.
In the North Bay portion of Solano County, about
68 percent of the irrigated crops consist of apricot,
pear, prune, almond, and walnut orchards. Many or-
chards are now irrigated by the basin method. Pas-
ture is irrigated by the border method. About 92
percent of the total crop acreage is irrigated with
surface water, most of which is supplied by the So-
lano Project from water stored at Lake Berryessa.
96
CENTRAL COAST HYDROLOGIC STUDY AREA
Population
County growth from either migration or natural
increase varied considerably within the Central
Coast HSA. San Luis Obispo and Santa Cruz Coun-
ties' growth came from migration, 85 and 80 percent
respectively, while 75 percent of the growth in Mon-
terey County was due to natural increase. Govern-
ment, trade, and services are the main employment
industries.
Significant urban development occurred in San
Luis Obispo and Santa Barbara Counties during the
mid-1970s. The Santa Marganta-Paso Robles and San
Luis Obispo-Pismo Beach areas and the Santa Maria
and Lompoc Valleys experienced very noticeable ur-
ban growth. Increased aerospace research at Van-
denberg Air Force Base was partially responsible for
the urban expansion in the Santa Maria and Lompoc
areas. Urban growth was severely limited m southern
Santa Barbara County during much of the 1970s, due
in large measure to the desires of the local citizens.
Shortages of sufface and ground water supplies and
land limitations caused certain water agencies to re-
strict new housing construction.
Irrigated Agriculture
Irrigated land in the Central Coast HSA increased
by 50,000 acres between 1972 and 1980. Expansion of
vineyards accounted for 34,000 acres of this growth.
Sprinklers are used for frost protection, irrigation.
and high-temperature control, where needed. Or-
chards declined by 10,000 acres and were mostly re-
placed by vineyards. Irrigated gram increased by
5.000 acres; alfalfa, by 13,000 acres; and vegetables,
by 50,000 acres. Pasture declined by 6,000 acres, and
field crops declined by 4.000 acres.
San Luis Obispo and Santa Barbara Counties
Irrigated area has expanded in San Luis Obispo
and Santa Barbara Counties. Much of the pasture has
been converted to alfalfa. The area is supporting
more irrigated small grains and truck crops. Field
crop acreage in Santa Barbara County has been re-
placed by higher cash value truck crops, and citrus
crops, or vineyards. Much of the truck crop acreage
in Santa Barbara County is in nursery crops. Drip
irrigation and low-pressure sprinklers have enabled
farmers to plant citrus and avocado trees on steep
lands. Large increases in vineyards have been the
most recent noticeable change, along with more cit-
rus fruit (mostly lemons) and avocados.
Urban encroachment has forced agriculture to
move into marginal lands. Multiple cropping (more
than one crop on the same parcel of land during the
year) has become more prevalent in the Santa Maria
and Lompoc Valleys.
The increased use of sprinkler and drip systems for
irrigation in the southern part of the Central Coast
TABLE 23
NET WATER USE AND WATER SUPPLY
CENTRAL COAST HYDROLOGIC STUDY AREA— 1980
(In 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urban
188
902
7
2
1.099
Local surface water
Major local imports
Ground water
39
Irrigated agriculture
768
Energy production
Central Valley Project
Otfier federal projects
State Water Project
Waste water reclamation
54
Wildlife and recreation
9
Conveyance losses
Use of dependable water supply
Reserve supply
TOTAL DEVELOPED WATER ,
870
TOTAL
17
887
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use Met by
Ground Water Overdraft
Urban Shortage
1.099
870
224
5
97
AVERAGE ANNUAL PRECIPITATION - 12,090.000 acre-feet
AVERAGE ANNUAL RUNOFF - 2.450.000 acre feet
IRRIGATED LAND -459.000 acres
POPULATION - 1,005,000
J
IRRIGATED LAND
URBAN LAND
Santa Barboro
Figure 30.
CENTRAL COAST HYDROLOGIC STUDY AREA
98
HSA represents attempts by farmers to increase on-
farm efficiency and reduce water demand.
Salinas Valley
Nearly 20,000 acres of grapes have been planted in
the Salinas Valley, where about half the plantings
replace other irrigated crops and half occurred on
new lands. Total truck crop planting in the Salinas
Valley increased by 35,000 acres. This reflects an in-
crease in multiple cropping, as well as an increase in
irrigated lands. Broccoli, cauliflower, and lettuce
were among the crops that gained. Sugar beet plant-
ing has decreased, and it will drop even more with
the closing of the processing plant near Salinas.
San Benito County
Irrigated crop areas have increased by just over
10,000 acres, almost entirely in row crops. Among
truck crops, tomatoes, broccoli, and onions showed
substantial increases. Sugar beets was the field crop
that increased the most, but acreages will probably
decrease m the future with the closing of the proc-
essing plant near Salinas. Vineyards remained con-
stant, and deciduous orchards continued to
decrease.
Santa Clara Valley
About half the irrigated land in the Santa Clara
Valley area is planted in truck crops, including
cucumbers, lettuce, peppers, tomatoes, and other
vegetables. Orchard crops include apricots, prunes,
and walnuts. Ground water provides the primary irri-
gation water source. Irrigation efficiency is high,
about 80 percent, with much of the irrigation done
with sprinklers.
Santa Cruz County
Irrigated acreage did not exhibit much change. De-
ciduous orchards and field crops declined, but this
was compensated for by an increase in vegetable
crops.
99
AVERAGE ANNUAL PRECIPITATION - 4,440,000 acre-feet
AVERAGE ANNUAL RUNOFF - 580.000 acre-feet
IRRIGATED LAND - 118,000 acres
POPULATION - 7,927,000
i
Legend
IRRIGATED LAND
URBAN LAND
MILES
Figure 31.
LOS ANGELES HYDROLOGIC STUDY AREA
100
1980
LOS ANGELES HYDROLOGIC STUDY AREA
Population
The Los Angeles HSA contains the Los Angeles-
Long Beach standard nnetropolitan statistical area,
the largest such area in California, and in the nation,
both in ternns of area and population.
The Los Angeles HSA has a strong economic base,
with aerospace and service industries the dominant
industrial activities. The area contains 40 percent of
the State's aerospace industries, receives 70 percent
of its foreign travelers, and houses Universal Studios,
one of the ten leading visitor attractions in the United
States. In recent years. 58 percent of the residential
construction in this HSA was multiple-family units.
Irrigated Agriculture
Overall, the Los Angeles HSA shows a net loss of
2,000 acres of irrigated land since 1972 due to urban
encroachment. In addition, double-cropped area de-
clined by 3,000 acres.
Most of the irrigated land in this HSA is located in
Ventura County, where both urban areas and agricul-
tural irrigated acreage are expanding. Many farmers
are planting avocado and citrus trees in foothills that
were previously not irrigated. Other farmers are prac-
ticing more double-cropping, and some are even tri-
ple-cropping. Deciduous fruits and nuts and alfalfa
are declining.
Higher energy and water costs, ground water qual-
ity problems, and possible water supply shortages
are forcing farmers to improve their irrigation effici-
encies. The use of sprinkler, drip, and low-flow sprin-
klers for seed germination and normal irrigation; the
leveling of land to reduce irrigation runoff: and closer
control of amounts of water applied are all examples
of improved irrigation practices occurring in the
area. New plantings of citrus and avocado trees are
being irrigated with drip emitters and low-flow sprin-
klers, and older orchards are being converted to
these newer systems.
Ground water overdraft in Ventura County has
continued at about 70.000 acre-feet per year since
1970. This has caused identification of the Ventura
County Ground Water Basin as subject to critical
conditions of overdraft.
The dairy industry in the Chino-Ontario area of San
Bernardino County has started to relocate into the
San Jacinto Valley of Riverside County because of
urban encroachment and environmental controls.
TABLE 24
NET WATER USE AND WATER SUPPLY
LOS ANGELES HYDROLOGIC STUDY AREA— 1980
(In 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urban
Irrigated agriculture
Energy production....
Wildlife and recreation..
Conveyance losses
TOTAL .
1.534
276
7
8
81
1.906
Local surface water
Major local imports
Ground water
Central Valley Project
Other federal projects
State Water Project
Waste water reclamation
Use of dependable water supply..
Reserve supply
TOTAL DEVELOPED WATER
29
752
483
20
481
59
1.824
164
1.988
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use Met by
Ground Water Overdraft
Urbar) Shortage
1.906
1.824
82
—
101
DETAILED 1980 HYDROLOGIC BALANCES
The purpose of the following four tabulations is to provide a detailed analysis
of the sources of water used (applied and net) in this HSA and to describe what
happens to the water in the process of its use. The tabulations show the type
of infornnation displayed schematically for the entire State in Figure 27. Applied
water totals in these tabulations do not necessarily agree with totals in Table
16 because such items as artificial recharge are counted as applied water to
show in more detail the complex interrelationship between supply and use.
DETAILED 1980 HYDROLOGIC BALANCES— LOS ANGELES HSA
(in 1,000s of acre-feet)
SOURCES OF APPLIED WATER
Surface Water
Local
29
Federal
20
APPLIED WATER DISBURSEMENT
Imports: Los Angeles Aqueduct
Mono Basin
Owens Valley
Colorado River
SWF
Waste Water Reclamation
_ _ 98
369
242
443
_M
Subtotal 1.260
Ground Water
Prime Supply:
Natural Recharge
Artificial Recharge of Local Surface Supplies
Artificial Recharge:
Planned Reclamation
Imported Surface Supplies _
Sea-water Intrusion Barrier
Deep Percolation from:
Urban Use
Agricultural Use
Incidental Reclamation
Withdrawal from Ground Water Storage
Subtotal „ _
TOTAL .
263
220
22
150
43
103
72
17
82
972
2.232
Urban Use
ETAW _ „. 472
Incidental Reclamation _ _ 17
Planned Reclamation ..._ 59
Flows to Salt Sinks _._ _ 1.001
Deep Percolation _ __ 103
Subtotal __ 1.652
Agricultural Use
ETAW „
Flows to Salt Sinks
Deep Percolation
Subtotal _ _.
Other Use
Wildlife:
ETAW
Rows to Salt Sinks .
Recreation
Energy Production:
ETAW _.
Rows to Salt Sinks .,
Subtotal
Artificial Recfiarge
Reclaimed Water
Imported Surface Supplies..
Sea-water Intrusion Barrier..
Salinity Repulsion
Subtotal
TOTAL
217
59
72
348
4
3
1
5
_2
15
22
150
43
2
217
Z232
102
Los Angeles HSA (Continued)
NET WATER SUPPLY
Local 29
Federal (non-CVP) 20
Mono Basin 100
Owens Valley 382
Colorado River 270
SWP 481
Waste Water Reclamation 59
Ground Water Prime Supply 483
TOTAL DEPENDABLE SUPPLY 1,824
Withdrawal from Ground Water Storage 82
TOTAL NET SUPPLY 1.906
NET WATER USE
Urban Use
ETAW 472
Flows to Salt Sinks 1.001
Planned Reclamation 59
Artificial Recharge for Salinity Repulsion 2
Subtotal 1.534
Agricultural Use
ETAW 217
Flows to Salt Sinks 59
Subtotal 276
Other Use
Wildlife 7
Recreation 1
Energy Production:
ETAW « 5
Flows to Salt Sinks 2
Subtotal 15
Conveyance Loss
Mono Basin 2
Owens Valley 15
Colorado River 28
SWP _38
Subtotal 82
TOTAL 1,906
103
AVERAGE ANNUAL PRECIPITATION - 2,550.000 acre-feet
Legend
IRRIGATED LAND
AVERAGE ANNUAL RUNOFF - 310.000 acre-feet
URBAN LAND
IRRIGATED LAND - 147.000 acres
POPULATION - 2,974,000
O 10 20 30
I I
MILES
Figure 32.
SANTA ANA HYDROLOGIC STUDY AREA
104
1980
SANTA ANA HYDROLOGIC STUDY AREA
Population
The Santa Ana HSA incorporates portions of Or-
ange, Riverside, and San Bernardino Counties. Popu-
lation gams in Orange County result from suburban
development due to rapid employment growth of the
Los Angeles metropolitan area. Aerospace, electron-
ics, and service (tourism) industries provide the eco-
nomic base. Two of the ten leading visitor attractions
in the United States — Disneyland and Knott's Berry
Farm — are located in Orange County.
As a result of rapid urbanization, and other eco-
nomic forces, the price of the average home has
soared, forcing many people to seek more affordable
housing in Riverside and San Bernardino Counties.
San Bernardino's favorable location for warehousing
and distribution has led to a concentration of many
freight carriers. From 1972 to 1980, migration ac-
counted for approximately 75 percent of the growth
in the Santa Ana HSA.
Irrigated Agriculture
Irrigated agriculture in the Santa Ana HSA de-
clined by 38,000 acres between 1972 and 1980. All
crop categories show a loss, primarily due to urban
expansion, especially in Orange County. Some of the
reduction has been offset through the relocation of
agriculture into hillside areas not previously irrigated.
New plantings of avocado and citrus trees and vine-
yards have occurred on these hillsides, although de-
velopment costs have been high and special
irrigation techniques are needed, such as low-flow
sprinklers and drip systems.
TABLE 25
NET WATER USE AND WATER SUPPLY
SANTA ANA HYDROLOGIC STUDY AREA— 1980
{In 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urban
586
320
9
2
45
962
Local surface water
93
Irrigated agriculture
Major local imports
Ground water
Central Valley Project
290
402
Energy production
Otfier federal projects
State Water Project
138
Wildlife and recreation
Waste water reclamation
29
Conveyance losses
Use of dependable water supply
Reserve supply
TOTAL DEVELOPED WATER
952
TOTAL
203
1,155
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use Met by
Ground Water Overdraft
Urban Shortage
962
952
10
—
105
DETAILED 1980 HYDROLOGIC BALANCES
The purpose of the following four tabulations is to provide a detailed analysis
of the sources of water used (applied and net) in this HSA and to describe what
happens to the water in the process of its use. The tabulations show the type
of information displayed schematically for the entire State in Figure 27. Applied
water totals in these tabulations do not necessarily agree with totals in Table
16 because such items as artificial recharge are counted as applied water to
show in more detail the complex interrelationship between supply and use.
DETAILED 1980 HYDROLOGIC BALANCES— SANTA ANA HSA
{In 1,000s of acre-feet)
SOURCES OF APPLIED WATER
Surface Water
Local 93
Imports; Colorado River 273
SWP 110
Waste Water Reclamation 29
Subtotal 505
Ground Water
Prime Supply:
Natural Recharge 278
Artificial Recharge of Local Surface Supplies 124
Artificial Recharge:
Planned Reclamation 1
Imported Surface Supplies 118
Sea-water Intrusion Barrier 2
Deep Percolation from:
Urban Use 74
Agricultural Use 92
Incidental Reclamation 74
Withdrawal from Ground Water Storage 10
Subtotal _773
TOTAL 1.278
APPLIED WATER DISBURSEMENT
Urban Use
ETAW 170
Incidental Reclamation 74
Planned Reclamation 29
Flows to Salt Sinks 383
Deep Percolation 74
Subtotal 730
Agricultural Use
ETAW 252
Flows to Salt Sinks 92
Deep Percolation 68
Subtotal 412
Other Use
Recreation 2
Energy Production:
ETAW 8
Flows to Salt Sinks 1
Subtotal 11
Artificial Recharge
Reclaimed Water 1
Imported Surface Supplies 118
Sea-water Intrusion Barrier 2
Salinity Repulsion 4
Subtotal 125
TOTAL 1.278
106
Santa Ana HSA (Continued)
NET WATER SUPPLY
Local 93
Colorado River 290
SWP 138
Waste Water Reclamation 29
Ground Water Prime Supply 402
TOTAL DEPENDABLE SUPPLY 952
Withdrawal from Ground Water Storage 10
TOTAL NET SUPPLY 962
NET WATER USE
Urban Use
ETAW 170
Flows to Salt Sinks 383
Planned Reclamation 29
Artificial Recharge for Salinity Repulsion 4
Subtotal 586
Agricultural Use
ETAW 252
Flows to Salt Sinks 68
Subtotal 320
Other Use
Recreation 2
Energy Production:
ETAW 8
Flows to Salt Sinks 1^
Subtotal 11
Conveyance Loss
Colorado River 17
SWP _J8
Subtotal 45
TOTAL 962
107
AVERAGE ANNUAL PRECIPITATION - 3.770,000 acre-feet
AVERAGE ANNUAL RUNOFF - 330,000 acre-feet
IRRIGATED LAND -100,000 acres
POPULATION - 2,068.000
;
SAN CLEMENTE
San Oiego
■mTTTco
20 30
Legend
IRRIGATED LAND
URBAN LAND
Figure 33.
SAN DIEGO HYDROLOGIC STUDY AREA
108
SAN DIEGO HYDROLOGIC STUDY AREA
Population
Growth m the San Diego HSA has been occurring
in the suburbs. Migration has accounted for about
three-fourths of this growth, and about 75 percent of
the new residents came from outside the State. Em-
ployment in the city of San Diego is concentrated in
the aerospace, electronics, government (military),
and service (tourism) industries. The San Diego Zoo
IS the fourth most popular of the ten leading visitor
attractions in the United States. Half the residential
construction in this HSA was multiple-family units.
This was the second highest such proportion in the
State.
Irrigated Agriculture
Irrigated area in the San Diego HSA experienced
a net increase of 12,000 acres between 1972 and 1980,
despite the pressure of urban spread. Avocado, cit-
rus, and grain acreages all increased, with avocado
and citrus together showing a 20,000-acre increase
and irrigated gram, a 6,000-acre increase. Pasture and
truck crop acreages each declined by about 10,000
acres. All other crops remained stable.
Urban growth has been extensive in this area,
while new orchards have been established on rough
and steep hillsides, irrigated with drip systems.
In recent years, irrigation of most of its older citrus
and avocado trees has been converted to drip and
low-flow sprinkler systems because of the high price
of imported water. These systems have also been
used to irrigate some truck and field crops. Furrow
irrigation systems are also still in use, although closer
attention is being given to management.
TABLE 26
NET WATER USE AND WATER SUPPLY
SAN DIEGO HYDROLOGIC STUDY AREA— 1980
(In 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urban
389
198
7
40
634
Local surface water
Major local imports
Ground water
37
Irriaated aarJculture
290
77
Central Vallev Proiect . ...
Other federal projects
State Water Project
Waste water reclamation
221
9
Convevance losses
Use of dependable water supply
634
TOTAL
Reserve supply
TOTAL DEVELOPED WATER
46
680
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use Met by
Ground Water Overdraft
Urban Shortage
634
634
-
—
109
DETAILED 1980 HYDROLOGIC BALANCES
The purpose of the following four tabulations is to provide a detailed analysis
of the sources of water used (applied and net) in this HSA and to describe what
happens to the water in the process of its use. The tabulations show the type
of infornnation displayed schematically for the entire State in Figure 27. Applied
water totals in these tabulations do not necessarily agree with totals in Table
16 because such items as artificial recharge are counted as applied water to
show in more detail the complex interrelationship between supply and use.
DETAILED 1980 HYDROLOGIC BALANCES— SAN DIEGO HSA
(In 1,000s of acre-feet)
SOURCES OF APPLIED WATER
Surface Water
Local 37
Imports: Colorado River 273
SWP 198
Waste Water Reclamation 9
Subtotal 517
Ground Water
Prime Supply 77
Artificial Recharge:
Planned Reclamation 1
Imported Surface Supplies 50
Deep Percolation from:
Agricultural Use 30
Subtotal _!58
TOTAL 675
APPLIED WATER DISBURSEMENT
Urban Use
ETAW 105
Planned Reclamation 9
Flows to Salt Sinks 275
Subtotal 389
Agricultural Use
ETAW 146
Flows to Salt Sinks 52
Deep Percolation ^
Subtotal 228
Other Use
Recreation 2
Wildlife 5
Subtotal 7
Artificial Recfiarge
Reclaimed Water 1
Imported Surface Supplies 50
Subtotal 51
TOTAL 675
NET WATER SUPPLY
Colorado River 290
SWP 221
Waste Water Reclamation 9
Ground Water Natural Recharge 77
TOTAL DEPENDABLE SUPPLY 634
NET WATER USE
Urban Use
ETAW 105
Flows to Salt Sinks 275
Planned Reclamation 9
Subtotal 389
Agricultural Use
ETAW 146
Flows to Salt Sinks 52
Subtotal 198
Other Use
Recreation 2
Wildlife 5
Subtotal ^
Conveyance Loss
Colorado River 17
SWP _23
Subtotal _40
TOTAL 634
110
SACRAMENTO HYDROLOGIC STUDY AREA
Population
Most of the people migrating into the Sacramento
HSA come from the metropolitan areas of Los Ange-
les, San Diego, and San Francisco. For many, their
reasons for relocating include lower home prices,
less congestion, better air quality, and closeness to
rural and mountain areas. El Dorado County, for in-
stance, owes 90 percent of its growth to immigration.
The Sacramento HSA also has an abundant supply of
reasonably priced industrial and commercial proper-
ty which IS attracting new industry and business.
Government employment opportunities are also im-
portant. Currently. 30 percent of the jobs in State
government exist in Sacramento, Placer, and Yolo
Counties.
Irrigated Agriculture
The Sacramento HSA underwent an increase of
354.000 acres of irrigated land between 1972 and
1980. In addition, double-cropping increased by
73,000 acres. Two crops are primarily responsible for
this large change. Irrigated gram (320,000 acres), pri-
marily wheat, replaced dry-farmed gram, primarily
barley. The second crop, rice, increased by 178,000
acres. This was brought about by the increased world
demand, coupled with new varieties that produced
greater yields, which has meant greater dollar returns
per acre (see the sidebar, "The Sacramento Valley
Rice Bonanza" earlier in this chapter). Alfalfa and
pasture declined by 44,000 and 76,000 acres, respec-
tively, while orchard acreage remained stable. Vege-
table production increased by 31.000 acres, mostly in
melons and tomatoes. The double-cropping pattern
practiced m the area is small grams, followed by field
corn (for silage), milo, dry beans, melons, or squash.
Sacramento Valley Floor Area
The water for increased irrigation was supplied by
the Tehama-Colusa Canal, increased use of other sur-
face supplies, and ground water. Irrigated agriculture
in the Sacramento Valley has developed mainly by
the appropriation of gravity-flow water supplies for
large irrigation districts and, to a lesser extent, by
individual diverters who exercise riparian water
rights. Surface water costs in the Sacramento Valley
are very low, generally averaging $5 to $7 per acre-
foot or even less. Approximately 30 percent of the
TABLE 27
NET WATER USE AND WATER SUPPLY
SACRAMENTO HYDROLOGIC STUDY AREA— 1980
(In 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urban
Irrigated agriculture
Energy production....
Wildlife and recreation..
Conveyance losses
TOTAL .
493
6.682
160
129
7.464
Local surface water
Major local imports
Ground water
Central Valley Project
Other federal projects
State Water Project
Waste water reclamation
Use of dependable water supply..
Reserve supply
TOTAL DEVELOPED WATER
2,866
9
1.798
2,422
259
17
7.371
535
7.906
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use Met by
Ground Water Overdraft
Urban Shortage
7.464
7.371
85
8
111
AVERAGE ANNUAL PRECIPITATION - 51,590,000 acre-feet
AVERAGE ANNUAL RUNOFF - 22,390,000 acre-feet
IRRIGATED LAND - 2,084,000 acres
POPULATION - 1.674,000
SISKIYOU
GoosaK
L
Al turns J
^^t
SHASTA
Pjl-
.^*
MODOC
LASSEN
V^
^
Shasta
fLoke
Legend
IRRIGATED LAND
URBAN LAND
COLUSA
'yolo'
JO 30
/— \ Clear
V\ I Woodland \v 4-^jd
'\\u7iire Berryessa -igp^n!-
'\ Wf-^-iSTA^^ ^ ,,.
SAC,
Figure 34.
SACRAMENTO HYDROLOGIC STUDY AREA
water used today is derived from ground water. Esca-
lation of costs for well drilling and energy for pump-
ing has increased the cost of ground water to over
$10 per acre-foot in many areas. Most ground water
is currently applied to orchard lands where on-farm
irrigation efficiencies are high, approaching 70 per-
cent.
Growers in western Yolo County are beginning to
replace dry-farmed gram with irrigated gram and
bean crops, using large wheel-line and center-pivot
sprinkler systems.
Butte County growers are using both drip and
sprinkler systems to grow kiwi fruit. Drip is used prin-
cipally for irrigation, while most sprinkler systems are
employed for frost protection.
In 1980, small grams and corn accounted for about
half the irrigated acreage in the Sacramento HSA
portion of the Sacramento-San Joaquin Delta. Other
important crops, in numbers of acres, are tomatoes,
safflower, sugar beets, and pasture. This part of the
Delta is one of the few areas in the State that grows
Bartlett pears, and, in recent years, the culture of
quality wine grapes has come into prominence.
Precision land leveling, now commonly used, has
greatly aided in maintaining desired water levels in
rice culture. Traditionally, nee farmers have irrigated
rice by turning on the headgate in early May, allow-
ing the water to flow continuously through the rice
paddy and spill into drains at the end of the field.
Applied water of 9 to 10 acre-feet per acre or even
higher were common. It has been demonstrated that
rice can be grown with 6 or fewer acre-feet per acre
of applied water where soils are sufficiently impervi-
ous and the paddies can be leveled accurately
enough to enable close control of water. Rice proba-
bly will always be flood-irrigated, but application
rates should continue to decline as varieties with
shorter growing seasons are developed and some of
the recently developed irrigation practices become
more common.
Mountains and Valleys of the Northeast Area
Agriculture in the Pit River drainage area under-
went some significant changes between 1972 and
1980, with the greatest change taking place within
the most recent years. After a long period of un-
changing agricultural activity, irrigated acreage in-
creased from 48,100 to 53,000 acres. Most of the
increase was due to the planting of alfalfa and grain.
The cropping pattern also changed on the older irri-
gated land. Alfalfa and gram replaced pasture on
some of the deeper, well-drained soils. Sprinkler irri-
gation was used only to a limited extent in 1972, pri-
marily to irrigate some alfalfa and grain; this has in-
creased greatly m recent years. The trend of
conversion from flood to sprinkler irrigation is con-
tinuing. Sprinklers are being used on all areas recent-
ly developed for irrigation using ground water. The
center pivot's labor-saving features are important to
the farmer in this labor-short area. Wheel-line sprin-
kler irrigation systems have also become common.
The Dorris Lake area southeast of Alturas and the
area north of Alturas along State Highway 395 as far
as the shore of Goose Lake produce high yields of
good quality ground water. Most of the wells have
been drilled m known alluvial basins. There is a great
uncertainty involved m drilling wells in volcanic rock.
Success or failure depends entirely on encountering
fractures or interconnected spaces in the rock that
contain a sufficient quantity of water to supply a well
continuously.
Reserve Water Supply
The 535,000 acre-feet of "reserve supply" in this
HSA is principally Central Valley Project yield for
which neither conveyance systems have been com-
pleted nor contracts been signed with water users.
113
DETAILED 1980 HYDROLOGIC BALANCES
The purpose of the following four tabulations is to prov.oe a detailed analysis
of the sources of water used (applied and net) in this HSA and to describe what
happens to the water in the process of its use. The tabulations show the type
of information displayed schematically for the entire State in Figure 27. Applied
water totals in these tabulations do not necessarily agree with totals in Table
16 because such items as artificial recharge are counted as applied water to
show in more detail the complex interrelationship between supply and use.
The net water supply and net water use tabulations are based on information
developed for each subarea of the HSA. Therefore, in some cases, the values
given for return flows sometimes include outflows from one subarea that
become part of the water supply to downstream subareas within the HSA. A
balance is obtained by including these quantities in the value given for local
surface water supply. The sum of these return flows is shown as "Return Flow
to Downstream Area in HSA."
DETAILED 1980 HYDROLOGIC BALANCES— SACRAMENTO HSA
(In 1,000s of acre-feet)
SOURCES OF APPLIED WATER
Surace Water
Local
Imports by Locals
CVP
Other Federal (norvCVP) ...
Waste Water Reclamation .
Z8^
9
1324
259
17
Subtotal - - 5.444
Local Conveyance Loss to Ground Water .
Surface Reuse:
Urban -
Agnculture .._
Wildlife
Subtotal
Ground Water
Prime Supply _
Local Conveyance Loss
Deep Percolation from Agricultural Use....
Withdrawal from Ground Water Storage ..
Subtotal _
TOTAL
-45
77
Z074
10
7.560
1.798
45
467
85
2.395
9.955
APPLIED WATER DISBURSEMENT
Urban Use
ETAW
195
Waste Water Reclamation
Return flow to Delta _
Return flow to Downstream Areas in HSA
Other 1 oss<*s ._ _
17
161
54
66
f^eijs^a — Surface Water
77
Subtotal _ ._
570
Agricultural Use
ETAW _ _
Return Flow to Delta -
Return Flow to Downstream Areas in HSA _
Riparian and Distribution System ET
. 4.921
530
680
551
Reuse — Surface Water _ _
Reuse — Ground Water...
. Z074
467
Subtotal _ — -
. 9.223
Other Use
Wildlife ETAW;
from Applied Water
from Conveyance Loss
Reuse — Surface Watef_.
Recreation _ __
Subtotal -
Total Need for Applied Water-
Reduction in Use Due to Shortage _..
TOTAL .
112
45
10
3
170
9.963
9.955
114
Sacramento HSA (Continued)
NET WATER SUPPLY
Local Surface 2,866
Imports by Locals 9
CVP 2,422
Other Federal (non-CVP) 259
Waste Water Reclamation 17
Ground Water Prime Supply 1,798
TOTAL DEPENDABLE SUPPLY 7^
Withdrawal from Ground Water Storage 85
TOTAL NET SUPPLY 7,456
Spillage to Downstream Areas in HSA (Local Conveyance
Loss) -77
Return Flow to Downstream Areas In HSA -734
Return Flow to Delta -691
TOTAL SUPPLY AVAILABLE FOR DEPLETIONS 5,954
NET WATER USE
Urban Use
ETAW 195
Waste Water Reclamation 17
Return Flow to Downstream Areas in HSA 54
Return Flow to Delta 161
Other Losses 66
Subtotal 493
Agricultural Use
E\mi 4,921
Return Flow to Downstream Areas in HSA 680
Return Flow to Delta 630
Riparian and Distribution System ET 551
Subtotal 6.682
Other Use
Wildlife ETAW:
from Applied Water 112
from Conveyance Losses 45
Recreation 3
Other Conveyance Losses
Spillage to Downstream Areas in HSA 77
Evaporation and ET 52
Subtotal 289
TOTAL NET USE 7^464
Reduction in Use Due to Shortage -8
Spillage and Return Flow to Downstream Areas in HSA -811
Return Flow to Delta -691
TOTAL DEPLETIONS 5^954
115
AVERAGE ANNUAL PRECIPITATION - 22,950 000 acre-feet
Legend
AVERAGE ANNUAL RUNOFF - 7.930,000 acre-feet
IRRIGATED LAND - 2,062.000 acres
POPULATION - 1,014,000
IRRIGATED LAND
URBAN LAND
MiLLi
Figure 35.
SAN JOAQUIN HYDROLOGIC STUDY AREA
116
SAN JOAQUIN HYDROLOGIC STUDY AREA
Population
Population growth in the various parts of the San
Joaquin HSA has either equalled or exceeded sub-
stantially the State's overall growth rate of 15 per-
cent. The city of Stockton, for example, grew 36
percent from 1970 to 1980. The increase is attributa-
ble to reasonably priced land, labor, and housing.
Housing construction remains predominantly single-
family dwellings. Agriculture and government are the
principal employers.
Irrigated Agriculture
Gross value of agricultural production in the San
Joaquin HSA was about S2.9 billion in 1980, nearly
triple the 1972 value, and more than one-fifth of the
State's total. Merced, San Joaquin, and Stanislaus
Counties ranked fourth, fifth, and eighth in gross val-
ue of agricultural production among the counties of
the State in 1980.
A large amount of new irrigated land has been put
into production since 1972: however, the net increase
was only 33,000 acres, because of considerable urban
growth that occurred on formerly irrigated crop land.
The cities of Stockton and Modesto were the most
notable examples of urban encroachment.
Areas of increase in agricultural irrigation are
located principally along the San Joaquin River,
where alkali lands were reclaimed and planted to
field crops, and along the east side of the valley on
hardpan terraces and in rolling foothills. The hardpan
was broken up with special heavy equipment (rip-
pers) and, along with the foothill areas, was planted
to almonds, wine grapes, and, in eastern Madera
County, additional pistachio nut trees. Both the recla-
mation of alkali land and the movement of irrigation
into the eastern foothills continues trends that were
evident in 1972.
In addition to development of new land, changes
took place in the relative proportion of crops on
previously developed land. The largest increases oc-
curred in almonds, wine grapes, small grains, and
cotton. There was a rather large decrease in irrigated
pasture and alfalfa.
The Delta
In the 1950s, asparagus was the major crop in the
Sacramento-San Joaquin Delta, with about 80,000
acres harvested annually. But, with the loss of the
European market to Taiwan and labor problems in
TABLE 28
NET WATER USE AND WATER SUPPLY
SAN JOAQUIN HYDROLOGIC STUDY AREA— 1980
(In 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urban
Irrigated agriculture
Energy production....
Wildlife and recreation..
Conveyance losses
TOTAL .
249
5.892
15
74
111
6,341
Local surface water
Major local imports
Ground water
Central Valley Project
Other federal projects
State Water Project
Waste water reclamation ,
Use of dependable water supply..
Reserve supply
TOTAL DEVELOPED WATER
3,055
972
1,838
65
8
21
5,949
191
6.140
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use Met by
Ground Water Overdraft
Urban Stiortage
6.341
5,949
391
1
117
the early 1960s, asparagus declined until, in 1980, few-
er than 20,000 acres of asparagus were harvested.
Field corn is the predominant crop in the Delta today.
Amador County
In Amador County, small family-size vineyards (10
to 300 acres) are being established. This activity is
centered m the Shenandoah Valley. Currently, the
county has 13 wineries, and more are in the planning
stage. About 1,500 acres are planted to vineyards;
about half are irrigated. An additional 2,000 acres of
land at the 1,000-to-2, 000-foot elevation have avail-
able water and suitable climate and soil characteris-
tics for grapes.
Folsom South Canal Service Area
About 60 percent of the agricultural land in the
Folsom South Canal service area is irrigated. About
25 percent of this irrigated area is planted in pasture;
25 percent, in field crops; 25 percent, in fruit and nuts
and vineyard; 10 percent, in grain; and 15 percent, in
rice, alfalfa, and truck crops. The remainder is dry-
farmed grain or used for dry-land pasture which is
gradually being developed for irrigated agriculture.
Much of the dry-land pasture, however, is expected
to remain in its present use as open grasslands.
Generally speaking, soils of the Folsom South Ca-
nal service area are either older terrace hardpan or
recent alluvial floodplain soils. The hardpan soils,
which occupy most of the area, are limited to grow-
ing shallow-rooted crops such as pasture and grain.
The floodplain soils are relatively deep and suitable
for a wide range of crops, including orchard, vine-
yard, and row crops. Considerable urban encroach-
ment has occurred on lands suitable for agriculture
near Sacramento, Stockton, and Lodi.
Eastern Stanislaus and Merced Counties
In the Montpelier area in eastern Stanislaus and
Merced Counties, between the Merced and Tuol-
umne Rivers, about 10,000 acres were developed for
irrigation between 1972 and 1980, all with ground wa-
ter. The soils in this area are predominantly gently
rolling high terrace or upland soils with hardpan or
substrata that restricts rooting depths. Growers have
altered these into highly productive soils by ripping
them. Almonds are the predominant crop. There are
also large plantings of wine grapes.
The highest field corn yield in the nation often occurs in the Deltc.
118
Water Supply
Surface Water Supply
The amount of surface storage for regulation of
local streannflow has increased significantly in recent
years, as indicated in the following table.
Gross Storage Capacity
(In acre-feet)
Va^r
Dam
Origmal
Construction
Enlargement
Enlargement
Completed
Exchequer
289 000
1.026.000
2.030,000
2.400.000
5.456.000
1967
Don Pedro
Melones
TOTAL
289.000
112.500
690.500
1971
1979
In addition, new dams have been constructed on
the Chowchilla River (Buchanan) and Fresno River
(Hidden) with gross capacities of 150,000 and 90,000
acre-feet, respectively. This additional storage has
increased operational flexibility and provided long-
term carryover storage (as well as seasonal
carryover), thereby firming up water supplies and
increasing production of energy. Operations studies
by the U.S. Army Corps of Engineers indicate that the
Hidden and Buchanan projects each provide a
24,000-acre-foot annual new water supply.
Ground Water Overdraft
Ground water overdraft (currently about 390,000
acre-feet) has developed in the San Joaquin HSA,
principally in the area east of the San Joaquin River
and north of the Chowchilla River outside the bound-
aries of organized water agencies. A smaller over-
drafted area has also developed in an area between
the Tuolumne and Merced Rivers outside the bound-
aries of organized water agencies.
Land use surveys made by the Department of Wa-
ter Resources in Stanislaus, Merced, and Madera
Counties indicate that, between 1958 and 1975, irri-
gated lands on the valley floor increased by 210,000
acres and 80 percent of this increase occurred on
lands in which surface deliveries accounted for only
about 15 percent of the applied water. The remaining
85 percent of applied water was derived from ground
water pumping.
Ground Water Pumping Lifts and Costs
Ground water pumping lifts range from a minimum
of 15 feet near the confluence of the Merced and San
Joaquin Rivers to over 200 feet in the uplands area
east of the city of Madera. The average pumping lift
was 98 feet, based on pumping plant performance
tests by Pacific Gas and Electric Company from 1972
through 1977. Shallow lifts are generally encountered
within areas having adequate surface water supplies.
The greatest lifts are encountered in developed
areas where the surface water supply is inadequate
and where ground water extraction has exceeded
recharge. Examples of such areas are western Ma-
dera County and the uplands in Madera, Merced, and
Stanislaus Counties.
Ground water pumping costs in 1982 ranged from
about 20 to 30 cents per acre-foot per foot of lift in
most of the San Joaquin HSA. Costs per acre-foot
range from an average of about $12, with a 50-foot
lift, to $40 in the eastern Madera County valley floor,
with a lift of about 160 feet.
Reserve Supply
The 191,000 acre-feet of reserve water supply takes
in Central Valley Project supplies for which contracts
have not been signed, including that from New Me-
lones Reservoir (see Chapter V for projected build-
up in use of total CVP supplies) . New Melones Reser-
voir has been the focus of controversy for several
years.
119
DETAILED 1980 HYDROLOGIC BALANCES
The purpose of the following four tabulations is to provide a detailed analysis
of the sources of water used (applied and net) in this HSA and to describe what
happens to the water in the process of its use. The tabulations show the type
of information displayed schematically for the entire State in Figure 27. Applied
water totals in these tabulations do not necessarily agree with totals in Table
16 because such items as artificial recharge are counted as applied water to
show in more detail the complex interrelationship between supply and use.
The net water supply and net water use tabulations are based on information
developed for each subarea of the HSA. Therefore, in some cases, the values
given for return flows sometimes include outflows from one subarea that
become part of the water supply to downstream subareas within the HSA. A
balance is obtained by including these quantities in the value given^ for local
surface water supply. The sum of these return flows is shown as "Return Flow
to Downstream Area in HSA."
DETAILED 1980 HYDROLOGIC BALANCES-
(In 1,000s of acre-feet)
-SAN JOAQUIN HSA
SOURCES OF APPLIED WATER
APPLIED WATER DISBURSEMENT
5^ -see ^V^.V'
loca
CVP
Other Federal (non-CVP) .
SWP
Waste Water Reclamation .
Subtotal
Local Conveyance Loss to Groundwater .
Spillage to Downstream Areas in HSA
Surface Reuse:
Urban
Agricultural
Wildlife
Subtotal
Groundwater
Prime Supply .
Artificial Recharge
Local Conveyance Loss.
Deep Percolation From:
Urter Use
Agncuitural Use
Wildlife
Withdrawal frtjm Ground Water Storage .
Subtotal
TOTAL.
3.065
1.727
55
8
21
4.866
-527
-203
79
506
19
'S.74C
972
76
527
75
1.279
3
391
3.323
a063
Urvar Use
ETAW
Waste Water Reclamation
Return Flow to Downstream Areas in HSA .
Other Losses
Reuse — Surface Wa:er_
Reuse — Ground Water-
Subtotal
cTAyV
Return Flow to Delta .
Return Flow to Downstream Areas in HSA.
Riparian and Distributian System ET
Other Losses
Reuse— Surface Water-
Reuse— Ground Water -
Subtotal
Other Use
Wildlife:
ETAW
Reuse — Surface Water-
Reuse— Ground Water -
Recreation
Energy Production— ETAW .
Subtotal
AfiJfKial Recharge of Ground Water —
Total Need for Applied Water-
Reduction in Use Due to Shortage
TOTAL
139
21
62
27
79
75
403
4.474
382
358
298
177
506
1.279
7.474
64
19
3
10
15
111
76
a064
-1
6t063
120
San Joaquin HSA (Continued)
NET WATER SUPPLY
Local 3,055
CVP 1.838
Other Federal (non-CVP) 55
SWP 8
Waste Water Reclamation 21
Ground Water Prime Supply 972
TOTAL DEPENDABLE SUPPLY 5.949
Withdrawal from Ground Water Storage 391
TOTAL NET SUPPLY 6,340
Spillage to Downstream Areas in HSA -203
Return Flow to Downstream Areas m HSA -420
Return Flow to Delta -382
TOTAL SUPPLY AVAILABLE FOR DEPLETIONS 5.335
NET WATER USE
Urban Use
ETAW 139
Waste Water Reclamation 21
Return Flow and Spillage to Downstream Area in HSA 62
Other Losses 27
Subtotal 249
Agricultural Use
ETAW 4,474
Return Flow and Spillage to Downstream Areas in HSA 561
Return Flow to Delta 382
Riparian and Distribution System ET 298
Other Losses 177
Subtotal 5.892
Other Use
Wildlife 64
Recreation 10
Energy 15
Subtotal 89
Conveyance Losses (CVP) Ill
TOTAL NET USE 0340
Reduction in Use Due to Shortage —1
Spillage and Return Flows to Downstream Areas in HSA -623
Return Flow to Delta -382
TOTAL DEPLETIONS M35
121
AVERAGE ANNUAL PRECIPITATION - 13,960.000 acre-feet
AVERAGE ANNUAL RUNOFF - 3,310.000 acre-feet
IRRIGATED LAND - 3,312,000 acres
POPULATION - 1,178,000
Legend
IRRIGATED LAND
URBAN LAND
MILES
Figure 36.
TULARE LAKE HYDROLOGIC STUDY AREA
122
TULARE LAKE HYDROLOGIC STUDY AREA
Population
Growth in the Tulare Lake HSA between 1972 and
1980 was caused by expansion of existing industries,
diversification of industries, and availability of afford-
able housing. The area's major employers are agricul-
ture and government.
Irrigated Agriculture
Tulare Lake HSA encompasses one of the richest
and most diverse agricultural areas in the world. In
1980, the gross value of agricultural production for
this area was approximately $5 billion, more than
one-third of the State's total for that year and more
than three times its 1972 level of production.
Fresno, Kern, and Tulare Counties ranked first, sec-
ond, and third, respectively, in gross value of agricul-
tural production in California in 1980. Fresno County
led all counties m the nation in 1980 with just over $2
billion. Moreover, 47 of the top 50 crops in the State,
ranked according to value, were produced in Fresno
County in 1980.
This large increase in gross value of farm produc-
tion in the Tulare Lake HSA occurred because of
sharply increased prices for many commodities, an
increase in total irrigated acreage, and a larger pro-
portion of total acreage devoted to production of
higher value crops.
Growth of irrigated land in the Tulare Lake HSA
between 1972 and 1980 amounted to more than
296,000 acres. About 100,000 acres of this land is situ-
ated in western and southern Kern County and is
irrigated solely with water from the California Aque-
duct (State Water Project), About 20,000 of 85,000
acres of newly irrigated land in central Kern County
can be irrigated with either SWP water or ground
water.
Cotton acreage soared during this period, increas-
ing from about 715,000 acres in 1972 to a record high
of nearly 1,300,000 acres in 1978, and then dropped to
about 1,250,000 acres in 1980. Field corn, sugar beets,
milo, pasture, and small grains were among the crops
displaced by the growth in cotton acreage. Some of
these crops also gave way to permanent crop plant-
ings, which increased by over 100,000 acres. Almonds
were the most prominent of these; almond plantings
in Kern County doubled from 33,000 acres to 66,000
acres during this period. Wine grapes and soft fruits,
primarily nectarines and plums, also figured promi-
nently in the increase in permanent crops in eastern
Fresno and Tulare Counties. Citrus acreage declined,
most often being replaced by deciduous trees. Fig
acreage continued to lose out to urban spread
around the city of Fresno. More than 2,000 acres
were displaced during the 1972-1980 period.
Reclamation of alkali lands in the Tulare Lake HSA
continues. These lands adjacent to the basin trough
are generally planted to field crops. Along the east
side of the valley, rolling lands near the foothills are
still being developed for orchard and grapes.
Drip irrigation has become prevalent in young or-
chards and many young vineyards. As energy costs
increase and costs of pumping ground water nse,
irrigation systems are being improved and new types
of systems developed. The most significant improve-
ment in irrigation has been the advent of laser-con-
trolled land leveling. Laser technology, which is now
in general use, allows for more precise land grading
and thus more precise control of water. Most promi-
nent among the newly developed systems is the lin-
ear-move sprinkler system, which provides extremely
uniform and efficient water application.
Water Supply
Surface Water Supply
No new surface water storage projects have been
constructed on local streams since Terminus Dam on
the Kaweah River was completed in 1962. The aggre-
gate active storage capacity on the San Joaquin,
Kings, Kaweah, Tule, and Kern Rivers is only about 60
percent of the aggregate average annual runoff of
these streams. Furthermore, dams along the foothill
line on these streams were built by the U. S. Army
Corps of Engineers with flood control as a primary
purpose; therefore, much of the storage is reserved
to control flood flows. The remaining conservation
storage is used primarily for seasonal regulation of
flows: long-term carryover storage is provided by the
ground water basin.
Before deliveries from the Friant-Kern Canal began
in 1950, local surface water development was the
sole source of surface water deliveries to farmers.
