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Full text of "California water plan update"

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1no.160- 

93 
IExec. 



California 

Water Plan 

Update 



Executive Summary 

Bulletin 160-93 
October 1994 