With the advent of the State Water Project (SWP)
and the Central Valley Project (CVP), local streams
accounted for only about 40 percent of the 7.3-mil-
lion-acre-foot dependable water supply to the Tulare
Lake HSA.
123
Ground Water Overdraft
Development of irrigated agriculture in the Tulare
Lake HSA resulted in water demands that out-
stripped local water supplies as early as the 1930s.
Historically, this HSA has led all other California
HSAs in terms of the magnitude of overdraft. Annual
average overdraft from 1958 to 1967 was 1.5 million
acre-feet. In 1967, overdraft amounted to 1.8 million
acre-feet, and in 1972. it had dropped to 1.3 million
acre-feet. By 1980. estimated annual overdraft was
reduced to almost 900.000 acre-feet by supplies from
the CVP and SWP that totaled more than 4.2 million
acre-feet.
The buildup of SWP deliveries in Kern County has
greatly reduced the former severe overdraft that ex-
isted there. Since the critical drought year of 1977.
large quantities of surplus SWP water have been
made available to SWP Kern County water contrac-
tors, as well as to contractors in Kings County. In
Westlands Water District west of Fresno, import of
CVP surface water supplies has reduced (except for
1977) the former 1.0-million-acre-foot annual ground
water pumping to about 100.000 acre-feet, and land
subsidence has virtually ceased.
On the east side of the valley in Fresno, Kings, and
Tulare Counties, ground water overdraft continues
to increase, mostly where lands lying outside the
boundaries of organized water agencies have been
developed to irrigated agriculture without surface
water supplies.
Ground Water Pumping Lifts and Costs
Based upon pumping plant performance tests
made by the Pacific Gas and Electric Company
(PGandE) from 1972 through 1977, ground water
pumping lifts ranged from a minimum of 20 feet in
the Centerville Bottoms area on the Kings River fan
east of Fresno to more than 900 feet in western Kings
County. At present, virtually all ground water extrac-
tions occur with lifts between 40 and 600 feet. The
average pumping lift in the Tulare Lake HSA, weight-
ed according to amount of pumping, is about 175
feet. The greatest pumping lifts are encountered on
the west side of the valley in Fresno and Kings Coun-
ties, on the southern and eastern Kern County valley
floor, and on the southeastern Tulare County valley
floor.
Ground water pumping costs in 1982 ranged from
about 20 to 30 cents per acre-foot per foot of lift in
most of the Tulare Lake HSA. Southern California
Edison Company (SCE) serves nearly all of Tulare
County, about one-third of Kings County, and a small
portion of Kern County. Historically, SCE's energy
rates have been slightly higher than PGandE's.
Other than the extremely shallow and extremely
deep lifts, ground water pumping costs range from
about $15 per acre-foot (for a lift of 50 feet) to about
3100 per acre-foot (for a lift of 500 feet) . The average
cost is about $40 for a lift of 175 feet.
TABLE 29
NET WATER USE AND WATER SUPPLY
TULARE LAKE HYDROLOGIC STUDY AREA— 1980
(In 1,000s of acre-feet)
Net Water Use
Depenaabie Water Supply
Urban
236
7.781
10
38
123
8.188
Local surface water
2.199
Major local imports
Ground water
551
Central Valley Project
2.736
Other federal projects
243
1.536'
WilHIifp ;)nri rprrp;)tinn
Waste water reclamation
67
Conveyance losses
Use of dependable water supply
Reserve supply
TOTAL DEVELOPED WATER
7.332
TOTAL
56
7,388
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use Met Dy
Ground Water Overdraft
Urban Stiortage
8.188
7.332
856
-
' Includes SWP surplus water delivenes.
124
One of the largest increases in crop acreage has been cotton
in the southern San Joaquin Valley.
125
DETAILED 1980 HYDROLOGIC BALANCES
The purpose of the following four tabulations is to provide a detailed analysis
of the sources of water used (applied and net) in this HSA and to describe what
happens to the water in the process of its use. The tabulations show the type
of information displayed schematically for the entire State in Figure 27. Applied
water totals in these tabulations do not necessarily agree with totals in Table
16 because such items as artificial recharge are counted as applied water to
show in more detail the complex interrelationship between supply and use.
DETAILED 1980 HYDROLOGIC BALANCES— TULARE LAKE HSA
(In 1,000s of acre-feet)
SOURCES OF APPLIED WATER
Surface Waie;
Local Reuse of Return Flows
Other Federal (norvCVP)
SWP
Waste Water Reclamation -
Subtotal _
Ground Water
Pnme Supply
Artificial Recharge
Deep Percolation from:
Urban Use
Agricultural Use
Wildlife _
Incidental Reclamation
Withdrawal from Ground Water Storage
Subtotal
APPLIED WATER DISBURSEMENT
Z199
82
Z6«
243
1.506
67
6.740
551
409
148
3.561
14
41
856
5.580
12.320
ETAW..
Reclamation
-eclamation
Flows to Salt Sinks
Reuse — Ground Water..
Subtotal .._
Agricultural Use
ETAW
Reuse — Surface Water .
Reuse — Ground Water-
Flows to Salt Sinks —
Loss to Moisture-Deficient Soils
Evaporation from Local Conveyances
Evaporation of Return Flows _._
Evapotranspiration from Riparian Vegetation .
Subtotal
Other Use
Wildlife:
ETAW.._
Reuse — Ground Water..
Recreation..
Energy Production:
ETAW
Flows to Salt Sinks ..
Subtotal
Artificial Recharge .
TOTAL
151
41
67
10
8
148
425
7.326
82
3561
276
74
64
10
31
11.424
31
14
7
3
7
62
409
12.320
126
Tulare Lake HSA (Continued)
NET WATER SUPPLY
Local 2,199
CVP 2.736
Other Federal (non-CVP) 243
SWP 1,536
Waste Water Reclamation 67
Ground Water Prime Supply 551
TOTAL DEPENDABLE SUPPLY 7,332
Withdrawal from Ground Water Storage 856
TOTAL NET SUPPLY 8,188
NET WATER USE
Urban Use
ETAW 151
Planned Reclamation 67
Evaporation 10
Flows to Salt Sinks 8
Subtotal 236
Agricultural Use
ETAW 7,326
Flows to Salt Sinks 276
Evaporation from Local Conveyances 64
Loss to Moisture-Deficienl Soils 74
Evaporation of Return Flows 10
Evapotranspiration from Riparian Vegetation 31
Subtotal 7,781
Other Use
Recreation 7
Wildlife 31
Energy Production:
ETAW 3
Flows to Salt Sinks 7
Subtotal 48
Conveyance Losses
CVP 93
SWP _J0
Subtotal _123
TOTAL 8.188
127
ORE
AVERAGE ANNUAL PRECIPITATION - 6.960.000 acre-feet
AVERAGE ANNUAL RUNOFF - 1. 840.000 acre-feet
IRRIGATED LAND - 148,000 acres
POPULATION - 61.000
Legend
IRRIGATED LAND
URBAN LAND
C <0 K 3C
fu
rC£='
^t>on
\
Figure 37.
NORTH LAHONTAN HYDROLOGIC STUDY AREA
128
1980
NORTH LAHONTAN HYDROLOGIC STUDY AREA
Population
The population in the North Lahontan HSA, with
the exception of the Lake Tahoe area, is characteris-
tically sparse and widely scattered, and urban com-
munities are relatively small. The largest, South Lake
Tahoe, has a population of 21,000.
Between 1972 and 1980, this area experienced both
the lowest numerical population increase and the
highest rate of growth in California. The area has the
highest ratio of single-to-multiple residences in the
State, 84 percent single-family units and 16 percent
multi-family units. Agriculture is the major economic
activity in the North Lahontan HSA, and the raising
of livestock predominates. Recreation and tourism
are important economic activities in the Lake Tahoe
area.
Irrigated Agriculture
Total irrigated acreage in the North Lahontan HSA
has changed very little since 1972, but some notable
changes have taken place in crop patterns, with irri-
gated grain and alfalfa replacing pasture land, princi-
pally in Surprise Valley. Major increases in the use of
sprinkler irrigation for alfalfa have occurred there.
Water formerly used to produce meadow hay is now
more efficiently spread by wheel-line or center-pivot
sprinkler systems to grow high-quality, high-dollar-
return alfalfa.
Little change has taken place in total irrigated acre-
age south of Lake Tahoe. Irrigated pasture, 37,500
acres, and alfalfa, 3,600 acres, were the principal
crops in this area in 1980. The limited amount of de-
veloped dependable water supplies has restricted
the expansion of irrigated agriculture in this area.
Topaz Lake near Coleville and Bridgeport Reservoir
at Bridgeport are used largely to develop and regu-
late irrigation water supply.
TABLE 30
NET WATER USE AND WATER SUPPLY
NORTH LAHONTAN HYDROLOGIC STUDY AREA— 1980
(!n 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urban
23
387
11
421
Local surface water
312
Irrigated agriculture
Major local imports
Ground water
11
B8
Energy production
Central Valley Project
Otfier federal projects
Stale Water Project
Waste water reclamation
Use of dependable water supply
Reserve supply
TOTAL DEVELOPED WATER
Wildlife and recreation
5
Conveyance losses
416
TOTAL
17
433
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use Met by
Ground Water Overdraft
Urban Shortage
421
416
5
—
129
Figure 38.
SOUTH LAHONTAN HYDROLOGIC STUDY AREA
\
.\
UONO
AVERAGE ANNUAL PRECIPITATION - 11.420.000 acre-feet
AVERAGE ANNUAL RUNOFF - 1,330,000 acre-feet
IRRIGATED LAND - 78.000 acres
POPULATION - 303,000
8B«^,
\.
\
^v-*-
* A
♦ ifxJeDefKjence
^
Legend
IRRIGATED LAND
URBAN LAND
:o 50
I 4 ,
■^
\
\
\
rNYO
SAN BERNARDINO
\
\
k
\
k
\
\
k
\
<e
%
W"^^^
f^LOS ANGELES
SOUTH LAHONTAN HYDROLOGIC STUDY AREA
Population
Government employment in the South Lahontan
HSA has been growing m recent years because of
increased activity at Edwards Air Force Base, the
U.S. Naval Weapons Center, and the new federal
prison at Boron. Mining activity has also increased in
Kern County.
Irrigated Agriculture
Irrigation in the South Lahontan HSA has remained
somewhat stable, with irrigated area and length of
irrigation period increasing in wet years and decreas-
ing in dry years.
Irrigation in the Mono-Owens area is regulated by
the amount of water the city of Los Angeles releases
locally.
Farmers in Benton Valley, northeast of the town of
Bishop, have begun using center-pivot sprinklers for
their alfalfa. Native pasture land irrigation continues
with the wild flooding technique. In the areas of In-
dian Wells, Fremont, and Antelope Valley, irrigation
of alfalfa continues with hand-move sprinkler sys-
tems, although center-pivot systems are also begin-
ning to be used in Antelope Valley.
Agricultural production in Antelope Valley is likely
to decline in the future because of falling ground
water levels. Increasing prices for fossil fuel and elec-
tricity for pumping and greater competition with
new urban developments for existing water supplies
have caused some farmers to give more attention to
improving irrigation efficiency in order to continue
farming profitably.
TABLE 31
NET WATER USE AND WATER SUPPLY
SOUTH LAHONTAN HYDROLOGIC STUDY AREA— 1980
(In 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urban
60
338
2
12
7
419
Local surface water
44
Major local imports
Ground water
178
Fnprav nrnriurtinn
Central Valley Project
Other federal projects
State Water Proiect
85
Wildlife and rprreation
Waste water reclamation
9
Use of dependable water supply
Reserve supply
TOTAL DEVELOPED WATER
316
TOTAL
33
349
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use Met by
Ground Water Overdraft
Urban Stiortage
419
316
103
-
131
AVERAGE ANNUAL PRECIPITATION- 5.690.000 acre-feet
AVERAGE ANNUAL RUNOFF- 180,000 acre-feet
IRRIGATED LAND ~ 604.000 acres
POPULATION - 320,000
Legend
IRRIGATED LAND
J
URBAN LAND
Figure 39.
COLORADO RIVER HYDROLOGIC STUDY AREA
132
COLORADO RIVER HYDROLOGIC STUDY AREA
Population
Most of the population in the Colorado River HSA
lives in the Coachella and Imperial Valleys. The major
source of employment continues to be agriculture in
the Imperial Valley. The city of Palm Springs in the
upper Coachella Valley also provides substantial em-
ployment through the services and tourism sectors.
Imperial Valley has the second largest potential for
geothermal power generation of any area in the na-
tion. Development of this resource essentially began
in 1980.
Irrigated Agriculture
Since 1972, irrigated acreage has increased slightly
in Imperial, Palo Verde, and Chuckwalla Valleys. In
Palo Verde Valley, irrigation has expanded on the
mesa area with new plantings of alfalfa, cotton, jojo-
ba, and wheat. These crops have been irrigated by
sprinklers. The amount of double-cropping has var-
ied from year to year. Irrigated land in Coachella
Valley has declined because of urban encroachment.
A switch from furrow to drip irrigation systems in
Coachella Valley for all varieties of grapes has im-
proved the irrigation efficiency of this crop. Approxi-
mately 50 percent of the 10,000 acres of grapes in the
area are irrigated with drip systems.
Water Conservation in Imperial Valley
Recent legal problems regarding disposal of agri-
cultural drain water to the Salton Sea have resulted
in increased efforts to more efficiently manage irriga-
tion water. Steps being taken by the Imperial Valley
Irrigation District to improve irrigation and convey-
ance efficiencies include lining the major lateral ca-
nals in the valley with concrete to reduce seepage
losses, installing pumps next to the main unlined ca-
nals to pump seepage water back into the canal, and
exaf'ting assessments to penalize farms that produce
excess irrigation runoff. A program designed to as-
sist farmers in lining their own canals and ditches is
being subsidized by the district.
A recent study by the Department of Water Re-
sources, reported in Investigation Under California
Water Code Section 275 of Use of Water by Imperial
Irrigation District, identified opportunities and poten-
tial means for water savings. This study is discussed
in Chapter V. The U.S. Bureau of Reclamation, with
the cooperation of this Department and other agen-
cies, is currently conducting an intensive study of the
total water management system to further aid the
District.
TABLE 32
NET WATER USE AND WATER SUPPLY
COLORADO RIVER HYDROLOGIC STUDY AREA— 1980
(In 1,000s of acre-feet)
Net Water Use
Dependable Water Supply
Urbsn
102
3,434
3
20
543
4,102
Local surface water
4
tvlajor local imports
Ground water
68
Central Valley Project
Other federal projects
3,970
State Water Project
30
Wildlife and recreation
Waste water reclamation
Use of dependable water supply
Reserve supply
TOTAL DEVELOPED WATER
3
Conveyance losses
4,075
TOTAL
4
4,079
WATER BALANCE
Net Water Use
Use of Dependable
Water Supply
Use /i4et by
Ground Water Overdraft
Urban Sfiortage
4,102
4,075
71
—
133
Lining ditches and canals is a major element in the continuing
effort by the Imperial Irrigation District to reduce waste of
water.
134
CHAPTER IV
FUTURE WATER USE— 1980 TO 2010
This chapter basically is concerned with the devel-
opment of estimates of future uses of water in Cali-
fornia to 2010. Trends in population growth,
market-place competition for agricultural produce,
patterns in land use. water costs and prices, the im-
pact of water conservation — these are the major fac-
tors having influence on future use of water in the
State. These and other significant factors are dis-
cussed in this chapter. The projections include the
following key findings.
• Total net water use is projected to increase about
10 percent over the next 30 years, compared to a
9-percent increase over the previous 8 years.
• The increase in urban net water use will exceed the
increase in agricultural net water use.
• Population will continue to increase but at a slower
rate.
• Statewide, irrigated cropland will continue to ex-
pand, although at a slower rate. Irrigated acreage
is expected to increase significantly in the two ma-
jor agricultural areas, the Central Valley and the
Imperial Valley. The percentage increase in pro-
jected total State acreage between 1980 and 2010
is the same as the percentage increase that oc-
curred between 1972 and 1980.
• Water conservation will significantly reduce the
unit amount of water applied for both urban and
agricultural purposes.
• The impact of water conservation on net water use
will vary greatly, depending on the hydrologic
characteristics of each area that influence the
amount of reuse of excess applied water.
These and other projections reported in this chap-
ter are based upon a series of key assumptions re-
garding water supply availability and costs. These
assumptions, which are summarized in the next sec-
tion of this chapter, were selected to represent the
future circumstances and trends that seemed most
probable at the time the studies were made. A basic
premise was that, for any anticipated increase in net
water use, an affordable water supply must be identi-
' For agriculture, "affordable supply of water" means that the cost of water
to farmers does not exceed their ability to pay it.
fied. This premise was particularly significant to the
studies of future agricultural water use.'
The projection process consisted of several
phases. Projections of agricultural water use re-
quired estimates of future irrigated crop acreages,
irrigation efficiencies, and other water conservation-
related considerations. Projections of urban water
use required estimates of future population levels,
including geographical distribution, and per capita
applied water, including probable impacts of water
conservation. In addition, estimates were made of
future water use by wildlife management areas, by
public parks (other than those included in the urban
use estimate), for power plant cooling, and for en-
hanced oil recovery.
Computation of net water use required estimates
of three elements: evapotranspiration of applied wa-
ter, irrecoverable losses connected with water sup-
ply delivery, and outflow from the area of analysis.
Estimated savings in water supply due to water con-
servation were based primarily on the reduction of
return flow to the ocean, to saline ground water, and
to other salt sinks.
Results of the Department's analyses of water use
and water supply are summarized in this report by
Hydrologic Study Areas (HSAs) for the entire State.
The actual studies, however, were conducted by
smaller analysis areas termed Planning Subareas
(PSAs) and Detailed Analysis Units (DAUs). Plan-
ning Subareas are made up of Detailed Analysis
Units, just as Hydrologic Study Areas are made up of
Planning Subareas. The boundaries of all three areas
are determined principally by hydrologic features,
specifically the boundaries of stream drainage basins
and ground water basins. However, except in the
case of Hydrologic Study Areas, boundaries for large
valley floor areas are commonly delineated to in-
clude the service areas of one or more water agen-
cies, such as irrigation districts. In the major
agricultural areas, a DAU typically covers 100,000 to
300,000 acres.
One of the purposes of periodically updating the
California Water Plan is to identify water supply
shortages and other water management problems.
135
Northeastern California produces premium quality alfalfa hoy.
136
Fundamental to the process is the examination of the
current relationship between net water use and wa-
ter supply (including the ways in which both may
affect future water management needs), and the es-
timation of future net water use-water supply rela-
tionships. From these, future study needs are
determined and the probable impacts of alternative
water management decisions can be inferred. Future
water use projections are presented by type of use
in this chapter, while the relationship of water supply
to those projections is addressed in Chapter V.
Assumptions of Water Supply
Availability and Prices
To develop the projections of water use described
in this chapter, certain assumptions were made re-
garding the amount — and, in the case of agriculture,
the price — of the supplemental water supplies that
would be available during the period of analysis,
1980-2010. These assumptions are summarized here,
and some of them are discussed more fully in Chap-
ter V. They were based on what were foreseen, at the
time these studies were begun, as the most likely
conditions to exist between 1980 and 2010.
Key Assumptions
. New Surface Water Facilities Will Be Devel-
oped As Scheduled. Preparation of this report
began in 1979. The initial assumption was that the
proposed SWP facilities (shown on Plate 1), as
subsequently embodied in Senate Bill 200 (enact-
ed by the Legislature in 1980), would be authorized
and built as scheduled. In the June 1982 elections,
however, the vote on Proposition 9 rejected SB
200. Accordingly, only those projects and pro-
grams not affected by Prop. 9 were included in
projecting dependable water supplies for the
SWP.2
Federal project supplies assumed to be available
during the analysis period were: New Melones
Reservoir (CVP), San Felipe Division (CVP), and
the Warm Springs Project (Corps of Engineers).
Central Valley Project facilities that are not defi-
nitely scheduled but that could (if authorized and
funded) become available before 2010 to meet
supplemental water needs include Auburn Reser-
voir, the Mid-Valley Canal, and enlarged Shasta
Lake. In addition, local agencies might complete
' An analysis was made to determine the impact of not developing the yield
of SB 200 or equivalent facilities on schedule. The analysis indicated
that most of the shortages in future deliveries to the SWP agricultural
service areas in the San Joaquin Valley could be made up by increased
ground water overdraft. However, no specific alternative supplies were
identified to compensate for the potential shortages that would occur
in the SWP urban service areas of Southern California.
' Present rights of the Indians are 55.000 acre-feet per year. An additional
82.000 acre-feet has been recommended by the special master, but this
amount has not yet been adopted by the Supreme Court. For this
report, it was assumed that the Indian tribes will not be granted the
additional amount.
several other water supply projects by 2010. These
include the South Fork American River Project, the
Cosumnes River Water and Power Project, and
the North Fork Stanislaus River Project. Water sup-
plies from these projects were not included in de-
veloping projections. If available, they would
reduce identified shortages or ground water over-
draft, depending on the particular area served.
• A vailability of Colorado River Supplies Will Be
Reduced. The Central Arizona Project will be
completed on schedule, reducing California's firm
right to Colorado River water to 4.4 million acre-
feet annually by 1990. Of this amount, 55,000 acre-
feet will satisfy water rights granted to the Indian
tribes along the Colorado River,^ and 3,000 acre-
feet will satisfy present perfected rights of other
local users.
. Diversion of Mono Lake Inflow Will Continue
at Present Levels. The issue over preservation
of Mono Lake, which involves possible reductions
of existing water rights of the city of Los Angeles,
will remain unresolved, and full diversions from the
basin will continue.
• Instream Flow Requirements Will Remain Un-
changed. No major change in instream require-
ments will occur for streams in which essentially all
water is already appropriated (true of most of the
Central Valley and Southern California). Further-
more, all existing instream requirements for wild
and scenic river systems, flow maintenance agree-
ments, water rights decisions, and basin water
quality control plans not mentioned elsewhere in
these assumptions will be unchanged. Relicensing
of many hydropower plants will increase down-
stream release requirements, but these changes
will not significantly affect water supplies for off-
stream uses, which, in most cases, are diverted
farther downstream. The Trinity River fish flow re-
lease has been increased to 287,000 acre-feet per
year and may later be increased to 340,000 acre-
feet per year, as ordered in January 1981 by Secre-
tary of the Interior Cecil Andrus.
• Useof Reclaimed Water Will Increase. Use of
reclaimed water will be increased to the maximum
extent feasible. Projected reclamation will be
based on studies of local projects judged to have
potential for implementation during the period of
analysis. Limitations on use are based on public
health standards that either exist or are assumed to
exist at the time the project is added.
• Ground Water Use Will Remain Largely Unre-
stricted. Current trends in ground water use will
not be significantly altered by changes m water
rights laws. Ground water pumping will be essen-
tially unrestricted, except for adjudicated basins
and as reduced by availability of alternative sup-
plies, economic constraints, and existing local
management practices.
137
Electrical Rates for Ground Water Pumping
Will Increase. Electrical energy costs for
ground water pumping were assumed to increase
2 percent per year in real terms: that is. m addition
to the increase due to inflation.
Ground Water Supplies Will Be Adequate.
Additional ground water supplies will be obtained
m the San Joaquin Valley through extraction of
ground water in storage (overdrafting). Outside
the San Joaquin Valley, new or greatly expanded
ground water development is occurring in several
areas of the State, especially in Northern Califor-
nia. Presently available information is insufficient
to determine the potential for long-term sustained
pumping from these basins. For this report, availa-
bility and cost of water m these areas were as-
sumed to place no limits on the projections.
» Surface Water Price Increases Will Vary
Widely. The price of water provided through
currently authorized facilities by the U. S. Bureau
of Reclamation will be increased as present con-
tracts are renewed in the 1990s. State Water
Project prices reflect the increase in energy costs
with the expiration of initial contracts m 1983. The
relative price of presently developed local surface
water supplies will not change appreciably. The
following examples of the approximate price of
water per acre-foot (unescalated) from the State
and federal systems do not include the cost of
local distribution and treatment.
Further discussion of the effect of water prices on
farm operations is presented in the sidebar. "Poten-
tial Impacts of Future Water Prices on Irrigated
Agriculture."
1980
rGCl6r3 1 (currently authorized facilities)
Sacramento Valley S3.50
San Joaquin Valley (east side of the valley and Delta-Mendota Canal) 3.50
San Joaquin Valley (San Luis Service Area) 10.00
State
Soutfi Bay Aqueduct 44.00
San Joaquin Valley (Kern County Water Agency) 29,00
Southern California (The Metropolitan Water District of Southern California) 123.00
1990
$3.50
3.50
10.00
120.00
80.00
275,00
2000
S9.00
12.00
17.00
120.00
80,00
275,00
20W
S12,00
16.00
24.00
120.00
80.00
245.00
Agricultural Water Use
California's agricultural producers not only com-
pete actively in national and foreign markets but also
with one another within the State. Moreover, they
are in competition with importers who bring into Cal-
ifornia substantial quantities of food products from
other regions of the United States and from foreign
nations. An affordable supply of water for irrigated
agriculture has allowed the State's producers to
maintain a favorable competitive position. An identi-
fied source of affordable water was considered by
the Department of Water Resources to be a prereq-
uisite for projecting any additional development of
irrigated land.
Projections of future net water use by irrigated
agriculture are based on projections of crops. Cali-
fornia was growing at least 200 commercial crops on
9.5 million acres of irrigated land in 1980.
Steps in the process of estimating future net water
use by irrigated agriculture by decade to 2010 in-
clude:
• Determination of present crop acreages (see
Chapter III).
• Determination of sources of affordable water sup-
plies.
• Projection of crop acreages.
• Selection of unit evapotranspiration of applied wa-
ter (ETAW) for each crop for each area.
• Estimation of increased irrigation efficiencies.
• Calculations of agricultural applied water and
ETAW.
• Calculation of net water use, considering water
reuse, total ETAW, distribution system irrecovera-
ble losses, and outflow (see Chapter III for discus-
sion of net water use).
The process employed to project crop acreages,
depicted on Figure 40, involved analysis of potential
markets, costs of water and other production factors,
available land and water supplies, and outputs of
several computer models. An economic model was
employed to evaluate the impact of several factors
on agriculture in the Central Valley, another model
was used to analyze factors affecting feed and for-
age production, and other models were used to ana-
lyze markets and transportation costs. Information
was obtained on historical specialization in specific
crops: regional crop growing preferences: typical
138
crop rotation patterns: potential market outlook by
crop; regional marketing structures; and acreage lim-
its based on soil, water supply, and climate con-
straints. Information from all tfiese sources and
findings of various studies were integrated witfi in-
formation on current land use and land and water
availability to provide crop projections for the entire
State.
POTENTIAL IMPACTS OF FUTURE WATER PRICES
ON IRRIGATED AGRICULTURE
Large variation exists in water prices around the State.
Currently, districts that use CVP water charge farmers
between $5 and $25 per acre-foot, while those using SV/P
water charge from about $ 1 0 to more than $40 per acre-foot.
Variations in pumping lifts cause ground water costs to range
from about $10 to more than $100 per acre-foot. Prices of
water diverted from streams and local storage projects are
generally lower.
Although significant increases are expected in some cases
at some time in the future, changes will not be uniform, and
the impact on agriculture will be variable. California's agricul-
ture has a large share of the market for many of its products
and the potential for a wide diversity of crop production due
to the nature of its climate and soils. Farmers have demon-
strated, at least partially, the ability to offset increases in the
price of water by better irrigation management, by changing
to higher value or lower water-use crops to the extent that
market conditions allow, and by reducing other production
costs.
The price of water today is a relatively small portion of
total farm production costs. Water prices as a percentage of
total production costs of 20 crops are given in Table 33. The
effect of the price of water on net form income is not as
significant as the effect of some other factors. For a typical
cotton grower, for instance, a 10-percent increase in the price
of water will lower net income per acre by 7 percent, at most.
A 10-percent decrease in the price of cotton or a 10-percent
decrease in yield, on the other hand, can reduce a farmer's
net income by as much as 40 percent. To state it another way,
only a 1.5-percent increase in the yield or the price received
for cotton would be needed to compensate for a 10-percent
increase in the price of water. However, in some areas, the
future percentage change in water prices will likely be much
greater than the increase in prices received for crops or the
increase in yield.
TABLE 33
1975 WATER COSTS AS A PERCENTAGE OF TOTAL CROP PRODUCTION COSTS
FOR SELECTED REGIONS
Crop
Kern and Kings Counties
Average
Low
High
Tulare, Fresno, and Madera Counties
A verage
Low
High
Cotton
Barley
Alfalfa
Wheat
Grapes
Sorghum
Sugar beets
Irrigated pasture....
Oranges
Tomatoes
Rice
Carrots
Field corn
Onions
Almonds
Melons
Walnuts
Plums and prunes..
Peaches
Lettuce
19
19
17
21
11
11
22
31
20
8
20
6
24
15
9
6
7
9
5
5
9
21
11
5
12
2
17
5
26
26
21
26
15
15
27
36
31
12
22
7
32
17
10
11
16
10
4
9
16
34
6
8
12
12
4
7
7
3
2
4
4
4
6
5
2
5
5
15
3
29
24
22
22
8
10
27
39
11
13
16
13
2
7
9
15
3
12
1
5
1
3
6
15
Source, University of California. Davis. Agricultural Water Use and Costs in California.
Bulletin 1896. July 1980
139
Figure 40. STUDIES AND INFORMATION USED IN
PROJECTING IRRIGATED CROPS
140
Studies and Considerations for Projecting
Irrigated Crop Acreages
Several studies of the trends and influences of fac-
tors thiat affect irrigated agriculture in California
were significant in guiding the projection of future
irrigated crop acreage.
National Inter-Regional Agricultural Produc-
tion Model. Information on future foreign and do-
nnestic markets for crops produced m California was
obtained from analyses of the U. S. Department of
Agriculture's National Inter-Regional Agricultural
Production (NIRAP) model, which provided esti-
mates of a growth rate for total crop production in
the United States. The NIRAP model, developed by
the U. S. Economic Research Service, is a computer-
ized simulation of the food and agricultural system in
the nation. The model consists of a series of equa-
tions, with variables for real prices, real income, and
export demand, and several policy variables. Curves
were plotted to display the model's results and then
shifted in accordance with population increases or
changes in relationships between variables in the
economy. The NIRAP study indicated that;
• U. S. food exports will increase.
• California will maintain its present share of food
exports.
• Per capita consumption of most foods and other
farm products will remain at the present level until
2010.
Factors Affecting Competition from Other
Producing Areas of the U. S. California accounts
for more than 90 percent of the production of more
than a dozen crops, mostly fruits and nuts. For many
more crops, primarily vegetables, it is virtually the
sole producer during certain times of the year. No
change in competition is expected for such crops.
Future transportation costs and future availability
of water for irrigation are two factors that will proba-
bly influence market competition between key pro-
ductive regions m the nation for other crops.
Transportation costs are likely to rise with increasing
energy costs, and California's ability to compete with
other areas in shipping specialty crops to eastern and
midwestern regions of the United States may be af-
fected. To help predict the impact, a study was un-
dertaken for these important crops: cantaloupes,
carrots, celery, table grapes, lettuce, nectarines,
oranges, strawberries, and fresh tonnatoes.
A cost-minimizing mathematical model was devel-
oped in which California. Arizona, Florida, and Texas
were the principal competitors for these crops. New
York City and Chicago represented eastern and
midwestern markets. The purpose of the model was
to determine how widely transportation costs could
vary before a competing region could supply these
foods less expensively than could California. Con-
sumer demand was assumed to be at recent levels.
The study indicated that, for many crops that com-
pete with those in other states. California's produc-
ers and wholesalers will be able to accommodate
large increases in real (inflation-adjusted) fuel costs
before the marketing advantages of this State are
lost.
To further assess California's ability to maintain its
share of the market, the water supply situation in
competing regions was considered. In two such
areas, Arizona and the High Plains-Ogallala aquifer
region, diminishing water supplies probably pose a
more serious threat to agriculture than is the case in
California. Arizona has taken strong measures to
manage its precarious water demand-supply balance
by enacting laws to control both agricultural and ur-
ban water use. In some parts of Arizona, no expan-
sion of agriculture will be permitted, and, over time,
some phasing out of existing irrigated acreage is ex-
pected.
The Ogallala is a ground water aquifer underlying
a vast area m six of the High Plains states: Nebraska,
Colorado. Kansas, New Mexico, Oklahoma, and Tex-
as. The aquifer is the principal source of water for
irrigation in this region. Since World War II. irrigated
acreage has expanded tremendously, with the result
that ground water overdraft is widespread — 14 mil-
lion acre-feet annually — in the Texas-Oklahoma High
Plains area, and ground water levels have dropped
significantly. Greater pumping lifts, coupled with
high energy costs, have adversely affected crop pro-
duction and cropping patterns. Without augmenta-
tion with surface water, irrigated land in parts of the
California leads the U.S. in the production of nectarines and
other fresh fruit.
141
Cattle graze in an irrigated pasture in northeastern California.
region will likely revert to dry farming or rangeland
over the next 30 years.
In Florida, there is concern that its major ground
water aquifers cannot supply future needs, as was
once thought. One-time recharge areas used to re-
plenish the State's basins are now occupied by com-
mercial and residential development, and large
portions are underlain by salt-water deposits.
Thus, in several important instances, other areas of
the United States that might otherwise compete with
California in production of certain crops are facing
severe water shortages. Therefore, over the long
term, California is expected to retain or even improve
its comoetitive marketing oosition for those crops.
Study of the Livestock Industry and Its Need
for Feed and Forage. A :"ough California is better
known for its specialT\ '' ^ :s, nuts, and vegetables, its
production of feed ana 'cage crops presently ac-
counts for about 40 percent of total applied irrigation
water in the State. In recent years, beef production
elsewhere has risen in relation to that in California.
With the likelihood of increased water costs in some
areas, questions have been raised regarding the abili-
ty of the State's livestock industry to maintain its
competitive position in relation to other regions of
the United States. To obtain a basis for projecting
the State's future feed and forage production, the
Department analyzed the livestock and poultry indus-
tries.
First, a study was conducted to assess changes in
production methods, feed and forage consumption
by animal type, and associated changes in feed and
forage production from 1961 to 1978. Then, Califor-
nia's probable ability to continue in competition with
other states in producing, transporting, and market-
ing livestock and poultry was analyzed. Finally, using
the results of these studies, the opinions of an advi-
sory committee composed of industry experts, and
the results from an economic model, a most likely set
of projections was developed of California's animal
numbers and related acreages of feed and forage
crops.* The study indicated;
• The rate of increase in beef consumption per per-
son in California will gradually taper off to a level
only 10 percent higher in 2010 than in 1976-1978.
• Poultry production in California will increase sig-
nificantly, doubling the 1976-1978 level by 2010.
• Cattle marketing from California's feedlots is likely
to continue its downward trend, although the
trend will level off. Feedlot marketing m 2010 is
expected to be the same as in 1976-1978. An in-
creasing proportion of beef consumed in Califor-
nia will come from other states.
• Milk production per cow will continue to increase
but not at the high levels of recent years. The num-
ber of milk cows in 2010 is expected to be 95 per-
cent of the 1976-1978 level.
Based on these findings regarding livestock and
poultry production trends, the study concluded that
the potential demand for California-produced alfalfa
hay, irrigated pasture, and feed grains in 2010 will be
* Details of these studies, including model descriptions, are given in the
Departments report Outlook for Water Consumption by California's
Feed and Forage Industry tfirough 2010. Bulletin 212. February 1982.
Corn silage production is expected to continue as a significant
agricultural activity.
142
Almonds being harvested with a tree-shaker. Almost the sole
producer of almonds in the U.S., California exports about half
its crop. Almond acreage increased from 270,000 acres in
1972 to 370,000 in 1980 and is projected to continue expand-
ing.
about the same as in 1976-1978. The study did not
consider the impact of competition for land and wa-
ter to produce other crops; however, this factor did
enter into the final crop projection process. In the
final analysis, because production of other crops will
continue to increase, the proportion of total water
used by feed and forage crops will continue to de-
cline. The evapotranspiration of applied water
(ETAW) by projected feed and forage crops will
drop from about 40 percent in 1980 to about 33 per-
cent of total agricultural ETAW in 2010.
Central Valley Agricultural Model. The De-
partment also developed a linear programming mod-
el of Central Valley agriculture. The model
considered 41 crops and incorporated data on crop
yields, production costs, commodity demands, water
costs, and land availability. It allocated acreages of
crops among 54 Detailed Analysis Units (DAUs) in a
pattern that would reflect maximum net farm income
for the entire valley. Although the output did not
necessarily represent what is likely to occur, crop by
crop and DAU by DAU, it did indicate the overall
impact on irrigated crop acreages of changes in wa-
ter costs and expanded markets for agricultural
products. The findings indicated:
• The crops that could be grown and where, given
the assumed increases in energy and water costs
and the availability of water and suitable land.
• The tendency toward increases or decreases in
crop acreage with changing market conditions.
• The economic feasibility of additional irrigated
acreage in the Central Valley.
With on-going modifications and additional experi-
ence in its use, the model can become a primary tool
for projecting agricultural crops.
Other Information and Considerations. In ad-
dition to the models and related studies just dis-
cussed, a wide variety of other information, data, and
expert judgment was called upon to provide the ba-
sis for the projection of irrigated crops. These includ-
ed, for each area:
• Identified sources and prices of water supply.
• Historic pattern of land use.'
• Availability and suitability of land for potential de-
velopment and changes in crop production.'
• Determination of the historic rate of development
of irrigation.'
• Local factors that may influence cropping patterns
(including apparent crop specialization or prefer-
ences).'
• Characteristics of undeveloped land, compared
with those of adjacent irrigated land and other
relevant site-specific information.'
• Market outlook information for specific crops, in-
cluding the effect of general population growth
and other recent or anticipated trends.
*The Department's land use maps, described in Chapter III. and its land
classification maps, prepared to show the suitability of the land for
specific irrigated crops, were the basis for this analysis.
143
Projections of Acreages of Irrigated Crops
The impact of the foregoing factors, including the
model results, was translated into acres of specific
irrigated crops in specific geographic areas. This
work was carried out by Department staff members
who have gained extensive knowledge of California's
irrigated agriculture from their experience and re-
sponsibilities for land use and land classification
mapping and agricultural economic studies. The ad-
vice and opinions of other knowledgeable people
also were used. The results were projections of spe-
cific crop acreages in each study area (by DAUs. m
some cases; by PSAs, in others). These are summa-
rized by Hydrologic Study Area in Table 34 for 1980
and 2010.
TABLE 34
COMPARISON OF IRRIGATED CROP ACREAGE AND LAND AREA
BY HYDROLOGIC STUDY AREA
1980 and 2010
(In 1,OOOs of acres)
Crop
S''
cc
S3
Grair'
Kce-
Conoii-
?Ww^rtr DGCtS —
Coni_
Other fieU'
AtfdIlS .
Pssture —
Tomatoes -
Other mick'
Other dedduois*
CmusOive'
Grapes
TOTAL CROP ACHES-
D0U81ECB0P
TOTAL LAND AREA.
j"
5
;
—
;•:
5
420
1*J
li)
|i|
Ui
liSf
,13)
(3S9)
580
(491)
—
5
(10)
-
—
—
180
(140)
5
S
55
IS
—
240
(3)
(4)
(51)
(8)
(15)
(5)
(ISO)
65
45
5
160
(51)
(1)
(51)
(2)
(11)
(1)
(105)
IX
5
20
10
360
(125)
(4)
(26)
(3)
(13)
(4)
(369)
_
20
130
—
—
(IS)
—
—
—
(MB)
S
n
310
SO
20
20
55
(W)
(15)
(2^)
(51)
(21)
(18)
(32)
IW
m
w
5
25
5
2K
(9)
(W)
(32)
(2)
U)
(1)
(178)
15
60
35
60
15
—
—
(12)
(64)
(52)
(60)
(14)
35
30
m
W
5
25
(»)
(27)
(54)
(2)
(13)
(3)
(7)
3G0
60
570
in
120
90
2550
(314)
(66)
(531)
(134)
(153)
(H6)
(2.176)
85
25
H)
10
MO
—
(2)
(72)
(W)
(6)
(5)
(32)
360
60
485
85
in
80
Z380
(314)
(54'
/jCOl
JIIOI
f1j-7t
"00>
'ice«>
li*D;
liX,
SO
(41)
(13)
2B0
(197)
1.420
(1239)
70
(66)
5
(39)
270
(207)
100
(96)
no
(211)
140
(151)
180
(181)
270
(319)
2«
(301)
55
(67)
no
(GO)
80
(38)
120
(86)
WO
(115)
ZN
(WT)
MO
(12B)
190
(146)
190
(153)
20
(8)
MO
(166)
230
(176)
480
(363)
Z410
(Z142)
(3t3BI)
ISO
(80)
IX
(72)
22B0
'2062'
31510
'J3'2>
5
(1)
55
(34)
90
(101)
im
(148)
MO
(2)
X
(45)
15
(20)
(2)
(2)
50
(78)
SO
IX
(109)
40
(X)
X
(25)
220
(186)
X
(18)
150
(119)
(1)
40
(33)
W
(W)
8X
(683)
MO
(89)
670
'6W1
630
(SiSI
1S30
(15«l
195
(210)
(442)
(686)
lim
(9861
336
(1JH1)
330
(221)
920
(7«l
(407)
636
(5»)
425
(4091
3%
(683)
ML950
(9.924)
7X
(434)
10220
'9-1901
Note: 1980 nalues are stmnm in parecnheses.
* Pncnanty befley. wfiaat. oat gram, and grairviiay.
' Oy beans. saffloiMer. mia sunflovrer. etc
* PuumeSL melons, leitucCL etc
'Wdkiuts. peaches, pnaies. phsns, etc
'Also inckides avocados.
144
Some of the highlights of the projected changes in
statewide irrigated acreage between 1980 and 2010
(Figure 41) are:
• Small Grains. Double cropping (grain plus an-
other crop on the same land in one year) is expect-
ed to become more common; however, with the
pressure of competition from other crops for land
and water, total acreage of grain is expected to
decrease slightly.
• Field Crops. Cotton and rice are projected to
continue to dominate the San Joaquin Valley (cot-
ton) and Sacramento Valley (rice). Corn is pro-
jected to increase about 25 percent. Although
some changes are expected in the proportional
mix, the total of all other field crops is expected to
remain about level. These include dry beans, milo,
safflower, and sunflower.
Alfalfa and Pasture. The combined acreage of
hay and forage crops is expected to remain about
level, with irrigated pasture land giving way to
higher income crops in some areas.
Truck Crops. The total production of vegeta-
bles, berries, and nursery stock, which make up this
category, is projected to increase about 30 per-
cent, principally in keeping with growth of U. S.
population.
Tree Fruits and Nuts. Shifts in the ratios of spe-
cific fruits and nuts are expected; the total acreage
should increase about 10 percent by 2010.
Grapes. Wine grape production is projected to
continue increasing. Total grape acreage will rise
30 percent by 2010.
Figure 41. CHANGE IN STATE TOTAL IRRIGATED ACREAGE, BY CROPS
1980 TO 2010
CROP
GRAIN
RICE
COTTON
SUGAR BEETS
CORN
OTHER FIELD
ALFALFA
PASTURE
TOMATOES
OTHER TRUCK
ALMONDS
PISTACHIOS
OTHER DECIDUOUS
CITRUS-OLIVES
GRAPES
D
J_
100
0 100
Thousands of Acres
200
300
145
Wine grape acreage continues to grow markedly, with an-
other 15,000 acres planted in 1980.
146
California produces more than half the nation's nine major
processed vegetables, including green lima beans, here being
harvested for freezing. Production of these and other proc-
essed vegetables in the State is expected to increase.
Total irrigated land in California (Table 35) is pro-
jected to increase from the 1980 level of 9,490,000
acres to 10,220,000 acres by 2010, an 8-percent in-
crease over the 30-year period. This percentage in-
crease is the sanne as that which occurred in the
eight years between 1972 and 1980. The intensity of
land use is expected to increase, reflected in in-
creased double cropping. With double cropping, to-
tal irrigated crops are expected to increase by 10
percent to 10,950,000 acres.
The greatest expansion in irrigation is projected to
occur in the Sacramento HSA, with irrigated land
growing by 300,000 acres and double cropping in-
creasing by 70,000 acres. The San Joaquin and Tulare
Lake HSAs are each projected to increase total irri-
gated crops by about 250,000 acres. These projec-
tions for the Central Valley were given limited testing
to determine how they would be affected by major
TABLE 35
IRRIGATED CROP ACREAGE AND LAND AREA BY HYDROLOGIC STUDY AREA
BY DECADES TO 2010
(In 1,000s of acres)
Year
NC
SF
CC
LA
SA
SO
SB
SJ
TL
NL
SL
CR
TOTAL
IRRIGATED CROP ACREAGE
1980
1990
2000
2010
1960 to 2010 change
IRRIGATED LAND AREA
1980
1990
2000
2010
1980 to 2010 ctiange
' Includes double crop.
314
340
350
360
+ 46
314
340
350
360
+46
531
560
570
570
+ 39
469
480
480
486
+ 26
134
130
120
110
-24
118
110
100
85
-33
153
140
130
120
-33
147
130
120
110
-37
105
100
100
90
-15
100
100
90
80
-20
2,176
2.420
2,480
2.550
+ 374
2,084
2.290
2,340
2,390
+ 306
2,142
2.210
2.300
2,410
+ 268
2,062
2.110
2,180
2,260
+ 198
3.384
3,470
3.640
3.640
+ 256
3,312
3,370
3.430
3.510
+ 198
148
160
160
160
+ 12
148
160
160
160
+ 12
693
750
810
830
+ 137
604
630
660
670
+ 66
9,924
10.410
10.680
10,960
+ 1.026
9.490
9.850
10,030
10,220
+ 730
147
changes in the assumptions regarding water availa-
bility and energy costs. These results a^e reported in
the sidebar. "Effects of Alternative Assjmptions for
Water Supply and Energy Costs."
A projected irrigation water saving througn con-
servation in the Colorado River HSA nnade it possible
to project an increase in irrigated crop acreage of
about 140.000 acres, half from newly developed land
and half from increased double cropping. Some
lesser increases are projected for the North Coast
Central Coas:. and North Lahontan HSAs. Urban en-
croachment on presently irrigated lands will reduce
such land in the San Francisco Bay. Los Angeles.
Santa Ana. and San Diego HSAs by a total of nearly
100.000 acres. Irrigated land in the South Lahontan
HSA is projected to decrease by about 30.000 acres
because declining ground water levels and increased
costs of energy will make ground water too costiy for
some farming operations. Further importation is no
solution in the South Lahonta HSA because SWP
prices exceed the ability of agriculture in •rat a^ea to
pay for water.
The complexity of factors that influence Califor-
nia's agriculture is such that projecting iong-range
agricultural activity with accuracy is unlikely. Howev-
er, barring such events as major economic problems
at the national or international level, devastating pest
invasions, or similar situations that cannot be fore-
seen, irrigation can be expected to continue increas-
ing as long as suitable land and affordable wa:e' a-e
available.
EFFECTS OF ALTERNATIVE ASSUMPTIONS
FOR WATER SUPPLY AND ENERGY COSTS
Projections of irrigated crops to 2010 we-e zziez c- ;1)
certain assumptions regarding the liming of c- : :: '-of
oddHional surfoce water supplies and (2) the p.-e~.s« rnot
real energy prices would incieose steocfily at the rate of 2
percent per year. It now appears that new SWP water sup-
pGes wS not be made avoSable as soon as had been as-
sumed. Moreover, some experts believe that real energy
prices wil not increase beyond 1982 levek for at least the
next 10 years.
The possible effects of these alternative ossumptions on
irrigated agriculture were estimated by using the Central
Valey agricultural model referred to in this chapter.
K ertergy prices increase only at the rote of inflation, the
farmer's costs for fertSzer. equipment, operotion, artd water
would be less, compared to costs with o 2-percent increose
per year in real energy prices. The lower water costs would
be particularly significtvit in those areas requirirtg energy to
pump water from ttte Delta artd in those areas that rely
extensively on grour>d water. Acconfing to the model analy-
sis, ttte net effect of cortstont ertergy prices, compared to the
projected 2-percent increase in reat energy costs, would be:
• An averoge artnual increase in irrigated crop acreage of
50,000 ocres in tfte Central Voley, compered to 30,000
ocres with a 2-percent ittcreose.
• A different crop ocreoge (fistribution within the volley.
• Some chartges m cioppirtg patterns.
The effect on the protected acreage by 2010 among areos
in the Centrd VoBey is shown graphicaly in the uccompuny-
ing figure.
PERCENTAGE CHANGE IN
PROJECTED 2010 ACREAGE FROM
CONSTANT REAL ENERGY PRICES
DECREASE
INCREASE
CENTRAL VALLEY -Total
SACRAMENTO
HSA
!
SAN JOAQUIN HSA
TULARE LAKE HSA
; C 2 .i f 8
Ac teage change in pet cent
148
The more optimistic energy price forecasts hove the great-
est impact in the Tulare Lake HSA because of its reliance on
ground water supplies and use of SWP surface supplies, both
of which are energy-intensive. Increases there in irrigated
acreage would be offset, in part, by reductions in the Sacra-
mento HSA, reflecting the greater competitive advantage in
the Tulare Lake HSA.
A delay in providing additional SWP facilities to meet
projected requirements would not cause the change in total
projected acreage that the energy price scenario would
cause. With no additional SWP facilities, upstream depletions
resulting from further development in the Sacramento Valley
would reduce present yield from 2.3 million to 1.7 million
acre-feet. The model analysis indicates that, under this supply
reduction scenario, the following changes would take place.
• Ground water pumping would increase in the Tulare Lake
HSA to moke up for much of the SWP supply deficiency
in that area.
• With the increased overdraft and resultant greater pump-
ing lifts, ground water would become more expensive than
would SWP supplies, but farming would still be profitable.
• Crop acreage would be distributed differently among Cen-
tral Valley HSAs.
• Acreage would be slightly lower in the Tulare Lake HSA,
higher in the San Joaquin HSA, and lower in the Sacra-
mento HSA, compared to projections based on no delay in
providing additional SWP facilities. The net change in the
Central Valley would be almost negligible, however, as
illustrated in the accompanying figure.
The primary shift predicted by the model would be o small
movement from relatively water-intensive cotton to less wa-
ter-intensive grains. This is the reverse of the trend indicated
under the constant energy price scenario. Moreover, shifts in
competitive advantage cause more of a chain reaction under
the reduced water supply scenario than with the constant
energy price scenario. As farmers in the Tulare Lake HSA
move from cotton to grain acreage, the Son Joaquin HSA
would shift from grain production to increased acreage of
other crops at the expense of smaller increases in Sacramento
HSA production.
In summary, from the indicated changes in crop distribution
and changing rate of annual increase in crop acreages, it is
obvious that the assumption of reduced SWP deliveries has
a lesser impact on crop production than do changes in energy
price.
PERCENTAGE CHANGE IN
PROJECTED 2010 ACREAGE
RESULTING FROM REDUCED
SWP SUPPLY
DECREASE
CENTRAL VALLEY
Total
INCREASE
SACRAMENTO HSA
rl
TULARE LAKE HSA
u
_l I L.
1
SAN JOAQUIN HSA
J
J
4 2 0 2 4
Acreage change In percent
MAJOR CROP PATTERN CHANGES BY
2010 AS A RESULT OF ALTERNATIVE
ASSUMPTIONS
AREA
CONSTANT ENERGY
PRICES
NO ADDITIONAL
SWP FACILITIES
Gain
Loss
Gain
Loss
CENTRAL VALLEY-
TOTAL
COTTON
GRAPES
GRAIN
SUGAR BEETS
TOMATOES
GRAIN
COTTON
SACRAMENTO
HSA
GRAIN
SUGAR BEETS
CORN
GRAPES
PASTURE
GRAPES
SAN JOAQUIN
HSA
PASTURE
GRAPES
FIELD CROPS
TOMATOES
PASTURE
GRAPES
TULARE LAKE
HSA
COTTON
GRAPES
GRAIN
GRAIN
COTTON
149
k-^^m
Rice harvester. Average irrigatian efficiency for rice is project-
ed to rise from the present 45 percent to about 55 percent
by 2010.
Future Changes in Irrigation Efficiency
California's irrigation, historically, has continuous-
ly become more efficient.' Talcing the State as a
whole, the weighted average irrigation efficiency has
been steadily rising, as new systems with higher ef-
ficiencies are brought into use and the management
of existing systems is improved. System changes
have continued to take place because of the:
• Need to replace worn-out irrigation systems, often
resulting in installation of better-designed systems.
• Desire to convert to systems requiring less labor,
some of which are easier to operate efficiently.
• Interest in new types of equipment for specialized
applications that prove to be more advantageous
and are usually more efficient than their predeces-
sors.
The new types of equipment include drip systems,
linear-move and center-pivot systems, electronically
controlled systems, and laser-leveled surface flood
systems. An apparent trend toward greater skill in
* Irrigation efficiency, the percentage of ttie irrigation water used by the
plant and evaporated from ttie soil, is the efficiency with wtiich a farmer
applies water: it should not be confused with the efficiency of opera-
tion of an irrigation district, or tlie efficiency of a total hydrologic
system, the values for each of which are derived from a different basis.
overall farm management has meant more care given
to irrigation scheduling. These improvements have
been observed even where water price is only a very
small part of total operation cost.
Despite this trend toward greater efficiency,
however, some notable exceptions do occur. Low
efficiencies are still found in some mountain valleys
where low-value pasture land is irrigated by stream
diversions that usually provide less than a full sea-
son's water supply. The low economic return from
pasture and the uncertainty of the water supply have
not been conducive to investment in improved irriga-
tion systems. An example is part of Honey Lake Val-
ley in Lassen County. Low efficiencies also occur
where systems of unlined canals built many years
ago deliver low-priced water on a fixed schedule, as
in the rice-growing areas of Sacramento Valley. At
the other extreme, high efficiencies have long been
common where irrigation water is relatively scarce
and costly. These conditions prevail in San Diego
County and parts of San Joaquin Valley, where max-
imum practical efficiency has been reached in many
cases.
Overall, irrigation efficiency is- expected to contin-
ue to increase and, with increasing costs of energy,
labor, water, and other production factors, is likely to
150
accelerate in some areas. However, in other cases,
even where water price is low, nneasurements of wa-
ter application rates indicate that under-irrigation is
occurring, and improved irrigation management may
actually increase water application, with concomi-
tant increases in production.-
For this study, future levels of irrigation efficiency
were estimated for each crop or group of crops by
each DAU. These estimates were based on evalua-
tion of:
• Historic and current irrigation efficiencies.
. Range of soil characteristics and normal climate
patterns.
• Current irrigation systems and irrigation practices.
• Current and expected future water prices (includ-
ing energy cost impacts).
• Characteristics and operation of surface water dis-
tribution systems.
Although efficiencies of 80 percent or more can be
achieved under ideal conditions, such rates rarely
occur because of variations in soil characteristics,
water quality, water prices, water delivery systems,
and farming practices. Thus, in most cases, the
weighted average irrigation efficiency estimated for
2010 for any crop over a relatively large area does not
exceed 70 to 75 percent.
The variation in values is demonstrated by informa-
tion shown in Table 36, which compares the weight-
ed average irrigation efficiency for a number of crops
in the;
• Maricopa-Wheeler Ridge DAU (composed of
most of the Maricopa-Wheeler Ridge Water Stor-
age District, a portion of the Arvin-Edison Water
Storage District, and some unorganized areas).
• Kern Valley Floor PSA (composed of the Mari-
copa-Wheeler Ridge DAU and seven other DAUs) .
• Tulare Lake HSA (composed of the Kern Valley
Floor PSA and two other PSAs).
The table demonstrates the influence of the many
variables on the weighted average irrigation effi-
ciency as increasingly larger areas are considered.
Agricultural Applied Water and Net Water
Use — 1980 and Projected
Agricultural applied water and ETAW were com-
puted by DAUs, aggregated by PSAs for the hy-
drologic analysis, and summarized by HSAs. Applied
water and ETAW were computed from the projected
crop acreages, unit applied water, and unit ETAW. A
hydrologic analysis considering reuse, ETAW, ir-
recoverable distribution system losses, and outflow
from each PSA provided the estimate of net water
use.
Total agricultural applied water and related net
water use by Hydrologic Study Area for 1980, 1990,
2000, and 2010, and changes in agricultural net use
between 1980and 2010are presented in Table 37. The
total change in agricultural net water use from 1980
to 2010 is depicted in Figure 42. The largest increase
in net water use is projected to occur in the Tulare
Lake HSA, followed closely by the San Joaquin and
Sacramento HSAs. In total, net water use by agricul-
ture in the Central Valley is projected to increase by
more than 1.6 million acre-feet between 1980 and
2010. Conversely, the San Francisco Bay, Los Ange-
les, Santa Ana, and San Diego HSAs are expected to
reduce their agricultural net water use by a total of
nearly 250,000 acre-feet per year. Net water use in the
South Lahontan HSA is expected to decline about
100,000 acre-feet from 1980 to 2010.
TABLE 36
EXAMPLES OF WEIGHTED AVERAGE IRRIGATION EFFICIENCIES
BY CROP
1980 and 2010
(In percent)
Maricopa-Wheeler Ridge
DAU
Kern {/alley Floor
PSA
Tulare Lake
HSA
Crop
1980
2010
1980
2010
1980
2010
Grain .
71
69
69
70
70
69
70
70
69
71
69
80
75
76
70
75
75
75
75
75
75
75
75
80
65
68
65
63
59
49
70
70
65
67
70
70
73
74
69
74
64
52
72
74
74
73
78
75
70
67
58
64
62
61
70
69
66
66
67
56
74
Cotton
72
Corn
65
Other field crops
69
Alfalfa
67
Pasture
57
73
Otfier truck crops
73
73
Otfier deciduous
71
70
Grapes
59
151
TABLE 37
AGRICULTURAL APPLIED WATER AND NET WATER USE
BY HYDROLOGIC STUDY AREA
BY DECADES TO 2010
(In 1,000s of acre-feet)
Year
NC
SF
CC
LA
SA
SD
SB
SJ
TL
NL
SL
CR
TOTAL
1960....
APPLIED WATER
1990
2000-
2010-.
1980....
NET WATER USE
1990
2000
2010
CHANGE IN NET WATER USE
1980 to 2010
821
900
910
930
714
780
790
810
+ 95
121
110
100
90
121
110
lOO
90
1.189
1.240
1.230
1,200
902
940
940
930
+ 30
348
310
270
230
276
250
220
190
-86
412
360
310
260
320
290
250
220
-100
228
220
200
190
198
190
9.223
9.350
9.000
9.070
6.682
7.030
7,010
7,140
+460
7,474
7,470
7,510
7,680
5,892
6,050
6,160
6,370
+ 480
11,424
11,390
11,390
11,540
7,781
7,955
8,185
8,475
+ 690
442
470
470
480
387
410
410
420
+ 35
493
410
350
280
338
300
270
230
-110
3.460
3,590
3,730
3,700
3,434
3,560
3,700
3.680
+ 245
35,636
35,820
36.470
36,650
27,045
27,865
28,215
28.725
+ 1,680
Figure 42. CHANGE IN AGRICULTURAL NET WATER USE
BY HSA 1980 TO 2010
HYDROLOGIC
STUDY AREA
NORTH COAST
SAN FRANCISCO BAY
CENTRAL COAST
LOS ANGELES
SANTA ANA
SAN DIEGO
SACRAMENTO
SAN JOAQUIN
TULARE LAKE
NORTH LAHONTAN
SOUTH LAHONTAN
COLORADO RIVER
-100
200 300 400
Thousands of Acre-Feet
500
600
152
Urban Water Use
Projections of urban applied water are based on
estimates of future population and future per capita
applied water. Estimates of urban net water use are
obtained from a hydrologic balance analysis, includ-
ing consideration of applied water, water reuse, total
evapotranspiration of applied water, irrecoverable
losses, and outflow. California's population is expect-
ed to continue growing substantially; because of wa-
ter conservation and other factors, however, per
capita applied water is not expected to increase as
rapidly as it has in the past. Rather, it will tend to level
off m many areas, and in some will be decreasing by
2010. Present projections indicate that, by 2010, total
statewide urban net water use will increase by nearly
40 percent, from the current level of 5.0 million acre-
feet to 6.8 million acre-feet per year.
Population Projections
According to a policy adopted by the Governor m
1978 ^ State funding of capital projects must be
based on the regional population projections devel-
oped by Councils of Governments (COGs) that have
been approved by the State Office of Planning and
Research. Further, to be approved, these regional
projections cannot exceed the regional projections
prepared by the State Department of Finance
(DOF) . For the counties not covered by COG projec-
tions, the DOF projections are to be used. Later in
1978, the Governor extended his policy by ordering
that all policies, actions, and programs conform to
these requirements.
When the 1980 census figures for the State
became available, they showed that the existing
population projections for 1980 were lower than ac-
tual population in many parts of California. In some
counties, even the projections for 1985 and 1990 fell
below the actual 1980 census results. The DOF subse-
quently issued a set of interim population projec-
tions for counties, extending them to 1990, based on
the 1980 census. The Department of Water Re-
sources further extended these projections to 2010,
using the same procedures DOF used for 1990. Re-
vised COG projections were not available in time for
the analyses used in this report.
The rates of both natural increase (births minus
deaths) and migration have changed, but the effect
of both on population growth is upward. In the case
of natural increase, the decline in fertility rates during
the 1960s and into the 1970s was one of the most
striking recent demographic trends. Earlier reports in
the Bulletin 160 series had assumed fertility rates of
2.5 to 3.1 children per woman of childbearing age. For
this report, the current low rate of 2.1 was assumed
to continue to 2010. Even so. natural increase ac-
counts for more than half, or 5.8 million, the project-
ed population growth of 10.6 million by 2010.
Net migration — the difference between in-migra-
tion and out-migration — has probably fluctuated
more than has any other component of population
change. Since World War II. the increase caused by
net migration has ranged from slightly more than
100.000 to 350.000 per year. The trend since 1970 has
been upward and. in the last few years, has averaged
about 250.000 per year. Part of this increase reflects
changes m migration policies. Since 1979, half the
migration has originated in the United States and half
has been of foreign origin. Projections of net migra-
tion for this report have been placed at 150,000 annu-
ally, toward the lower end of the historical range. Net
migration accounts for nearly 5 million of the total
population increase of 10.6 million expected over the
next 30 years.
California's total projected population for 2010 is
34.4 million, which amounts to 12.5 percent of the
projected national total. National and State projec-
tions by decade are tabulated below.
U. S. and California Population
1980 and Projected
(In millions)
Year
a S
California
California
as a Percent
of U. S.
1980
227.7
23.8
27.9
31.3
34.4
10.5
1990
2000
2010
243.5
260.4
275.3
11.5
12.0
12.5
'The guidelines for this policy are outlined m a report. An Urban Strategy
for California, issued by the State Office of Planning and Research in
1978.
About half the future increase in population in California is
expected to be derived from births and half from in-migrofion.
153
California's share of U. S. population is projected
to increase nearly 20 percent over the 1980 level. The
increases by decades are shown by Figure 43.
Population Distribution. The 1980 census
population statistics by census tracts and enumera-
tion districts were used to determine population in
each Detailed Analysis Unit. Projections for DAUs
were based on the projections by county prepared
by the Department of Finance (to 1990) and the De-
partment of Water Resources (1990 to 2010) and on
information gained from local planning agencies and
the regional Councils of Governments regarding the
directions that future growth is most likely to take.
Present and projected population figures by HSAs
are summarized m Table 38.
Taken as a whole, the urban areas m Southern
California dominate the outlook, accounting for
about 50 percent of total State growth. The popula-
tion increase in the Santa Ana HSA, which encom-
passes most of Orange County and the western
sections of San Bernardino and Riverside Counties,
is expected to surpass that in any other region. Other
major areas of growth, outside the South Coastal
region, in decreasing order, are the Sacramento, San
Francisco Bay, San Joaquin, and Tulare Lake HSAs.
Per Capita Applied Water Projections
The process for projecting per capita applied wa-
ter involved two steps.
• First, the trends from about 1960 through 1975 (the
year before the drought) were extrapolated to
2010, considering apparent and expected changes
in some of the major influencing factors, excluding
water conservation.
Figure 43. PROJECTED POPULATION
INCREASE BY DECADES 1980-2010
1960
TO
1990
4.1
Million
1900
TO
2000
3.4
Million
^^^^^000
TO
201^^^
3.1
Million
1
• Then, the impact of specific water conservation
actions from 1976 to 2010 were estimated and the
extrapolated values adjusted downward accord-
ingly. These two sets of values provided a basis for
calculating future urban applied water, both with
and without conservation.
Projection of Trends (Without Conserva-
tion). In nearly all urban areas of the State, per
capita applied water through 1975 trended upward.
In recent years, changes appear to have been occur-
ring which, even without the specific water conser-
vation actions that have either been implemented or
been planned, would tend to slow the rate of in-
crease. In some communities, this will actually cause
per capita applied water to level off in the near fu-
ture. Although climatic fluctuations commonly cause
TABLE 38
CALIFORNIA POPULATION
BY HYDROLOGIC STUDY AREA
BY DECADES TO 2010
(In thousands)
HSA
1980
1990
2000
2010
Increase
1980-2010
Percent
of State
Increase.
1980-2010
NC
459
4,790
1,005
7.927
2.974
2,068
1.674
1.014
1.178
61
303
320
23.773
570
5.250
1,190
8.650
3,790
2.580
2,200
1.330
1.440
80
400
430
27.910
660
5,600
1.340
9,140
4,430
3,040
2.590
1,630
1,670
100
510
540
31.250
760
5.900
1.490
9,650
5,060
3.440
2,930
1,910
1,920
120
570
630
34,380
300
1,110
480
1,720
2,090
1.370
1.230
900
740
60
270
310
10,610'
3
SF
10
cc . .
5
LA
16
SA
20
SD
13
SB
12
SJ
8
TL
7
NL
SL
3
CR
3
STATE TOTAL
100
' Statewide increase is 44 percent
154
per capita use to vary significantly from year to year,
an important aspect of urban applied water is that
fundamental long-term changes in average per capi-
ta values for a large metropolitan area usually occur
slowly. This is because of the large established base
of water use in the area. Except where water conser-
vation measures are at work, or where water prices
have risen markedly, long-term trends are not normal-
ly altered by changes in practice by individual water
users. Rather, changes in average per capita applied
water occur as a result of the increase in proportion
of the population having higher (or lower) per capita
rates. As an example, after World War II, suburban
living became popular. Much of the housing develop-
ment since then has typically had higher rates of use
than the older-city type of development, primarily
because of more extensive landscaping. Since about
half of residential water use is for landscape irriga-
tion, the increasing proportion of total population
living in the suburbs compared to that living in the
older city areas has contributed to the increasingly
upward trend in average annual per capita applied
water seen in the larger metropolitan areas.
Climate is another factor which has strongly in-
fluenced the change in the overall average per capita
applied water value in the State's coastal metropoli-
tan areas. Water use for landscapes is considerably
greater in inland regions than along the coast. In both
the San Francisco Bay area and the South Coastal
region, most of the land near the ocean (typically
cooler than inland areas) has already been devel-
oped. As the inland proportion of the total metropoli-
tan area increases in comparison to the area
influenced by the cooler ocean climate, the weighted
average per capita applied water value increases.
The foregoing factors were considered in evaluat-
ing the impact of expected changes in other specific
characteristics of water use, most of which should
gradually slow the rate of increase in per capita ap-
plied water in most urban areas. In some cases, they
may cause a leveling off and, eventually, a decrease.
Some of them are:
• Housing Density. The relative proportion of
people living in multi-unit housing and mobile
homes is expected to increase. In addition, the
average size of new single-family home lots is ex-
pected to continue to decrease. Both of these fac-
tors should reduce the average landscape area per
capita for new development. This, in turn, would
tend to reduce per capita applied water.
• Household Size. The average number of per-
sons per household is expected to continue to de-
cline slightly. This should tend to increase per
capita applied water because certain residential
water uses are relatively independent of
household size. Among these uses are house
cleaning, food preparation, clothes and dish wash-
ing (to some extent), landscape irrigation, swim-
ming pool maintenance, and car washing.
• Increased Energy Conservation. Real energy
costs are expected to continue rising. This will like-
ly reduce the use of hot water, lowering per capita
applied water.
• Water Prices. In recent years, water prices to
consumers in many urban areas have risen faster
than prices for other commodities. The prospect is
for further increases, particularly in Southern Cali-
fornia, where higher energy costs for pumping
State Water Project water will have their greatest
In Son Francisco, close-set homes, little irrigatecJ landscaping,
and a cool climate result in much lower residential per capita
applied water than is typical of heavily landscaped suburbs
in warm interior valleys, such as in Contra Costa County.
155
impact. As this occurs, it will tend to reduce per
capita applied water.
The trend in per capita applied water through 1975
for each Detailed Analysis Unit was developed on
the basis of historical annual delivery data provided
by water service agencies and estimates of the popu-
lation served. The trend for each area was extrapolat-
ed to 2010, considering the likely impacts in each
area of the foregoing (and other) factors. The im-
pact of water conservation actions was excluded.
The result, generally, was a continuing decline in the
rate of increase.
Results of Per Capita Applied Water Projec-
tions (Without Conservation). The 1980 and
2010 per capita applied water values (without con-
servation) for each Hydrologic Study Area are pre-
sented in Table 39. Values shown are weighted
averages derived from the values and population of
each of the many DAUs that make up each HSA.
Average values for such large areas as HSAs are
sometimes difficult to interpret because of the wide
variation occurring within them. Some of the factors
involved in the changes in per capita values project-
ed without conservation are:
• North Coast HSA. The large amount of water
used by the pulp and paper mills situated at Hum-
boldt Bay, as a proportion of total urban water use,
IS responsible for the relatively high 1980 value for
per capita applied water. This value is expected to
drop 14 percent by 2010. Population is expected to
grow, but water use by the pulp and paper mills is
not expected to change.
• San Francisco Bay, Los Angeles, Santa Ana,
and San Diego HSAs. By 2010, an even larger
TABLE 39
PROJECTED CHANGE IN WEIGHTED
AVERAGE PER CAPITA APPLIED WATER
WITHOUT CONSERVATION
STATEWIDE AND
BY HYDROLOGIC STUDY AREA
1980 to 2010
(In acre-feet per person)
HSA
1980
2010
Percent
Change
NC
0.336
0.201
0.236
0.208
0.247
0.188
0.340
0.398
0.361
0.377
0.314
0.372
0.242
0.289
0.229
0.240
0.239
0.280
0.235
0.331
0.389
0.376
0,375
0.398
0.435
0.274
-14
SF
14
CC
2
LA
15
SA
13
SD
25
SB
-3
SJ
2
TL
4
NL
-1
SL
26
CR
17
STATEWIDE
13
proportion of the population is expected to be liv-
ing in warm inland areas than in the cooler coastal
areas. The increase of 13 to 25 percent is due large-
ly to this projected trend.
• Sacramento, San Joaquin, Tulare Lake, and
North Lahontan HSAs. In contrast to the
coastal metropolitan areas, climate-related factors
will not be responsible for a change in average per
capita values. Instead, these values will be in-
fluenced by some of the other factors, discussed
earlier, that are expected to cause per capita ap-
plied water to level off and then, in most areas, to
decrease.
. Central Coast HSA. Unlike the other coastal
metropolitan areas, land is still available near the
coast, where a large part of the population growth
IS expected to occur. Further, this area generally
has a limited water supply, a condition that will
tend to counteract the impact of any increases in
population locating in the warmer inland areas.
• South Lahontan and Colorado River HSAs.
The principal reason for projecting increases in
these areas is the continued growth in tourism and
similar part-time visitation that is expected. A large
transient population tends to increase the values
for per capita applied water because per capita
values are derived by dividing total applied water
by permanent population.
Impacts of Expected Water Conservation on
Per Capita Applied Water. For this report, urban
water conservation is defined as any action deliber-
ately undertaken to reduce the amount of water ap-
plied. This distinguishes water conservation impacts
from the impacts of such factors as housing trends
and family size. The extent to which water conserva-
tion is expected to be practiced in various parts of
the State was estimated m several ways, depending
on the characteristics of urban water use and its sig-
nificance in an area compared to other water uses.
Where urban water use is a relatively small portion
of an area's total applied water, projections of ap-
plied water "without conservation" were simply ad-
justed downward by 15 percent to obtain an estimate
of applied water "with conservation." This level of
conservation, which is about the same as that deter-
mined by detailed analysis for the major metropoli-
tan areas, was assumed to be achieved by 2000 or
2010, depending on the area. In areas in which per
capita water use is already low, a smaller percentage
reduction was used.
Projections for the San Francisco Bay, Santa Ana,
Los Angeles, and San Diego HSAs; and for San Luis
Obispo and Santa Barbara Counties were made by
first separating the quantity of urban applied water
into the categories of use: interior residential, exte-
rior residential, commercial and governmental, and
industrial. The amount of conservation expected in
156
each category was calculated for the proportion of
the population that would be affected at a particular
point in time. These reductions were then added to
obtain total water conservation on a per capita basis.
The result was subtracted from the projection of per
capita applied water "without conservation." The es-
timate of future per capita applied water, so derived,
has been used to calculate the projections of future
urban applied water presented in this report. In areas
with exemplary conservation programs of one kind
or another, applied water reductions were assumed
to be achieved sooner than indicated in the list of
assumed water conservation actions that follows.
For example, in the San Francisco Bay area, where
East Bay Municipal Utility District has pioneered in
the detection and repair of leaks in water supply
systems, the applied water reductions of 4 percent
from this program were assumed to be achieved in
1982 rather than by 2000.
The conservation measures and actions consid-
ered in projecting water use reductions and the as-
sumptions made on the rate of implementation were;
• Interior Residential Water Conservation.
Toilet flushing is by far the largest component of
interior water use, averaging about 35 gallons per
person daily when a conventional toilet requiring 5
to 7 gallons per flush is used. State law now re-
quires that all new dwellings have toilets using no
more than 3.5 gallons. Accordingly, the Depart-
ment's projections of applied water reflect a re-
duction to account for ttie installation of
low-water-using toilets in all new development.
Water use in existing toilets can be reduced by
installing a displacement bag or bottle in the tank.
More than three million bags and bottles have
been distributed by water utilities and the Depart-
ment of Water Resources since 1973. Surveys
made after the devices were distributed indicate
that about 25 percent of households install and
retain them. These programs are a very cost-effec-
tive way of reducing applied water, and they will
probably continue. By 1990, all households with
conventional toilets will have had an opportunity
to install a displacement device, and it was as-
sumed that 25 percent of the households will actu-
ally install and retain them.
In accordance with State plumbing regulations,
the Department's projections of applied water re-
flect a reduction resulting from the installation of
low-flow faucets and showerheads in new devel-
opment.
Shower flow restrictors for existing showerheads
usually accompany toilet displacement bags in
conservation device distribution programs. The in-
stallation rate of shower flow restrictors is general-
ly lower than that for displacement bags — 13
percent, rather than 25 percent. By 1990, flow res-
trictors will have been distributed to all households
in the State, and it was assumed that 13 percent of
households will install and retain them.
Unlike toilets, which rarely require replacement,
showerheads and faucets are replaced from time
to time. It was assumed that, by 2000, all shower-
heads and lavatory faucets used in the State will be
the low-water-using kind.
Newer models of clothes washers and dishwash-
ers use less water than those manufactured in the
past. A study by the Department indicates that
clothes washers manufactured in 1980 use about
15 percent less water than 1975 models; 1980
dishwashers use 25 percent less water than 1975
models. Consequently, appliances installed in new
homes will use less water than do old appliances;
also, as older appliances wear out, they will be
replaced with models using less water. Although
the average life of these appliances is ten years, it
was conservatively assumed that all pre- 1975
clothes washers and dishwashers will be replaced
by models using less water by 2000.
In most domestic water-heating systems, the pipes
delivering hot water are not insulated. Conse-
quently, the heated water cools while it is standing
in the pipes, and householders must allow it to flow
for a time until hot water is delivered from the
faucet. State regulations that took effect in 1982
require the insulation of hot water pipes in new
residences. The projections of applied water re-
flect this.
Personal water use will also be affected by the
many public education programs that have been
introduced by the Department and public water
utilities. In-school education programs have intro-
duced water conservation to hundreds of thou-
sands of school children. These and other
programs have heightened the public's awareness
of water conservation and the State's water prob-
lems. This IS expected to lead to changes in water
use habits, which should reduce interior water use
over and above the reductions achieved as a result
of water-saving plumbing fixtures and other meas-
ures. Based on experience m recent years, it was
assumed that, by 2000, interior use will be reduced
by an additional 5 percent as a result of increased
awareness of water conservation.
Exterior Residential Water Conservation.
Nearly half of all residential water supplied in the
State is used outdoors for watering lawns and gar-
dens. Landscapes can easily be designed to re-
quire much less water than does traditional
landscaping. Current trends suggest that an in-
creased proportion of new landscapes will be low-
water-using. Accordingly, it was assumed that, by
2010, landscapes requiring 40 percent less applied
157
On the average, about half the total residential water is used
to irrigate londscaping. More care in watering could signifi-
cantly reduce urban applied water in some communities.
water than do traditional landscapes will be in-
stalled on 50 percent of the new home lots.
The watering of traditional landscapes can also be
improved. By avoiding excessive percolation, run-
off, and evaporation, there may be about a 20-per-
cent reduction of the water so applied. It was
assumed that, by 2000, water applied to existing
landscapes will be reduced by W percent.
Commercial and Governmental Water Con-
servation. Water use by the commercial and
governmental categories is much more diverse
than residential water use and accounts for a much
smaller proportion of total urban applied water.
Consequently, the analyses of future water conser-
vation and applied water by business and govern-
ment were much less detailed than those for
residential use. Nevertheless, reductions in applied
water will probably also be achieved in these sec-
tors. Parks, golf courses, and street and highway
landscaping are being irrigated with greater effi-
ciency than before; many new parks and highways
are landscaped with low-water-using plants. Low-
water-using showerheads and faucets will be in-
stalled in new commercial and public buildings.
Low-flush toilets are required in all new hotels and
motels, and legislation now under consideration
would require low-flush toilets in all new commer-
cial and public buildings. Clothes washing and
dishwashing account for much commercial use,
and commercial appliances are also becoming
more efficient. Many businesses and government
agencies began strong conservation programs dur-
ing the drought. Some of these continue today.
More opportunities for conservation will occur as
older equipment is replaced and as new facilities
are built. Accordingly, it was assumed that, by
2000. commercial and governmental unit applied
water will be 15 percent lower than would occur
without conservation.
Opportunities to reduce applied water also exist in
the operation of municipal water systems, princi-
pally in the repair of leaks in the distribution sys-
tem. The Department and the State Water
158
Resources Control Board are currently beginning a
$1.9 million research and assistance program to
reduce municipal water system leakage. By imple-
menting leak detection and repair programs, water
utilities could reduce such losses from the present
average of about 10 percent of total deliveries to
about 6 percent. It was assumed that, by 2000. leak
detection and repair would bring about a 4-percent
reduction in applied water.
• Industrial Water Conservation. Industrial wa-
ter users began vigorous conservation efforts well
before the 1976-1977 drought in an effort to reduce
their waste water disposal fees and to respond to
waste discharge regulations. The Federal Water
Pollution Control Act Amendments of 1972 re-
quired that all firms discharging industrial waste to
public waste water treatment plants repay all costs
allocated to the treatment of their waste. In many
cases, firms have reduced their use of water signifi-
cantly by recycling and other means and have sub-
stantially reduced their discharges of waste, thus
lowering their waste water discharge bills. As older
equipment is replaced, even greater savings will be
possible. It was assumed that, by 2000. industrial
applied water will be 15 percent lower than the
historical unit rate of use.
Reductions in 2010 Per Capita Use Due to Con-
servation. The total impact of all these conserva-
tion actions in terms of per capita applied water was
estimated for each DAU and then, based upon the
projected population in each DAU. the weighted av-
erage value for each HSA was calculated. These are
presented in Table 40, which compares the "without
conservation" and "with conservation" values for
2010. The impact of water conservation on the need
for water supply is discussed in the last section of
this chapter.
TABLE 40
EFFECTS OF WATER CONSERVATION ON
WEIGHTED AVERAGE PER CAPITA APPLIED
WATER IN 2010. STATEWIDE AND
BY HYDROLOGIC STUDY AREA
(in acre-feet per person)
HSA
Without
Conservation
With
Conservation
Percent
Reduction
Due To
Conservation
NC
0.289
0.229
0.240
0.239
0.280
0.235
0.331
0.389
0.376
0.375
0.398
0.435
0.274
0.259
0.197
0.215
0.202
0,233
0.195
0.286
0.343
0.330
0.325
0.333
0.367
0.235
-10
SF
-14
CC
-10
LA
-15
SA
-17
SD
-17
SB
-14
SJ
-12
TL
-12
NL
-13
SL
-16
CR
-16
STATEWIDE
-14
Manufacturing industries are expected to continue taking
measures to reduce their fresh water requirements.
159
Urban Applied Water and Net Water
Use — 1980 and Projected
Projections of urban applied water were calculat-
ed by DAU from projected population and per capita
applied water values. Estimates of quantities of ex-
cess applied water not available for reuse (including
waste and storm drain water discfiarged to thie
ocean), togetfier with calculated ETAW, formed tfie
basis for estimating net water use.
Total urban applied water and related net water
use by HSA for 1980, 1990, 2000, and 2010 are present-
ed in Table 41. Urban net water use, statewide, is
projected to increase by 1,860,000 acre-feet — from
4,978,000 acre-feet in 1980 to 6,840,000 acre-feet in
2010. Sixty percent of ttie projected increase is in tfie
coastal metropolitan HSAs (San Francisco Bay, Cen-
tral Coast, Los Angeles, Santa Ana, and San Diego).
About 30 percent is in tfie Central Valley in the Sacra-
mento, San Joaquin, and Tulare Lake HSAs.
According to these projections, the largest per
decade increase in net use — 692,000 acre-feet — will
occur between 1980 and 1990. The increase will slow
to only 535,000 acre-feet between 1990 and 2000 and
then rise by 635,000 acre-feet between 2000 and 2010.
The reason for the lesser increase between 1990 and
2000 IS the interaction between projections of popu-
lation trends and the effect of water conservation
measures. As shown in Figure 43, projected popula-
tion increases are most rapid between 1980 and 1990
and then tend to level off. Water conservation meas-
ures are projected to have their greatest impact
between 1990 and 2000. After 2000, the effect of wa-
ter conservation on per capita urban use is projected
to remain at substantially the same level.
The distribution among HSAs of increases in urban
net water use from 1980 to 2010 is shown in Figure 44.
The largest increase in net water use is projected to
take place in the Santa Ana HSA, where the greatest
population growth is expected to occur. The three
South Coast HSAs (Santa Ana, Los Angeles, and San
Diego) are projected to account for 860,000 acre-feet
out of a total increase for the State of 1,860,000 acre-
feet. Also expected to show relatively large in-
creases, in declining order, are the Sacramento, San
Francisco Bay, and San Joaquin HSAs. The smallest
increases, reflecting the small change in population
that is projected, should take place in the North La-
hontan HSA and the North Coast HSA.
Fish, Wildlife, Recreation, and Related
Water Management Needs
The public's interest in fresh-water recreation, fish-
eries, and wildlife has increased markedly in recent
years and is expected to continue to grow. This
growth will come not only from the increases in
population, but also from greater per capita partici-
pation in specific water-related leisure pursuits and
greater concern for protection and enhancing fisher-
ies and wildlife.
In this chapter, data have been shown by decade
to 2010 wherever possible. However, this section dif-
fers somewhat because projections for the entire
1980-2010 period were not always obtainable. Data
and projections for fish and wildlife originated with
the Department of Fish and Game, and, for water-
related recreation, with the Department of Parks and
Recreation. Projections for angler participation days
were available only to 1990. No projections were
available for sales of angling and hunting licenses,
but some assumptions are presented in the text re-
garding trends that might be expected to occur. Pro-
jections for water-related recreation extend only to
2000.
TABLE 41
URBAN APPLIED WATER AND NET WATER USE
BY HYDROLOGIC STUDY AREA
BY DECADES TO 2010
(In 1,000s of acre-feet)
Year
NC
SF
CC
lA
SA
SD
SB
SJ
TL
NL
SL
C/?
TOTAL
1980....
APPLIED WATER
153
170
180
200
151
170
180
190
+ 40
967
1.050
1.090
1.170
967
1.050
1.090
1,170
+ 205
231
270
290
320
188
210
230
250
+ 60
1.654
1.760
1.830
1.950
1.534
1.630
1.680
1.790
+ 255
734
900
1.030
1,180
586
710
800
910
+ 325
389
480
580
670
389
480
580
670
+ 280
570
670
750
830
493
590
660
730
+ 235
403
490
570
660
249
310
360
420
+ 170
425
500
550
630
236
280
310
350
+ 115
23
30
35
40
23
30
35
40
+ 15
95
120
160
190
60
80
110
120
+ 60
118
160
200
230
102
130
170
200
+ 100
5.762
1990
6,600
2000
7.265
2010
8,070
1980..
NET WATER USE
4.978
1990
6.670
2000 „
6.205
2010
6.840
CHANGE IN NET WATER USE
1980 to '010
+ 1,860
160
Figure 44. INCREASE IN URBAN NET WATER USE BY HSA 1980 TO 2010
HYDROLOGIC
STUDY AREA
NORTH COAST
SAN FRANCISCO
CENTRAL COAST
LOS ANGELES
SANTA ANA
SAN DIEGO
SACRAMENTO
SAN JOAQUIN
TULARE LAKE
NORTH LAHONTAN
SOUTH LAHONTAN
COLORADO RIVER
X
100 200
Thousands of Acre-Feet
300
400
Sport fishing will probably increase in popularity.
161
TABLE 42
ANGLING LICENSE SALES IN CALIFORNIA
1950 to 1980
Year
Sales
per
too persons
Year
Sales
per
too persons
Year
Sales
per
100 persons
1950
9.2
9,1
94
98
9.9
10.0
102
10.1
9.4
9.6
1960
1961
93
91
9.4
97
98
10-0
10.5
10.4
11.1
11.0
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979 :
11.6
1951
11.2
1952
1962
10.6
1953
1963
11.2
1954
1964
11.2
1965
1965
1966
10.6
1956
10.2
1957
1967
1968
1969
9.7
1958
10.4
1959
10.2
1980
10.7
Source; California Depaflment of Fisfi and Game. Draft Ftsh and Wildlife Plan. 1981
Future Use of Fishery Resources
Sport fishing m California is increasing, due not
only to the growth in population but also to a greater
per capita participation. Table 42 shows the nunnbers
of angling licenses sold in California from 1950
through 1980. The most significant feature of these
data IS that angling licenses per 100 persons aver-
aged about 9.7 during the 1950s and about 10.7 during
the 1970s. Although this growth did not occur with-
out ups and downs, it firmly establishes sport fishing
as a progressively stronger activity in California. The
need to support the fishery resources that sustain it
is expected to continue.
Sport fishing in California includes angling for
trout, marine fish, warmwater fish, and anadromous
(migratory) fish. Angler use estimates for 1980 and
projections for 1990 are shown in Table 43, which
also shows individual species and types of fishing
access. The projections to 1990 are in proportion to
the estimate of future statewide population growth,
with the same per capita participation rates that
were observed in 1980.
Speculation is possible, based on experience, con-
cerning negative influences on the future of fish
populations and sport fishing. The pressure placed
on the resource by increasing numbers of anglers will
be intensified by conversion of land and water to
other uses. The latter will tend to impair fishery habi-
tat by degrading water quality. Public access to f isha-
ble waters may also be impeded. However, several
influences are at work to benefit the resource. The
Department of Fish and Game (DFG) has a body of
law and the budgetary support necessary to make it
a strong force in the protection of fishery resources.
Many private organizations are also increasing their
support for preservation of fish and fish habitat.
Despite the growing use of water resources, both
instream and reservoir fisheries will probably receive
TABLE 43
ESTIMATED ANGLER PARTICIPATION IN
CALIFORNIA BY TYPE OF FISHING
1980 and 1990
(In millions of angler-days)
Activity
Trout Fishing
Cultured trout
Wild trout
Privately stocked trout
Total
Marine Fishing
Piers
Shore
Private boats .
Party boats
Other
Total
Warmwater Fishing
Catfish
Bass
Sunfish
Total..
Anadromous Fishing
Striped bass (inland and marine)
Ocean salmon
Inland salmon
Steelhead
Sturgeon
American Shad
Total
TOTAL. ALL TYPES
tm)
1990
7.0
8.2
6.1
7.2
1.9
2.3
15.0
17.7
6.1
7.2
3.8
4.5
1.8
2.1
1.0
1.1
0.3
0.4
13.0
15.3
3.1
3.6
2.9
3.4
2.8
3.3
8.8
10.3
2.0
2.4
1.0
1.2
0.4
0.5
0.3
0.3
0.1
0.1
0.1
0.1
3.9
4.6
40.7
47.9
Source: California Department of Fisti and Game. Draft Fis/i and Wildlife Plan. 1981
increasing protection in water rights permits and en-
ergy development licenses. As these permits and li-
censes are periodically revised or renewed,
conditions for fisheries may be bettered over those
of original projects.
162
Future Use of Wildlife Resources
The principal habitat for many wildlife species is
closely associated with streams, lakes, or marshes,
and for some, their continuing existence depends
entirely on the presence of wetlands or bodies of
water. California's wildlife is diverse and widely dis-
tributed. Many species are classified as game and
are hunted under strictly regulated conditions. Many
other birds and animals are classified as nongame
species and are not hunted, although many of these
(along with game species) are of intense interest to
many people and provide significant enjoyment, edu-
cation, and other values.
Although hunting is not expected to increase much, bird-
watching, wildlife photography, and similar nonappropriatlve
uses of wildlife should grow substantially.
163
TABLE 44
HUNTING LICENSE SALES IN CALIFORNIA
1950 to 1980
Year
Sales per
100 persons
Year
Sales per
100 persons
Year
Sales per
too persons
1960
4.6
4.8
5.1
5.1
5.0
5.0
4.9
4.6
4.1
4.0
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
4.0
3.9
3.8
3.7
3.8
3.8
3.8
4.0
3.9
3.8
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
3.8
1951
3.5
1952
3.1
1953
3.2
1954
3.1
1955
2.9
1956
2.6
1957
2.6
1958
2.3
1959
2.2
2.3
Source: California Department of Fish and Game. Draft Fish and Wildlife Plan. 1981.
Unlike fishing, the sport of hunting is declining in
relative popularity. As shown in Table 44. the sale of
hunting licenses dropped between 1950 to 1980 from
about 5.0 to nearly 2.0 per 100 persons. DFG expects
this percentage participation rate to continue to de-
cline slowly, although total number of hunter-days
will increase due to population growth.
The use and enjoyment of wildlife for purposes
other than hunting (referred to by DFG as nonappro-
priative use) is growing rapidly. Bird watching, wild-
life photography, and similar activities are attracting
numerous participants: and, although no statewide
studies have been conducted to document the level
of such use, other evidence indicates growing popu-
larity. According to DFG estimates, nonappropriative
uses of fish and wildlife in California in 1980 amount-
ed to 48 million days of participation; such use is
projected to reach over 70 million by 1990. These
figures can be compared with their estimate of 7.4
million hunter-days in 1980 and 9.5 million hunter-
days projected by 1990. Maintenance of wildlife habi-
tat will continue to be an important consideration in
preparing and implementing water management
plans.
Future Water-Associated Recreation
According to data developed by the Department
of Parks and Recreation (DPR), participation m wa-
ter-related recreation in California for some time has
been nearly 90 days per person annually, with some
activities becoming more popular and some less.
A statewide analysis of recreation needs by DPR,
which included data on 55 types of water-associated
recreation, indicated that participation in most of
these activities was on the rise. The study estimated
the extent of use in these categories in terms of per
capita participation-days and projected these figures
to 2000. Table 45 presents the projections for the
kinds of recreation activities that are clearly associat-
TABLE 45
SELECTED WATER-ASSOCIATED
RECREATION ACTIVITIES IN CALIFORNIA
1980 and 2000
(In per capita participation-days)
Activity
Lake fishing
Stream fishing
Fresh-water swimnning
Water sibling
Power boating
Sailing
Other boating (including rafting).
Waterfowl hunting
TOTAL
1980
4.812
2000
0.907
0.930
0.706
0.732
1.137
1.199
0.727
0.711
0.522
0.563
0.401
0.496
0.340
0.398
0.072
0.064
5.093
Source. California Department of Parks and Recreation. Division of Planning. Statewide
Recreation Needs Analysis. December 1981.
' Selected from a study of 55 activities by ttie Department of Parks and Recreation to
include ifiose wfiicfi directly involve tfie use of fresfi-water streams and lakes or
bodies of brackisn water.
ed with fresh-water streams and lakes and fresh and
brackish water marshes. Sailing (including salt-water
sailing) is projected to increase 25 percent. If this
occurs, total participation-days in 2000 will be 15.5
million, compared to 12.5 million days with no in-
crease in per capita participation. "Other boating" —
primarily rafting — is expected to increase about 20
percent; power boating should also increase. While
the per capita rates for lake and stream fishing and
fresh-water swimming are projected to rise slightly,
water skiing and waterfowl hunting are expected to
decline. Overall, the projections show a 5-percent
increase m participation per person, which, coupled
with the expected population growth in California,
will result in an increase of about 65 million participa-
tion-days for all water-associated recreation by 2010
(Figure 45).
Future Offstream Water Use for Fish, Wildlife,
and Fresh-Water Recreation
Offstream water use refers to uses supported by
164
Figure 45. PARTICIPATION-DAYS IN
VARIOUS WATER-ASSOCIATED
RECREATION ACTIVITIES
1980 AND 2000
: 80
I 60
140
I 20 •
Q
I 00
o o
o o
Oo
OO
oo
o o
CO o
CO o
CD O
CO o
00 o
00 O
(Tl O
a> o
05 o
05 O
a>o
en o
— OJ
— CJ
— CJ
— CJ
— CJ
— CJ
water diverted from a stream. The 1980 and project-
ed estimates of offstream water use for wildlife man-
agement areas and for parks lying outside urban
areas are presented in Tables 46 and 47. (Water use
by parks within urban areas is included in the urban
water use figures.)
For wildlife management areas, no significant in-
creases between 1980 and 2010 are expected. The
only increase — 15,000 acre-feet by 1990 — is projected
in the North Coast HSA, where expansion of wildlife
management areas is expected. No other such
changes are projected in any part of the State by
2010.
For nonurban public parks, water use is expected
to more than double between 1980 and 2010 — from
43,000 acre-feet in 1980 to 100,000 acre-feet in 2010. Of
the total increase of 57,000 acre-feet, 37,000 acre-feet
is projected to occur in the first decade. The greatest
increase in any HSA in any one decade — 1 1,000 acre-
feet — is expected to take place between 1980 and
1990 in the South Lahontan HSA. About half that
increase is related to the State Water Project. While
only a nominal increase should occur in most of the
HSAs, three of them — Los Angeles, Santa Ana, and
South Lahontan — account for 36,000 acre-feet of the
total increase of 57,000 acre-feet by 2010.
Future Protection and Enhancement of
Instream Water Uses
Determination of instream flows needed to sup-
port the fish population and instream recreation re-
quires a case-by-case assessment. This has not yet
been performed on a statewide or regional basis.
New techniques have been developed within the last
10 years to better determine the amount of water
needed in a stream or river to maintain fish and wild-
life at suitable levels. The U. S. Fish and Wildlife Serv-
ice's "Instream Flow Incremental Methodology" and
other techniques should allow more realistic determi-
nation of instream flow needs and establishment of
adequate flows below water diversions and hydro-
power projects.
A bill relating to streamflow protection standards
was enacted by the Legislature in 1982. Assembly Bill
3493 (Chapter 1478 of the Public Resources Code)
requires the Director of the Department of Fish and
Game to identify and list the streams and water-
courses m the State for which minimum flow levels
need to be established to ensure the continued viabil-
ity of stream-related fish and wildlife resources. The
bill authorizes the Director of DFG to submit the list
to SWRCB for consideration on any application for
permits and licenses to appropriate water.
Water Use For Energy Production
Comparatively small increases in water use are
projected for power plant cooling and enhanced oil
recovery. In some cases, however, such use occurs
in water-deficient areas where it has local signifi-
cance. Where this happens, fresh-water use is ex-
pected to be minimized through the use of treated
waste water, sea water, and/or water that may be
produced by the oil recovery process.
Water Use for Power Plant Cooling
For almost a decade, the California Energy Com-
mission (CEC) has periodically revised its forecasts
of electricity demands, each time providing a lower
estimate than before. Large price increases for elec-
trical energy, coupled with private and public conser-
vation actions, have contributed heavily to the
downward direction of these forecasts. Moreover, a
165
TABLE 46
WATER USE FOR WILDLIFE MANAGEMENT AREAS
BY HYDROLOGIC STUDY AREA
BY DECADES TO 2010
(In 1,000s of acre-feet)
Year
NC
SF
CC
LA
SA
SO
SB
SJ
n
NL
SL
CR
TOTAL
APPLIED WATER
iggO -
260
270
215
230
100
100
94
94
-
7
7
7
7
5
5
5
5
167
167
157
157
86
88
64
64
45
45
31
31
10
10
10
10
3
3
3
3
17
17
17
17
700
1990 3000 2010
710
NET WATER USE
1980 -
603
1990 2000 2010
618
TABLE 47
WATER USE IN NONURBAN PUBLIC PARKS
BY HYDROLOGIC STUDY AREA
BY DECADES TO 2010
(in 1,000s of acre-feet)
year
.\c
SF
CC
LA
SA
SO
SB
SJ
TL
IVL
SL
Cff
TOTAL
APPLIED WATER AND NET WATER USE'
1980
iggO
1
i
+ 1
2
3
3
3
+ 1
2
3
5
5
+3
1
7
11
14
+13
2
8
9
10
+8
2
3
3
4
+2
3
5
5
5
+ 2
10
14
14
14
+4
7
10
10
11
+4
1
1
1
2
+ 1
9
20
21
24
+ 15
3
5
6
6
+3
43
80
89
2010
100
CHANGE IN NET WATER USE
1980 to 3010
+57
' Applied water was assumed to equal net water use
This reservoir at Rancho Seco nuclear powerplant near Sacra-
mento provides both recreation and water for powerplant
cooling.
166
different mix among electrical power-producing
facilities has resulted in more modest projections of
water requirements for cooling. This is reflected in
Table 48. which presents estimates of fresh-water
needs for power plant cooling by HSA, based on the
CEC's latest forecasts of electricity demand.
The projections are in keeping with policies adopt-
ed by both the Department of Water Resources and
the State Water Resources Control Board. In effect,
water for power plant cooling should be obtained in
the following order of priority: ( 1 ) waste water being
discharged into the ocean; (2) ocean water; (3)
brackish water from irrigation return flow; (4) inland
waste water having low amounts of total dissolved
solids: and (5) other inland water. Where the State
has jurisdiction, the use of fresh inland water for
cooling will be approved only when other sources
are insufficient in quantity and/or quality or
economically unsound.
The largest increase, amounting to more than half
the additional statewide needs of 69,000 acre-feet, is
the 40,000 acre-feet expected to occur in the Colo-
rado River HSA, using reclaimed brackish drain wa-
ter. Other significant increases should occur in the
San Francisco Bay and South Lahontan HSAs. The
current use of 8,000 acre-feet in the Santa Ana HSA
will be eliminated by the retirement of existing oil/
gas-fired plants in an effort to improve air quality.
Enhanced Oil Recovery
Enhanced oil recovery, which includes water
flooding, thermal stimulation, and chemical stimula-
tion, is used to extend the life of old oil fields and
facilitate extraction of heavy oils. While water flood-
ing and thermal methods have been used on a com-
mercial scale for some time in California, chemical
methods are projected to be used commercially in
the near future, especially in the coastal areas. The
water requirements associated with these methods
will continue to be met by production water (water
produced along with the oil), sea water, treated
waste water from both urban and agricultural
sources, and fresh water. Projected water require-
ments for enhanced oil recovery are summarized in
Table 49.
Water is used for enhanced oil recovery in only
four HSAs — Tulare Lake, Los Angeles, Central Coast,
and Santa Ana. Total water use is projected to in-
TABLE 48
WATER USE FOR POWER PLANT COOLING
BY HYDROLOGIC STUDY AREA
BY DECADES TO 2010
(In 1,000s of acre-feet)
Year
/VC
SF
cc
LA
SA
SD
SB
SJ
n
/Vi
SL
CF
TOTAL
APPLIED WATER AND NET WATER USE'
1980 . .
6
2
17
17
+ 11
_
-
6
1
2
2
-3
8
1
-8
-
2
2
+ 2
16
20
20
20
+ 5
3
-3
1
1
+ 1
2
6
16
26
+ 24
3
19
31
43
+40
42
1990
49
2000
89
2010
111
CHANGE IN NET WATER USE
1980 to 2010
+ 69
' Applied water was assumed to equal net water use
TABLE 49
WATER USE FOR ENHANCED OIL RECOVERY'
BY HYDROLOGIC STUDY AREA
BY DECADES TO 2010
(In 1,000s of acre-feet)
1980
1990
2000
2010
198010
2010
Change in
Fresh
Water Use
HSA
Total
Fresh
Total
Fresh
Total
Fresh
Total
Fresh
TL .
63
95
15
27
200
7
2
7
1
17
191
210
65
JO
496
25
32
15
1
73
181
122
59
J5
387
40
24
15
1
80
180
82
47
_25
334
40
16
12
1
69
+33
LA
+ 14
CC
+ 5
SA
TOTAL
+ 52
' Applied water and net water use.
167
Water use for enhanced oil recovery is expectecJ to show
consicJerable growth, particularly in southern San Joaquin
Valley.
crease from 200,000 acre-feet to 496.000 acre-feet per
year by 1990, when maximum oil production will be
attained, and then decline to 334,000 acre-feet by
2010 as Oil production drops. For fresh-water use, the
maximum amount of 80,000 acre-feet is projected to
be reached by 2000 and then decline by 2010 to 69,000
acre-feet. Total water use and the proportion of fresh
to total water use from 1980 to 2010 vary for each of
the four HSAs, but the Tulare Lake HSA is the only
area projected to show a significant increase in use
of fresh water during the entire 30-year period. In
2010, 40,000 acre-feet of the statewide total of 69,000
acre-feet of fresh water is projected to be used for
enhanced oil recovery in the Tulare Lake HSA.
Summary of Applied Water and Net
Water Use
Projections of annual water use in California —
both applied and net — show a fairly constant in-
crease to 2010 for most purposes. This trend is shown
in Tables 50 through 53. Total change in net water use
IS shown in Figure 46.^ As discussed earlier, net water
use IS the measure of water use that determines the
adequacy of water supplies. Some of the significant
findings regarding net water use include;
• Total net water use, statewide, is projected to in-
crease between 1980 and 2010 by 3.5 million acre-
■ Total State net water use for 1960. 1967, and 1972 (presented m Bulletins
160-66. 160-70. and 160-74, respectively) and the 1980. 1990. 2000. and
2010 values presented in this report are shown in Chapter II. Figure 3.
feet from 33.8 million acre-feet to 37.3 million acre-
feet. This is roughly a 10-percent increase over the
30-year period. To put this m perspective, the in-
crease from 1972 to 1980 was 2.8 million acre-feet,
a 9-percent increase in only eight years.
Agriculture continues to be, by far, the major water
user. Total net water use by agriculture is expected
to increase by 1.65 million acre-feet between 1980
and 2010 — a 6-percent increase. Agricultural water
use, including its pro rata share of conveyance
losses, was 83 percent of total net use in 1980 and
is projected to be 79 percent in 2010.
Total urban net water use, although significantly
less than net water use by agriculture, is projected
to increase by 1.86 million acre-feet between 1980
and 2010 — a 38-percent increase — which exceeds
the projected increase in agricultural use, both in
percentage and quantity. Urban use, with its pro
rata share of conveyance losses, will increase from
15 percent of total net use in 1980 to 19 percent in
2010.
The only area of the State in which total net water
use IS projected to decline is the South Lahontan
HSA. Although urban use will double, use by
agriculture will drop to about two-thirds of the 1980
level.
Both agricultural and urban net water use in the
three Central Valley HSAs — Sacramento, San Joa-
168
quin, and Tulare Lake — are projected to increase
significantly (2.15 million acre-feet) over the 30-
year period, with the total increase in net water use
announting to 2.24 million acre-feet. These three
areas account for almost two-thirds of the total
statewide increase of about 3.51 million acre-feet
by 2010.
The largest increase in net water use in any HSA
between 1980 and 2010 is projected to take place
in the Tulare Lake HSA. Total net use will increase
by 842.000 acre-feet, with 694.000 acre-feet of this
amount for agricultural use.
. The three South Coast HSAs— Los Angeles. Santa
Ana. and San Diego — are expected to show an
increase of 663,000 acre-feet of total net water use,
or almost one-fifth of the statewide increase
between 1980 and 2010. However, urban use is ex-
pected to increase by 861.000 acre-feet, while agri-
cultural use is projected to decline by 214,000
acre-feet, reflecting the increasing urbanization of
that region.
The effects of increases in net water use on specif-
ic water supplies and related water management
needs for each HSA are discussed in Chapter V.
TABLE 50
TOTAL APPLIED WATER AND NET WATER USE
BY HYDROLOGIC STUDY AREA
1980
(In 1,000s of acre-feet)
NC
SF
CC
LA
SA
SD
SB
SJ
TL
NL
SL
CR
TOTAL
APPLIED WATER
821
153
260
1
1,235
714
161
216
1
1,081
121
967
100
2
6
1,196
121
967
94
2
6
14
1.204
1,189
231
2
7
1,429
902
188
2
7
1.099
348
1.664
7
1
7
2,017
276
1.634
7
1
7
81
1.906
412
734
2
9
1.157
320
686
2
9
45
962
228
389
5
2
624
198
389
5
2
40
634
9.223
670
167
3
9.963
6.682
493
167
3
129
7.464
7.474
403
86
10
16
7.988
5.892
249
64
10
15
111
6.341
11.424
426
45
7
10
11.911
7.781
236
31
7
10
123
8.188
442
23
10
1
476
387
23
10
1
421
493
95
3
9
2
602
338
60
3
9
2
7
419
3.460
118
17
3
3
3,601
3.434
102
17
3
3
643
4.102
35.635
Urban . .
6.762
Wildlife '
700
43
Energy Production ^
59
TOTAL
42,199
NET WATER USE
27,046
Urban
4,978
Wildlife'
603
Recreation^
43
59
1,093
TOTAL
33,821
' Water used on public wildlife management areas-
^ Water used at nonurban public parks.
'Water used tor power plant cooling and for enhanced oil recovery.
TABLE 51
TOTAL APPLIED WATER AND NET WATER USE
BY HYDROLOGIC STUDY AREA
1990
(In 1,000s of acre-feet)
NC
SF
CC
LA
SA
SD
SB
SJ
TL
NL
SL
CR
TOTAL
APPLIED WATER
900
170
270
1.340
780
170
230
1,180
110
1,050
100
5
1.265
110
1,050
95
5
16
1,275
1,240
270
5
15
1,530
940
210
5
16
6
1,176
310
1.760
5
6
30
2.110
250
1,630
5
5
30
76
1,995
360
900
10
1,270
290
710
10
40
1,060
220
480
5
5
710
190
480
5
5
35
715
9,350
670
170
5
10,195
7,030
590
160
5
150
7,935
7,470
490
85
16
20
8.080
6.050
310
65
15
20
120
6,580
11,390
600
45
10
25
11,970
7,955
280
30
10
25
126
8,425
470
30
10
510
410
30
10
460
410
120
5
20
5
560
300
80
5
20
6
6
415
3.590
160
16
5
20
3,790
3,560
130
15
5
20
360
4,090
35.820
Urban ., , ,
6,600
Wildlife '
710
Recreation ^
86
Energy Production ^
115
TOTAL
43.330
NET WATER USE
27.865
Urban
5.670
Wildlife '
620
Recreation '
86
116
Conveyance Losses
930
TOTAL
36,285
' Water used on public wildlife management areas.
'Water used at nonurban public parks
'Water used tor power plant cooling and for enhanced oil recovery.
169
TABLE 52
TOTAL APPLIED WATER AND NET WATER USE
BY HYDROLOGIC STUDY AREA
2000
(In 1,000s of acre-feet)
NC
SF
CC
LA
SA
SD
SB
SJ
TL
NL
SL
CR
TOTAL
APPLIED WATER
Agriculture
910
180
270
1.360
790
180
230
1.200
100
1.090
100
5
15
1.310
100
1.090
95
5
16
20
1.325
1.230
290
6
15
1.640
940
230
6
16
5
1.196
270
1,830
6
10
26
2.140
220
1.680
5
10
25
75
2.015
310
1,030
10
1.350
260
800
10
40
1.100
200
580
5
6
790
180
580
6
6
36
806
9.000
750
170
5
9.925
7.010
660
160
6
150
7.965
7.510
570
85
15
20
8.200
6160
360
66
16
20
130
6.760
11,390
660
45
10
40
12.036
8.186
310
30
10
40
125
8.700
470
35
10
615
410
35
10
465
360
160
6
20
16
550
270
110
5
20
16
6
426
3.730
200
15
5
30
3.980
3.700
170
16
6
30
280
4,200
36470
Urban
7.266
Wildlife '
710
90
Energy Production '
160
TOTAL
43696
NET WATER USE
28.215
Urban
6,205
Wildlife'
620
Recreation' _
90
160
866
TOTAL
36.156
' Water used on public wildlife management areas.
'Water used at nonurban public parks.
* Water used for power plant cooling and for enhanced oil recovery
TABLE S3
TOTAL APPLIED WATER AND NET WATER USE
BY HYDROLOGIC STUDY AREA
2010
(In 1,000s of acre-feet)
NC
SF
CC
LA
SA
SD
SB
SJ
TL
NL
SL
CR
TOTAL
APPLIED WATER
930
200
270
1.400
810
190
2»
1.2X
90
1.170
100
5
16
1.380
90
1.170
95
5
15
20
1.396
1.200
320
5
10
1.535
930
250
5
10
5
1.200
230
1.960
6
15
20
2.220
190
1.790
5
15
20
75
2.096
260
1.180
10
1.450
220
910
10
40
1.180
190
670
5
5
870
170
670
6
6
40
890
9.070
830
170
5
10.076
7.140
730
160
6
150
8.185
7.680
660
86
16
20
8.460
6.370
420
65
16
20
130
7.020
11.540
630
46
10
40
12.266
8.476
350
30
10
40
125
9.030
480
40
10
530
420
40
10
470
280
190
5
25
26
525
230
120
5
25
25
6
410
3.700
230
16
6
45
3.996
3.680
200
15
6
46
280
4.225
36.660
Urban
8.070
Wildlife'
Recreation' „
Energy Production ' „
TOTAL
710
100
176
44.706
NET WATER USE
28.726
Urban
6840
Wildlife'
620
100
Energy Production'
175
870
TOTAL
37.330
' Water used on public wildlife management areas.
'Water used at nonurban public parks.
' Water used for power plant cooling and for enhanced oil recovery.
170
Figure 46. CHANGE IN TOTAL NET WATER USE BY HSA 1980 TO 2010
HYDROLOGIC
STUDY AREA
NORTH COAST
SAN FRANCISCO BAY
CENTRAL COAST
LOS ANGELES
SANTA ANA
SAN DIEGO
SACRAMENTO
SAN JOAQUIN
TULARE LAKE
NORTH LAHONTAN
SOUTH LAHONTAN [
COLORADO RIVER
■
1
1
100
200 400
Thousands of Acre-Feet
600
800
Impacts of Water Conservation
Assumptions
Projections of applied water reflect likely water
conservation measures and actions, including in-
creases in irrigation efficiency. The extent to which
these actions actually create a savings in water sup-
ply depends upon how they influence net water use.
Net water use for a given study area will be re-
duced to the extent that water conservation meas-
ures and actions reduce crop or urban landscape
ETAW, irrecoverable losses from distribution sys-
tems, or outflow from the area. In all cases, reduc-
tions in ETAW and irrecoverable losses are savings
in water supply. The question of whether a saving in
water supply is attained by reducing outflow from
the area, however, depends on whether the outflow
normally goes into an unusable source such as a salt
sink (the ocean or saline ground water), supplies a
downstream user, or accomplishes some special
beneficial purpose, such as satisfying Delta outflow
needs. In the latter two cases, there would be no
water supply savings because the outflow fulfills a
need that otherwise would have to be met from an-
other source.
Although water conservation may not always
achieve equivalent savings in water supply, signifi-
cant energy savings may be achieved because re-
pumping of excess applied irrigation water that
percolates to ground water is reduced. Energy sav-
ings may also result from reduced delivery system
pumping and treatment of water supplies and waste
water.
Water Supply Savings from Water
Conservation
For both the urban and the agricultural sectors,
each DAU was examined to evaluate the reduction
171
in ETAW, irrecoverable losses from distribution sys-
tems, and outflow to a salt sink (or where otherwise
unavailable for reuse) that would be achieved by the
assumed water conservation actions, including in-
creased irrigation efficiency. As discussed earlier, ur-
ban conservation included the impact of measures
and actions taken from 1975 to 2010, while agricul-
tural conservation was assumed to be any projected
increase in irrigation efficiency and related measures
after 1980.
In the urban sector, ETAW will be reduced be-
cause less water will be used to support landscape
vegetation, principally reflecting increased use of
drought-tolerant plants. For the agricultural sector,
the ETAW reduction was calculated on the basis of
assumptions regarding the extent to which drip irri-
gation will be used on young orchards and grapes.
The ETAW reductions result from the wetting of a
smaller soil area and, therefore, less evaporative loss.
As the trees and vines mature and the root systems
expand, however, the water savings potential
becomes slight, if any.
Reduction in irrecoverable losses from distribution
systems (seepage to saline ground water) was deter-
mined for the Imperial Valley, based upon the results
of a study by the Department.^
The quantity of outflow to a salt sink or other unus-
able water body was determined through a hydrolog-
' Investigation Under California Water Code Section 275 of Use of Water
by Imperial Irrigation District. Department of Water Resources. Decem-
ber 1981.
ic balance analysis relating net water use to net
water supply.
Reductions in applied water and the related water
supply savings in each HSA by 2010 are presented in
Table 54. The urban water supply savings are about
50 percent higher than the agricultural savings. This
is due primarily to the proximity of the major metro-
politan areas to the ocean, where large portions of
urban waste water and runoff (including storm drain
flow) become outflow to the ocean. The remaining
excess applied water percolates to ground water or
IS otherwise available for reuse. The urban water sup-
ply savings in inland areas is accomplished principal-
ly by reducing landscape evapotranspiration.
The very large reduction in applied water from in-
creased irrigation efficiency in the Central Valley —
nearly 3 million acre-feet — provides only 120,000
acre-feet in water supply savings because of the
reuse of the excess applied water and the need to
maintain specified outflows through the Delta. Ex-
cess irrigation water in the Central Valley, other than
that consumptively used by native vegetation along
drains and streams or in wetland areas, either perco-
lates into ground water basins or drains back into
rivers that flow to the Delta. During most of the irriga-
tion season. Delta outflows are controlled to main-
tain water quality standards set by the State Water
Resources Control Board. Under normal conditions,
these required flows are such that any reduction in
irrigation return flow to the Delta must be offset by
increased reservoir releases (or by reducing export
diversions).
TABLE 54
ANNUAL APPLIED WATER REDUCTIONS AND RELATED WATER SUPPLY SAVINGS
IN 2010 RESULTING FROM WATER CONSERVATION ' BY HYDROLOGIC STUDY AREA
(In 1,000s of acre-feet)
Urban
Agricultural
TOTAL
HSA
Applied
Water
Reductions
Water
Supply
Savings
Applied
Water
Reductions
Water
Supply
Savings
Applied
Water
Reductions
Water
Supply
Savings
NC
25
190
25
360
240
140
130
85
90
5
40
45
20
190
25
290
160
140
30
25
25
10
40
955
5
5
40
45
40
30
1.480
580
810
35
50
360
3.480
5
5
25
10
110
340
m
645
30
195
65
405
280
170
1.610
665
900
40
90
405
4.855
20
SF
195
cc
30
LA
290
SA
160
SD
165
SB
30
SJ
35
TL
135
NL
SL
10
CR On-farm
380
CR Distribution system
150
TOTAL
1,375
1.600
Reductions and savings trom the level of water use that would occur without the
projected conservation actions.
172
The relatively large savings of 135,000 acre-feet
projected for the Tulare Lake HSA primarily reflect
reduced percolation of excess applied water to sa-
line high water tables and moisture-deficient soils. '°
A large water savings potential exists in the Colo-
rado River HSA because excess applied water m the
Imperial Valley and much of the Coachella Valley
enters saline drains or saline ground water and can-
not be reused. Where this occurs, any reduction in
excess applied water represents a water savings.
Substantial savings are also expected from distribu-
tion system improvements to reduce seepage to sa-
line ground water and excess spillage to the Salton
Sea.
The water conservation assumptions presented in
this report represent what is now believed will likely
occur. However, wider use of the conservation meas-
ures described in these assumptions or use of other
water-saving measures could bring about even great-
er savings.
Energy Savings from Water Conservation in
the Central Valley
A cursory estimate was made of the effect of a
' Soils described as moisture-deficient are extraordinarily dry and have an
unusually high capacity for retaining moisture. Water absorbed by
moisture-deficient soils is "locked up" and unavailable to plants. More-
over, It does not percolate to a usable ground water source and thus
represents a loss. These soils are confined primarily to a relatively small
area along the southwestern edge of the valley floor in the Tulare Lake
HSA.
projected increase in irrigation efficiency on the use
of electrical energy in the Central Valley. Part of the
excess applied water in the valley runs off and is
reused downstream or becomes part of the Delta
outflow. The remainder percolates to ground water
and is pumped and reused. With an increase in irriga-
tion efficiency, less deep percolation of excess ap-
plied water would occur and less repumpmg would
be necessary to satisfy applied water needs. This,
along with estimates of pumping lifts and other fac-
tors affecting energy use, provide the basis for cal-
culating the energy savings in 2010 due to
agricultural water conservation.
Annual Energy Savings from Increased Irrigation
Efficiency in the Central Valley in 2010
Million
Hydrologic Study Areas kilowatthours
Sacramento 20
San Joaquin 80
Tulare Lake 300
TOTAL 400
As would be expected, the projected reduction in
electrical energy use is greatest m the Tulare Lake
HSA, where most pumping lifts by 2010 are expected
to range between 250 and 450 feet. Lesser savings are
expected in the San Joaquin HSA, where lifts are
expected to range between 100 and 200 feet. The
savings in the Sacramento HSA would be even less,
with lifts of 50 to 100 feet.
173
CHAPTER V
PROJECTED USE OF WATER SUPPLIES TO 2010
This chapter analyzes the supply of water needed
in California to satisfy the net water use projected to
occur by 2010. It presents the situation related to
existing and potential future surface water develop-
ment, together with the role that ground water and
reclaimed waste water are expected to play in meet-
ing future needs. The chapter concludes with a sum-
mary of current and projected net water use and
water supply and a discussion of water use and wa-
ter supply conditions in each HSA.
The analysis shows that projected increases in ur-
ban and agricultural net water use will be supported
by presently uncommitted Central Valley Project
(CVP) supplies, reserve supplies of local projects,
additional ground water overdraft, and increased
waste water reuse. Except for the Cottonwood
Creek Project, with yield allocated to nonfederal use,
no new federal water supply reservoirs were as-
sumed to be completed in the next 30 years. Howev-
er, it was recognized that the Auburn and enlarged
Shasta projects could be built within this period.
A similar situation exists with the State Water
Project (SWP) . Only relatively small additions to the
yield of the SWP can definitely be identified at this
time. The amount and timing of other water supply
additions to the SWP are uncertain, although the
possibility of substantially augmenting the yield of
the SWP from new water supply facilities before
2000 is not likely because of the time required for
authorization and construction. The Department of
Water Resources has plans under way to select the
best possible additional projects and schedule.
No new local projects were identified as definitely
available by 2010 to meet projected needs. However,
it was assumed that supplemental needs in the rapid-
ly growing Sierra Nevada foothills could be provided
for by such projects as the Upper South Fork Ameri-
can River Project and the Upper Stanislaus River
Project. Local projects being considered in the Cen-
tral Coast HSA would reduce the need to import CVP
or SWP water to that area.
For the SWP, the yield from existing and planned
facilities is inadequate to meet projected contractual
commitments. Because the scheduling of future de-
pendable supplies is uncertain, the potential shortfall
is shown in the figures in this chapter as an SWP
shortage. In most cases, the shortage could be offset
by the use of ground water, thereby further increas-
ing ground water overdraft.
Only a substantial commitment to large-scale sur-
face water storage and conveyance facilities would
enable the major water supply problems in the State,
including ground water overdraft, to be brought un-
der control in the next 30 years. As noted above,
except for Auburn Dam, which is in the final design
stage but must be reauthorized by Congress, and the
Cottonwood Creek project of the Corps of Engi-
neers, it could be as much as 30 years before any
other new major surface water supply projects — fed-
eral or State — can be put into operation. As a result,
ground water overdraft in the San Joaquin Valley is
projected to increase from 1.2 million acre-feet at the
1980 level of development to 2.4 million acre-feet and
could go as high as 3.2 million acre-feet by 2010. The
real increase, however, will depend on the extent to
which reserve CVP supplies can be used in the Mid-
Valley Canal service area or made available to the
SWP and the extent to which SWP shortages will be
offset by increased ground water use. Outside the
San Joaquin Valley, an overall reduction in ground
water overdraft is projected, with only the Sacra-
mento and Colorado River HSAs showing any signifi-
cant increase.
The other major problem area, the South Coastal
region, where half the State's population lives, is
faced with the potential of a shortage in dependable
supplies occurring as early as the end of this decade.
Identified supplies from the SWP in 1990 will be less
than projected requirements by 215,000 acre-feet. By
2010, the shortage increases to 410,000 acre-feet.
These potential shortages could occur, even though
the use of reclaimed waste water savings from water
conservation are expected to increase considerably.
In the event of a prolonged drought such as occurred
from 1928 to 1934, SWP supplies could not meet
needs in this region. Extreme measures that could
directly affect business, industry, and agriculture
would be necessary to cope with such a situation.
There is no assurance that surplus Colorado River
supplies will be available to California, once the Cen-
175
Figure 47. REMAINING DEVELOPABLE SURFACE WATER IN CALIFORNIA
Long-Term Average-1980 Development Level
MILLIONS OF ACRE-FEET
78.5
I.SLandUse Changes a/
1.4 Inflow from OregoiT,
COLORADO RIVER
DIVERSIONS
4.8
SURFACE RUNOFF
FROM PRECIPITATION
70.8 ty
100%
2%
78.5
6%
6%
27%
59%
1,2 EVAPORATION
GROUND WATER
RECHARGE
4.6 ^
COLORADO RIVER
DIVERSIONS
4.8
STORAGE OR DIRECT
DIVERSION OF
IN-STATE WATER
21.3
REMAINING IN STREAMS
46.6
a/ Gain in unimpaired runoff due to change
from native vegetation to paved areas,
buildings, and other land uses.
b/ Water Resources Board Bulletin No. 1, 1951
c/ Percolation from streambeds. Excludes
planned recharge and direct percolation
through the soil.
d/ Total is 5.1 million acre-feet, the balance
of which comes from release of stored
water and return flows
e/Of the 5.5 million acre-feet, about 4.6 is
estimated to be in the Sacramento HSA
46.6
O
DEVELOPMENT
IMPROBABLE
Over 8.5
POSSIBLE x/,,V>^
VELOPMENT/^
POTENTIAL s/V/
y Less than 5.5
3.6
1.2
OTHER NORTH
COAST SOURCES
10.0
NORTH COAST WILD
AND SCENIC RIVERS
17.8
SALINITY REPULSION d/
OUTFLOW TO NEVADA
EXISTING SUPPLIES
PRESENT DISPOSITION
OF EXISTING SUPPLIES
DISPOSITION OF
REMAINING RUNOFF
176
tral Arizona Project is in operation. Ground water
overdraft could provide emergency supplies, but this
would require institutional changes in the operation
of several adjudicated ground water basins.
Additional surface water supplies could be devel-
oped within the Sacramento Valley and could be
used to meet or greatly reduce much of the need for
supplemental supplies. The amount available and the
projects being considered to develop this supply are
presented in the following section of this chapter.
Surface Water Supplies
California's surface water available under the 1980
level of development averages 78,500,000 acre-feet
per year. The sources and their present disposition
are shown m Figure 47. The extent of present com-
mitments on flows currently remaining in streams
and the balance that has potential for development
are shown by the right-hand bar. This distribution is
in accordance with the basic assumption on water
supply availability described m the preceding chap-
ter. Out of the total of 24.0 million acre-feet of uncom-
mitted remaining runoff, only 5.5 million acre-feet is
considered developable. The reasons for this are
both physical and economic. Likewise, North Coast
flows amounting to about 10 million acre-feet are not
considered to be a potential source of supply during
the period of analysis.
Elsewhere in the State, the unregulated flow oc-
curring in small coastal streams in the San Francisco
Bay. Central Coast, Los Angeles, Santa Ana, and San
Diego HSAs offer only limited opportunities for de-
velopment. The same is true of runoff in the Southern
California desert areas. In effect, it appears at this
time that the opportunities for any significant further
development of California's water resources are lim-
ited essentially to the Central Valley.
Present planning recognizes the need for equal
consideration of instream and offstream uses of wa-
ter. The center bar of Figure 47 shows the amount of
water remaining in streams after allowance is made
for imported water and present use. As depicted, 60
percent of California's surface water supplies pres-
ently remain in streams and rivers. Even if all the
surface water estimated to be developable were
eventually diverted. 52 percent of the State's surface
water would remain in streams and rivers.
Additional surface water development has been
planned or considered that would develop a portion
of the 5.5 million acre-feet identified as "potentially
developable." Some of these include development
of local supplies to meet local needs and are de-
scribed later in this chapter. The greatest need.
however, exists in the San Joaquin. Tulare Lake, and
South Coastal region HSAs and involve large-scale
interbasin transfers. Consequently, further major sur-
face water development probably can be accom-
plished only by the State through additions to the
SWP and by the federal government, primarily
through additions to the CVP.
State Water Project Supply
Dependable supply from existing and proposed
facilities of the SWP under present and projected
conditions is shown on Figure 48. About half the
present SWP yield is derived from Lake Oroville, and
the remainder is developed from surplus flows in the
Delta and re-regulated in San Luis Reservoir. SWP
project yield declines with time because Delta inflow
IS depleted by irrigation and urban development pro-
jected to occur in the areas of origin and because the
CVP will be using Delta CVP supplies that are cur-
rently available to the SWP.'
For the next several years, SWP requirements can
be met in average and wet years, but the risk of
shortages will increase with the delay in adding facili-
ties. Some additional yield (60,000 acre-feet) can be
provided by installing the last four pumps in the Har-
vey 0. Banks Delta Pumping Plant, bringing it up to
its design capacity, and by proceeding with the
ground water storage program to the extent possible
without a Delta facility (200,000 acre-feet). Enlarge-
ment of the East Branch of the California Aqueduct
will facilitate delivery of water to Southern California
^ After studies for tfiis report were completed, otfier more recent studies of
coordinated SWP-CVP operation and revised operation of Oroville Res-
ervoir sfiow that tfie firm yield of the SWP is about 200,000 acre-feet
greater for the period 198O-2010. This would reduce the potential short-
ages shown for the SWP later in this chapter.
Harvey O. Banks Delta Pumping Plant near Tracy, an SWP
facility, lifts water from the Delta 244 feet into the California
Aqueduct. The Delta Operations and Maintenance Center is
situated at left, and Bethany Dam and Reservoir appear at
top. Addition of the final four pumps to bring the plant to
design capacity of 10,300 cubic feet per second will improve
operational flexibility and provide additional supplies for the
SWP.
177
Figure 48. SWP PROJECTED WATER REQUIREMENTS AND
WATER SUPPLY SOURCES
ground water basins for storage underground;
however, it does not add yield to the system. The
Cottonwood Creek Project presently being planned
by the Corps of Engineers (175.000-acre-foot yield)
was assumed to proceed as planned.
SWP Ground Water Storage Program. SWP
yield can be increased significantly by a conjunctive
operation program that involves storage of surplus
water supplies in ground water basins in SWP serv-
ice areas in the San Francisco Bay, Tulare Lake, Los
Angeles, and Santa Ana HSAs. Surplus water would
be stored during wet years and pumped for use dur-
ing dry periods as part of the SWP yield.
Conjunctive operation of surface and ground wa-
ter supplies has been practiced for many years in
areas such as the Salinas Valley, Santa Clara County,
the San Joaquin Valley, and in several parts of South-
ern California. This has been accomplished largely
with local surface supplies. The SWP provides the
opportunity for a substantial increase in conjunctive
use through long-distance transfer of excess north-
ern water. Six areas identified on Figure 49 appear to
be the most promising for further evaluation. The
basins ultimately selected, operated in conjunction
with excess flows delivered through the California
Aqueduct and its branches, could develop an es-
timated 200,000 acre-feet per year of dependable
supply.
Conjunctive operation of the SWP and ground wa-
ter basins will require:
• Basins having suitable location, empty storage
capacity, adequate infiltration and transmissibility
characteristics for recharge, and good water qual-
ity.
• Excess water at the Delta for conveyance to basins
for recharge after all entitlements and water qual-
ity standards have been met.
• Capacity in the California Aqueduct between the
Delta and the selected ground water basin at the
same time the excess water is available at the Del-
ta.
178
Figure 49. POTENTIAL GROUND WATER
FEASIBILITY STUDY AREAS FOR
STATE WATER PROJECT
South Bay
Basins,
Oran
/
/
\
\
Fan Area Basins
ernando Basin
Chino Basin \
Bunker Hill- \
San Tlmoteo- •
Yucaipa Basins^
Two methods of operation to augment water yield
are possible — direct and indirect. Both methods de-
pend on the availability of excess water in the Delta
and capacity in the California Aqueduct.
The direct method would involve the use of SWP
water for direct recharge of ground water basins.
The recharged water would be extracted and deliv-
ered to SWP contractors during dry years. Surface
facilities for this type of operation consist of spread-
ing areas, conveyance facilities, and pumping facili-
ties for future water extraction.
The indirect method would provide additional
SWP water in wet years, in lieu of pumping water
from the underlying ground water basin. Thus,
ground water storage would be allowed to increase
through normal recharge of the basin. The stored
ground water would be pumped and used during
drought periods when surface water deliveries were
inadequate to meet requirements. Use of the indirect
method would eliminate the need to construct
spreading facilities required for a large-scale, direct-
method operation.
Many issues must be resolved before ground water
storage programs to augment SWP supplies can pro-
ceed. These include the equitable sharing of basin
storage space, allocation of costs and benefits, and
appropriate management procedures. For example,
current SWP contracts allow for the sale of "surplus
water" at a price equal to the cost of delivering the
water, which is well below that of contract entitle-
ment water. Under a ground water storage program,
some of this more favorably priced water now being
purchased by agricultural contractors would proba-
bly have to be diverted, instead, to ground water
recharge.
SWP Brackish Water Reclamation Program.
The Department of Water Resources is proceeding
with implementation of a program to desalt brackish
agricultural drainage water that could increase sup-
plies for the SWP. The principal elements of the pro-
gram are:
• To operate a demonstration desalting facility to
obtain information needed for design and cost es-
timating of large-capacity plants.
• To determine possible sites for desalting facilities.
• To evaluate desalting facilities, delivery of brackish
agricultural drainage water to desalters, convey-
ance of desalted water to places of use, and dis-
posal of brine.
• To determine a schedule of demand for desalted
water and availability of proposed desalting facili-
ties.
• To develop a coordinated plan of operation for
desalting facilities.
• To determine the feasibility of using brine from the
desalter for salt-gradient solar ponds that would
provide the energy for operating the desalter.
179
Preliminary determinations of existing and project-
ed locations and characteristics of agricultural drain-
age water are already available from previous
studies. The Department has evaluated the technol-
ogy of desalting agricultural drainage in the San Joa-
quin Valley with pilot plant studies and is
constructing a demonstration desalting plant to ob-
tain design and cost data. The demonstration plant
capacity of the desalter is 344,000 gallons per day.
The data obtained from the facility will be used to
evaluate large-scale desalting facilities designed to
produce nominally 25.000 acre-feet per year. Desalt-
ing systems use considerable energy, and on-site en-
ergy recovery and power generation from
salt-gradient solar ponds would reduce net energy
requirements.
Projected Use of SWP Supply. The dependa-
ble supply of existing facilities o' :r~e SWP is shown
in Figure 48. The line showing projected require-
ments reflects the effect of projected conservation
measures and actions. Projections of supply are
based on the assumption that certain facilities would
be constructed as scheduled. The impact of poten-
tial SWP water shortage on growth, as well as other
means of coping with the deficiencies, have not been
determined.
The water use and water supply summaries for the
San Francisco Bay, Tulare Lake, Los Angeles. Santa
Ana, and San Diego HSAs presented later in this
chapter discuss allocation of existing dependable
SWP supplies. These allocations include the addi-
tional yield developed by the Cottonwood Creek
Project, installation of the remaining Delta pumps,
and a ground water storage program yielding 200,000
acre-feet. The remaining requirements of the SWP
are shown as a potential shortage in dependable wa-
ter supplies. A large portion of this potential shortage
in the Tulare Lake HSA would probably be translated
into ground water overdraft. In wetter-than-normal
years, some of the shortage can be met from surplus
water. It is also possible that other sources of supply
can be added before 2010 to increase the yield of the
SWP. The most promising of these are a Delta water
transfer facility and purchase of uncontracted-for
water from the CVP. Until additional water supplies
are provided, the threat of shortages that are more
frequent and more severe than under the present
dry-year deficiency contract provisions will exist.
Federal Central Valley Project Supply
The net water supply capability of the existing
Central Valley Project is projected to ultimately
(beyond 2010) be about 9.45 million acre-feet per
year, assuming full use of water by present and po-
tential water contractors. The northern portion of the
system (the Sacramento, American, and Trinity Riv-
ers) will contribute 7.7 million acre-feet of this
amount for use in the Sacramento River, American
River, and Delta service area. The other units — New
Melones, Friant, Hidden and Buchanan, Sly Park, and
Sugar Pine Reservoirs — account for the remaining
1.75 million acre-feet.
The estimate for the northern CVP system is based
on coordinated operation with the SWP to maintain
Delta water quality standards in accordance with the
State Water Resource Control Board's Decision
1485. The current level of Trinity River fish releases is
assumed to continue indefinitely. The estimate does
not include supply from the proposed Auburn Reser-
voir.
CVP water supply is predicated upon a considera-
ble amount of reuse; that is, return flow to the Sacra-
mento River and the Delta from upstream CVP
service areas is counted again as project supply
available for rediversion or to meet Delta outflow
requirements. Therefore, if upstream use does not
increase as projected, the CVP water supply would
be reduced.
Under the 1980 operating criteria and level of de-
velopment, the net water supply from the northern
portion of the CVP system is about 6.5 million acre-
feet per year. Since this total is not needed in all
years to meet present contractual obligations, and
because some conveyance systems have not been
completed, operational spills and a portion of the
releases to maintain instream flows indirectly
become part of the Delta water supply and are
shared with the SWP. In the future, these reserve
supplies will be used to satisfy service area obliga-
tions and there will be a reduction in the Delta supply
shared by the SWP.
The dependable supply potential of New Melones
Reservoir is 210,000 acre-feet per year. The dependa-
ble supply of the Friant Division is 800,000 acre-feet
annually, plus an average of 657,000 acre-feet of non-
firm supplies. The nonfirm supplies are used con-
junctively with ground water in the service areas of
the Friant-Kern and Madera Canals and result in firm
supplies to those users. Hidden and Buchanan Reser-
voirs near Madera, completed by the Corps of Engi-
neers in 1979, have been added to the CVP. and each
provides 24,000 acre-feet per year to project yield.
Sugar Pine Reservoir will provide 2,800 acre-feet an-
nually to meet supplemental needs in the service
area of the Foresthill Divide Public Utility District.
The San Felipe Division, presently under construc-
tion, will deliver water from San Luis Reservoir to
Santa Clara and San Benito Counties. Facilities may
be extended later to provide service to Monterey and
Santa Cruz Counties. Principal features of the project
are shown on Plate 1 and Figures 21 and 60. The
project will provide about 216,000 acre-feet annually
by 2020 — 145,000 acre-feet to Santa Clara County,
40,000 acre-feet to San Benito County, and 20,000
acre-feet to Santa Cruz and Monterey Counties.
180
About 60 percent of the water delivered to Santa
Clara County will be used for recharge of the ground
water basin. Nearly all the water provided to San
Benito County will be delivered as surface water to
replace boron-contaminated ground water and to
bring agricultural land into production. Construction
of project facilities to supply Santa Cruz and Monte-
rey Counties is being deferred for the present time.
Because of limited capacity m the Delta-Mendota
Canal, the Department has agreed to wheel water for
San Felipe through the California Aqueduct, pro-
vided the U. S. Bureau of Reclamation (USBR) first
meets its share of Decision 1485 requirements.
Possible future additions to the CVP include the
proposed Mid-Valley Canal, completion of Auburn
Dam and Reservoir, and enlargement of Shasta Dam
and Reservoir. A Mid-Valley Canal that could deliver
water to areas of serious ground water overdraft in
the eastern San Joaquin Valley has been studied
jointly by USBR and the Department. The proposed
alignment is shown on Plate 1 and Figures 66 and 68.
The project would supply annually 500,000 acre-feet
of dependable supply and 150,000 acre-feet of non-
firm water from existing and planned CVP reservoirs
in the Sacramento River Basin and from surplus v/\n-
ter and spring flows in the Delta. Full realization of
the project yield would require a Delta water transfer
facility. Water would be conveyed from the Delta
through the California Aqueduct or an enlarged Del-
ta-Mendota Canal.
There are several issues and problems in connec-
tion with the proposed project that would require
resolution before the project could move forward. If
the California Aqueduct were used, capacity avail-
able for conveying the water would need to be deter-
mined. Water management measures to control the
use of water in the service area would have to be
implemented to ensure that overdraft was reduced
and no additional land was irrigated. Allocation of
CVP water supply for the project would need to be
made. The cost, excluding new storage project
costs, would be between $600 and S700 million at
January 1980 price levels, depending on the alterna-
tive means assumed to convey the water from the
Delta. Cost of irrigation water would depend on the
extent of financial integration with the CVP, the ef-
fect of recent revisions of reclamation law, and the
amount of CVP dependable supply that can be made
available.
Construction of Auburn Dam was suspended in
Auburn Dam site on the North Fork American River. Down-
stream view shows the present status of construction. A 200-
foot-high upstream cofferdam is situated in the foreground,
with the dam's keyway or "notch" in the canyon visible just
above. V^ork on the dam has been suspended, pending rede-
sign to meet higher seismic criteria and reauthorization by
Congress.
181
1975 because of increased seismic requirements. The
dam has since been redesigned. The Auburn-Folsom
South Unit of the CVP is being re-evaluated by the
USBR, and a bill, H.R. 2219. for reauthorization of the
unit was submitted to Congress in 1983. As planned.
Auburn Reservoir would have a gross storage capaci-
ty of 2,326,000 acre-feet. Initial power plant installed
capacity would be 300 megawatts. An additional 450
megawatts could be added later. The reservoir
would add about 318,000 acre-feet per year to the
dependable water yield of the CVP. Other project
purposes are recreation, fish and wildlife enhance-
ment, and flood control needed to control the stand-
ard project flood in the lower American River.
The estimated first cost of the Auburn-Folsom
South Unit IS S2.06 billion in 1982 prices. Of this
amount, about $310 million had been expended
through September 1981 on Sugar Pine Dam and
Pipeline, Folsom South Canal, and Auburn Dam and
Powerplant.
Enlargement of Shasta Reservoir also is the subject
of joint study by USBR and the Department. Shasta
Lake is the principal water storage facility for the
CVP and has a storage capacity of 4.55 million acre-
feet, which is only 80 percent of the long-term aver-
age annual runoff at the dam site. Consequently,
there is sufficient unregulated runoff to justify sub-
stantial storage enlargement.
Studies conducted in 1978 by USBR indicate that
the optimum upper limit of storage capacity would
be 14 million acre-feet. Preliminary estimates indicate
that about 1.4 million acre-feet of dependable dry-
period yield could be developed from a reservoir of
this size. The enlarged reservoir, together with an
enlarged power plant, would increase present aver-
age annual generation of 2 billion kilowatthours by
some 30 percent, depending on the mode of opera-
tion. The estimated first cost is $1.8 billion at 1981
prices.
Projected Use of CVP Supply. As stated earlier
in this section, the long-range net supply (yield) of
the CVP presently available for allocation to water
users IS about 9.45 million-acre feet per year. The
entire Fnant Division supply is presently committed.
In the Auburn-Folsom South Unit. Sugar Pine Reser-
voir has just been completed, and its 2,800-acre-foot
Shasta Dam and Reservoir of the Central Valley Project,
showing the outline of the proposed enlargement. Raising the
present height of the dam by another 200 feet would create
a 14-million-acre-foot reservoir and increase the dependable
water supply by about 1.4 million acre-feet per year.
182
The Sacramento-San Joaquin Delta. Water right permits for
the SWP and CVP require water quality in Delta channels to
be maintained at prescribed levels as a condition for export
of water from the Delta.
supply was assumed to be fully used by 2000. The
dependable supply from New Melones Reservoir,
210,000 acre-feet, was assumed to be reserved for the
designated service area within San Joaquin, Stanis-
laus. Tuolumne, and Calaveras Counties.
No additional conservation storage was assumed
to be added to the CVP between now and 2010. The
Folsom South Canal and the San Felipe Division were
assumed completed, and the present Cross Valley
Canal conveyance arrangement was assumed to
continue.
Future water needs to be met from the CVP were
projected to be 8.1 million acre-feet per year by 2010.
This IS an increase of one million acre-feet over the
1980 level. The major increases are projected to oc-
cur in the Tehama-Colusa Canal, American River, Fol-
som South Canal, and San Felipe service areas.
There are potential demands in the proposed West
Sacramento Canal and Mid-Valley Canal service
areas, but those facilities are not now authorized and
were not included in the foregoing estimates.
Impact of Delta Outflow Requirements on
Operations of SWP and CVP
Both the SWP and the CVP develop part of their
yield from surplus flows to the Delta. The Delta is the
focal point of operations for the SWP and, to a con-
siderable extent, for the CVP. The amount of Delta
surplus flows available for export depends on
amounts of inflow. Delta area consumptive uses, and
Delta outflow requirements. These surpluses occur
during winter and spring. During summer and fall,
however, water must be released from both SWP
and CVP reservoirs to comply with Delta outflow
requirements.
Outflow requirements are established by the State
Water Resources Control Board (SWRCB) as a con-
dition of water rights issued for the CVP and the
SWP. For the Delta, the SWRCB has reserved juris-
diction over terms and conditions affecting Delta wa-
ter supplies in three general areas: (1) salinity
control, (2) protection of fish and wildlife, and (3)
coordination of terms and conditions of the respec-
tive permits for the CVP and SWP. In its water rights
Decision 1485, which sets forth the terms and condi-
tions currently in effect, the SWRCB recognized the
uncertainty associated with future project facilities
and the need for additional information on the ef-
fects of project operations and water quality condi-
tions in the Delta and Suisun Marsh.
183
Figures 50 and 51 show uses of Delta inflow at the
1980 and 2000 levels of development. For both levels.
in about 8 out of 10 years, annual Delta inflows are
more than adequate to meet uses. In the other years.
exports by the CVP and SWP would have to be re-
duced, as would required outflow under Decision
1485.
Figure 52 shows the monthly disposition of Delta
inflow for a near-average water year (1928) and a
very dry water year (1929) under the 1980 level of
development. As typified by these two years. Delta
exports for the CVP and the SWP are a combination
of water released from storage and use of surplus
flows. The cross-hatched area shows the extent to
which release of stored water is required not only to
meet export needs but also to meet local consump-
tive uses and water quality criteria in the Delta chan-
nels.
The Legislature has determined that an adequate
water supply for all beneficial uses in the Delta must
be maintained. Based on legislative declaration and
statutory powers, the SWRCB has concluded that an
adequate supply may require releases of a reason-
able quantity of water from storage. Over the years,
upstream water use has increased until net Delta
outflow during July and August in all but above-nor-
mal runoff years would be inadequate, if it were not
for CVP and SWP operational releases.
Figure 50. ANNUAL DELTA INFLOW
AND ITS USES
1980
1980 LEVEL OF DEVELOPMENT
WrTH EXISTING FACHTES
D-1485, AND NORTH DELTA
WATER AGENCY AGBEEfcENT
Figure 51. ANNUAL DELTA INFLOW
AND ITS USES
2000
PERCENT OF YEARS EQUALLED On EsCEEOED
PERCENT OF YEAflS EQUALLED OR EXCEEDED
184
Figure 52. MONTHLY DELTA INFLOW AND ITS USES
FOR AN AVERAGE AND A DRY YEAR
1928 AND 1929
lU
u.
I
UJ
a.
o
<
(0
z
O
^
Legend
TOTAL INFLOW WITHOUT CVP AND SWP
TOTAL INFLOW TO DELTA
CVP - SWP EXPORTS
DELTA CONSUMPTIVE USE
REQUIRED OUTFLOW FOR D-1485
CVP AND SWP STORAGE WITHDRAWAL FOR
DELTA REQUIREMENTS AND EXPORT
OUTFLOW IN EXCESS OF REQUIRED
FLOOD CONTROL RELEASES
1980 LEVEL OF DEVELOPMENT
With existing facilities;
D-1485; and North Delta
Water Agency Agreement
i^
Oct. Dec. Feb. Apr. Jun. Aug. Oct. Dec. Feb. Apr. Jun. Aug. Oct. Dec.
1927
1928
1929
185
Water rights decisions for the CVP and the SWP
recognize that the two projects should be compen-
sated for the allocated cost of providing enhance-
ment flows, but the SWRCB has no authority to
specify the source of funds. Future legislation will
have to provide for reimbursement of these allocated
costs.
Figure 51 shows the effect of projected future de-
velopments in the Central Valley on Delta inflow and
outflow. While the total volume of outflow is re-
duced somewhat from 1980 levels, peak flows, such
as those shown for March 1928 in Figure 52. will not
be significantly diminished.
Other Federal Water Projects
Other federal water projects include those con-
structed or proposed by the Corp of Engineers or
USBR that are not part of the CVP. Information on
completed projects that contribute to meeting water
requirements within the State are shown in Table 55.
Authorized projects and their present status are de-
scribed here.
The Corps of Engineers' Cottonwood Creek
Project (Tehama and Dutch Gulch Reservoirs) is the
only new federal water supply project assumed to be
available by 2010. As presently proposed, the SWP
would acquire the project yield under provisions of
the federal Water Supply Act of 1958. However, be-
cause of increased nonfederal cost-sharing recently
proposed by the Corps, the Department is consider-
ing State construction of the project as an alterna-
tive.
The Butler Valley Dam and Blue Lake project on
the Mad River was authorized by Congress in 1968
(see Plate 1). The project was proposed to provide
a supplemental water supply for the mid-coastal
Humboldt County region, flood protection for down-
stream areas, and reservoir-associated recreation.
The project has been inactive since 1974.
The proposed Marysville Reservoir on the Yuba
River has been under study by the Corps of Engineers
since congressional authorization in 1966. In 1977, the
Corps identified the Parks Bar site as the most desira-
ble location for construction of a reservoir providing
flood control, hydroelectric energy, water supply,
recreation, and fish and wildlife benefits. The Corps
discontinued study in 1980 after the USBR deter-
mined that it was not feasible to integrate the water
supply into the CVP. Local interests in Sutter and
Yuba Counties, seeking additional flood protection,
proposed an agreement between the Yuba County
Water Agency and the North Kern Water Storage
District for a project that could provide local bene-
fits, as well as export water supplies to alleviate
ground water overdraft in portions of the Tulare Lake
HSA. Yuba County voters rejected the proposal in
November 1981, and the Marysville Reservoir project
IS now inactive.
Colorado River Water Allocation to California
Priorities for the use of Colorado River water in
California are based on the 1931 Seven-Party Agree-
ment, as modified in 1964 by the U.S. Supreme
TABLE 55
FEDERAL WATER SUPPLY PROJECTS IN CALIFORNIA
OTHER THAN THE CENTRAL VALLEY PROJECT
Reservoir
Clear Lake '
Lake Mendocino
Lake Sonoma ^..,
Salinas
Twitchell
Cachuma
Casitas
East Park
Stony Gorge
Black Butte
Lake Berryessa...
New Hogan
Pine Flat
Terminus
Success
Isabella
Stampede
Capacity
(acre-feet)
Stream
Hydrologic
Study
Area
Yield
(acre-feet
per year)
527.000
122.000
281,000
26,000
240,000
205,000
252,000
51,000
50,000
160,000
1,602.000
325.000
1,000,000
150,000
85,000
570,000
225,000
Lost River
Russian River
Dry Creek
Salinas River
Santa Maria River
Santa Ynez River
Coyote Creek
Stony Creek
Stony Creek
Stony Creek
Putah Creek
Calaveras River
Kings River
Kaweah River
Tule River
Kern River
Little Truckee River
NC
NC
NC
CC
CC
CC
SC
SB
SB
SB
SB
SJ
TL
TL
TL
TL
NL
54,000
115,000
5,000
21,200
27,800
20,400
108,000
209,000
55,000
165,000
21,000
7,000
50.000
6,000'
' In Modoc County
^ Not estimated
'Completion 1984
* State of California share
186
Court's decree in Arizona v. California. Under the
Seven-Party Agreement, a total of 5,362.000 acre-feet
per year of Colorado River water was allocated to
California (Figure 53). Additional present perfected
rights of 55,000 and 3,000 acre-feet per year, respec-
tively, were allocated for Indian reservation lands and
miscellaneous entities.
In 1964, the U.S. Supreme Court, in Arizona v. Cali-
fornia, apportioned to California 4.4 million acre-feet
per year of the first 7.5 million acre-feet available for
use by the three Lower Basin States (California, Ne-
vada, and Arizona) . The court also ruled that, if more
than 7.5 million acre-feet were available. California
would be entitled to 50 percent of the surplus. If
insufficient water is available to provide the first 7.5
million acre-feet per year, then present perfected
rights are first satisfied in order of their priority dates.
After that, the Secretary of the Interior apportions
the remaining available water, with the stipulation
that no more than 4.4 million acre-feet per year, in-
cluding present perfected rights, is apportioned to
California.
in 1980. California used about 4.8 million acre-feet
of Colorado River water. Of this amount, about 4.0
million acre-feet was used for irrigation, and The
Metropolitan Water District of Southern California
(MWD) used about 850.000 acre-feet.
When the Central Arizona Project begins deliver-
ing water (scheduled for 1985). California can no
longer depend upon receiving more than 4.4 million
acre-feet per year. As the junior appropriator. MWD
will be limited to 550.000 acre-feet per year of fourth
priority water under the Seven-Party Agreement, less
the water taken by the three Indian reservations and
miscellaneous present perfected right holders. This
would reduce the total for MWD to about 492,000
acre-feet. After deducting 50,000 acre-feet per year
for delivery system operating losses (seepage and
evaporation), MWD will have a usable supply of
about 442,000 acre-feet per year.
In addition, the annual supply of water available to
agencies using Colorado River water could be fur-
ther reduced by as much as 82,000 acre-feet, if the
1982 report by the special master, which recommend-
ed awarding further rights for water to Indian tribes
in California along the Colorado River, is upheld by
the U.S. Supreme Court. If MWD were to bear all
those losses, the agency's cumulative losses by 2000
could be 190.000 acre-feet. The water delivered to
Southern California by MWD would thus be reduced
to 360.000 acre-feet per year.
Local Water Supply Projects
Total statewide dependable water supplies from
projects developed by local water agencies, together
with direct diversion of streamflow for local use, on
an average, amounts to 11.1 million acre-feet per
year. Major local water supply projects are shown on
Plate 1 and Figure 21. Possible future local agency
developments for water supply and other purposes
are shown on Plate 1 and on figures presented in the
HSA summaries later in this chapter. Several larger
proposed hydroelectric power projects are also
shown on Plate 1. Because the schedules for these
projects are uncertain, the water supplies that would
be developed were not included in future dependa-
ble water supplies. Their availability would reduce
shortages indicated or would contribute to addition-
al net water use.
While the supplemental water needs in many areas
of the State must rely on service from the CVP and
SWP. several local agencies have reserve supplies
available that are adequate to meet all or part of their
supplemental needs to 2010. However, in some in-
stances, such as Yuba County, use of the supply will
require construction of conveyance or distribution
facilities.
The water supplies available and the assumptions
made regarding their future use are presented in the
HSA summaries later in this chapter.
Ground Water Availability and Use
Statewide, total ground water in storage is estimat-
ed to be 857 million acre-feet; even in basins partially
depleted by long-term overdrafting, substantial quan-
tities of ground water remain. With the basic as-
sumption that there would be essentially no controls
on ground water pumping before 2010, projected in-
creases in use would be governed largely by pump-
Havasu Pumping Plant at Lake Havasu on the Colorado River,
a facility of the Central Arizona Project. Full use is expected
by 1990, at which time California can no longer depend on
receiving more than 4.4 million acre-feet per year.
187
Figure 53. ALLOCATION OF CALIFORNIA'S COLORADO RIVER WATER SUPPLY
(IN ACRE-FEET)
PRESENT
Before Central Arizona Project begins operations
MISCELLANEOUS
PERFECTED RIGHTS'
3.000
INDIAN WATER RIGHTS
55,000
IMPERIAL I.D
PALO VERDE I.D
COACHELLA VALLEY CWD
METROPOLITAN WATER
DISTRICT
(PRIORITIES FOR USE OF 5,362,000 ACRE-FEET ARE AS SPECIFIED UNDER SEVEN-PARTY AGREEMENT)
FUTURE
After Central Arizona Project reaches full operation about 1990
J/ Could be increased by 82,000 if the
1982 recommendation by the U.S.
Special Master is upheld by the
Supreme Court
METROPOLITAN WATER
DISTRICT
_^ INDIAN WATER RIGHTS
55,000
MISCELLANEOUS
PERFECTED RIGHTS
3.000
4,400,000
(APPORTIONMENT WHEN CALIFORNIA IS LIMITED TO 4.400,000 ACRE-FEET PER YEAR)
ing costs. Information on the availability of and depth
to ground water is presented in Chaptei III.
In most areas of the Central Valley, ground water
of good quality is available within economic pump-
ing limits for projected needs. Results of economic
modeling studies of Central Valley agricultural devel-
opment indicated that increasing costs for ground
water pumping, due to greater pumping lifts and
higher energy costs, would not significantly slow the
growth of irrigated agriculture during the next 30
years.
Outside the Central Valley, new or greatly expand-
ed ground water extractions are occurring in several
areas of the State, especially Northern California.
The information available is insufficient to determine
the potential for long-term sustained pumping from
most of these basins. In deriving projections of future
net water use, it was assumed that availability and
cost of water in these areas would not be limiting
factors, except m the South Lahontan HSA, where
high water costs resulted in reduced irrigated area.
Ground Water Use
In 1980, ground water provided 39 percent of the
applied water in California. Between 1980 and 2010,
the statewide average annual overdraft is projected
to increase from 1.8 million acre-feet to 2.9 million
acre-feet, largely as the result of additional irrigated
agriculture in the San Joaquin and Tulare Lake HSAs.
Ground water overdraft estimates for the San Joa-
quin and Tulare Lake HSAs show an increase of
about 300,000 acre-feet and 900,000 acre-feet, respec-
tively, by 2010. In the SWP service area of the Tulare
Lake HSA, the overdraft situation will worsen if the
SWP cannot meet its contractual commitments. This
could increase ground water overdraft at 2010 by as
much as 600,000 acre-feet per year. Surplus SWP wa-
ter and CVP nonfirm supplies have been used in re-
cent years in place of ground water pumping and for
direct recharge of ground water basins.
Dependable ground water supplies and present
and projected overdraft are discussed in the HSA
summaries at the end of this chapter. The discussion
also includes local ground water conditions and po-
tential quantity and quality problems.
Reclaimed Waste Water
.At the 1980 level of development, reclaimed waste
water provided 0.5 percent of the applied water in
California. This represents only a small part of the
total waste water produced. Constraints on the use
of reclaimed waste water because of health, physi-
cal, and economic reasons are discussed in Chapter
III. A higher level of use is expected in the future.
based on the following assumptions:
• Reuse of water supplies will become more inten-
sive because of economic conditions and the con-
servation ethic.
• Ground water recharge will become the most sig-
nificant form of future reuse, and guidelines for
increasing such use will be adopted by health
agencies.
Legal Requirements and Public Acceptance
Regulations and requirements regarding the qual-
ity of water from all sources subject to public use are
set by federal. State, and local authorities. State regu-
lations and requirements are prescribed in the Water
Reclamation Law (Division 7, Chapter 7 of the State
Water Code). Statewide waste water reclamation
criteria are set by the Department of Health Services
(DHS) for those uses of reclaimed waste water that
affect the public health. Theregional water quality
control boards set requirements regarding the waste
water reclamation criteria on either the producer or
the user, or both.
Results from on-going studies on the effects of
reclaimed waste water will probably lead to relaxa-
tion of the criteria for controlling use, thereby allow-
ing additional municipal and industrial reuse.
Criteria to protect public health have been estab-
lished for recreation impoundments and landscape
irrigation. While DHS has not yet established waste
water criteria for ground water recharge, it has is-
sued a position paper pertaining to the development
of basin plans for the SWRCB. The current rule pro-
hibits direct injection to ground water and requires
consideration of surface spreading on a case-by-case
basis. DHS further recommends against waste water
reuse in small ground water basins because the quan-
tity to be reused would be large in relation to the total
quantity of water in the basin.
The public is conscious of the need for conserving
water resources, and many persons feel that use of
reclaimed waste water is acceptable, provided that
precautions are taken to protect public health.
However, the public does not generally support the
use of reclaimed waste water for direct domestic
uses.
Role of the Department of Water Resources
The Department of Water Resources has for many
years had statutory responsibility to study and pro-
mote waste water reclamation. This responsibility
was reiterated and updated by the 1973-74 Legisla-
ture in Assembly Bill 3815, referred to as the Waste
Water Reuse Law of 1974. In addition to re-express-
ing State policy that "There should be maximum
reuse of waste water," the bill directs the Depart-
ment to study the technology for reusing waste wa-
189
ter and further the reasonable application of such
use.
The Department's waste water reclamation activi-
ties include:
• Support of research in waste water reclamation
technology.
• Participation in regional waste water reclamation
planning and development.
• Determination of the feasibility of local waste wa-
ter reclamation projects for inclusion in the SWP.
The Department supports research and demon-
stration programs to provide information for assess-
ing health concerns and environmental impacts,
determining statewide marketability of reclaimed
water, and developing low-energy waste water recla-
mation projects, it has also participated in a number
of regional studies on the use of reclaimed waste
water.
Development of regional waste water reclamation
plans has been completed for the San Francisco Bay
area and Los Angeles/Orange Counties. The plan-
ning study in San Diego County is nearing comple-
tion.
Possibilities for using treated municipal waste wa-
ter for irrigated agricultural use in the Castroville
area are being evaluated by the Monterey Regional
Water Pollution Control Agency. It is conducting a
seven-year study, of which five years are being spent
in field studies that will be completed in 1986. Pro-
gram costs are estimated to be S7.5 million. The De-
partment of Water Resources is providing technical
assistance and is contributing S80.000 annually.
Projected Use of Reclaimed Waste Water
Preset: a.scnarge reqjirenents for sewage I'eat-
ment plants result in the production of effluent that
either meets or approaches health criteria for land-
scape irrigation such as parks and golf courses, cer-
tain industrial uses, and ground water recharge.
More highly treated waste water is being produced
than is being put to beneficial use. Projected waste
water reclamation for the major urban areas is shown
in Table 56. Table 57 summarizes the projected use of
reclaimed waste water for each HSA. Use of re-
claimed waste water for beneficial purposes will
reduce the need for additional fresh water supplies.
Almost half the increase in the use of reclaimed
waste water is projected to occur in the Los Angeles
HSA. and. by 2010. almost 60 percent of total waste
water use will take place in the South Coastal region.
Comparison of Water Supply and
Projected Use
For tne purposes ot anaiysis, oepenaaoie supplies
were balanced against projected use for a normal
year. This means that, for a normal year, supply and
net use would be in balance, with no shortages. For
wetter years, there would be surplus surface water
supplies; for dry years, deficiencies as a percentage
of normal-year requirements would be imposed by
the CVP and SWP. in accordance with their con-
tracts. Other users relying on surface supplies would
face varying degrees of shortage in dry years.
Ground water supplies are based on long-term aver-
ages. Pumping in dry years will cause the water table
:o drop, but the level recovers in wet years.
TABLE 56
PROJECTED INCREMENTAL INCREASE IN USE OF
RECLAIMED WASTE WATER BY MAJOR URBAN AREAS ^
BY DECADES TO 2010
(In acre-feet)
Region
JXC
San Luis Obispo County ' .
Santa Barbara Coonty'
Ventura County ' .
Orange-Los Angetes Counties '
San Befnardino-ftrverside Counties *_
San D>ego County'
TOTAL.
CC
cc
LA
LA.SA.SD
SA
SD
10.000
15.700
48.200
11.000
20.000
109.400
IXC
0
3.900
118.100
0
10.000
134.000
0
0
76.400
0
0
76.400
24Z700
11.000
x.ooo
319.800
' Assunes swne reiaxaoon ot Department o( Health Senices' restrictions on recharge
of groml water basvis.
' Jenis and Adamson. Consulting Santary and Civ< Engineers. South San Luis Obispo
CoiMitr Santabon Disthct — Wastetnimer Treatment Plant knprtniements and Effkt-
ent Disposal ProfecL Pro/ect Heport March 1976.
Jenis and Harrison. Consiiting Sanitary and Crri Engineers. Wasxemaar Treat-
ment Disposal and fleelamation FacUbes for itie City of San Lue CMiispa ianaiy
\9n.
Jdm Carolo Engineers. Mom Bay—Cayucos WasteMaier Treatment and Disposal
Factoes. Prtitect Hepon. September 1978.
'City of Santa Barbara. Sana a9f«o»a/tec4am»oaF'/^D(ect Phase L Landscape Irriga-
tion. Conceptual Report January 19B2.
mcitups. Goleta County Water District 20I Faotties Plan for Wasteiiater Recla-
mation. Protect Report May ISSa
* C-i^ Hd and County of Ventura. Venti^a Courrr^ -^ ,',as:e^ater Reuse Study.
FacSties Plan. December ISBi.
Department of Water Resoirces. Ventura Cotrttymde Water Reuse Study. Memo-
randixn Report. Joie 19B2.
■ Orange arvi Los Angeles Counties' Water Reuse Study. SiMnmary racSHes /%a Apri
1982.
■ Oeoartment of Water Resoixces. Southern Dslnct Tast Mx £ Etakjam Axtumiaf
kVastewarar Redamation Protects i Souttiem CaSfomia. June 1978.
' San D«go City/County Water Reuse Study Group. San Diego CityA^oumy Water
Reuse Study— Work Plan. iiMV 1978.
Depertment of Water Resources. Southern District Status fieport on San Diego
City/County Water Reuse Study. Memorandum Report. Ji^ie 196Z
190
TABLE 57
PRESENT AND PROJECTED USE OF RECLAIMED WASTE WATER
BY HYDROLOGIC STUDY AREA
BY DECADES TO 2010
(In 1,000s of acre-feet)
HSA
1980
1990
2000
2010
Increase
1980-2010
NC
9
10
9
59
29
9
17
21
67
5
9
3
247
10
I
101
47
43
22
25
78
6
13
401
10
13
27
196
73
55
23
29
86
7
15
567
10
15
27
267
78
55
25
33
99
8
15
J5'
677
1
SF
5
CC
18
LA
208
SA
49
SD
46
SB
8
SJ'
12
TL'
32
NL
3
SL
6
CR
42
TOTAL
430
Does not include planned reclamation of agricultural drainage water.
Includes reclaimed agricultural return flows (normally lost to the Salton Sea) for power plant cooling
Dependable supply is defined as the maximum an-
nual quantity of water that normally can be made
available each year under an assumed reoccurrence
of historic hydrologic conditions and a specified
delivery schedule that may include specified defi-
ciencies during critical dry periods. For large systems
such as the SWP and the CVP, the critical period is
all or part of the sequence of years from 1928 through
1934. For projects with less carryover storage, the
critical period may be only two years or less. For
smaller local water storage projects and direct diver-
sion from rivers, average water supplies were as-
sumed as the dependable supply. Where conjunctive
use of surface and ground water supplies is prac-
ticed, as in many areas of the Tulare Lake HSA and
the South Coastal region HSAs, the ground water
storage regulates the average surface supply essen-
tially into a dependable supply.
V/ater Factory 21 in Orange County. Operation of this plant,
together with the primary and secondary treatment of munici-
pal waste water at the plant appearing at top, involve most
of the treatment processes in use today. Treated water pro-
duced by advanced treatment and desalted water are blend-
ed with water from deep wells and then injected underground
to form a barrier to sea water intruding into the ground water
in the region.
191
Figure 54. WATER YEAR NATURAL BASIN RUNOFF
October 1, 1 976-September 30, 1977
-KLAMATH RIVER 23'
SALMON RIVER 21 = =
Cigi'nj
% WATER YEAR RUNOFF IN PERCENT
OF NORMAL
e ESTIMATED
WATERSHED BOUNDARY
^^^ -■; = 3L0GIC BASIN BOUNDARY
RUSSIAN RIVER 6%
PUTAH CREEK 5°.
NAPA RIVER 2",
COSUMNES RIVER 7%
MOKEIUMNE RIVER 19^
COYOTE CREEK 0=
ORESTIMBA CREEK S°Jt,
ARROYO SECO 5%
NACIMIENTO RIVER 5%
LOS GATOS CREEK 5°=<el
SANTA YNEZ RIVER 15=ce,
TOTAL INFLOW
I TO SHASTA 48°o
SUSAN RIVER 30°o/e
FEATHER RIVER 2i\
YUBA RIVER 15%
•,^TRUCKEE RIVER 22%
AMERICAN RIVER 14%
WEST FORK CARSON RIVER 27%
EAST FORK CARSON RIVER 25%
-^WEST WALKER RIVER 27%
EAST WALKER RIVER 25%
STANISLAUS RIVER 15%
TUOLUMNE RIVER 19°'o
MERCED RIVER 16%
OWENS RIVER 56%
SAN JOAQUIN RIVER 22°.
KINGS RIVER 25°,
^ KAWEAH RIVER 24%
TULE RIVER 12°/o
X ^ KERN RIVER 30%
MOJAVE RIVER 35°.(el
^
SAN LUIS REY RIVER 70°o(el
192
Figure 55. CUMULATIVE UNIMPAIRED RUNOFF FOR TWO YEAR
DROUGHTS FOR SELECTED CENTRAL VALLEY SUPPLY SOURCES
(WATER YEARS IN PERCENT OF NORMAL)
RIVER AND AGENCY
SERVED
TUOLUMNE
San Francisco Wate
Department
MOKELUMNE
East Bay Municipal
Utility District
AMERICAN
Bureau of Reclamatii
Central Valley Project
FEATHER
Dept. of Water Resource^
State Water Project^^ — -
SACRAMENTO«> SHASTA
Bureau of Reclamation ■
Central Valley Project
1930
19 7(1
1977
1931
1930
19 7 6
1977
1931
1930
1 c> 7 R
1977
1931
w//M}?si'mm.
1976
1934
1977
///////////////////l
1 976
1977
Percent
■1
Effects of 1976-1977 Drought Period on
Estimates of Dependable Supply
The recent drought years, 1976 and 1977, were the
two driest consecutive years in recorded history for
most of the northern and central regions of Califor-
nia. Runoff from Sierra Nevada river basins was far
less than the previous driest two-year periods, 1930-
1931 or 1933-1934. Runoff from the northern Cascade
Range was essentially equal to that of the previous
driest period, 1923-1924. Figure 54 shows computed
and estimated natural runoff of river basins in per-
cent of normal for the 1977 water year.
Figure 55 compares these dry periods for streams
that are the primary sources of supply for the San
Francisco Bay area, the CVP, and the SWP. It shows
that the principal water supply sources for the San
Francisco Bay area were more severely affected by
the 197&-1977 drought than by the previously worst
two-year period, 1930-1931. The figure also reveals
that the drought of 1976-1977 was less severe to the
north, with the impact on inflow to Shasta Lake
about half as severe as the impact on American River
inflow to Folsom Lake.
For the Bay area supply sources, the new dependa-
ble supply IS less than The estimate of dependable
supply based on the 1928-1934 critical period. For the
East Bay Municipal Utility District, dependable sup-
ply was reduced the greatest amount — 30 percent.
While this reduction appears severe, there is a com-
pensating factor made apparent by the recent
drought. A policy of imposing additional conserva-
tion measures in dry years could partially offset the
effect of the new critical operating period on system
dependable supply. Previously, in determining de-
pendable surface water supply, the usual practice
was to assume no supply deficiencies for urban uses,
and variable deficiencies for agricultural uses. During
the drought, urban areas showed that average water
193
use could be reduced by up to 25 percent from pre-
drought levels without serious problems in most
cases. This would indicate that planning for some
urban shortages during severe droughts could be an
acceptable management practice. However, similar
reductions m use in the future cannot be as easily
achieved because of the extent to which urban water
conservation is now being practiced.
Dry-Year Realities. A comparison of dependa-
ble water supplies with average water use is accepta-
ble for long-range planning where a high degree of
accuracy in determining shortages is not essential.
However, it should not be presumed that, during a
severe drought, water needs can be met within the
specified level of deficiencies assumed for project
yield analysis. This shortcoming became apparent
during the drought, especially for those projects with
little or no dependable supplies in excess of current
needs. Basically, two related things happened. First.
water requirements increased over average-year re-
quirements because soil moisture available to crops
from winter rainfall was below normal. Second,
streamflow m some cases was less than expected
because of increased percolation to ground water
from stream channels. For example, the Sacramento
River, a major conveyor for the CVP and the SWP,
lost water in its lower reaches to ground water re-
charge because of increased ground water pumping
near the river. This caused the water table near the
river to fall below the river level and water to perco-
late from the river into the adjacent ground water
aquifer.
During a drought period, crop and lawn irrigation
may begin earlier and, for perennial vegetation, con-
tinue later in the year. When project operation stud-
ies were conducted, water supply deficiencies for a
dry year were based on water uses in an average
year. However, actual shortages for a particular year
may be much greater than the amount so computed.
Cosumnes River near Sloughhouse, as it oppeared in Novem-
ber 1977. Lowered ground water tables during the drought
caused more water to percolate from stream channels, reduc-
ing or, OS here, entirely depleting streams that flowed across
alluvial areas.
194
Statewide Summary of 1980 and
Projected Net Water Use
and Water Supplies
This section, along with the following section,
which summarizes net water use and supply by Hy-
drologic Study Areas, brings together the present
and projected net water use and the water supplies
that will be needed by decades to 2010, The data
summarized in Tables 58 and 59 show that an imbal-
ance between use and supply in some major water-
using areas will increase steadily to 2010. This imbal-
ance, which includes shortages in the SWP, is ex-
pected to increase ground water overdraft
substantially.
Dependable supplies for both the CVP and the
SWP are less than the average supply available in
about four out of five years. Although annual ground
water overdraft is projected to increase about 1.1
million acre-feet between 1980 and 2010, it is expect-
ed that, in above-normal water years, excess surface
water will be available for use in lieu of pumping
ground water or for direct recharge, provided there
is an adequate conveyance system. Consequently,
the projected overdraft amounts may be overstated
for some HSAs. An example of the use of excess
surface water supplies to reduce ground water over-
draft exists in the Tulare Lake HSA. The overdraft
shown in 1980 is less than in earlier years because of
the use of surplus surface SWP supplies. However,
the SWP will likely be in a shortage situation, at least
in the near future, and available supplies will be need-
ed to meet projected requirements. Therefore, no
reduction in overdraft was projected because sur-
plus water will likely be available only in the very
wettest years.
In some HSAs overdraft is projected to continue
but, at the same time, substantial reserve surface
supplies are indicated. Reserve supplies are devel-
oped but these supplies are not available to other
parts of an HSA because distribution facilities or in-
stitutional arrangements are lacking.
Further details pertaining to net water use and
related water supplies are presented for each HSA in
the following section of the report.
TABLE 58
PROJECTED STATEWIDE USE OF WATER SUPPLIES
BY DECADES TO 2010
(In 1,000s of acre-feet)
1980
1990
2000
2010
Change
1980-
2010
NET WATER USE
27,045
4,978
646
59
1,093
33,821
27.865
5.670
700
120
930
35.285
28,215
6,205
710
160
865
36,155
6.840
720
175
870
37.330
1.680
Urban
1.862
74
116
-223
TOTAL
3.509
DEPENDABLE WATER SUPPLY
9,274
1,808
5,839
7,077
5,115
247
2,656 '
32,016
9,350
1,455
6,010
7,690
5,110
400
2.310
32,325
9,350
1,440
5,980
7,950
5,180
560
2,320
32,780
9.390
1.455
5.990
8.110
5.200
675
2,315
33.135
116
-353
Ground Water
151
Central Valley Project
1.033
Other Federal Water Development
85
Waste Water Reclamation .
428
State Water Project
-341
TOTAL
1.119
GROUND WATER OVERDRAFT
1,790
15
1.413
1,950
1,010
820
2,245
1.130
860
2.875
1.320
955
1.085
SHORTAGE
1.305
RESERVE SUPPLY
-458
' Includes SWP surplus water deliveries.
195
TABLE 59
SUMMARY OF PRESENT AND PROJECTED NET WATER USE AND WATER SUPPLY
BY HYDROLOGIC STUDY AREA
BY DECADES TO 2010
(In 1,000s of acre-feet)
Year
NC
SF
CC
LA
SA
SD
SB
SJ
TL
NL
SL
CR
TOTAL
1980..
NET WATER USE
1.081
1.180
1.200
1.230
1.080
1.180
1.200
1.230
0
0
0
0
1
0
0
0
9
85
75
60
1.204
1.276
1.325
1.395
1.197'
1.225
1,260
1.330
7
20
0
0
0
30
65
65
138
110
190
220
1.099
1.175
1.195
1.200
870
985
1.005
1.015
224
180
180
175
5
10
10
10
17
0
0
0
1.906
1.995
2.015
2.095
1,824
1,870
1,956
2.030
82
0
0
0
0
125
60
66
164
0
0
0
962
1.050
1.100
1.180
962
1.050
1.085
1.095
10
0
0
0
0
0
15
86
203
0
0
0
634
716
805
890
634
625
625
630
0
0
0
0
0
90
180
260
46
0
0
0
7.464
7.936
7.986
8,185
7.371
7,835
7.885
8.015
85
70
60
120
8
30
40
50
535
275
340
370
6.341
6,580
6.750
7.020
5.949
6.130
6.240
6.280
391
430
470
680
1
20
40
60
191
320
220
230
8188
8,425
8,700
9.030
7,332 '
6,580
6,590
6,600
856
1,190
1,450
1.770
0
665
660
660
56
10
0
0
421
460
455
470
416
440
450
460
5
10
5
10
0
0
0
0
17
20
20
20
419
415
426
410
316
365
355
310
103
40
50
70
0
20
20
30
33
0
16
66
4.102
4,090
4.200
4.226
4.075
4.050
4.130
4.140
27
10
30
60
0
30
40
35
4
0
0
0
33 821
1990
35 286
2000
36156
2010
37 330
1980.
DEPENDABLE WATER SUPPLY
32.016 '
1990
32 310
2000
32 695
2010
33 050
1980.
GROUND WATER OVERDRAFT
1 790
1990 ...
1 960
2000
2 245
2010
2 875
1980.
SHORTAGE
15
1990
1025
2000
1 216
2010
1,406
1980.
RESERVE SUPPLY
1.413
1990 .
820
2000
860
2010
955
' Includes SWP surplus water deliveries.
196
HYDROLOGIC STUDY AREA SUMMARIES OF NET WATER USE
AND WATER SUPPLY
This section compares present and projected net
water use with dependable water supply for each of
the 12 Hydrologic Study Areas (HSAs). Deficiencies
in supply appear in the tables as ground water over-
draft or shortage. The section also highlights related
water nnanagement issues within the HSAs. Net wa-
ter use values in the tables include the effect of an-
ticipated water conservation measures.
Following are explanations of terms that identify
the types of water use and the sources of supply
presented in the HSA summary tables.
• Irrigation, Urban, and Wildlife and Recreation
Net Water Use. Derived as described m Chap-
ter IV.
• Energy Production. Includes both power plant
cooling and enhanced oil recovery as described in
Chapter IV.
• Conveyance Losses. Water irrecoverably lost
while supplies are being conveyed from the source
to the area of use.
• Total Net Water Use. The sum of evapotranspi-
ration of applied water (ETAW), irrecoverable dis-
tribution system losses, and outflow from each
Planning Subarea (PSA).
• Local Surface Water Development. Includes
local project supplies and direct diversion of sur-
face water other than federal and State Water
Project diversions.
• Imports by Local Water Agencies. Interbasm
diversions (from one HSA into another) by a local
agency.
• Ground Water. Annual average recharge from
natural sources, plus recharge from local reser-
voirs operated to augment natural stream percola-
tion, or to supply recharge basins. It does not in-
clude percolation of imported supplies.
• Central Valley Project. Existing facilities, plus
the San Felipe Division.
• Other Federal Water Development. Corps of
Engineers' projects and USBR projects other than
the CVP.
• Waste Water Reclamation. Reclaimed waste
water used to meet needs that would otherwise be
met by fresh water.
• State Water Project. Existing facilities, plus
specific additions shown m Figure 48.
• Ground Water Overdraft. Long-term excess of
withdrawals over replenishment.
• Shortage. The difference between dependable
supply and projected requirements.
• Reserve Supply. Dependable surface water
supply that is available but not needed at a particu-
lar time and that cannot be distributed to other
areas of need because of a lack of conveyance
facilities and/or institutional arrangements.
The bar charts compare the sum of net water use
(by type) with the related water supply (by source) .
The shaded extension of the net use bar represents
the reduction in need for water supply resulting from
projected urban and agricultural water conservation.
197
Iron Gate R»s.,
.J~
C - CroseW
Hctty
u
..L
lA^^J
?ott
Copco
Lakm
L»k» Sliattint
"^"-^T
\
Clair t
&ngte
Lake
1 ^r^ji^cy-
Weaverville .^-^t_ Lewlston «os.
Clear Creek
Tuanel
Lake Plllsbury
Lower
Klamath
Lake
Tule
Lake
Clear
Lake
Legend
•f
c:;_^;z?' existing projects
SANTA ROSA-SONOUA
AQUEDUCT
PETALUUA
AQUEDUCT
Figure 56. SURFACE WATER PROJECTS -
NORTH COAST HYDROLOGIC STUDY AREA
Figure 57. WATER SUPPLY AND USE SUMMARY
NORTH COAST HYDROLOGIC STUDY AREA 1980-2010
0
i_
NET USE
SUPPLY
Millions of Acre-Feat
1 1.5 0
1980
NET USE
SUPPLY
2010
1.5
Reduction in need for water supply due to conservation
Thousands
of acre-
-feet
CHANGE
NET WATER USE
1980
1990
2000
2010
1980-2010
1
IRRIGATION
714
780
790
810
100
H URBAN
151
170
180
190
40
B WILDLIFE AND RECREATION
216
230
230
230
10
H ENERGY PRODUCTION
m CONVEYANCE LOSSES
—
—
TOTAL
1081
1180
1200
1230
150
DEPENDABLE WATER SUPPLY
LOCAL SURFACE WATER DEVELOPMENT
368
370
375
375
10
IMPORTS BY LOCAL WATER AGENCIES
2
2
2
2
0
GROUND WATER
243
310
320
330
90
CENTRAL VALLEY PROJECT
OTHER FEDERAL WATER DEVELOPMENT
458
485
490
510
50
WASTE WATER RECLAMATION
9
10
10
10
STATE WATER PROJECT
—
— J
—
—
—
TOTAL
1080
1 180
1200
1230
150
GROUND WATER OVERDRAFT
SWP SURPLUS WATER DELIVERY
SHORTAGE ^
1
___
___
____
— .
RESERVE SUPPLY^
9
85
75
60
-^
Totals for 1990, 2000, 20 10, and CHANGE are rounded.
J/ LOCAL URBAN
2/ KLAMATH PROJECT AND LOCAL, 1980: WARM SPRINGS PROJECT, FUTURE
199
NORTH COAST HYDROLOGIC STUDY AREA
Total annual net water use in the North Coast HSA
is projected to increase by about 150,000 acre-feet by
2010. This increase will be supported primarily by
90.000 acre-feet of ground water. Lake Sonoma, a
federal facility in Sonoma County, and other federal
projects in Siskiyou and Modoc Counties will supply
another 50,000 acre-feet. The remainder will come
from local surface supplies. The reserve supply
shown for this HSA is primarily from Warm Springs
Dam and Reservoir (Lake Sonoma). Yield from the
reservoir will probably not be fully used until after
2010.
As discussed in Chapter III, the nature of irrigated
agriculture in Siskiyou and Modoc Counties has
changed considerably in the last ten years due to the
increased development of ground water. This has
brought modern irrigation systems into an area that
before had typically been irrigated by the wild flood
technique, which relies on streamflow when it is
available. Now, with water available for the full grow-
ing season, crop production has increased. If ground
water pumping costs do not become prohibitive,
more of the same kind of development can be ex-
pected.
Some of the prospects for, and impacts of. in-
creased ground water use and other water-related
topics in specific locations within the North Coast
HSA are discussed in the following sections.
Butte Valley
Ground water pumping is still increasing in Butte
and Red Rock Valleys, almost entirely for the produc-
tion of alfalfa. A new alfalfa pelletizing mill has been
constructed and is operating in Red Rock Valley. Fu-
ture alfalfa production will be a function of prices
and energy costs. Historically, alfalfa raised in this
region has brought higher-than-average prices be-
cause of its high protein content. The costs of energy
used for pumping ground water could become a con-
straint in the future.
Shasta Valley
["creasec ground water pumping in the Big
Springs and Little Shasta River area is probably start-
ing to impair flows in the Shasta River. Big Springs
artesian flow has been diminishing over the past few
years. Water use on the many new residential farms
(2- to 20-acre "ranchettes") in the juniper lands east
of Big Springs also may be impairing Shasta River
flows.
Scott Valley
Over the past 10 years or so, irrigation develof>-
ment, together with increases in ground water pump-
ing, has so increased that no flow can be observed
in the Scott River in the northern portion of the valley
in late summer. Available valley lands and the water
supply to irrigate them are essentially in equilibrium
today. This leaves little water for salmon and steel-
head production, which is the major problem facing
this area. Methods of augmenting flows for instream
200
uses, such as improving irrigation efficiency, devel-
oping additional storage, or relocating points of sur-
face water diversion to improve flows in critical
stretches of the river are being studied.
Trinity River
Major water problems on the main stem of the
Trinity River are related to inadequate fish flows be-
low Trinity Lake. Decline in salmon and steelhead
runs are blamed on large-scale transbasin diversions
of Trinity River water to the Sacramento Valley to
meet CVP demands, along with increased siltation
caused by poor logging and road building practices.
Flow reregulation and watershed and spawning grav-
el improvement are the major local issues currently
under negotiation in the region. Construction of a
debris dam on Grass Valley Creek should greatly im-
prove the situation, especially if it is augmented by
some sand dredging in the Trinity River.
Humboldt Bay Region
Water supply and use in this region are essentially
in balance. The major water purveyor. Humboldt Bay
Municipal Water District, has nearly reached the limit
of its ability to meet increasing future needs with its
water supply from the lower Mad River. Upstream
storage options are limited and costly. Existing sup-
plies may be stretched through institutional arrange-
ments with the pulp paper industries so that they can
reduce water use by using more chemical reagents
in the pulp bleaching process. Conjunctive use of
surface and ground water in the Mad River Basin
may provide some assistance.
Mendocino Coast
Very little irrigated agriculture remains on the
Mendocino Coast. Water use is restricted mainly to
residential use and a few industrial uses, such as the
sawmill at Ft. Bragg. The major water problems exist
where residential users and small communities such
as Mendocino and Albion extract ground water from
the coastal terraces. Aquifers on the shallow terraces
produce limited amounts of water, some of it of poor
quality because of high sulfide and iron levels. Few
deep alluvial ground water bodies are present in this
area.
Russian River
With the availability of water from Warm Springs
Dam and Reservoir (Lake Sonoma) in 1984, the major
water supply problems m the lower Russian River
area will be solved. That supply should meet the
needs in the lower Russian River beyond 2010. The
remaining major water problem concerns the stretch
of the Russian River above Dry Creek.
Lake Mendocino supplies water to agricultural and
urban users m Mendocino, Sonoma, and Mann Coun-
ties, and for instream requirements in the Russian
River. Pacific Gas and Electric Company (PGandE)
has filed an application with the Federal Energy Reg-
ulatory Commission (FERC) for relicensmg of the
Potter Valley Project, owned and operated by
PGandE. The project diverts water from the Eel River
through a tunnel and the Potter Valley Power Plant
into the East Fork Russian River. The water then
flows into Lake Mendocino. Humboldt County, the
Department of Fish and Game, and the Department
of Water Resources requested FERC to require
greater flows in the Eel River to improve the fisheries
in the basin. This would reduce the flows diverted
into the Russian River. (Recommended operation
schedules are described m Eel-Russian River Stream-
flow Augmentation. Bulletin 105-5, published by the
Department of Water Resources in 1976.) At a settle-
ment conference led by FERC in May 1979, all parties
accepted an interim schedule of minimum flows to
be released down the Eel River below Cape Horn
Dam for a three-year study period. The proposed
flows were lower than those proposed by the Depart-
ment in Bulletin 105-5 but higher than previous
PGandE releases. During the three-year period, be-
ginning on November 1. 1979. the parties analyzed
the effects of the increased flows on the Eel River
fishery and the effects of reduced flows on the Rus-
sian River water supply. A final report on the Eel
River fishery studies was published in December
1982.
After extensive negotiations, the parties agreed to
a permanent flow schedule and, in November 1982,
filed a proposed settlement agreement with the Ad-
ministrative Law Judge for the FERC. The judge cer-
tified the settlement agreement in May 1983 and
submitted it to FERC staff for final review before
issuance of the license.
Additional issues of concern:
• Lake Mendocino's recreation use has become an
important factor in Mendocino County's economy.
The reservoir level in Lake Mendocino is drawn
down as a result of diversions and instream re-
quirements in the Russian River. Urban and agricul-
tural water diverters. recreational users, and the
fishery are all competing for a limited supply of
water in dry years. The problem may be intensified,
if less water is diverted from the Eel River to the
Russian River.
• The Santa Rosa Plain remains the principal area of
ground water use in the Russian River basin. This
basin is generally in hydrologic balance, although
the distribution of ground water pumpage
throughout the basin is not uniform, indicating a
need for further ground and surface water man-
agement planning, particularly in light of anticipat-
ed municipal and industrial use and availability of
supplies from Lake Sonoma.
201
Legend
d>
EXISTING PROJECTS
POSSIBLE FUTURE PROJECTS
SANTA ROSA-SONOMA
AQUEDUCT
PETAL UMA
AQUEDUCT
PUT AH SOUTH
CANAL
NOR TH BA y
AQUEDUCT
MOKELUUNE
AQUEDUCT
CONTRA COSTA
CANAL
SOUTH BAY
AQUEDUCT
Lake Del Valle
Coyote Lake
20
30
MILtS
Figure 58. SURFACE WATER PROJECTS-
SAN FRANCISCO BAY HYDROLOGIC STUDY AREA
202
Figure 59. WATER SUPPLY AND USE SUMMARY
SAN FRANCISCO BAY HYDROLOGIC STUDY AREA 1980-2010
Millions of Acrm-Fmmt
1.5 0
I I
1.5
1980
2010
NET USE
SUPPLY
NET USE
SUPPLY
Shortage
Reduction in need for water supply due to conservation
Thousand;
3 of acre-
-feet
CHANGE
NET WATER USE
1980
1990
2000
2010
1980-2010
1
IRRIGATION
121
110
100
90
-30
1
URBAN
967
1050
1090
1 170
200
WILDLIFE AND RECREATION
96
100
100
100
—
ENERGY PRODUCTION
6
2
15
15
10
CONVEYANCE LOSSES
14
15
20
20
10
TOTAL
1204
1275
1325
1395
190
DEPENDABLE WATER SUPPLY
LOCAL SURFACE WATER DEVELOPMENT
228
228
228
228
0
IMPORTS BY LOCAL WATER AGENCIES
454
460
445
455
—
GROUND WATER
21 1
220
220
220
10
CENTRAL VALLEY PROJECT
81
120
160
210
130
OTHER FEDERAL WATER DEVELOPMENT
56
60
60
60
—
WASTE WATER RECLAMATION
10
10
10
15
10
STATE WATER PROJECT
150
125
140
140
-10
TOTAL
1 190
1225
1260
1330
140
GROUND WATER OVERDRAFT
7
20
-10
SWP SURPLUS WATER DELIVERY
7
-10
SHORTAGE U
_
30
65
65
70
RESERVE SUPPLY i/
138
1 10
190
220
Totals for 1990. 2000, 20 10, and CHANGE are rounded.
ly SWP SOUTH BAY AQUEDUCT SERVICE AREA
JJ IMPORTS BY LOCALS AND CVP; WARM SPRINGS PROJECT
203
204
SAN FRANCISCO BAY HYDROLOGIC STUDY AREA
Total annual net water use in the San Francisco
Bay HSA is projected to increase by about 190,000
acre-feet by 2010, reflecting continued urban growth.
By 2010, urban uses will account for about 85 percent
of total net water use. Although agricultural net wa-
ter use is expected to decline somewhat because of
urban encroachment on irrigated land (mostly in the
South Bay area), it will still be significant — about
90,000 acre-feet annually.
The increase in use by 2010 will be partially sup-
ported by an additional import of 130,000 acre-feet
from the CVP (the San Felipe Division). Essentially
no change is projected in total annual net use of
ground water. SWP water delivered through the
North Bay and South Bay Aqueducts is expected to
total 140,000 acre-feet in 2010. In the absence of ade-
quate future water supply facilities to augment the
existing yield of the SWP, shortages in the amount of
65,000 acre-feet will most likely occur. Water trans-
fers and exchanges could offset the effects of these
shortages.
North Bay
When Phase II of the North Bay Aqueduct is com-
pleted in the mid-1980s, the total water supply of the
North Bay area will be more than adequate to meet
projected needs beyond 2010. However, a problem
of water supply distribution will exist in Napa
County. Conveyance facilities will be too costly to
permit communities in the northern part of the
county to obtain water from the North Bay Aque-
duct, which terminates in the southern part of the
county. As an alternative, a local plan is being de-
vised that will allow SWP entitlements and northern
Napa County surface water to be exchanged
between the cities of Calistoga and Napa.
Other water management problems include;
• Lack of a more complete evaluation of the ground
water resources m the Napa Valley.
• Need to determine the water quality and quantities
for achieving a desirable ecological balance in the
Suisun Marsh and means of implementing the bal-
ance.
South Bay
The Department of Water Resources has been
conducting planning studies to determine when sup-
plemental water is needed m this area and to evalu-
ate the potential for increasing the effectiveness of
existing and future supplies through pooling or ex-
changes by interconnection of delivery systems and
adjustments of service areas.
Although the South Bay may have sufficient water
supplies on a regional basis beyond 2010, certain
areas have been identified that will have supplemen-
tal water needs in excess of current reserve supplies.
However, if local water agencies cooperate in im-
provement of the overall delivery systems, these sup-
plemental needs can be met, and new water supply
projects will not be required until after 2010.
Water management problems and issues in the
area include:
• Alameda County Water District will have supple-
mental water needs m excess of current reserve
supplies, beginning about 2000. Alternatives avail-
able include an increase in deliveries from the San
Francisco Water Department (SFWD), surplus lo-
cal water supplies from the Alameda County Flood
Control and Water Conservation District, Zone 7,
or SWP entitlement exchanges between Zone 7
and the Santa Clara Valley Water District.
• Deliveries under East Bay Municipal Utility Dis-
trict's (EBMUD) contract with the U.S. Bureau of
Reclamation (USBR) for deliveries from the Fol-
som South Canal have been included as a part of
EBMUD's future available water supplies. Not all
of this supply is projected to be required by
EBMUD before 2010.
• With completion of the San F >lipe Division of the
CVP (scheduled for 1987) .vdter management
problems — especially ground water overdraft and
land subsidence in Santa Clara County — will be
alleviated.
• SFWD has proposed construction of a fourth bar-
rel of the Hetch Hetchy Aqueduct to transport the
full yield of San Francisco's Sierra Nevada reser-
voirs to the Bay area. SFWD's projections indicate
that supplemental water needs will equal current
reserve supplies shortly before 2000. Their projec-
tions also indicate that, shortly before 1990, the
existing system for importing the water from the
Sierra Nevada reservoirs will be inadequate to
meet peak daily demands. Projections by the De-
partment of Water Resources, however, do not
indicate that SFWD will need additional delivery
capacity until beyond 2010.
205
I
y-
Legend
c;jr> EXISTING PROJECTS
POSSIBLE FUTURE PROJECTS
10 20 30
SOUTH COAST CONDUIT-
Santa Barbara
Figure 60. SURFACE WATER PROJECTS-
CENTRAL COAST HYDROLOGIC STUDY AREA
206
Figure 61. WATER SUPPLY AND USE SUMMARY
CENTRAL COAST HYDROLOGIC STUDY AREA 1980-2010
Millions of Acre-Feot
1.5
1^
_J
1980
2010
NET USE
SUPPLY
NET USE
SUPPLY
Overdraft and shortage
Reduction in need for water supply due to conservation
(Thousands of acre-
-feet)
CHANGE
NET WATER USE
1980
1990
2000
2010
1980-2010
H
IRRIGATION
902
940
940
930
30
URBAN
188
210
230
250
60
WILDLIFE AND RECREATION
2
5
5
5
.
ENERGY PRODUCTION
7
15
15
10
__
jj
CONVEYANCE LOSSES
5
5
5
10
TOTAL
1099
1 175
1 195
1200
100
DEPENDABLE WATER SUPPLY
LOCAL SURFACE WATER DEVELOPMENT
39
54
54
54
10
IMPORTS BY LOCAL WATER AGENCIES
.
,,^_
GROUND WATER
768
768
768
768
0
CENTRAL VALLEY PROJECT
40
60
70
70
OTHER FEDERAL WATER DEVELOPMENT
54
54
54
54
0
WASTE WATER RECLAMATION
9
30
30
30
20
STATE WATER PROJECT
0
40
40
40
40
TOTAL
870
985
1005
1015
140
GROUND WATER OVERDRAFT
224
180
180
175
-50
SWP SURPLUS WATER DELIVERY
H SHORTAGE
5
10
10
10
10
RESERVE SUPPLY i/
17
0
0
0
Totals for 1990, 2000, 20 10, and CHANGE are rounded.
1/
1/
LOCAL URBAN SUPPLIES. 1980: SWP. FUTURE
NACIMIENTO RESERVOIR AND SWP
207
208
CENTRAL COAST HYDROLOGIC STUDY AREA
Total annual net water use in the Central Coast
HSA :s projected to increase by about 100,000 acre-
feet by 2010. The Monterey Bay area will use 70,000
acre-feet, of which 40,000 acre-feet will represent ur-
ban net water use. Nearly all the 20,000-acre-foot in-
crease in San Luis Obispo and Santa Barbara
Counties will support urban use.
The entire increase in net water use in the Monte-
rey Bay area will be satisfied by imports from the
federal San Felipe Division of the CVP. The increase
in San Luis Obispo and Santa Barbara Counties was
assumed to be met by construction of the distribu-
tion facilities from Nacimiento Reservoir and the
State Water Project's Coastal Branch Aqueduct or
local alternatives.
The Monterey County Flood Control and Water
Conservation District completed construction of
Nacimiento Dam and Reservoir in 1958. The reservoir
has a capacity of 350,000 acre-feet and a yield of
85,000 acre-feet per year, much of which is released
to the Salinas River for ground water recharge. In
1959, an agreement between the counties of Monte-
rey and San Luis Obispo gave San Luis Obispo
County an annual entitlement to 17,500 acre-feet. The
county is presently diverting about 2,400 acre-feet for
use near the reservoir, but it has not yet built a distri-
bution system to deliver water to other areas. San
Luis Obispo County officials scheduled an election
on a bond issue to finance construction of such a
system for November 1980, but the board of supervi-
sors decided to postpone the election.
Santa Barbara County has asked the Department
of Water Resources to determine whether Gibraltar
Reservoir and Cachuma Reservoir enlargement,
Camuesa Canyon Dam construction, and Santa Bar-
bara Wastewater Reclamation are eligible for fund-
ing as part of the State Water Project. Santa Barbara
County has reduced its entitlement from the SWP
and is pursuing local projects as an alternative to the
Coastal Aqueduct. It will be able to meet its water
requirements through a combination of local
projects, and remaining supply from the Coastal
Aqueduct.
Following are highlights of the major water man-
agement issues and examples of some with more
limited impact in the HSA.
Monterey, San Benito, and Santa Cruz
Counties
Precipitation is highly variable, and most ground
water basins are relatively small in the northern part
of the Central Coast HSA. This causes large variation
m water supplies from year to year, with resultant
large changes in ground water levels. Severe short-
term water shortages can occur during years of
drought. In addition, some ground water basins are
already in an overdraft condition.
To support the growing water needs and alleviate
the overdraft in these counties, the water supply to
certain parts of the area must be increased. This may
be accomplished by developing local supplies or by
importing water.
Specific areas where problems exist and some of
the possible solutions are discussed in the following
sections.
Salinas Valley. The present hydrologic balance
indicates a total overdraft of about 60,000 acre-feet
per year in the Salinas Valley, a substantial increase
over the 16,000 acre-feet of annual overdraft that oc-
curred during the 1969-1975 period. On the valley's
east side, where there is little natural ground water
recharge, pumping lowers the ground water levels
and causes large subsurface flows from the western
side. This, together with excessive pumping in the
western region, has lowered the ground water table
below sea level near the coast, and sea water is in-
truding into the ground water basin.
A project formulated to alleviate these problems
was endorsed by Monterey County in September
1982. Project features include: (1) a dam on Arroyo
Seco River at the Pools Reservoir site with a capacity
of 100,000 acre-feet; (2) a 4.7-megawatt power plant
at the dam; (3) an Arroyo Seco-Salinas Conveyance
Canal for delivery of the water to the Salinas River;
(4) a Castroville Pipeline; and (5) an East Side Pipe-
line. Project features are shown on Figure 60. The
reservoir would have an annual yield of 43,000 acre-
feet and provide flood control and recreation bene-
fits. Energy production is estimated at 19 million kilo-
watthours annually. Project costs are estimated to be
approximately $80 million at December 1981 prices.
Water deliveries to the East Side service area
would alleviate ground water overdraft. Deliveries to
the Castroville service area would reduce ground wa-
ter extractions and sea-water intrusion.
Monterey Peninsula and Carmel Valley. The
municipal and industrial demands of the Monterey
Peninsula, which far exceed the local ground water
supply, are met by imported surface and ground wa-
ter from Carmel Valley. The present hydrologic bal-
ance indicates a small overdraft of about 2,000
I
209
acre-feet per year in the Monterey Peninsula and
2,000 acre-feet per year in the Carnnel Valley. Sea-
water intrusion has also been identified in the vicinity
of Marina.
The potential exists for further development of the
Carnnel River, where an average of 70,000 acre-feet
per year flows to the ocean. Presently, water is
stored in two small reservoirs; however, there are no
major reserve supplies to be drawn on in the event
of a drought. During the drought of 1976 and 1977,
severe shortages occurred, and water rationing was
instituted on the Monterey Peninsula. In the future,
as population grows and water needs increase, the
development of an additional supply from waste wa-
ter reclamation or surface storage will assume even
greater importance, even with strong water conser-
vation programs.
To meet these needs, the Monterey Peninsula Wa-
ter Management District is currently proposing the
enlargement of San Clemente Reservoir to increase
its active storage capacity to 27,000 acre-feet. If voter
approval is obtained, construction could begin by
1986.
The District has also approved a ground water re-
charge project in Seaside, east of Monterey, that
would convey excess flows from the Carmel River in
wet years to local recharge basins.
Elkhorn Slough and Pajaro Valley. Overdrafts
of about 4,000 acre-feet per year in the Elkhorn
Slough area and about 16,000 acre-feet per year in
the Pajaro Valley were estimated for 1980. This over-
draft has reversed the natural seaward gradient of
the ground water table, and sea-water intrusion is
occurring in both areas for several miles on each side
of the mouth of the Pajaro River. Increasing water
use in the future will worsen the situation, unless new
supplies are developed or the overdraft is curtailed.
The Pajaro ground water basin has been defined by
the Department as a basin subject to critical condi-
tions of overdraft.
South Santa Clara, Hollister, and San Juan
Valleys. Extensive agricultural development has
resulted m a present overdraft of about 28,000 acre-
feet per year. This is a significant increase from the
11,000-acre-foot annual overdraft calculated in the
hydrologic balance for the 1969-1975 period. In addi-
tion, pumping has been limited in some parts of east-
ern Hollister Valley by concentrations of boron and
chloride in the ground water that limit its suitability
for agricultural use.
A supply of imported water will become available
to the area when the San Felipe Division of the Cen-
tral Valley Project is completed. Much of the import-
ed water will be used to recharge the ground water
basin. Surface water will be delivered to replace
poor-quality ground water in the Hollister Valley.
San Luis Obispo County
City of Morro Bay. During the past 25 years, the
city of Morro Bay has frequently rationed water, and.
since 1976. has had an active water conservation pro-
gram. Based on studies that indicated water short-
ages in Morro Bay would continue, the State Coastal
Commission imposed a building moratorium in 1978.
Recently, a study by the Department showed that the
problem is not one of supply but rather of location
and number of wells. Nevertheless, facilities to in-
crease recharge of the ground water basins and to
import additional water will be necessary to ensure
adequate supplies of good quality water will be avail-
able.
Los Osos — Baywood Park Area. This area, sit-
uated 4 miles south of Morro Bay, obtains its water
from the underlying ground water basin. The popula-
tion of this area is growing rapidly. As urban growth
continues, central waste water treatment facilities
may be needed to replace septic tanks and protect
ground water quality. Additional water will be need-
ed in the future.
City of San Luis Obispo. Projections of water
use by the city of San Luis Obispo indicate that the
city's dependable water supply will not satisfy all
needs by the mid-1980s. Salinas Reservoir, in the Up-
per Salinas Valley, is one of the city's water sources.
Negotiations are under way to enlarge the reservoir's
capacity, but the city of San Luis Obispo and the
communities in the northern portion of the county
have not resolved related water rights issues.
Santa Barbara County
South Coast Area. The south coast area, in-
cluding the communities of Carpinteria, Summer-
land, Santa Barbara, and Goleta, is water-deficient.
The area is predominantly urban, with limited ground
water sources and fixed entitlements to surface wa-
ter supplies. Additional sources of water are needed
to curtail overdrafting of the ground water basin and
to meet supplemental needs, should further urban
growth take place.
San Antonio Basin. In this basin, which lies
between the Santa Maria and Santa Ynez Valleys,
water use by Vandenberg Air Force Base and irrigat-
ed agriculture exceeds the supply from existing
sources. The base has expressed interest in obtaining
water from the State Water Project. The amount
needed and the extent to which additional conserva-
tion and reclamation could reduce needs have not
been determined, but may be significant.
Lompoc Area. Although present use in the Lom-
poc ground water basin is estimated to exceed sup-
ply by about 3,000 acre-feet per year, the ground
water levels remain near the surface along the Santa
Ynez River near Lompoc, with only relatively small
210
amounts of vacant storage space available. More-
over, the ground water supply in the zone with avail-
able storage space is high in total hardness and total
dissolved solids. In the city of Lompoc, all water is
softened in a municipal plant. Use of home water
softeners adds to the problem by increasing the total
dissolved solids in water returning to the ground wa-
ter basin. Salsipuedes Dam and Reservoir Project on
Salsipuedes Creek, a major tributary of the Santa
Ynez River, has been investigated at various times as
a means of augmenting water supplies in the Lom-
poc area. This could be accomplished through a
ground water replenishment program or by direct
surface deliveries. A 50,000-acre-foot capacity reser-
voir could yield up to 6.500 acre-feet per year, de-
pending on the method of operation. Estimated unit
costs of water in 1982 prices range from S650-S850
per acre-foot for ground water replenishment and
from $1,400-S1,900 per acre-foot for surface delivery.
The location of the proposed reservoir is shown on
Plate 1.
Santa Maria Valley. Although the Santa Maria
Valley has a relatively large ground water basin, stud-
ies indicate that urban and agricultural use of ground
water exceeds the annual rate of replenishment and
that the mineral concentration is high. Therefore, ad-
ditional water will be needed in the future. A con-
junctive use program that makes use of the ground
water basin and additional surface water supplies
could increase the yield and help improve water
quality.
211
.WEST BRAMCH CALIFO/tUIA AQUEDUCT
. LOS AHGELES AQUEDUCT
COLORADO mVER
AQUEDUCT
SANTA ANA
Legend
JO
EXISTING PROJECTS
POSSIBLE FUTURE PROJECTS
San Diego
SAN DIEGO
Lo»er Otay Rms
vrTco
Figure 62. SURFACE WATER PROJECTS - LOS ANGELES,
SANTA ANA. AND SAN DIEGO HYDROLOGIC STUDY AREAS
212
Table 60 WATER SUPPLY AND USE SUMMARY
LOS ANGELES HYDROLOGIC STUDY AREA 1 980-20 10
(Thousands
of acre-
-feet)
CHANGE
NET WATER USE
1980
1990
2000
2010
1980-2010
IRRIGATION
276
250
220
190
-90
URBAN
1634
1630
1680
1790
260
WILDLIFE AND RECREATION
8
10
16
20
10
ENERGY PRODUCTION
7
30
25
20
10
CONVEYANCE LOSSES
81
75
76
76
__
TOTAL
1906
1995
2015
2096
190
DEPENDABLE WATER SUPPLY
LOCAL SURFACE WATER DEVELOPMENT
29
29
29
29
0
IMPORTS BY LOCAL WATER AGENCIES
762
640
640
640
-1 10
GROUND WATER
483
483
463
483
0
CENTRAL VALLEY PROJECT
_
_
_
OTHER FEDERAL WATER DEVELOPMENT
20
20
20
20
0
WASTE WATER RECLAMATION
69
100
195
266
210
STATE WATER PROJECT
481
600
690
590
1 10
TOTAL
1824
1870
1955
2030
210
GROUND WATER OVERDRAFT
82
-80
SWP SURPLUS WATER DELIVERY
—
—
SHORTAGE 1/
___
126
60
65
60
RESERVE SUPPLY 2/
164
—
—
' X."
Table 61 WATER SUPPLY AND USE SUMMARY
SANTA ANA HYDROLOGIC STUDY AREA 1980-2010
(Thousands of acre-feet)
NET WATER USE
1980
1990
{ 1 CHANGE
2000 2010 ; 1980-2010
IRRIGATION
URBAN
WILDLIFE AND RECREATION
ENERGY PRODUCTION
CONVEYANCE LOSSES
320
586
2
9
45
290
710
10
40
250
800
10
40
220
910
10
40
-100
320
10
-10
TOTAL
962
1050
1 100
1180
220
DEPENDABLE WATER SUPPLY
LOCAL SURFACE WATER DEVELOPMENT
IMPORTS BY LOCAL WATER AGENCIES
GROUND WATER
CENTRAL VALLEY PROJECT
OTHER FEDERAL WATER DEVELOPMENT
WASTE WATER RECLAMATION
STATE WATER PROJECT
93
290
402
29
138
93
120
402
50
38 5
93
120
402
70
400
93
120
402
80
400
0
-170
0
50
260
TOTAL
952
1050
1085
1095
140
GROUND WATER OVERDRAFT
SWP SURPLUS WATER DELIVERY
SHORTAGE \J
10
—
15
85
-10
90
RESERVE SUPPLY 2/
203
1/ SWP, BASED ON FIGURE 48 _2/ SWP
Totals for 1990, 2000, 20 10, and CHANGE are roundei).
213
Table 62 WATER SUPPLY AND USE SUMMARY
SAN DIEGO HYDROLOGIC STUDY AREA 1980-2010
(Thousands
of ace
-•■eet)
CHANGE
NET WATER USE
1980
1990
2000
2010
1980-2010
IRRIGATION
198
190
180
170
-30
URBAN
389
480
580
670
280
WILDLIFE AND RECREATION
7
10
10
10
ENERGY PRODUCTION
CONVEYANCE LOSSES
40
35
35
40
TOTAL
634
715
805
890
250
DEPENDABLE WATER SUPPLY |
1 ' ' 1
LOCAL SURFACE WATER DEVELOPMENT
37
37
37
37
0
IMPORTS BY LOCAL WATER AGENCIES
290
21 5
21 5
21 5
-80
GROUND WATER
CENTRAL VALLEY PROJECT
OTHER FEDERAL WATER DEVELOPMENT
77
77
77
77
0
WASTE WATER RECLAMATION
9
40
50
55
50
STATE WATER PROJECT
221
255
245
245
20
TOTAL
634
625
625
630
0
GROUND WATER OVERDRAFT
1
SWP SURPLUS WATER DELIVERY
—
SHORTAGE \_J
90 1
180
260
260
RESERVE SUPPLY 2/
46
1
—
—
1/ SWP, BASED ON FIGURE 48 _2/ SWP Totals for 1990, 2000, 20 10, and CHANGE are rounded
214
Figure 63. WATER SUPPLY AND USE SUMMARY LOS ANGELES,
SANTA ANA, AND SAN DIEGO HYDROLOGIC STUDY AREAS 1980-2010
NET USE
SUPPLY
millions of Acre Foot
3
_J_
5
_L
6
_L
7
8
_L
9
_i_
10
1980
NET USE
^"
SUPPLY
2010
Reduction in need for water supply due to conservatioi
Overdraft and stiortage
Thousands
, of acre-
feet
CHANGE
NET WATER USE
1980
1990
2000
2010
1980-2010
1
IRRIGATION
794
730
650
580
-210
H URBAN
2509
2820
3060
3370
860
H WILDLIFE AND RECREATION
17
30
35
40
20
H ENERGY PRODUCTION
16
30
25
20
—
1
CONVEYANCE LOSSES
166
150
150
155
-10
TOTAL
3502
3760
3920
4165
660
DEPENDABLE WATER SUPPLY
LOCAL SURFACE WATER DEVELOPMENT
159
159
159
159
0
IMPORTS BY LOCAL WATER AGENCIES
1332
975
975
975
-360
GROUND WATER
962
962
962
962
0
CENTRAL VALLEY PROJECT
—
—
—
—
—
OTHER FEDERAL WATER DEVELOPMENT
20
20
20
20
0
WASTE WATER RECLAMATION
97
190
315
400
300
STATE WATER PROJECT
840
1240
1235
1235
400
TOTAL
3410
3645
3665
3755
340
■
GROUND WATER OVERDRAFT
92
-90
SWP SURPLUS WATER DELIVERY
—
■ SHORTAGE ^
0
215
266
410
410
RESERVE SUPPLY 2/
413
0
0
0
Totals for 1990, 2000, 20 10, and CHANGE are rounded.
ly SWP, BASED ON FIGURE 48
2/ SWP
215
Los Angeles Times photo
216
SOUTH COASTAL REGION (LOS ANGELES, SANTA ANA,
AND SAN DIEGO HYDROLOGIC STUDY AREAS)
Total increase in average annual net water use
from 1980 to 2010 in the South Coastal region is pro-
jected to be about 660,000 acre-feet. Agricultural net
water use will decrease by about 210,000 acre-feet by
2010 because of urban expansion onto irrigated
lands. Urban net water use will increase by about
860,000 acre-feet by then.
The additional 1,020,000 acre-feet of water supply
required is much larger than the increase in total net
water use, because the mandated reduction of water
imported from the Colorado River will reduce sup-
plies about 360,000 acre-feet per year below present
levels of use. No cooling water use was projected
from these supplies by 2000. The SWP is expected to
provide 400,000 acre-feet of additional supplies. Ad-
ditional waste water reclamation was projected to
provide about 300,000 acre-feet. Assuming prolonged
delays in providing additional water supplies for the
SWP, shortages in dependable supplies are project-
ed to reach 410,000 acre-feet per year by 2010.
The total increase in net water use for the region
reflects the effect of water conservation measures
implemented between 1980 and 2010. These meas-
ures result in a reduction in need for water supplies
in 2010 of 375,000 acre-feet per year. By 1980. conser-
vation efforts had reduced annual water supply
needs by an estimated 140,000 acre-feet below the
level it would otherwise have reached.
The major water management issues are dis-
cussed in the following sections.
City of Los Angeles
About 80 percent of the city's present water supply
— 467,000 acre-feet per year — is obtained from the
Owens Valley-Mono Lake area. This supply could be
significantly reduced if the courts rule against the
city in the litigation related to the export of water
from Mono Lake and the Owens Valley. Should this
occur, the city would have to increase the supply
obtained from The Metropolitan Water District of
Southern California (MWD). This would be in addi-
tion to the 660,000 acre-feet of additional supply that
the entire South Coastal region is expected to need
by 2010.
Oxnard Plain
In the Oxnard Plain area of Ventura County,
ground water pumping for both urban and agricul-
tural uses has created sea-water intrusion problems
in the Ventura Central ground water basin. The basin
has been designated by the Department of Water
Resources as subject to critical conditions of over-
draft. A physical plan involving ground water basin
management has been developed to control that
problem, and an assessment district has been formed
to finance the plan. The Department and the State
Water Resources Control Board (SWRCB) will con-
tinue to monitor the situation.
Upper Santa Ana Area
A local agency proposal to increase its use of Colo-
rado River water has been approved by SWRCB. The
plan changes the method of averaging limitations of
the total dissolved solids in the effluent at certain
waste water treatment plants. This would allow for
optimum use of Colorado River water in the basin.
MWD and the Department are jointly funding a
feasibility study, in cooperation with the Chino Basin
Municipal Water District, to develop a ground water
basin storage program in conjunction with the SWP
and local facilities. A similar study involving the San
Bernardino Valley Municipal Water District and the
San Gorgonio Pass Water Agency is also being con-
ducted for some other areas.
San Diego County
Because of low rainfall and limited ground water
supply, the county relies heavily on imported water
to meet its requirements. Therefore, any interruption
of imported water supplies would be critical to the
area. Various public agencies within the county have
embarked on a variety of programs to help bridge the
gap between future uses and supplies.
Renewed interest has also been expressed in the
construction of the Santa Margarita Project in north-
ern San Diego County. The project, which would
consist of Fallbrook Dam and DeLuz Dam on the
Santa Margarita River, and associated distribution
facilities, would provide flood control and supple-
mental water supplies to the Fallbrook Public Utility
District and the Marine Corps base at Camp Pendle-
ton. The U.S. Bureau of Reclamation is currently
(1982) updating the feasibility report and the Envi-
ronmental Impact Statement on the project to reflect
local conditions that have changed since the original
reports were completed in 1969. Legislation has been
introduced in Congress to authorize construction of
the project.
i
217
SISKIYOU
MODOC
GOOM* ^
L.
Y
LASSEN
Bnlarg*
ShB9
CImmt Cr. TunntI
20
MILES
-iP^.
Legend
i::^3:z> existing projects !
POSSIBLE FUTURE PROJECTS
Dlxl» Rttug*
PUTAH SOUTH
CANAL
MOffTN BAY AQUEDUCT '
■^ '
Figure 64. SURFACE WATER PROJECTS -
SACRAMENTO HYDROLOGIC STUDY AREA
Figure 65. WATER SUPPLY AND USE SUMMARY
SACRAMENTO HYDROLOGIC STUDY AREA 1980-2010
NET USE
SUPPLY
_L
Millions of Acre Feet
1980
10
_1
-Overdraft and shortage
2010
NET USE
SUPPLY
Reduction in need for water supply due to conservation''
Thousands of acre-feet
NET WATER USE
1980
1990
2000
CHANGE
2010 j1980-2010
IRRIGATION
URBAN
WILDLIFE AND RECREATION
ENERGY PRODUCTION
CONVEYANCE LOSSES
6682
493
160
129
7030
590
165
150
7010
660
165
150
7140
730
165
150
460
240
20
TOTAL
7464
7935
7985
8185
720
DEPENDABLE WATER SUPPLY
LOCAL SURFACE WATER DEVELOPMENT
IMPORTS BY LOCAL WATER AGENCIES
GROUND WATER
CENTRAL VALLEY PROJECT
OTHER FEDERAL WATER DEVELOPMENT
WASTE WATER RECLAMATION
STATE WATER PROJECT
2866
9
1798
2422
259
17
2950
9
1870
2710
270
20
5
2960
9
1900
2715
270
20
10
3010
9
1930
2760
270
25
10
140
0
130
340
10
10
10
TOTAL
7371
7835
7885
8015
640
GROUND WATER OVERDRAFT
SWP SURPLUS WATER DELIVERY
SHORTAGE ^
85
8
70
30
60
40
120
50
40
40
RESERVE SUPPLY 2/
535
275
340
370
2/
Totals for 1990, 2000, 20 I 0, and CHANGE are rounded.
LOCAL URBAN
CVP, AND LOCAL (PLACER COUNTY WATER AGENCY, YUBA COUNTY WATER AGENCY, AND OROVILLE-
WYANDOTTE IRRIGATION DISTRICT).
219
220
SACRAMENTO HYDROLOGIC STUDY AREA
The total projected increase in net water use from
1980 to 2010 IS about 720.000 acre-feet per year. Al-
though ETAW increases by 730,000 acre-feet, net wa-
ter use for agriculture increases by only 460,000
acre-feet because basin outflow from irrigation re-
turn flows will be substantially reduced by greater
irrigation efficiency. The increased irrigation effi-
ciency and a greater proportion of lower water-using
crops will reduce agricultural applied water by about
150,000 acre-feet below 1980 levels. An increase in
the average irrigation efficiency for rice from 45 per-
cent to 55 percent will have a great effect on the total
amount of applied water because of the high applica-
tion rates and the large acreages involved.
The increase in total annual net water use by the
urban sector in 2010 will be significant — 240.000 acre-
feet. That amount is about 35 percent of the total
increase.
The principal source of supply to meet the in-
creased use will be the current reserve supplies of
the Central Valley Project, with an increase in use in
2010 of about 340,000 acre-feet annually over 1980
levels. Increased net use of local surface supplies and
ground water will be about 140,000 and 130,000 acre-
feet, respectively.
The stepped-up Central Valley Project deliveries
will be provided to the southwestern part of the Sac-
ramento Valley through the Tehama-Colusa Canal.
Additional local surface water use will occur princi-
pally on the east side of the Sacramento Valley. In-
creased ground water use is expected to occur
throughout the valley floor and in the area upstream
of Shasta Lake.
Highlights of the major water management-related
issues and some examples of those of more limited
or local impact are presented in the following sec-
tions.
Sacramento Valley Floor
Large increases in irrigated land acreage have oc-
curred during the past decade. These increases are
related to the availability of new water supplies from
the Tehama-Colusa Canal, increased use of ground
water, and changes in crop patterns. In the latter
case, winter-planted and spring-irrigated wheat has
replaced as much as 95 percent of the formerly dry-
farmed barley crop. Rice, a high water-using, relative-
ly high income crop, has doubled in acreage. The
introduction of new and higher-yielding varieties of
rice and wheat and increasing domestic and foreign
demand for these crops are responsible for the in-
creased acreages.
One of the major water issues in the Sacramento
Valley is local control of ground water resources.
Valley farmers strongly defend their ground water
basin because they feel it is threatened by those
wishing to export this resource. Other major con-
cerns are bank erosion, seepage, and recreation tres-
pass along the Sacramento River. Declining fish runs
in the Sacramento River and the Delta is another
issue in the valley.
Chico Area Ground Water. The ground water
basin in and around the city of Chico is recharged
mostly by Big Chico, Little Chico, and Butte Creeks,
which drain volcanic rock areas to the east. Some of
the fairly shallow municipal wells around Chico are
exhibiting nitrate levels above public health
standards. Effluent from non-sewered residential
development, fertilization of agricultural crops, and
rainfall runoff into drainage wells located throughout
the city have been blamed for this contamination.
Discontinued use of high-nitrate domestic wells and
drainage wells and extension of the city's sewer
system will probably alleviate this problem.
Yolo-Solano Counties. Completion of Indian
Valley Dam and Reservoir on North Fork Cache
Creek has virtually eliminated the ground water over-
draft problem in Yolo County, except in local areas,
such as the Yolo-Zamora area, where Indian Valley
water is not available. Both Yolo and Solano Coun-
ties will need additional water after 2000. The
proposed West Sacramento Canal Unit of the CVP is
the most likely source of supplemental water sup-
plies for the area.
Upper Pit River
The number of wells in the upper Pit River basin
has increased by 300 percent between 1960 and 1980.
Most of this increase is for irrigating alfalfa, primarily
using sprinklers. Use of large center-pivot or wheel-
line sprinklers to irrigate alfalfa is now commonplace.
Some of this activity has replaced acreages of
meadow pasture that had been irrigated by wild
flooding from surface water supplies, when they
were available.
Big Valley, which relies on Pit River flows for its
main water supply, is receiving less water than it
221
s.
■^
, . • . . » ■
"*: -■::•..■-
<■•
received formerly because water use is increasing in
Warm Springs Valley and in the upper South and
North Fork Pit River regions. Sprinkler irrigation and
land leveling to improve surface irrigation of alfalfa
and summer-grown grain have increased farm in-
come substantially and changed once-pastoral val-
leys into fairly intensely irrigated agricultural regions.
With high costs of further surface water develop-
ment, future expansion of irrigation will probably rely
on ground water sources. Irrigation by ground water
in Fall River and Big Valley is currently being affected
by ever-increasing electrical energy costs. Some
farmers in Big Valley claim that 30 percent of their
gross revenue from alfalfa production is needed to
pay pumping energy charges. It remains to be seen
whether farm income can stay abreast of costs of
energy for pumping.
Shasta County
The foothill and mountain areas of eastern Shasta
County have become popular sites for subdivision
development. Residential water is provided almost
entirely from domestic wells drilled in low-yield vol-
canic rock. Water supplies vary from small to practi-
cally nonexistent. The sheer number of new wells has
caused existing wells to fail in summer-home areas at
middle and lower elevations. Shasta County is em-
barking on a multi-year study to help resolve this
problem.
Sierra Nevada Foothills
Rapid population growth in the Sierra Nevada
foothills IS taxing the developed surface and ground
water supplies. Surface water systems lack adequate
storage capacity. They were especially vulnerable
during the 1976-77 drought, with rationing common-
place. The community of Paradise and the Nevada
and El Dorado Irrigation Districts were all forced to
ration water. Ground water is a very unpredictable
source because of the geologic formations typical of
the area, which are characterized by underlying vol-
canic or fractured crystalline rock. Many wells went
dry during the drought. Ground water quality is a
problem in some areas.
Some of the water supply problems resulting pri-
marily from population growth in the El Dorado Irri-
gation District could be alleviated by the proposed
Upper (Mountain) South Fork American River
Project (SOFAR), which is sponsored jointly by the
district and the El Dorado County Water Agency.
The project consists of a diversion dam at Forni that
would divert part the South Fork water through a
series of reservoirs, tunnels, and powerhouses. Flow
in the amount of 30,000 acre-feet would be diverted
annually for urban and agricultural use, with the re-
maining flow returned to the South Fork near Pollock
Pines. Total gross storage capacity of the project
would be 199,000 acre-feet. Its total installed generat-
222
ing capacity would be 110 megawatts, with an aver-
age of 470 million kilowatthours of electricity
produced per year. Estimated first cost of the project
IS about S450.000.000 at 1983 first quarter price levels.
The voters of El Dorado County have authorized
the issuance of up to $560 million in revenue bonds
to finance construction of the project. A permit from
the State Water Resources Control Board was ap-
proved in the fall of 1982 and a permit from the Fed-
eral Energy Regulatory Commission for power
generation was pending at that time. Contractual
commitments for the sale of energy and the ability to
market bonds for construction capital will be re-
quired before SOFAR can proceed.
In March 1983, the U.S. Bureau of Reclamation
filed a lawsuit, asking the U.S. District Court to invali-
date any water rights granted by the State Water
Resources Control Board that give priority over fed-
eral water rights. USBR claims that it is not subject
to State water law that gives a local area priority
rights to local water, should it decide to build a water
project.
Meanwhile, local USBR representatives have been
cooperating with the El Dorado Irrigation District
and the El Dorado County Water Agency to clear the
way for the district to proceed while USBR and
SWRCB argue their positions in court. A proposal by
the district is being reviewed by the local USBR staff,
who will send a recommendation to Washington,
D.C., for review and approval.
223
FOLSOM SOUTH CANAL ■
[tfTCH^
Jackson
»lddle BaP
Res.
\Camanche , \y ^
.#rK "■■■ i
SAN JOASIUIN
"Stockton
v^ \/C^ STANISLAUS
•»\Vo
■s-\\o
FKIAHT KERN CANAL
20
JO
Legend
EXISTING PROJECTS
POSSIBLE FUTURE PROJECTS
Figure 66. SURFACE WATER PROJECTS-
SAN JOAQUIN HYDROLOGIC STUDY AREA
224
Figure 67. WATER SUPPLY AND USE SUMMARY
SAN JOAQUIN HYDROLOGIC STUDY AREA 1980-2010
NET USE
SUPPLY
SUPPLY
Minions of Acre Feet
-15 6
1980
NET USE I
2010
10
Reduction in need for water supply
y^ncuu^ii'-'M III ii^^u IV
/ due to conservation
1-^ Overdraft and shortage
Thousands of acre-
-feet
CHANGE
NET WATER USE
1980
1990
2000
2010
|1980-2010
M IRRIGATION
5892
6050
6160
6370
1 480
H URBAN
249
310
360
420
170
J WILDLIFE AND RECREATION
74
80
80
80
10
H ENERGY PRODUCTION
15
20
20
20
I
CONVEYANCE LOSSES
1 1 1
120
130
130
20
TOTAL
6341
6580
6750
7020
680
DEPENDABLE WATER SUPPLY
■""
LOCAL SURFACE WATER DEVELOPMENT
3055
3030
3020
3000
-60
IMPORTS BY LOCAL WATER AGENCIES
—
GROUND WATER
972
970
900
910
-60
CENTRAL VALLEY PROJECT
1838
2040
2230
2280
440
OTHER FEDERAL WATER DEVELOPMENT
55
55
55
55
0
WASTE WATER RECLAMATION
21
25
25
30
10
STATE WATER PROJECT
8
8
8
8
0
TOTAL
5949
6130
6240
6280
330
GROUND WATER OVERDRAFT
391
430
470
680
290
SWP SURPLUS WATER DELIVERY
—
—
—
—
SHORTAGE ^ j
1
20
40
60
60
RESERVE SUPPLY -^
191
320
220
230
Totals f(
r 1 990, 2
000. 20 1
0. and CHA
NGE are rounded
jy MOSTLY LOCAL
_Z/ MINOR LOCAL AMOUNTS AND CVP. 1980: ADDITIONAL CVP. FUTURE ( NEW MELONES )
225
•^■^ ¥V»1
SAN JOAQUIN HYDROLOGIC STUDY AREA
Total annual net water use is projected to increase
by about 680,000 acre-feet by 2010, including 480,000
acre-feet in agricultural use and about 170.000 acre-
feet in urban use. Delivery of Central Valley Project
reserve supply from New Melones and Folsom Reser-
voirs and the Sacramento-San Joaquin Delta would
provide about 440,000 acre-feet of the required in-
crease in supply. The remaining net use is expected
to be supplied from increased ground water over-
draft of about 290,000 acre-feet annually.
Ground Water Overdraft
Since the area will continue to rely on ground wa-
ter as a source for irrigated agriculture, water agen-
cies are attempting to alleviate the overdraft
conditions through artificial recharge and conjunc-
tive use programs. Immediate problems caused by
overdrafting are localized land subsidence, water
quality degradation near Stockton from salt-water
intrusion, and higher pumping costs.
Sierra Foothills Region
Surface water systems in this region lack adequate
storage to serve as dependable sources of water for
irrigation and urban use. Furthermore, because of the
geologic formations of this region, which are charac-
terized by fractured rock, ground water is an unrelia-
ble source. As a result, water resources undergo
wide seasonal and yearly fluctuations. This problem
was evident during the 1976-77 drought, when many
communities and rural users were forced to undergo
severe water rationing.
Supplemental water supplies to alleviate some of
the present shortage in Calaveras County would be
provided by the proposed North Fork Stanislaus Riv-
er Project. Calaveras County Water District
(CCWD) IS planning to construct a multipurpose
project to develop energy and regulate water to sup-
ply the future needs of the county. The project would
consist of several facilities upstream from New Me-
lones Reservoir, including enlargement of Spicer
Meadow Dam and Reservoir on Highland Creek and
construction of three diversion dams, three tunnels,
two power plants, and an afterbay. Approximately
192.000 acre-feet of storage and 205 megawatts of
hydroelectric generating capacity would be pro-
vided by this project. The estimated first cost is
between $300 and S350 million at 1982 prices.
Annual yield estimates range from 68.000 to 103,000
acre-feet. About 57.000 acre-feet of this yield is
planned for Calaveras County, and the balance
would be available for downstream power develop-
ment to assist in financing the project. The Northern
California Power Agency (NCPA) would participate
in the development of the project by purchasing the
power as agreed in a memorandum of understanding
between CCWD and NCPA in 1977. A license from
the Federal Energy Regulatory Commission (FERC)
was issued to CCWD in January 1982. However, both
the Pacific Gas and Electric Company and the
Friends of the River have protested the issuance of
the license. PGandE is protesting because the
proposed project would directly or indirectly affect
several of PGandE's power facilities in the portion of
the Stanislaus River watershed in Calaveras County.
Friends of the River's protest of the project involves
environmental concerns. Construction of a New
Spicer Meadow Dam and Reservoir would inundate
Gabbot Meadow, an area that supports a large deer
herd. The matter is now (1982) in the U.S. Court of
Appeals in Washington. D.C.
The Cosumnes River Water and Power Authority
226
was formed in March 1981 by a joint powers agree-
ment between the boards of supervisors of Amador
and El Dorado Counties. (Sacramento and San Joa-
quin Counties joined the Water and Power Authority
later.) Its purpose was to study the possibility of de-
veloping a water supply and power project on the
Cosumnes River and its tributaries. Prior studies by
the Cosumnes River Association showed that a
project including Steely. Bakersford. and Cape Cod
Dams, with a combined reservoir storage capacity of
about 500.000 acre-feet and four power plants having
a generating potential of about 217 million kilowatt-
hours per year, was potentially feasible. Some 94,000
acre-feet of water per year could be developed by
the project for water needs above the proposed
Cape Cod Regulating Reservoir. The project would
develop an additional 69.600 acre-feet for use down-
stream from Cape Cod Reservoir.
FERC preliminary applications have been made for
several new hydroelectric power projects in the
HSA. The East Bay Municipal Utility District has
proposed the Upper Mokelumne River Hydroelectric
Project, consisting of Middle Bar Dam. Railroad Flat
Dam. Middle Fork Diversion Dam. and two power
plants. The city and county of San Francisco and the
Modesto Irrigation District have proposed the
Clavey-Wards Ferry Project on the Tuolumne River
and tributaries. PGandE has applied for a Kerckoff II
project to further develop the head from Kerckoff
Reservoir to Millerton Lake. The Upper San Joaquin
Water and Power Authority has applied for a project
on Granite and Jackass Creeks.
Folsom South Canal Service Area
The Folsom South Canal service area of the CVP.
which includes portions of Sacramento and San Joa-
quin Counties in the Sacramento and San Joaquin
HSAs. is one of the areas experiencing ground water
overdraft. The problem is most evident near the city
of Stockton, an area that presently depends on
ground water as a major supply for irrigated agricul-
ture and urban development. Water agencies are
planning to eliminate ground water overdraft by im-
porting surface water for conjunctive use with
ground water. The alternative most often considered
for additional surface water is the Auburn-Folsom
South Unit of the CVP, which includes Auburn Dam
and completion of the Folsom South Canal. The Del-
ta and/or New Melones Reservoir have also been
mentioned as possible sources. The Auburn-Folsom
South Unit has been the subject of a major conflict.
The State of California contends that USBR, the
builder of the dam. must provide instream flows in
the lower American River in accordance with
SWRCB Decision 1400. USSR's position is that the
additional water developed by Auburn Reservoir is
not adequate to meet requirements in the Folsom
South Canal service area and also the instream flows
needed to meet the requirements of Decision 1400.
An attempt was made to negotiate a memorandum
of understanding between all parties to resolve the
conflict, but discussions were discontinued in 1978.
Because of uncertainties surrounding reauthoriza-
tion of Auburn Dam. the Department of Water Re-
sources investigated other water management
alternatives for satisfying the water needs of the Fol-
som South Canal service area. The Department's
investigation indicates that, by completing the Fol-
som South Canal, (1) water needs of the Folsom
South service area to 2000 can be met by use of firm
yield from Folsom Lake and conjunctive use of non-
firm yield and ground water, and (2) by using those
measures and other alternatives, water needs
beyond 2000 can be met without Auburn Dam. The
investigation was predicated on meeting the mini-
mum lower American River flows prescribed by Deci-
sion 1400 with relatively minor modifications. New
studies by USBR indicate partial agreement with the
Department's lower estimate of water needs in the
service area. As noted earlier in this chapter, this
CVP unit IS being re-evaluated by USBR in connec-
tion with authorization by Congress.
Delta Service Area
The mam source of water in the Sacramento-San
Joaquin Delta is the surface water in the channels,
which IS derived from unregulated streamflow. re-
turn flow from upstream uses, and releases from up-
stream storage reservoirs. The Delta channels also
serve as a collection point and water transfer system
for water drawn on by the two statewide water
projects, the CVP and the SWP. To protect this water
against salinity intrusion from San Francisco Bay. it is
essential to maintain a sufficient outflow of fresh
water.
Under State law. the Department and the U.S. Bu-
reau of Reclamation are required to maintain water
quality standards in the Delta channels as defined in
SWRCB water right Decision 1485, and as it may be
amended in the future. In addition, the Department
has reached an agreement with the North Delta Wa-
ter Agency and the East Contra Costa Irrigation Dis-
trict to maintain quality standards set by the
contracts within their boundaries. The standards set
forth in the contracts, or future standards set by
SWRCB. whicheverare higher, will prevail. Under the
provisions of a draft Coordinated Operations Agree-
ment, as yet unexecuted, both the CVP and the SWP
would be committed to meet the single set of speci-
fied water quality and outflow standards for the Del-
ta set forth in Decision 1485. In previous years, the
USBR has agreed to meet the Decision 1485 stand-
ards voluntarily, except possibly in critically dry
years. Water is released from upstream State and
federal reservoirs — Oroville. Clair Engle. Shasta, and
Folsom — to maintain quality and for other SWP and
CVP purposes. The Department has attempted to
negotiate agreements with other Delta water users
but has not yet succeeded.
227
i
Legend
i:;j:z> existing projects
MILES
POSSIBLE FUTURE PROJECTS
Figure 68. SURFACE WATER PROJECTS -
TULARE LAKE HYDROLOGIC STUDY AREA
228
Figure 69. WATER SUPPLY AND USE SUMMARY
TULARE LAKE HYDROLOGIC STUDY AREA 1980-2010
Minions of Acre-Feet
4 5 6
10
1980
NET USE
SUPPLY
NET USE
SUPPLY
2010
-Overdraft and shortage
Reduction in need for water
supply due to conservation
Thousands
of acre-
-feet
CHANGE
NET WATER USE
1980
1990
2000
2010
1980-2010
T| IRRIGATION
7781
7955
8185
8475
700
J URBAN
236
280
310
350
1 10
m WILDLIFE AND RECREATION
38
40
40
40
—
ENERGY PRODUCTION
10
25
40
40
30
1
CONVEYANCE LOSSES
123
125
125
125
—
TOTAL
8188
8425
8700
9030
840
DEPENDABLE WATER SUPPLY
LOCAL SURFACE WATER DEVELOPMENT
2199
2199
2199
2199
0
IMPORTS BY LOCAL WATER AGENCIES
—
—
—
—
—
GROUND WATER
551
551
551
551
0
CENTRAL VALLEY PROJECT
2736
2780
2790
2790
50
OTHER FEDERAL WATER DEVELOPMENT
243
243
243
243
0
WASTE WATER RECLAMATION
67
80
90
100
30
STATE WATER PROJECT
795
730
720
720
-70
TOTAL
6591
6580
6590
6600
10
■ GROUND WATER OVERDRAFT
856
1 190
1450
1770
910
SWP SURPLUS WATER DELIVERY 1/
741
. ,
-740
SHORTAGE 2/
0
655
660
660
660
RESERVE SUPPLY 3/ ^
56
10
0
0
Totals for 1990, 2000, 20 10, and CHANGE are rounded
L'' Value for 1980 reflects delivery of SWP surplus water supplies that were used in lieu of pumping ground woter ond for direct
rechorge, (Average delivery for 1979-1981 was 741,000 acre-feet). Surplus woter ovoilability will be reduced in the future to
meet increosing requirements ond is expected to be available only in wet yeors until substantial odditpons to dependoble supplies
are ovoilable for the SWP. Future overdraft could be reduced from the amount shown by the extent thot SWP surplus woter deliveries
con be made available 'but see note 2).
_2,/ S WP^ bosed on Figure 48 About 90 percent of this amount could be met from ground woler, odding to the pro|ected overdroft.
3/ CVP
229
230
TULARE LAKE HYDROLOGIC STUDY AREA
Total annual net water use in the Tulare Lake HSA
is projected to increase about 840,000 acre-feet by
2010, including 700,000 acre-feet of agricultural use
and 110,000 acre-feet of urban use. Tfie additional
needs are expected to be met by a small increase in
CVP supplies, additional waste water reuse, and a
substantial increase in ground water overdraft.
Ground Water Overdraft
The immense ground water overdraft in the Tulare
Lake HSA is one of the most significiant unresolved
water resource problems in California. The present
rate of overdraft is calculated to be about 860,000
acre-feet per year. The importation of SWP water
and the availability of 741,000 acre-feet of surplus
supplies (1979-1981 average) have reduced average
ground water overdraft from about 1,300,000 acre-
feet in 1972 to 860,000 acre-feet in 1980, This has been
achieved despite an increase in irrigated crop acre-
age of about 300,000 acres.
SWP surplus supplies will diminish as the require-
ments for water begin to exceed available supplies.
Assuming that, by 2010, the SWP is augmented by
only the projects shown in Figure 48, shortages m
dependable water supplies would reach 660,000 acre-
feet per year. About 90 percent of this shortage can
be made up from ground water, which would result
in a total overdraft in 2010 as high as 2,400,000 acre-
feet per year. However, in wetter-than-normal years,
some surplus surface supplies will continue to be
available for ground water recharge, to the extent the
California Aqueduct has capacity available to deliver
the water. Also, if additions to SWP yield can be
provided before 2010, ground water overdraft may
not reach the level indicated.
The proposed Mid-Valley Canal addition to the
Central Valley Project, discussed earlier in this chap-
ter, would also reduce the rate of ground water over-
drafting by providing replacement water to irrigated
areas. Preliminary studies indicate an average of
about 450,000 acre-feet per year would be provided
to the Tulare Lake HSA. (A north branch would pro-
vide about 160,000 acre-feet per year to the San Joa-
quin HSA.)
Recently, large increases in electrical energy costs
have given water agencies added incentive to inten-
sify ground water recharge efforts in an attempt to
reduce pumping lifts. The availability of SWP surplus
supplies and the completion of the Cross Valley Ca-
nal in 1975 have enabled Kern County Water Agency
to implement a large-scale program aimed at mitigat-
ing overdraft. This program is over and above all
other recharge programs and other projects using
surface water in lieu of pumping in the area.
Numerous public and private water agencies are
engaged in the acquisition, distribution, and sale of
surface water to growers in the Tulare Lake HSA.
Since most of the agencies overlie usable ground
water and use ground water conjunctively with sur-
face water, some of their operational practices such
as artificial recharge and use of "nonfirm" surface
supplies in lieu of ground water can be viewed as
elements of a ground water management program.
The agencies do not, however, have the power to
control ground water extractions. Such authority is a
requisite to comprehensive ground water manage-
ment.
Dinkey Creek Project
The large increases in the value of electrical ener-
gy have made some projects that were either infeasi-
ble, or only marginally feasible, financially more
attractive. As a result, the Kings River Conservation
District is investigating additional development of
the upper Kings River and its tributaries for power,
flood control, and water conservation. In addition to
adding power to Pine Flat Dam (now under construc-
tion), the Dinkey Creek Project on Dinkey Creek, a
tributary to the North Fork of the Kern River, was
found to be economically justified, and the Kings
231
• ? - .«••.
-ii£iW3;^^4r-.
■•«*«*• -«
'j'.**f^^ j
,.ii-
4*^-'
In the absence of a drainage export facility, evaporation
ponds are used as salt sinks to dispose of drainage water too
salty for reuse.
, ^.t
232
Figure 70. PROPOSED VALLEY DRAIN
River Conservation District has applied to the Fed-
eral Energy Regulatory Commission for a license. Al-
though the project would be operated primarily to
maximize power benefits, the 90,000-acre-foot reser-
voir would also develop about 10,000 acre-feet annu-
ally of new water for the Kings River service area.
Salt Management
The valley floor of the Tulare Lake HSA is essential-
ly a closed basin, and most salts brought into the
basin with water supplies, fertilizer, and soil amend-
ments are not removed. These conditions have been
studied extensively. The most recent, the San Joa-
quin Valley Interagency Drainage Program, was con-
ducted jointly by the Department, USBR, and
SWRCB, and culminated in a report. Agricultural
Drainage and Salt Management in the San Joaquin
Valley,'^ June 1979. The report defines the problem,
describes alternative solutions, and recommends a
plan for solution of the problem — export of brackish
water from the Tulare Lake HSA. The location of the
proposed valley dram is shown on Figure 70.
There is very little willingness at this time among
the beneficiaries of the drain to move ahead with the
recommended plan. At this time, only a few farmers
are threatened by a high water table because drain
water is unable to percolate at a sufficient rate
through underlying clay strata. The problem is of no
immediate or near future concern for the larger num-
ber of farmers who may eventually be affected and
who would be needed to spread the cost in financing
a master drain. As an interim solution, local interests
are constructing facilities to convey drainage water
to large evaporation ponds located on poor-quality
land, where the salts are concentrated.
' Agricultural Drainage and Salt Management in the San Joaquin Valley:
Final Report Including Recommended Plan and First-Stage Environ-
mental Impact Report, San Joaquin Valley Interagency Drainage Pro-
gram; US Bureau of Reclamation. California Department of Water
Resources, the California State Water Resources Control Board: witfi
Appendixes to Final Report, June 1979 (reprinted November 1979).
Stockton
LEGEND
Existing San Luis Droin
Proposed Extensions
Drainage Problem Areos
(present and potential )
Edge of Valley Floor
233
ORE.
Legend
(^JZ>- EXISTING PROJECTS
POSSIBLE FUTURE PROJECTS
20 30
MILES
Prosser Cr. Re
Truckee
River
Carson
River
Figure 71. SURFACE WATER PROJECTS -
NORTH LAHONTAN HYDROLOGIC STUDY AREA
234
Figure 72. WATER SUPPLY AND USE SUMMARY
NORTH LAHONTAN HYDROLOGIC STUDY AREA 1980-2010
Millions of Acre-Feet
1.5 0
_1
1.5
I
1980
2010
NET USE
SUPPLY
NET USE
SUPPLY
Overdraft
Thousands of acre-
-feet
CHANGE
NET WATER USE
1980
1990
2000
2010
1980-2010
■I IRRIGATION
387
410
410
420
30
URBAN
23
30
35
40
20
M WILDLIFE AND RECREATION
1 1
10
10
10
0
■ ENERGY PRODUCTION
J
CONVEYANCE LOSSES
—
TOTAL
421
450
455
470
50
DEPENDABLE WATER SUPPLY
LOCAL SURFACE WATER DEVELOPMENT
312
310
310
320
10
IMPORTS BY LOCAL WATER AGENCIES
1 1
1 1
1 1
1 1
0
GROUND WATER
88
1 10
120
120
30
CENTRAL VALLEY PROJECT
OTHER FEDERAL WATER DEVELOPMENT
WASTE WATER RECLAMATION
5
10
10
10
STATE WATER PROJECT
—
TOTAL
416
440
450
460
40
GROUND WATER OVERDRAFT
5
10
5
10
10
SWP SURPLUS WATER DELIVERY
_
SHORTAGE
...
RESERVE SUPPLY -l/
17
20
20
20
Ay
Totals for 1990, 2000, 2010, and CHANGE are round
MOSTLY LOCAL PROJECTS, PLUS SOME FROM STAMPEDE RESERVOIR.
235
NORTH LAHONTAN HYDROLOGIC STUDY AREA
In the North Lahontan HSA, annual net water use
in 2010 is projected to be about 50,000 acre-feet
greater than it was in 1980. The principal increases
will be about 30,000 acre-feet for irrigated agriculture
and about 20,000 acre-feet for urban uses.
Ground water will provide the principal source of
water, with annual net use projected to increase by
about 30.000 acre-feet by 2010. Expanded develop-
ment of local surface water will supply the remain-
der.
Nearly all the growth m agricultural water use is
expected to take place m Modoc and Lassen Coun-
ties. Little is known, however, about the potential
ground water yield in this part of the HSA and the
recent rapid increase in ground water pumping is
causing concern. An example of these concerns and
other water management-related issues important to
this HSA follows.
Surprise Valley Ground Water
Ground water pumping for the production of alfal-
fa by sprinkler irrigation has doubled since 1960.
Some areas of Surprise Valley, particularly around
Cedarville, may already be in overdraft. Wells located
nearer the mountains on the west side of the valley
nearly cease flowing in late July and August, but,
according to well measurement data, they recharge
fully by the following spring. Increased pumping
higher on the alluvial fan has reduced the water sup-
plies reaching some of the meadow pastures along
the margins of the alkali lakes in this area; this pump-
ing creates space for recharge from local creeks that
formerly irrigated the meadows. The Department of
Water Resources is presently studying Surprise Val-
ley to evaluate the probable impact of increased
pumping and to examine means of increasing ground
water recharge.
California-Nevada Interstate Compact
California and Nevada have agreed to allocate
between them the water supply of Lake Tahoe and
the Truckee. Carson, and Walker Rivers. The Califor-
nia-Nevada Interstate Compact was approved by the
California Legislature in 1970 and the Nevada Legisla-
ture in 1971. However, the compact will not go into
236
effect until it is approved by Congress. That approval
has been held up by federal agencies that believe (1 )
the United States should not be bound by terms of
the compact, and (2) the compact would prejudice
efforts to increase inflow to Pyramid Lake to pre-
serve the fishery.
The Tahoe Regional Planning Agency (TRPA) is
responsible for controlling land use in the Lake
Tahoe Basin to protect the lake from quality degrada-
tion. The State Water Resources Control Board has
made detailed studies of current and potential future
water use in the basin under the limitations imposed
by TRPA and the interstate water compact. Similar
studies have not been made for the Truckee, Carson,
and Walker River Basins; therefore, the projections in
this report for the three river basins are not as reliable
as those for the Tahoe Basin.
The Pyramid Lake Paiute Indian tribe has sued the
State of California, and others, to secure additional
water to maintain Pyramid Lake and provide ade-
quate flows for fish spawning in the Lower Truckee
River (between Derby Dam and Pyramid Lake).
USBR has declined to contract for the sale of water
from Stampede Reservoir on Little Truckee River un-
til this matter is resolved. In the interim, the reservoir
is being operated for fishery enhancement. A 1982
decision in Carson-Truckee Water Conservancy Dis-
trict, et al. V. Kleppe. et al. sets a higher priority for
fishery preservation than for municipal uses in the
operation of Stampede Reservoir. Thus, the availabil-
ity of water from the Truckee River will depend on
the outcome of current litigation.
In the Carson and Walker River Basins, most of the
irrigation water requirements are met by direct diver-
sion from streams. Surplus water is usually present
during the spring snowmelt period, but streamflows
are low during most of the irrigation season. Howev-
er, with a minor exception, storage projects studied
to date have not been economical. The compact and
the court decree, which is presently on appeal,
would give Alpine County water users the right to
store 2,000 acre-feet each year adverse to the federal
Lahontan Reservoir downstream in Nevada.
237
Figure 73. SURFACE WATER PROJECTS -
SOUTH LAHONTAN HYDROLOGIC STUDY AREA
MolBve Res.
Figure 74. WATER SUPPLY AND USE SUMMARY
SOUTH LAHONTAN HYDROLOGIC STUDY AREA 1980-2010
Minions of Acre-Feet
1.5
_J
0
1.5
I
NET USE
1980
SUPPLY
2010
NET USE
SUPPLY
Overdraft and shortage-
Reduction in need for water supply due to conservation-
Thousands of acre-
-leet
CHANGE
NET WATER USE
1980
1990
2000
2010
1980-2010
■ IRRIGATION
338
300
270
230
-1 10
H URBAN
60
80
1 10
120
60
H WILDLIFE AND RECREATION
12
25
25
30
20
H ENERGY PRODUCTION
2
5
15
25
20
I
CONVEYANCE LOSSES
7
5
5
5
0
TOTAL
419
415
425
410
-10
DEPENDABLE WATER SUPPLY
LOCAL SURFACE WATER DEVELOPMENT
44
45
45
45
0
IMPORTS BY LOCAL WATER AGENCIES
—
GROUND WATER
178
180
170
130
-50
CENTRAL VALLEY PROJECT
—
—
—
OTHER FEDERAL WATER DEVELOPMENT
■
WASTE WATER RECLAMATION
9
10
15
15
10
STATE WATER PROJECT
85
1 10
1 15
120
30
TOTAL
316
355
355
310
-10
GROUND WATER OVERDRAFT
103
40
50
70
-30
SWP SURPLUS WATER DELIVERY
SHORTAGE ^
20
20
30
30
RESERVE SUPPLY -^
33
0
15
55
— ii
Totals for 1990. 2000,20 10. and CHANGE are rounded.
jy SWP (MOJAVE WATER AGENCY AND CRESTLINE LAKE ARROWHEAD WATER AGENCY
2/ SWP. 1980: SWP ENTITLEMENT WATER USED FOR GROUND WATER RECHARGE IN ANTELOPE VALLEY. FUTURE.
239
■'!t:-
■>^
«?':v*fc
'^-
4'^
SOUTH LAHONTAN HYDROLOGIC STUDY AREA
Total annual net water use is expected to decline
by about 10.000 acre-feet between 1980 and 2010.
Agricultural net water use is expected to drop by
about 110.000 acre-feet, reflecting a decrease of
more than 30 percent in irrigated alfalfa and pasture
acreage as ground water availability and costs
become major problems in the area. However, urban
net water use is expected to double, reaching about
120.000 acre-feet. Water for power plant cooling will
add about 20,000 acre-feet to net use by 2010.
The large reduction in irrigated acreage projected
by 2010 is expected to reduce ground water net use
by about 80.000 acre-feet per year. Ground water
overdraft would decrease by about 30.000 acre-feet
per year. Much of the increase in urban net water use
is expected to be met by a 30.000-acre-foot increase
in SWP deliveries.
The water issues in the South Lahontan HSA in-
volve: (1) exportation of water from the Owens-
Mono area, and (2) local ground water quality and
quantity problems.
Exportation of Water
The Los Angeles Department of Water and Power
(LADWP) diverts both surface and ground water
from the Owens Valley and surface water from the
Mono Basin, totaling 483,000 acre-feet per year. In
recent years, after deduction of conveyance losses.
LADWP's supply averaged about 467.000 acre-feet,
with an average of 100,000 acre-feet annually from
the Mono Basin.
Since the commencement of LADWP's surface di-
version project in Mono Basin in 1941. the lake's sur-
face elevation has dropped more than 40 feet.
However, lake levels recovered m 1982 and 1983 be-
cause of above-normal runoff and reduced diver-
sions by LADWP.
240
In February 1983. the California Supreme Court is-
sued its decision in the Mono Lake Litigation. Na-
tional Audubon Society v. Superior Court. The
Supreme Court held that water rights licenses issued
to the city of Los Angeles to divert water tributary to
Mono Lake are subject to the public trust doctrine.
Under this doctrine, the State retains continuing
supervision over the taking and use of water. The
holder of a license issued by the State has no vested
right to the use of water m a manner harmful to the
trust. The public trust doctrine protects navigable
waters from harm caused by diversion of nonnaviga-
ble tributaries.
The court also held that there is no duty to exhaust
administrative remedies before the State Water Re-
sources Control Board: rather, the courts and
SvVRCB have concurrent jurisdiction to consider
whether the city's diversions violate the public trust.
H.R. 1341 (Richard Lehman. California), a bill that
would establish a Mono Basin National Forest Scenic
Area, is now being considered by Congress. If
passed, the bill would provide land-use guidelines to
preserve the scenic qualities of federally-owned
property in the Mono Basin. The Secretary of
Agriculture would manage the area in a manner con-
sistent with the protection of California water rights,
and this management would not affect or impair ex-
isting water appropriations and operations taking
place in the Mono Basin.
In Owens Valley, residents have objected to
ground water pumping by LADWP. contending that
the extractions will severely lower ground water lev-
els and adversely affect native plant and animal life.
They also claim that health problems will develop as
dust storms become more frequent. Pending resolu-
tion of this dispute, a court order has been issued
that restricts pumping to a maximum rate of 149.5
cubic feet per second. This reduces the quantity of
ground water available for delivery by the Los Ange-
les Aqueduct.
Both legal and legislative actions have been taken
by opponents of LADWP's programs. Lawsuits have
been filed by opponents (the Sierra Club, the Audu-
bon Society, Inyo County, and the Great Basin Uni-
fied Air Pollution Control District) to seek either an
end to or curtailment of the diversions by LADWP. In
1980, Inyo County voters passed a ballot measure to
manage ground water extractions in the valley. That
ordinance, which would have given the county the
authority to limit pumping by LADWP, was ruled un-
constitutional by the Superior Court in San Bernar-
dino County.
Local Ground Water Use
Greater urban and agricultural water use has
caused ground water levels to decline in Antelope
Valley, Fremont Valley, and Indian Wells Valley. Agri-
cultural net water use is projected to decrease from
338.000 acre-feet m 1980 to 230.000 acre-feet in 2010.
primarily because the income from crops commonly
grown here appears insufficient to pay the increased
cost of ground water pumping.
Because of concern over recent and projected
population growth and declining water levels in the
Indian Wells area, the major water users and the U.S.
Geological Survey are evaluating ground water re-
charge, the change in water levels, and the discharge
from Indian Wells Valley. However, the projected
economic base does not appear sufficient to support
importation of needed water supplies.
In the Mojave River area, levels of nitrate, fluoride,
and other mineral constituents in the ground water
supplies have increased. Some basins in the area
must continue to rely on ground water, despite de-
clining water levels, until the local distribution system
for State Water Project water is built.
241
Legend
<^
EXISTING PROJECTS
I
Figure 75. SURFACE WATER PROJECTS -
COLORADO RIVER HYDROLOGIC STUDY AREA
242
Figure 76. WATER SUPPLY AND USE SUMMARY
COLORADO RIVER HYDROLOGIC STUDY AREA 1980-2010
Millions of Acre-Feet
4 5 6
1980
NET USE
SUPPLY
1
2010
f
NET USE
SUPPLY
1
10
_l
Reduction in need for water supply due to conservation
" Overdraft and shortage
PROJECTED USE OF WATER SUPPLIES 1980-2010
Thousands of acre-feet
1
CHANGE
NET WATER USE
1980
1990
2000
2010
1980-2010
1
IRRIGATION
3434
3560
3700
3680
240
H URBAN
102
130
170
200
100
1 WILDLIFE AND RECREATION
20
20
20
20
0
I
ENERGY PRODUCTION
3
20
30
45
40
I
CONVEYANCE LOSSES
543
360
280
280
-260
TOTAL
4102
4090
4200
4225
120
DEPENDABLE WATER SUPPLY |
LOCAL SURFACE WATER DEVELOPMENT
4
4
4
4
0
IMPORTS BY LOCAL WATER AGENCIES
—
—
GROUND WATER
68
70
70
70
0
CENTRAL VALLEY PROJECT
OTHER FEDERAL WATER DEVELOPMENT
3970
3920
3990
3990
20
WASTE WATER RECLAMATION
3
20
30
40
40
STATE WATER PROJECT
30
40
40
40
10
TOTAL
4075
4050
4130
4140
70
M GROUND WATER OVERDRAFT
27
10
30
50
20
SWP SURPLUS WATER DELIVERY
SHORTAGE^'
30
40
35
30
RESERVE SUPPLY ^
4
0
0
0
jy SWP
2y SWP
Totals for 1990, 2000, 20 10, and CHANGE are rounded.
243
244
COLORADO RIVER HYDROLOGIC STUDY AREA
Total annual net water use between 1980 and 2010
is projected to increase by only about 120.000 acre-
feet, most of which is increased urban use. This sug-
gests little change in agricultural water use; however,
this IS not the case. By use of water saved by intensi-
fied conservation measures, irrigated acreage was
projected to increase significantly. This would result
in an increase in evapotranspiration of applied water
of more than 400,000 acre-feet by 2010, with essential-
ly the same water supply as is currently used, but
with considerably reduced losses to the Salton Sea
and to saline ground water. There are supplemental
water needs in other parts of the HSA that can be
met by a combination of State Water Project deliver-
ies and ground water overdraft. The Colorado River
Indian tribes were projected to use their full entitle-
ment of 55,000 acre-feet by 2000.
The following are the more significant water issues
in this HSA.
The Salton Sea
Concern about the rising level of the Salton Sea
has been a major factor in recent water conservation
efforts in this HSA. The water level in the sea is rising
and inundating surrounding land. The Salton Sea is a
natural sump and is maintained mainly by return irri-
gation flows from the Imperial and Coachella Valleys,
augmented by flows from occasional tropical storms.
It is recognized as a valuable fishery and wildlife ref-
uge. Reduction of return flows, either through con-
servation or as a result of their use in developing
geothermal resources in the area, could cause the
level of the sea to decline, increasing the concentra-
tion of salts in the water. This would impair fish life
and isolate shoreline development.
Imperial Valley Water Conservation
Over the past several years, efforts have increased
to improve the efficiencies of distribution and use of
irrigation water in the Colorado River HSA. The lining
of the Coachella Canal in 1980 is estimated to save
1 10,000 acre-feet of water per year that had previous-
ly been lost to seepage. Similarly, the lining of distri-
bution canals in Imperial Valley now saves an
estimated 130,000 acre-feet per year.
Continuing concern for better water management
in Imperial Valley has led the Imperial Irrigation Dis-
trict (IID) to implement water conservation pro-
grams directed toward reducing excess water use.
The findings of an investigation conducted by the
Department of Water Resources at the request of an
IID farmer were published in December 1981 in the
Department's report. Investigation under California
Water Code Section 275 of Use of Water by Imperial
Irrigation District. The study concluded that, based
on average conditions prevailing from 1975 to 1979,
an estimated 438,000 acre-feet of water could be
saved annually in the Imperial Valley through various
improvements in distribution systems and irrigation
management. Identified measures included lining of
portions of the Ail-American Canal, lining of addition-
al segments of the district's laterals, construction of
more regulatory reservoirs, elimination of canal
spills, expanded use of seepage recovery systems,
and implementation of irrigation management pro-
grams to reduce excess irrigation runoff. Some of
these actions, such as lining the Ail-American Canal,
may not be cost-effective for the district. Improve-
ments already being implemented are being funded
through higher water rates to customers and penalty
assessments to farmers found to be wasting water.
The salvaged water reportedly could be used in a
number of ways. First, the water could be put to use
on lands within the IID now being irrigated with Colo-
rado River water. The four California agricultural
agencies with rights to Colorado River water are
presently using about 80.000 acre-feet more than the
3.85 million acre-feet per year allocated under the
Seven Party Agreement. When the Central Arizona
Project becomes operational around 1985. these
agencies — the Palo Verde Irrigation District, the
Yuma Project, the IID. and the Coachella Valley Wa-
ter District — must reduce consumptive use to the
level of their firm entitlement. As a result, some of the
water salvaged by lining the Coachella Canal and
from improved conservation practices will probably
be used to sustain existing agriculture.
Second, not all the irrigable lands within the IID are
presently being irrigated. Landowners in these areas
would probably farm more land, if more water
becomes available on a firm basis. The water saved
could, therefore, be used for this purpose.
Third, agricultural water use varies widely from
year to year in response to climatic conditions, type
of crops planted, and other factors. Thus, the need
for water to accommodate those variations must be
recognized.
Fourth, if the conserved water could be made
available to coastal Southern California, that area
could reduce its purchase of SWP water, temporarily
reducing demands on the SWP system. However,
there are legal and institutional issues involved in
such a transfer.
In this report, it was estimated that 394.000 acre-
feet of water could be salvaged between 1980 and
2010 and would be put to use for irrigation of addi-
tional crops in IID.
245
CHAPTER VI
OPTIONS FOR THE FUTURE
The purpose of this chapter is to discuss some of
the options which should be examined by water
managers as they address means of meeting water
needs. Chapter V discussed the water supply situa-
tion as it relates to the increased demands being
placed on the developed resource. It was shown
that, statewide, net water use is expected to total
37.3 million acre-feet by 2010, while the developed
dependable supply is about 33 million acre-feet. In
the State Water Project service areas, requirements
are estimated to be 1.5 million acre-feet greater than
the yield of existing and authorized facilities. This is
the major identified water management issue.
In the first section of this chapter, net water use-
water supply relationships are reviewed for each ma-
jor region of the State. This is followed by a discus-
sion of the potential for developing additional water
supplies, water supply savings gained from more in-
tensive water conservation (beyond those presented
in Chapter IV), and other management options avail-
able to water managers. The chapter concludes with
a view of government agency roles.
Constraints on Water Management
The choice of water management options will be
constrained or influenced by a number of policy deci-
sions. Water quality decisions, for example, may con-
stitute an additional demand on the system. The
Delta Decision (Decision 1485) requires the mainte-
nance of minimum water quality standards in the
Sacramento-San Joaquin Delta. Under this decision,
slightly more than 5.0 million acre-feet annually, in-
cluding more than 1.0 million acre-feet of developed
supply, is needed as Delta outflow to meet these
standards. Any revision of these standards, there-
fore, would affect the supply capabilities of the State
Water Project and the federal Central Valley Project.
Other potentially serious water quality problems
include areas with high brackish water tables, par-
ticularly the San Joaquin Valley, where about 400,000
acres of irrigated land are now increasingly and seri-
ously threatened. Ultimately, more than 1.0 million
acres could be similarly threatened. Productive
' See Inventory of Instream Flow Requirements Related to Stream Diver-
sions. Bulletin 216. Department of Water Resources. December 1982.
capacity of these lands can be maintained only by
installation of adequate soil drainage and saline wa-
ter disposal systems.
Decisions regarding water supply allocations for
instream uses, including wild and scenic river desig-
nations, have a direct bearing on the amount of water
available for development and on the operation and
yield of existing and proposed projects. Estimates
and projections in this report are premised on satis-
faction of instream flows agreed upon through
negotiations and water rights procedures.' However,
as more knowledge is gained of instream uses and
related needs, further actions and decisions could
affect the water supply options discussed in this
chapter.
Finally, the water management options discussed
have not been studied sufficiently to assess engi-
neering, environmental, economic, or financial feasi-
bility. Although it is generally recognized in this
report that water costs will increase significantly in
coming years, benefits are expected to increase as
well. Moreover, actions by the federal government to
revise cost-sharing provisions associated with water
projects would shift a significant financial burden to
the states or other non-federal entities and may af-
fect project feasibility.
The Resource Supply Outlook
Consideration of water resources in California in-
volves two separate concepts — the total resource
and the developable resource. The developable re-
source is that portion of the resource that can rea-
sonably be converted to a usable supply. The two are
markedly different. This section identifies the total
resource, by major region, and discusses the ever-
widening gap between the total, or physical, re-
source and the remaining developable resource, as
limited by economic, political, and social constraints.
The Total Surface Water Resource
California's long-term natural (unimpaired) runoff
was evaluated intensively during the Statewide Wa-
ter Resources Investigation, authorized in 1947, the
results of which were published in Water Resources
in California (Bulletin 1, 1951). The total mean annual
247
natural runoff of all California streams for the 50-year
period from 1897 through 1947 was estimated to be
70.8 million acre-feet, excluding imports from the Col-
orado River and inflow from Oregon.
California's long-standing claim of 5.4 million acre-
feet from the Colorado River was reduced to 4.4 mil-
lion acre-feet by a decision of the U.S. Supreme
Court in 1964, which awarded an additional 1.0 mil-
lion acre-feet to Arizona for the Central Arizona
Project. Decisions are pending on further reductions
to satisfy Indian water rights. Such actions would be
at the expense of The Metropolitan Water District of
Southern California (MWD). For this discussion, the
Colorado River supply available to California is as-
sumed to be 4.4 million acre-feet per year. This brings
the total resource to 78.5 million acre-feet. (See Fig-
ure 47 in Chapter V.)
The Present Water Supply Situation
Because of an aggressive water development pro-
gram that covered several decades and ended m the
early 1970s with completion of the California Aque-
duct and terminal State Water Project reservoirs,
California's present water needs are generally being
satisfied by dependable water supplies. There are,
however, two notable exceptions. The first is com-
munities and agricultural areas dependent on local
streams, with small or no storage reservoirs. They are
often short of water toward the end of summer, and
are critically short during drought years. The other
important exception is areas that overdraft ground
water basins year after year. The most outstanding
example of this situation is the San Joaquin Valley,
where the persistent annual overdraft is about 1.2
million acre-feet. While water uses are presently be-
ing satisfied by overdraft, it is not a dependable sup-
ply. Eventually, economic forces or other restraints
will compel pumpers to cut back in some areas, caus-
ing changes in irrigated agriculture, unless provisions
are made for new imported supplies.
The Future Water Supply Situation
Several events, some of them recent, have cast
uncertainty over the ability to satisfy future water
needs. In some instances, opposition to proposed
projects has resulted from confusion arising from a
combination of economic, political, environmental,
and emotional concerns.
Any program to increase developed supply will be
affected by a variety of constraints that have con-
tributed to the delay or rejection of proposed
projects.
Basic Water Supply- Net Water Use Assump-
tions. Assumptions regarding the origin and mag-
nitude of water supplies available to satisfy future
net water use are summarized m this section. As de-
scribed earlier in this report, it was assumed that
additional surface water supplies developed by 2010
would be obtained from Central Valley sources.
• The South Coastal region derives its water supply
from underground storage, local surface storage,
and imports from the Colorado River, the Mono
Lake-Owens Valley area, and the State Water
Project. Local water supplies are fully developed,
including ground water. It is assumed that import-
ed water supplies from Mono Lake basin. Owens
Valley, and the Colorado River entitlements will
remain the same. Additional water supplies must
come from the Central Valley through the State
Water Project. However, there is potential for re-
ducing water use in the Imperial Valley that could
make additional supplies available. (See Chapter V
for a detailed discussion.)
• The Central Coast HSA will meet its future water
needs largely from increased local development
and from the San Felipe Division of the federal
Central Valley Project, which will serve water to
San Benito County and south Santa Clara Valley. In
addition to increased local water supplies, supple-
mental supplies for Santa Barbara and San Luis
Obispo Counties would have to come from the
State Water Project through the proposed coastal
aqueduct.
• The San Francisco Bay HSA will satisfy its future
water needs by increased imports from Central
Valley sources. These imports could be provided
by local agencies, the State Water Project, or the
Central Valley Project. The significant point is that
any increased delivery of water to the Bay area
would be derived from the Central Valley.
• The North Coast HSA will satisfy its future needs
from local sources. It is assumed that the north
coastal wild and scenic rivers will not be available
for export from that area. The exception is the
Trinity River, which is expected to continue to pro-
vide 850,000 acre-feet annually to the Central Val-
ley.
• The North Lahontan. South Lahontan. and Colo-
rado River HSAs include some locations that are
scheduled to receive deliveries from the State Wa-
ter Project. Aside from the SWP. these areas must
rely on water supplies within their respective re-
gions to satisfy future needs.
• The Central Valley, consisting of part of the Sacra-
mento, San Joaquin, and Tulare Lake HSAs, is the
area projected to experience the greatest increase
in net water use over the next 30 years and beyond.
The Sacramento HSA is the major source of supply
248
for regions that require additional imported water
supplies (including the San Joaquin and Tulare
LakeHSAs).
Demands on the Central Valley. Based on the
foregoing assunnptions. any further increases in wa-
ter supplies in the South Coastal region and the Cen-
tral Coast and San Francisco Bay HSAs (with the
exception of the city of San Francisco) would come
from the Sacramento HSA. The additional needs of
the State Water Project will constitute most of the
additional export demand on Central Valley sources.
In addition, the largest increases in water uses are
projected to occur within the Central Valley — the
Sacramento, San Joaquin, and Tulare Lake HSAs.
From a practical standpoint, the Sacramento HSA is
the only reasonable source available to meet the de-
mands of 2010 and at least the immediate decades
beyond.
The basic surface water resource within the Cen-
tral Valley, expressed as mean annual natural runoff,
is 33,640,000 acre-feet. This supply is augmented by
an average annual import of 850,000 acre-feet from
the Trinity River, for a total of 34.5 million acre-feet.
This is shown by major areas in Figure 77.
The remainder of this section discusses the availa-
bility of the Central Valley water supply in relation to
the projected uses of water to be satisfied. Net water
Figure 77. CENTRAL VALLEY SURFACE WATER SUPPLY
MAF = MILLION ACRE-FEET
TRINITY RIVER IMPORT
0.8 MAF
249
uses within the Central Valley are shown in Table 63
for 1980 and for decades to 2010 for the Sacramento
HSA and the combined San Joaquin and Tulare Lake
HSAs. The areas dependent on exports from the
Central Valley water resources are combined into a
single value. All values are expressed as net water
use and are consistent with those in Chapter V.
In addition to surface runoff, precipitation on the
Sacramento Valley floor contributes to ground water
recharge during wetter years and adds to the total
supply. Increased ground and surface water develop-
ment can satisfy future water needs in the Sacra-
mento HSA, but there is essentially no opportunity
for additional surface or ground water yield in the
San Joaquin and Tulare Lake HSAs, without addition-
al imported supplies.
The net water use in major areas in the Central
Valley in 1980 is illustrated in Figure 78. Net water use
in the San Joaquin and Tulare Lake HSAs does not
include the 1980 ground water overdraft of 1.2 million
acre-feet. The "Unavoidable Delta Outflow" in that
figure is defined as the large floodflows that occur
during winter months of wet years that could not be
captured economically or physically, even with addi-
tional reservoir storage in the Sacramento Valley.
The item "Remaining Potential Supply," 4.6 million
acre-feet, represents the balance of the total Central
Valley resource, 34.5 million acre-feet, after all cur-
rent needs, excluding ground water overdraft, are
met. This also represents the limit of future water
development in the valley.
Water Supply Options
This section discusses the sources of water sup-
plies, both surface and ground water, that could be
available to satisfy projected needs. For new water
supplies, it will not be a case of the use of one or
more sources to the exclusion of others, but rather
will probably be a combination of all sources.
Surface Water
The California Water Plan of 1957 demonstrated
that California had more than sufficient developable
water resources, after providing favorable conditions
for fish and wildlife, to satisfy potential ultimate ur-
ban and agricultural uses: however, it was recog-
nized that certain of the required works would be
extremely costly and that their need might never ma-
terialize.
North Coast. Streams on the North Coast could
provide sources of water to satisfy statewide needs
for urban and agriculture purposes beyond 2010.
However, wild and scenic instream laws, costly
dams, and long and costly conveyance systems keep
the North Coast streams from being potential
sources of water supply in the foreseeable future.
Sacramento Valley. Most streams m this area
have been intensively developed to provide water for
urban and agricultural use. If the funding situation
improves, prospects seem reasonable that, by 2000,
the Cottonwood Creek and Auburn Dam Projects
could be constructed and some local development of
new water supplies could be completed. These de-
velopments probably could provide a total new wa-
ter yield of about 500.000 acre-feet. Also, an enlarged
Shasta Reservoir with a potential new dry-period
yield of about 1.4 million acre-feet probably could be
completed by 2010 to provide a water supply beyond
that date.
Delta Transfer Facility. The amount of export
water available could be substantially increased with
a Delta transfer facility. More than 20 years of intense
effort has been made to identify the type of facility
that should be constructed to convey surplus water
to the Delta pumps for export to water-deficient
areas. The Peripheral Canal could have solved most
issues, including fish and wildlife, water supply, wa-
ter quality, recreation, and shipping. However, the
rejection of Proposition 9 left the transfer issue un-
resolved. Until a Delta transfer facility is provided,
full use cannot be made of the available surplus wa-
ter supplies of the Sacramento Valley.
Colorado River. Reduction in losses of Colo-
rado River water now serving the Coachella and Im-
perial Valleys might increase the supplies available to
the South Coastal region. However, there are signifi-
TABLE 63
PRESENT (1980) AND PROJECTED FUTURE NET WATER USES
DEPENDENT ON CENTRAL VALLEY WATER RESOURCES '
(In millions of acre-feet)
HSA 1980
Sacramento 7,5
San Joaquin and Tulare Lake 14.5
San Francisco Bay. Central Coast. Los Angeles, Santa Ana, San Diego. South Lahontan, and Colorado River V6
Total 23.6
Increase from the Present (1980) —
Excluding consideration of mandatory Delta outflows
1990 2000
2010
7,9 8.0
15.0 15.4
2.5 2.6
25,4
+ 1,8
26,0
-1-2,4
8,2
16,0
2,8
27.0
+ 3.4
250
Figure 78. PRESENT USE OF DEPENDABLE SUPPLY
San Francisco Bay
Central Coast
South Coast
South Lahontan
Colorado River
MAF= MILLION ACRE-FEET
1/ INCLUDES GROUND WATER PRIME SUPPLY
cant legal and institutional matters that must be re-
solved before this option can be exercised.
Ground Water
Ground water in storage is the major fresh water
reserve in California. Water storage capacity of the
major ground water aquifers totals over 1.0 billion
acre-feet; by comparison, the total surface reservoir
storage capacity is less than 40 million acre-feet.
More than 850 million acre-feet of fresh water is
stored in the ground water basins, about 500 million
acre-feet of which may be usable. Sea-water intru-
sion, water quality, and surface subsidence are some
of the factors affecting usability.
Sacramento Valley. This ground water basin
has not been developed to the full extent of its poten-
tial because the area is oriented primarily to the use
of surface water. The physical potential exists for
developing supplemental yield. This ground water
supply could be used for local purposes, particularly
during dry years, permitting surface water to flow to
the Delta for transfer to water-deficient areas. The
basin could easily be recharged during ensuing wet-
ter years, resulting in an increase in total developed
supply.
San Joaquin Valley. The valley contains the
largest ground water basin in the State, with more
than 200 million acre-feet of water in storage within
500 feet of the surface. Ground water in these areas
has been mined heavily to compensate for a shortage
of surface supplies, and there is currently more than
30 million acre-feet of usable empty storage capacity.
The principal method of increasing the supply in this
area is transferring surplus surface water from the
Delta during wetter years to recharge the basin, ei-
ther by direct recharge or indirectly by using the im-
251
ported supply in lieu of ground water pumping.
Transfer of surface flows would be accomplished by
conveyance facilities of the CVP or SWP.
Increasing ground water recharge in the San Joa-
quin Valley will depend on availability of Sacramento
Valley surplus supplies. However, transfer of these
supplies has two physical limitations: transfer across
the Delta and aqueduct capacity. The San Joaquin
Valley ground water basin is in a state of overdraft
and is being studied by the Depa-'tment to develop
a conjunctive use management plan. A Department
report. The Hydrologic-Economic Model of the San
Joaquin Valley (Bulletin 214, December 1982). de-
scribes the current state of the basin and the model-
ing systems developed to aid m analyzing operation
alternatives for conjunctive management of the
ground water resources with surface supplies.
South Coastal Region. This area is of particular
importance because it offers the potential for in-
creased use of underground storage capacity in
areas of high water use. especially in Orange. Los
Angeles, Riverside, and San Bernardino Counties.
However, greater use of ground water storage in
these areas requires long distance delivery of surplus
surface water during wet years from the Sacra-
mento-San Joaquin Delta or possibly the Colorado
River. Considerable vacant storage space is avail-
able, but the problems of limited aqueduct capacity
and the large amounts of energy required for pump-
ing the water to the storage basins cloud the future
of actions to enhance the yield of these basins. Addi-
tional degradation of ground water quality could oc-
cur with widespread recharge, using the saltier
Colorado River water. However, the local ground wa-
ter management agencies can draw on extensive ex-
perience in ground water management in developing
plans for optimum operation.
South Bay Area. With its proximity to the Delta
and with the federal San Felipe Project and the SWP
South Bay Aqueduct for delivery, this area offers
some opportunity for increased use of ground water.
Santa Ana River spreading grounds, a typical ground water
recharge operation. Local runoff regulated by Prodo Reser-
voir is replenishing the Orange County ground water basin.
The focility could be used in summer to spread surplus SWP
water, when it is available.
252
This use would augment an already extensive ground
water recharge program that has been practiced in
the Santa Clara Valley for many years.
Conjunctive Use
Surface water storage projects can be operated in
conjunction with ground water basins to develop ad-
ditional project yield (described in Chapter III). The
objective is to operate the surface reservoirs to maxi-
mize their yield and reduce ground water use during
wetter years and to augment surface supplies with
ground water during dry years. As is the case with
other future supplies, the surface water supply must
come from the Sacramento HSA, and a Delta trans-
fer facility is required to realize the full potential of
such a program.
Water Reclamation
California reclaims more waste water than does
any other state. Plans are under way to expand recla-
mation of urban waste water and brackish agricul-
tural drainage water. However, estimating future
quantities of reclaimed water is difficult due to a
complex set of constraints — principally public health
concerns. As circumstances change and more is
known about possible health risks and other factors,
use of reclaimed water may receive greater public
acceptance.
In addition, certain incentives encourage the
evaluation of future possibilities of integrating re-
claimed waste water into the overall water supply
picture. Increased reuse of urban waste water for
purposes such as landscaping would free potable
supplies for higher uses, thus improving the water
supply situation. Transportation costs would be
sharply reduced in the southern region of the State
by use of locally reclaimed supplies.
One such project is a 15-million-gallon-per-day ad-
vanced waste-water treatment plant operated by the
Orange County Water District. The plant produces
injection water for use in reducing intrusion of sea
water into the ground water supply. This project,
which is known as Water Factory 21, includes a num-
ber of advanced treatment steps. To meet the water
quality requirements for injection, one third, or 5 mil-
lion gallons, of the daily production of treated waste
water is also desalted, using a reverse osmosis de-
salting system. While larger plants do exist else-
where, this IS the largest desalter m the world
operating with treated municipal waste for its feed
supply.
A major plan for Los Angeles and Orange Counties
for the reuse of waste water was completed last year
(1982). The Orange and Los Angeles Counties Water
Reuse Study was an effort to determine how best to
incorporate water reuse into the water supply of the
area. The study identified 45 projects that could
possibly be implemented over a 30-year period. The
aggregate capacity of the 45 projects is about
250,000 acre-feet per year. Following up on a recom-
mendation produced by the study. The Metropolitan
Water District of Southern California (MWD) solicit-
ed local project proposals from its member agencies.
MWD selected 26 proposals for its Phase I demon-
stration program. The local projects could produce
42,000 acre-feet per year of new yield. MWD has
approved funding for some of these local projects,
which involve several thousand acre-feet per year of
water reuse.
The Monterey Regional Water Pollution Control
Agency is evaluating possibilities for using treated
municipal waste water for irrigated agriculture in
Castroville. It is conducting a seven-year study that
will be completed in 1986. The study compares both
health effects and crop production in pilot agricul-
tural test plots irrigated with (1) filtered secondary
treated effluent, (2) coagulated and filtered second-
ary treated effluent (as required by Title 22 of the
California Administrative Code), and (3) convention-
al ground water supplies. A progress report on two
years of the field studies, issued in the summer of
1982, shows little difference in crop production with
the different types of water. Also, reclaimed waste
water does not present a public health problem. Fur-
ther favorable results from this study could lead to
additional uses of waste water for agriculture
beyond those presently contemplated.
Brackish Agricultural Drainage Water. The
Department of Water Resources is investigating the
feasibility of desalting agricultural drainage water.
The Department is constructing a demonstration de-
salting facility at Los Banos with a desalting capacity
of 344,000 gallons per day. The plant will be used to
develop data for preliminary designs and cost esti-
mates for a desalting plant to produce a nominal
25,000 acre-feet per year. Although the Los Banos
facility is based on years of pilot plant developmental
work, many of the answers on cost and production
rates will not be available until at least 1985.
Desalting (Sea-Water Conversion)
Desalting of sea water has at various times been
suggested as a means of providing additional water
supplies for California, especially at sites near the
Pacific coast. Improvements in desalting technology
continue to be made, but the cost of water produced
is still considerably higher than that of alternative
supplies. At the present time, additional surface wa-
ter supplies can be developed and delivered to major
water-short areas in the state at less cost than provid-
ing desalted sea water. However, the high cost of
importing fresh water to some isolated coastal loca-
tions may provide economic justification for using
desalted sea water at those sites.
253
Weather Modification
In California, weather modification programs are
concerned with increasing rain and snow from exist-
ing storm systems. Although the overall potential of
weather modification to amplify the usable state-
wide water supply appears limited, results of consid-
erable scientific study conducted to date indicate
that augmentation can be achieved in varying de-
grees in some but not all storm events.
One drawback is that precipitation enhancement
is needed most during dry years when opportunities
to seed clouds are fewer. In wetter years, when
storms develop more often, the increased runoff pro-
duced artificially would require adequate regulatory
reservoir storage to ensure that it could be con-
served for later use. However, the potential to in-
crease precipitation by cloud seeding and the low
cost of seeding, particularly from ground-base gener-
ators, has provided sufficient inducement in recent
years to 13 agencies to conduct programs under of>-
erations permits.
In 1961, the federal government began working on
Project Skywater, a leading precipitation manage-
ment research program. One Skywater program, the
Sierra Cooperative Pilot Project, operates m Califor-
nia. It is a winter cloud-seeding experiment in or near
the American River basin that is attempting to deter-
mine the best way to seed mountain clouds. Results
indicate there could be significant precipitation in-
creases in the Sierra Nevada. However, more study
is needed to establish how much an operational pro-
gram could increase usable water supplies.
While the direct environmental effects of the seed-
ing agents — whether silver iodide or dry ice — are
minimal, some detriment may result from changing
the amount and intensity of precipitation. Continuing
research and careful analysis of the results are aimed
at identifying and then either mitigating or eliminat-
ing possible negative elements of weather modifica-
tion techniques.
Vegetation Management
Vegetation management could make more water
available by removing high-water-using vegetation of
no economic value. The recent development of pre-
scribed burning techniques has intensified interest in
managing chaparral, a community of woody-
stemmed perennial plants. The helitorch. a device
suspended from a helicopter, ignites and drops burn-
ing jellied gasoline and greatly reduces the cost of
brush removal. Helitorching can be carried out under
weather and fuel moisture conditions that reduce the
need for fire lines and standby firefighters. This
greatly lowers program costs.
'Amended Water Code Sections 109. 1010. 1011. and 1427: new Sections
380-387. 1435-1442.
The 1980 Legislature authorized a State program of
chaparral management for fire prevention, water-
shed management, range improvement, forest im-
provement, and wildlife habitat improvement, with a
provision for cost-sharing with landowners. This pro-
gram supplements the State Range Improvement
Program, which has been in operation since 1945.
Chaparral is estimated to cover about 20 million
acres of land in California. An estimated 5 million
acres of chaparral could be managed under the State
program; in addition, federal agencies are develop-
ing management programs for federal lands. The to-
tal statewide programs could ultimately reach about
8.4 million acres. However, there is no large-scale
program for analyzing the effects of management
programs to determine their economic effectiveness
in increasing water yield.
Nonstructural Water Supply Options
Careful management and efficient use o" a 'eaay-
developed supplies can delay the need to construct
additional water supply projects. The following es-
sentially nonstructural proposals offer the opportu-
nity to optimize use of existing water supplies,
particularly during drought periods or other times of
deficient supply.
Water Transfers
Water transfers involve changing the type or place
of use from one location to another, on either a short-
term or long-term basis. Transfers do not augment
statewide supplies because no new water supply is
created; however, they provide the opportunity to
shift water to more seriously affected areas during
such times of crisis as drought periods, or to allocate
water among uses.
The 1976-1977 drought focused attention on pos-
sibilities for temporary transfers of water to areas
with serious water shortages. Also, in 1978, the Gov-
ernor's Commission to Review California Water
Right Law recommended that water transfers be en-
couraged as one method of responding to needs dur-
ing very dry conditions. Since that time, transfers
have received more attention. Over the past few
years, numerous informal transfers have been made.
However, legal and institutional barriers to transfers
would need to be overcome before widespread im-
plementation could be possible.
In 1982, Assembly Bill 3491 ' was signed into law. It
amended the California Water Code to provide
greater incentives and a regulatory procedure for
water transfers. The legislation directs the Depart-
ment and the State Water Resources Control Board
to encourage voluntary transfers and provides for
transfers of water up to a period of seven years under
conditions approved by SWRCB. The law also allows
water that is made available by conservation or recla-
254
mation measures to be transferred or sold. Transfers
lasting longer and a more "permanent" transfer sys-
tem will require additional legislation and appropri-
ate physical facilities. Beyond thiat. thiere are certain
socioeconomic, institutional, and environmental con-
siderations associated with transfers that must be
considered.
In the past few years, much has been written about
the possibility of establishing a market approach to
water transfers; that is. to put water up to the highest
bidder. However, this would conflict in many areas
with California's existing water rights structure and
could have adverse impacts on other water users and
instream beneficial uses. While California law pro-
vides that no transfers may take place that injure
other water users, potential adverse impacts may be
difficult to determine. The most likely impact may
occur when the water transfer took place upstream
of other water users and downstream water users are
deprived of return flow from lands which transferred
the water.
In an economic sense, a market system should im-
prove the lot of both buyer and seller. The buyer
should gam because he acquired something he
needs and will profit from; the seller should gam be-
cause he received more in return than had he put the
resource to his own use. However, there is concern
that such transactions may not adequately compen-
sate those not directly involved in the buying and
selling process (farm laborers, food processors, re-
tailers, and the like). Where theoretical economists
may view the market as a means of realizing effi-
ciency, others see equity questions, including the
treatment or nontreatment of instream uses in a mar-
ket situation. Questions are being also raised as to
whether a market concept would really result in the
highest and best use of the resource. It may be more
a sign of comparative purchasing power among sec-
tors than an optimum use pattern for the benefit of
the whole society. The urban sector, for example,
could probably outbid agriculture for a given water
supply; but water used to water lawns or wash cars
may be of less economic and social value than water
used to produce food.
The problem is really not with short-term drought-
related transfers but in the long-term sale or lease of
a property right in water. Further study of this matter
is necessary to properly evaluate the ramifications of
long-term transfers.
Supply Dependability and Risk
The thrust in California water development over
the past few decades has been to increase water
supplies to match needs, and in many areas, to in-
crease the dependability of supplies. Much attention
has been given to this by the SWP and the CVP.
which were designed to withstand reoccurrence of
the 1928-1934 drought. Projects, facilities, and pro-
grams of other agencies have similar built-in-risks.
But uncertainty regarding the capability of increas-
ing developed supplies over the next several
decades may justify and in fact may require taking
greater risks in delivering water to customers.
Selection of the 1928-1934 drought to evaluate
yield was not based on the relation of drought fre-
quency to cost of facilities. Rather, it was based on
the fact that both the CVP and SWP received popu-
lar support following the 1928-1934 drought, and Cali-
fornians wanted the projects to provide essentially a
full supply during the entire drought, regardless of its
frequency of reoccurrence. Of course, during normal
and above-normal years, projects can deliver much
more water than is defined as yield under this crite-
rion. Surface water projects of other agencies use
different yield-determining dry periods, but the con-
cept is the same. This operational procedure works
well where adequate water supplies are already de-
veloped to meet existing and future uses. Unfortu-
nately, the State's water uses are outpacing the rate
at which increased supplies are being added.
Some water projects would take greater risks by
delivering a higher annual supply, leaving less car-
ryover storage in case of drought. This would allow
growing needs to be met in normal years. While the
final answer lies in what nature will actually provide,
there is a good argument that, in the present era of
uncertainty regarding future water development,
given the frequency of reoccurrence of droughts,
existing facilities may be operating in a more con-
servative manner than is necessary. The 1928-1934
dry period is estimated to have a reoccurrence of
one in 200 to 400 years. However, such dry periods
could occur in successive decades. Nevertheless,
with such a small frequency probability, it may be
that projects should take a greater risk and deliver a
higher annual average supply. This is illustrated on
Figure 79, which depicts a typical operation for the
State Water Project to meet demands for 2000, using
existing facilities.
Water Conservation
As discussed elsewhere in this report (in particu-
lar, under the section titled "Water Supply Savings
from Water Conservation" in Chapter IV) , water con-
servation efforts may or may not actually reduce the
quantity of water supply needed, depending on how
much reuse can be made of the excess applied wa-
ter. The projections of water use presented in this
report reflect the level of water conservation activi-
ties (and the amount of related water supply sav-
ings) considered most likely to occur on a regular,
nonemergency basis. A specific cost-effectiveness
determination or benefit-cost analysis was not made
for this report. As with the population projections,
the land use assumptions, and other long-range fore-
255
3.5
Figure 79. WATER SUPPLY CAPABILITY
STATE WATER PROJECT WITH 1982 FACILITIES
1 \ \ \
ui
ii.
I
tij
oc
o
<
o
CO
z
o
3.0
CONTRACT
DEFICIENCIES
2.5
2.0
FIRM WATER SUPPLY WITH
EXISTING STATE WATER
PROJECT FACILITIES
V)
UJ
cc
UJ
>
bl
Q
1.5
1.0
I
1
20 40 60 80
PERCENT OF YEARS AVAILABLE
100
256
casts, these projections of water conservation are
not viewed as the only possible set of answers,
however.
The experience of the 1976-1977 drought demon-
strates that significant additional urban water con-
servation effort is possible in emergency situations,
although there has been a tendency to return to past
levels of use when sufficient supplies once more
become available. What the public perceives as ex-
treme measures, compared to what may be consid-
ered an acceptable extension of conservation
measures assumed in this report, remains to be de-
termined. However, when convinced of the need and
equity of proposed actions, the public has demon-
strated a willingness to cooperate not only during
droughts but in certain situations where water short-
ages are a long-term prospect.
For irrigated agriculture, results of surveys by the
Department and others are consistent in finding that
increases in irrigation efficiency beyond that as-
sumed in this report are possible in many areas and
that investment to accomplish them will be made if
benefits can be demonstrated. Where incentives do
not currently exist or are not recognized, government
may influence additional increases by education and
technological development of applicable measures
and by provision of such economic incentives as tax
breaks, loan programs, or more direct participation in
the risks through government-sponsored programs.
Costs of the greater conservation efforts have not
been determined. Consequently, cost comparisons
with other alternatives or a determination of their
justification are not possible. But, even more impor-
tant, further analysis of actual water supply savings
is required before program feasibility can be deter-
mined. Water savings from conservation measures
depend on reductions in evapotranspiration and/or
outflow (or percolation) to unusable saline water.
These can be determined only on a case-by-case ba-
sis. The net result is that the amount of water actually
saved as a result of conservation varies statewide,
depending on the hydrologic characteristics of each
area (see Chapter IV, Table 54).
Project Costs and Financing
The increasing cost of new water development is
a major consideration in water management. Rapidly
rising construction and interest costs have made it
more and more difficult to finance new water project
construction in recent years and have led to a search
for new sources of funds and innovative financing
methods. The following paragraphs illustrate some
aspects of this situation.
Water Project Construction Costs
Costs of constructing water projects have risen
significantly faster than overall prices. The Bureau of
Reclamation Composite Index of Construction Costs
rose 169 percent from 1970 to 1981, while the GNP
Price Deflator Index, the base available measure of
inflation, rose only 1 12 percent during the same peri-
od. Construction costs are expected to continue to
rise at least as fast as overall prices during the next
few years.
Moreover, the cost of new water development will
continue to increase because the best available dam-
sites have already been developed. For instance, the
cost of an acre-foot of yield from Lake Oroville, the
original SWP reservoir, is $37 in 1980 dollars, while
the cost per acre-foot of yield from the proposed
Cottonwood Creek Project of the Corps of Engineers
IS estimated to be about $218 in 1981 dollars. Figure
80 illustrates the comparative costs of water supply
in 1980 dollars for several existing and proposed
projects.
Interest Rates
The record high levels of interest rates in the
United States during the past few years have greatly
increased the difficulty of obtaining funding of water
projects. As an example, the following table shows
the impact of the recent rise in interest costs on the
State's tax-exempt bonds and notes issued to finance
the SWP.
Selected SWP Bond Sales and Interest Rates
1964 to 1982
Date
Effective True
Interest Cost
Issue Name (percent per year)
SIOO.OOO.OOO Series "A" Water Bonds 3.63
5100,000,000 Series "M" Water Bonds 4.94
SIOO.OOO.OOO Series "N" Water Bonds .'. 5.67
595.800,000 Pyramid Hydroelectric Revenue Bonds 7.89
5150.000.000 Reid-Gardner Pro)ect. Series A, Bond Anticipation Notes 9.61
5100.000.000 Bottlerock-Alamo Bond Anticipation Notes 10.04
5200,000.000 Reid-Gardner Revenue Bonds 12.00
5200.000.000 10.00
2/18/64
10/22/68
2/2/71
10/23/79
6/30/81
12/81
7/82
11/82
257
Figure 80. HISTORICAL AND PROJECTED COSTS OF
WATER SUPPLY FACILITIES (1980 Dollars)
225
200
U. 150
O
I-
o
o
Li.
I
LiJ
q:
o
<
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0.
(/}
<
o
o
100
1/ Includes cost allocated to power
1940
1960
1970
YEARS
1980
1990
From the last half of 1980 until the limit was tempo-
rarily increased in September 1981, the Department
was unable to sell revenue bonds because the bond
marlcet rates exceeded the statutory limit of 8.5 per-
cent. Instead, the Department sold three-year bond
anticipation notes at relatively high interest costs.
The notes were to be redeemed with the proceeds
from the sale of long-term revenue bonds when bond
market conditions improved. Most other water
project sponsors do not have the financing capability
of the State and thus have been in even more of a
financing dilemma.
Funding and Financing
During the last four decades, California has re-
ceived federal funds averaging S250 million annually,
in 1980 dollars, for water development and flood con-
trol. However, in the past decade, the federal govern-
ment has become less involved in financing new
water projects. Proponents of water projects have
had to search for alternative sources of funds. Figure
81 illustrates the flow of federal funds for water sup-
ply facilities and flood control facilities in constant
1982 dollars over the past 46 years. Figure 82 shows
the expenditures that would be necessary in the fu-
ture, assuming 1982 dollars without inflation and an
assumed construction schedule.
Under present policies, federal spending will be
reduced and more federal functions will be shifted to
state and local governments. On October 12, 1982,
the Reclamation Reform Act of 1982 was signed into
law. An important element of this Act provides for
increased revenue from federal water service con-
tractors in order to recover more costs of existing
federal projects. Also, the Bureau of Reclamation has
announced that it is seeking to sell some of its exist-
ing reclamation projects to the users.
Whatever form cost-sharing finally takes, it ap-
pears unlikely that the federal government will, in the
near future, at least, provide the level of financial
258
Figure 81. HISTORICAL FEDERAL RECLAMATION & FLOOD CONTROL
APPROPRIATIONS IN CALIFORNIA
500
CO
«
o
O
*^
CJ
00
c
(B
(0
c
o
o
o
«
c
o
400
300 -
200 -
100
1937 1940 1945 1950 1955 I960 1965
FISCAL YEAR
1970
1975
1980 1983
Figure 82. PROJECTED FEDERAL WATER PROJECT APPROPRIATION
REQUIREMENTS IN CALIFORNIA
(ASSUMING CONSTRUCTION COST INCREASE AT 2% OVER AVERAGE INFLATION RATE)
800
£ 600
s
o
o
go
c
o
400
200
PROJECTS ACCOUNTED FOR
COTTONWOOD
STOCKTON « SACRAMENTO
SHIP CHANNELS
TEHAMA COLUSA CANAL
WESTLANDS WD DISTniBllTION
ENLAnOED SHASTA
AUBURN
WARM SPRINGS
SANTA ANA FCP
DELTA LEVEES IMP
FOLSOM SOUTH CANAL
SAN FELIPE
NEW MELONES
1984
1986
988 1990 1992
FISCAL YEAR
259
1994
1996
1998
2000
support for water development and flood control
that It did during the 1940-1980 period. This will re-
quire local water agencies and the State to bear con-
siderably nnore of the burden of financing water
projects. This all comes at the same time as the full
impact of Proposition 13 (1978), which has severely
reduced local tax revenues and is forcing local water
agencies to rely on new methods of water project
financing.
Water Agency Roles in Water
Management
Local. State, and federal water agencies historical-
ly have shared the job in California of developing
what has become the world's most complex water
supply and conveyance system. Now the roles and
responsibilities of the various water agencies are
changing. Willingness and ability to finance water
developments have become critical concerns at all
levels of government. Proposed changes in sharing
project costs could result in shifts m financial partici-
pation and agency responsibilities in planning, con-
struction, and operation of water projects.
The projected water needs presented in this report
could be satisfied by the water agencies through
some combination of the potential water supply op-
tions that have been discussed earlier in this chapter.
Surface water could be provided by State and fed-
eral water agencies; ground water could continue to
be obtained by individuals and increasingly by
planned operations of local districts; conservation
and reclamation could be undertaken by individuals
and water agencies; and short-term transfers of wa-
ter could be accomplished by all water agencies. All
these actions would be in accordance with water law
and public water policy.
Local Agencies
Local agencies and individuals are the major sup-
pliers of water for agricultural and urban use. from
both underground and surface water sources;
however, their development of surface water sup-
plies reached a peak m the 1960s and has since
tapered off. Except for a few comparatively small
projects, local agencies are presently doing little to
provide additional surface water for their needs. The
basic reason for this is that the remaining un-
developed sources are limited and development and
financing costs are high, generally beyond local fi-
nancial capability.
Control over ground water supplies occurs essen-
tially at the local and individual level. Proper use of
the ground water basins is a matter of wide concern.
This has resulted in attempts to change ground water
management criteria and policy. These changes,
however, are not expected to significantly alter the
ground water management role of local agencies.
Where conjunctive use operations are involved.
State and/or federal agencies will necessarily partici-
pate in joint operation programs.
State Agencies
The State Water Project is the most far-reaching of
California's water systems. It extends the length of
the State and is the key to coordinated water man-
agement. Local agencies have contracted for 4.2 mil-
lion acre-feet of SWP water, and the project
currently has a yield of about 2.3 million acre-feet.
Plans are being developed to provide the remaining
1.8 million acre-feet as needed.
The limited opportunities remaining statewide for
providing new surface water supplies, together with
the prospects for reduced development activities by
local and federal agencies, make it essential that ef-
forts to better manage California's water resources
be intensified. All options must be fully considered.
There could be substantial statewide benefits from
these efforts. The State must take the lead m working
for more harmonious water management by the vari-
ous water agencies, including exploration of innova-
tive and nontraditional alliances and cooperative
efforts.
Federal Agencies
Federal water programs in California have been
particularly important. Federal agencies have devel-
oped the Central Valley Project and a number of
other major storage and conveyance systems. Fur-
thermore, the State's complex flood control systems
have either been federally constructed or funded.
Also important has been federal funding of many
local water supply projects and conveyance systems
through loans and grant programs. But federal con-
struction activities that just a few years back were
moving forward actively are now proceeding at a
greatly reduced pace. Construction and project op-
eration costs are high, opportunities for water devel-
opment are limited, and reduced funding has slowed
water development programs. Proposed changes by
federal agencies in cost-sharing would shift more re-
sponsibility for water development to nonfederal en-
tities. Nevertheless, federal agencies are expected to
continue to have significant roles in managing the
State's water resources.
260
GLOSSARY
261
GLOSSARY
— A—
ACRE-FOOT — The quantity of water required to cover
one acre to a depth of one foot: equal to 3.560 cubic
feet or 325,851 gallons. Abbreviation: ac-ft.
ACTIVE STORAGE CAPACITY— The total usable reser-
voir capacity available for seasonal or cyclic water
storage. It is gross reservoir capacity minus inactive
storage capacity.
AFTERBAY — A reservoir that regulates fluctuating dis-
charges from a hydroelectric power plant.
ALLUVIUM — A stratified bed of sand, gravel, silt, and clay
deposited by flowing water.
ANADROMOUS— Pertaining to fish that spend a part of
their life cycle in the sea and return into fresh-water
streams to spawn.
ANGLER-DAY — Participation m a fishing activity by one
person for any part of a day.
APPLIED WATER— The quantity of water delivered to
the intake to a city's water system, the farm headgate,
the factory, and, for wildlife, the amount of water sup-
plied to a marsh or other wetland, either directly or by
incidental drainage flows.
AQUATIC ALGAE — Microscopic plants that grow in sun-
lit water that contains phosphates, nitrates, and other
nutrients. Algae, like all aquatic plants, add oxygen to
the water and are important in the fish food chain.
AQUIFER — A geologic formation that stores and trans-
mits water and yields significant quantities of water to
wells and springs.
ARID — A term describing a climate or region in which
precipitation is so deficient in quantity or occurs so
infrequently that intensive agricultural production is
not possible without irrigation.
ARTESIAN — An aquifer in which the water is under suffi-
cient pressure to cause it to rise above the bottom of
the overlying confining bed. if opportunity to do so
should be provided.
ARTIFICIAL RECHARGE— The addition of water to a
ground water reservoir by human activity, such as irri-
gation or induced infiltration from streams, wells, or
recharge basins. See also GROUND WATER RE-
CHARGE, RECHARGE BASIN.
— B—
BENEFITS — Net increase in the value of goods and serv-
ices which result from the project, as compared to
conditions without the project.
BENTHIC INVERTEBRATES— Aquatic animals without
backbones that dwell on or m the bottom sediments of
fresh or salt water. Examples; clams, crayfish, and a
wide variety of worms.
BIOTA — All living organisms of a region, as m a stream or
other body of water.
BRACKISH WATER— Water containing dissolved miner-
als in amounts that exceed normally acceptable stand-
ards for municipal, domestic, and irrigation uses. Con-
siderably less saline than sea water.
— C—
CHAPARRAL — A major vegetation type in California
characterized by dense evergreen shrubs with thick,
hardened leaves.
CLOSED BASIN — A basin whose topography prevents
visible surface outflow of water. It is considered to be
hydrologically closed if neither surface nor under-
ground outflow of water can occur.
CONFINED AQUIFER— A water-bearing stratum that is
bounded above and below by formations of imperme-
able, or relatively impermeable, material.
CONJUNCTIVE OPERATION— The operation of a
ground water basin in coordination with a surface wa-
ter storage and conveyance system. The purpose is to
recharge the basin during years of above-average wa-
ter supply to provide storage that can be withdrawn
during drier years when surface water supplies are
below normal.
CRITICAL DRY PERIOD— A series of water-deficient
years, usually an historical period, in which a full reser-
voir storage system at the beginning is drawn down to
minimum storage at the end without any spill.
CRITICAL DRY YEAR— A dry year in which the full com-
mitments for a dependable water supply cannot be
met and deficiencies are imposed on water deliveries.
— D—
DEEP PERCOLATION— The percolation downward of
water past the lower limit of the root zone of plants.
DEPENDABLE SUPPLY (WATER)— The annual quan-
tity of water that can be delivered under normal water
supply conditions, and with allowable deficiencies
during critical dry periods. See also CRITICAL DRY
YEAR. FIRM YIELD. PROJECT YIELD.
DEPLETION (WATER)— Water used and no longer avail-
able as a source of supply.
DESALTING — A process that converts sea water or
brackish water to fresh water or an otherwise more
usable condition through removal of dissolved solids.
Also called "desalination."
DETAILED ANALYSIS UNIT (DAU)— The smallest
study area used in the analysis of water use and sup-
ply, generally defined by hydrologic features or bound-
aries of organized water service agencies. In the major
agricultural areas, a DAU typically includes 100.000 to
300.000 acres.
DISCOUNT RATE — The interest rate used in evaluating
water (and other) projects to calculate the present
value of future benefits and future costs or to convert
benefits and costs to a common time basis.
DISSOLVED OXYGEN— The oxygen dissolved in water,
usually expressed in milligrams per litre, parts per mil-
lion, or percent of saturation. Abbreviation: DO.
263
DOUBLE CROPPING — The practice of producing two or
more crops consecutively on the same parcel of land
during a 12-month period. Also called multi-cropping.
DRAINAGE BASIN — The area of land from which water
drains into a river; as, for example, the Sacramento
River Basin, in which all land area drains into the Sacra-
mento River. Also called, "catchment area," "water-
shed." or "river basin."
— E—
ECOLOGY — The study of the interrelationships of living
organisms to one another and to their surroundings.
ECONOMIC DEMAND — The consumer's willingness and
ability to purchase some quantity of a commodity
based on the price of that commodity.
ECOSYSTEM — Recognizable, relatively homogeneous
units, including the organisms they contain, their envi-
ronment, and all the interactions among them.
EFFLUENT — Waste water or other liquid, partially or com-
pletely treated or in its natural state, flowing from a
treatment plant.
ENVIRONMENT — The sum of all external influences and
conditions affecting the life and development of an
organism or ecological community; the total social
and cultural conditions that influence the life of an
individual or community.
ESTUARY — The lower course of a river entering the sea
influenced by tidal action where the tide meets the
river current.
EVAPOTRANSPIRATION— The quantity of water tran-
spired (given off) and evaporated from plant tissues
and surrounding soil surfaces. Quantitatively, it is ex-
pressed in terms of volume of water per unit acre or
depth of water during a specified period of time. Ab-
breviation: ET.
EVAPOTRANSPIRATION OF APPLIED WATER— The
portion of the total evapotranspiration which is pro-
vided by irrigation. Abbreviation: ETAW.
— F—
FIRM YIELD — The maximum annual supply of a given
water development that is expected to be available on
demand, with the understanding that lower yields will
occur in accordance with a predetermined schedule
or probability. See also DEPENDABLE SUPPLY,
PROJECT YIELD.
FOREBAY — A reservoir or pond situated at the intake of
a pumping plant or power plant to stabilize water lev-
els.
FRY — A very young fish.
— G—
GRAY WATER — All waste water generated within the
home or small commercial establishment which does
not contain toilet waste.
GROSS RESERVOIR CAPACITY— The total storage
capacity available in a reservoir for all purposes, from
the streambed to the normal maximum operating level.
Includes dead storage, but excludes surcharge (water
temporarily stored above the elevation of the top of
the spillway) .
GROUND WATER— Water that occurs beneath the land
surface and completely fills all pore spaces of the allu-
vium or rock formation in which it is situated.
GROUND WATER BASIN— A ground water reservoir,
together with all the overlying land surface and the
underlying aquifers that contribute water to the reser-
voir. In some cases, the boundaries of successively
deeper aquifers may differ and make it difficult to
define the limits of the basin.
GROUND WATER MINING— The withdrawal of water
from an aquifer greatly m excess of replenishment; if
continued, the underground supply will eventually be
exhausted or the water table will drop below economi-
cally feasible pumping lifts.
GROUND WATER OVERDRAFT— The condition of a
ground water basin m which the amount of water with-
drawn by pumping exceeds the amount of water that
replenishes the basin over a period of years.
GROUND WATER PRIME SUPPLY— The long term av-
erage annual percolation to the major ground water
basins from precipitation falling on the land and from
flows in rivers and streams. Also includes recharge
from local source that has been enhanced by construc-
tion of spreading ground or other means. Recharge of
imported and reclaimed water is not included.
GROUND WATER RECHARGE— Increases in ground
water by natural conditions or by human activity. See
also ARTIFICIAL RECHARGE.
GROUND WATER RESERVOIR— An aquifer or an aqui-
fer system m which ground water is stored. The water
may be placed in the aquifer by artificial or natural
means.
GROUND WATER STORAGE CAPACITY— The space
contained in a given volume of deposits. Under opti-
mum use conditions, the usable ground water storage
capacity is the volume of water that can. within speci-
fied economic limitations, be alternatively extracted
and replaced in the reservoir.
GROUND WATER TABLE— The upper surface of the
zone of saturation (all pores of subsoil filled with wa-
ter), except where the surface is formed by an im-
permeable body.
— H—
HARDPAN — A layer of nearly impermeable soil beneath
a more permeable soil, formed by chemical cementing
of the soil particles.
HEAD DITCH— The water supply ditch at the head end of
an irrigated field.
HYDROLOGIC BALANCE— An accounting of all water
inflow to, water outflow from, and changes in water
storage within a hydrologic unit.
HYDROLOGIC BASIN— The complete drainage area up-
stream from a given point on a stream.
264
HYDROLOGIC STUDY AREA (HSA)— The largest
study area, consisting of one or more Planning Suba-
reas. It usually encompasses a major stream system
drainage area, such as the Sacramento River; a closed
hydrologic basin, such as the Tulare Lake HSA; or a
regional group of river basins, such as the North Coast
or Central Coast HSAs.
— I—
INCIDENTAL WASTE WATER RECLAMATION—
Treated waste water returned to fresh-water streams
or other water bodies. Additional use made of this
treated waste water is only incidental to waste water
treatment and disposal.
INSTREAM USE — Use of water that does not require
diversion from its natural watercourse. For example,
the use of water for navigation, waste disposal, recrea-
tion, fish and wildlife, esthetics, and scenic enjoyment.
INTENTIONAL WASTE WATER RECLAMATION—
The planned reuse of urban waste water for specific
beneficial purposes.
IRRIGATION EFFICIENCY— The efficiency of water ap
plication on a farm. Computed by dividing evapotran-
spiration of applied water (ETAW) by applied water
and converting the result to a percentage.
IRRIGATION RETURN FLOW— Applied water that is
not transpired or evaporated but that returns to a sur-
face or ground water supply.
ISOHYETAL — Indicating equal rainfall, generally ex-
pressed as lines of equal rainfall.
— L—
LAND SUBSIDENCE— The lowering of the natural land
surface in response to: earth movements; lowering of
fluid pressure; removal of underlying supporting
materials by mining or solution of solids, either artifi-
cially or from natural causes; compaction caused by
wetting (hydrocompaction); oxidation of organic mat-
ter in soils; or added load on the land surface.
LASER LAND LEVELING— Use of instruments featuring
laser beams to guide earthmoving equipment leveling
land for surface-type irrigation.
LEACHING— The flushing of salts from the soil by the
downward percolation of water.
LINEAR PROGRAMMING MODEL— A mathematical
approach to finding the least cost or maximum return
way of using available resources in the production of
a good. Linear programming models consist of a set of
linear equations that are used to describe the limiting
factors and the objective that is sought. Linear pro-
gramming models are normally solved using comput-
ers.
— M—
MEAN ANNUAL RUNOFF— The average value of annual
runoff amounts calculated for a selected period of
record for a specified area.
MEGAWATT— One million watts.
MILLIGRAMS PER LITRE— The weight in milligrams of
any substance dissolved in one litre of liquid. Nearly
the same as parts per million. Abbreviation: mg/L.
MOISTURE STRESS— A condition of physiological
stress in a plant caused by a lack of water.
MULTIPURPOSE PROJECT— A project designed to
serve more than one purpose. For example, one that
provides water for irrigation and recreation, controls
floods, and generates electric power.
— N—
NATURAL FLOW— The flow past a specified point on a
natural stream that is unaffected by stream diversion,
storage, import, export, return flow, or change in use
caused by modifications in land use.
NET RESERVOIR EVAPORATION— The difference
between the evaporation from the reservoir's water
surface and the evapotranspiration from the area inun-
dated by the reservoir under conditions that existed
before the reservoir was built.
NET WATER USE — The sum of the evapotranspiration of
applied water (ETAW) required in an area, the ir-
recoverable losses from the water distribution system,
and the drainage outflow leaving the area.
NONFIRM YIELD — The amount of water from a surface
water project that exceeds the long-term firm yield,
occurring only periodically as a function of variation in
runoff. Sometimes referred to as nonfirm supply.
NONPOINT SOURCE— Waste water discharge other
than from point sources. See POINT SOURCE.
NONREIMBURSABLE COSTS— Project costs allocated
to general statewide or national beneficial purposes
and funded from general revenues.
— P—
PATHOGENS — Any viruses, bacteria, or fungi that cause
disease.
PEAK LOAD (POWER)— The maximum electrical ener-
gy used in a stated period of time. Usually computed
over an interval of one hour that occurs during the
year, month, week, or day. The term is used inter-
changeably with peak demand.
PERCHED GROUND WATER— Ground water support-
ed by a zone of material of low permeability located
above an underlying main body of ground water with
which it is not hydrostatically connected.
PERCOLATION — The downward movement of water
through the soil or alluvium to the ground water table.
PERMEABILITY — The capability of soil or other geologic
formation to transmit water.
PHREATOPHYTES— Native plants that typically obtain
their water supply directly from the water table or
from the capillary fringe immediately above the water
table.
PHYTOPLANKTON— Minute plants, usually algae, that
live suspended in bodies of water and that drift about
because they cannot move by themselves or because
they are too small or too weak to swim effectively
against a current.
265
PLANNING SUBAREA (PSA)— An intermediate size
study area consisting of one or more Detailed Analysis
Unit(s).
POINT SOURCE — A specific site from wfiich waste water
IS discharged into a water body, the source of which
can be identified, as with effluent, treated or not. from
a municipal sewerage system, outflow from an indus-
trial plant, or runoff from an animal feedlot. See also
NONPOINT SOURCE.
POLLUTION (WATER)— The alteration of the physical.
chemical, or biological properties of water by the in-
troduction of any substance into water that adversely
affects any beneficial use of water.
PROJECT YIELD— The water supply attributed to all fea-
tures of a project, including integrated operation of
units that could be operated individually. Usually, but
not always, it is the same as firm water yield. See also
DEPENDABLE SUPPLY. FIRM YIELD.
PUMP-GENERATOR PLANT— A plant at which the tur-
bine-driven generators can also be used as motor-
driven pumps.
PUMPED STORAGE PROJECT— A hydroelectric pow-
erplant and reservoir system using an arrangement
whereby water released for generating energy during
peak load periods is stored and pumped back into the
upper reservoir, usually during periods of reduced de-
mand.
— R—
RECHARGE BASIN— A surface facility, often a large
pond, used to increase the infiltration of water into a
ground water basin,
RECLAIMED WASTE WATER— Urban waste water that
becomes suitable for a specific beneficial use as a
result of treatment.
RECREATION-DAY— See VISITOR-DAY.
REIMBURSABLE COSTS— Those costs of a water
project that are expected to be recovered, usually
from direct beneficiaries, and repaid to the funding
entity.
RESERVE SUPPLY — Developed but presently unused
surface water supply available to certain portions of
Hydrologic Study Area to meet planned future water
needs: the supply is not usually available to other areas
needing additional water because of a lack of physical
facilities and/or institutional arrangements. The re-
serves include the sum of the reserves in each Plan-
ning Subarea (PSA) from local development and
imports, the SWP and CVP. and other federal develop-
ment. Not all the total of these reserves is usable be-
cause some of it consists of return flows that become
part of the downstream reserve supply for a PSA.
Some of the reserve supply identified for a PSA may
also be included in the amount identified for one or
more other PSAs.
RETURN FLOW — The portion of withdrawn water that is
not consumed by evapotranspiration and returns in-
stead to its source or to another body of water.
REUSE — The additional use of once-used water.
RIFFLE — A shallow extending across a streambed that
causes broken or turbulent water.
RIPARIAN — Of. or on the banks of, a stream or other body
of water.
RIPARIAN VEGETATION— Vegetation growing on the
oanks of a stream or other body of water.
RUNOFF — The surface flow of water from an area; the
total volume of surface flow during a specified time.
— S—
SAFE YIELD (GROUND WATER)— The maximum
quantity of water that can be withdrawn from a
ground water basin over a long period of time without
developing a condition of overdraft. Sometimes re-
ferred to as sustained yield.
SALINITY — Generally, the concentration of mineral salts
dissolved in water. Salinity may be measured by
weight (total dissolved solids), electrical conductivity,
or osmotic pressure. Where sea water is known to be
the major source of salt, salinity is often used to refer
to the concentration of chlorides in the water. See also
TOTAL DISSOLVED SOLIDS.
SALINITY INTRUSION— The movement of salt water
into a body of fresh water. It can occur in either sur-
face water or ground water bodies.
SALT SINK— A body of water too salty for most fresh-
water uses.
SALT-WATER BARRIER— A physical facility or method
of operation designed to prevent the intrusion of salt
water into a body of fresh water.
SECONDARY TREATMENT— In sewage, the biological
process of reducing suspended, colloidal, and dis-
solved organic matter in effluent from primary treat-
ment systems. Secondary treatment is usually carried
out through the use of trickling filters or by the activat-
ed sludge process.
SEDIMENT— Soil or mineral material transported by wa-
ter and deposited in streams or other bodies of water.
SEEPAGE — The gradual movement of a fluid into,
through, or from a porous medium.
SELF-PRODUCED WATER— A water supply developed
and used by an individual or entity. Also called "self-
supplied water."
SERVICE AREA — The geographical land area included in
the distribution system of a water agency.
SEWAGE — The waste matter from domestic, commercial,
and industrial establishments.
SPAWNING— The deposit of eggs (or roe) by fish and
other aquatic life.
SPREADING BASIN— See RECHARGE BASIN.
SPREADING GROUNDS— See RECHARGE BASIN.
STREAMFLOW— The rate of water flow past a specified
point in a channel.
SURFACE SUPPLY— Developed water supply from
streams, lakes, and reservoirs.
266
SURPLUS WATER— As used in this report, the term re-
fers to developed SWP water supplies m excess of
contract entitlement water.
SUSPENDED SEDIMENT-
pended in a liquid.
-Particles of sediment sus-
— T—
TAIL WATER— See IRRIGATION RETURN FLOW.
TERTIARY TREATMENT— In sewage, the additional
treatment of effluent beyond that of secondary treat-
ment to obtain a very high quality of effluent.
TOTAL DISSOLVED SOLIDS— A quantitative measure
of the residual minerals dissolved in water that remain
after evaporation of a solution. Usually expressed in
milligrams per litre. Abbreviation: TDS. See also SA-
LINITY.
TRANSPIRATION — The process in which plant tissues
give off water vapor to the atmosphere as an essential
physiological process.
— U—
USABLE STORAGE CAPACITY— Ground water storage
capacity that is capable of yielding water to wells
economically and of being readily recharged.
— V—
VISITOR-DAY — Participation in a recreational activity by
one person for any part of a day.
— W—
WASTE WATER — The used water, liquid waste, or drain-
age from a community, industry, or institution.
WATER CONSERVATION— As used m this report, ur-
ban water conservation includes the impact of meas-
ures and actions taken from 1975 to 2010; agricultural
water conservation includes any increase in irrigation
efficiency and related measures after 1980.
WATER DEMAND SCHEDULE— A time distribution of
the demand for prescribed quantities of water for
specified purposes. It is usually a monthly tabulation of
the total quantity of water that a particular water user
intends to use during a specified year.
WATER QUALITY— A term used to describe the chemi-
cal, physical, and biological characteristics of water,
usually in regard to its suitability for a particular pur-
pose.
WATER RECLAMATION— The treatment of water of im-
paired quality, including brackish water and sea water,
to produce a water of suitable quality for the intended
use.
WATER REQUIREMENT— The quantity of water re-
quired for a specified use under a predetermined or
prescribed situation.
WATER RIGHT— A legally protected right to take posses-
sion of water occurring in a water supply and to divert
that water for beneficial use.
WATERSHED— See DRAINAGE BASIN.
WATER TABLE— See GROUND WATER TABLE.
WATER YEAR— A continuous 12-month period for which
hydrologic records are compiled and summarized. In
California, it begins on October 1.
267
CONVERSION FACTORS
Quanlily
To Convert from Metric Unit
To Customary Unit
Multiply Metric
Unit By
To Convert to Metric
Unit Multiply
Customary Unit By
Length
Area
Volume
Flow
Mass
Velocity
Power
Pressure
Specific Capacity
Concentration
Electrical Con-
ductivity
Temperature
millimetres (mm)
centimetres (cm) for snow deptfi
metres (m)
kilometres (km)
square millimetres (mm')
square metres (m')
fiectares (fia)
square kilometres (km')
litres (L)
megalitres
cubic metres (m^)
cubic metres (m')
cubic dekametres (dam')
cubic metres per second (mVs)
litres per minute (L/min)
litres per day (L/day)
megalitres per day (ML/day)
cubic deksmetres per day
(damVday)
kilograms (kg)
megagrams (Mg)
metres per second (m/s)
kilowatts (kW)
kilopascals (kPa)
kilopascals (kPa)
litres per minute per metre
drawdown
milligrams per litre (mg/L)
microsiemens per centimetre
(uS/cm)
degrees Celsius (°C)
incfies (in)
incfies (in)
feet (ft)
miles (mi)
square incfies dn')
square feet (ft')
acres (ac)
square miles (mi')
gallons (gal)
million gallons ( l(y gal)
cubic feet (ft')
cubic yards (yd')
acre-feet (ac-ft)
cubic feet per second
(ft'/s)
gallons per minute
(gal/min)
gallons per day (gal/day)
million gallons
per day (mgd)
acre-feet per day (ac-
ft/day)
pounds (lb)
tons (sfiort. 2,000 lb)
feet per second (ft/s)
fiorsepower (hp)
pounds per square inch
(psi)
feet head of water
gallons per minute per
foot drawdown
parts per million (ppm)
micromhos per centimetre
degrees Fahrenheit (°F)
0 03937
0 3937
3 2808
0 62139
000155
10 764
24710
0 3861
026417
026417
35315
1 308
08107
25 4
254
0 3048
1 6093
645 16
0 092903
0 40469
2 590
3 7854
3 7854
0 0283 1 7
0 76455
1 2335
0 0283 1 7
3 7854
3 7854
3 7854
1 2335
35 315
026417
026417
026417
0 8107
22046
1 1023
3 2808
1 3405
0 14505
0 33456
0 08052
1 0
1 0
(1 8 X °C) + 32 (°F-32)/1 8
0 45359
0 90718
0 3048
0 746
6 8948
2 989
12419
1 0
1 0
76521-950 3-84 5M
268
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,^^ . RECD SEP 2 7 1993
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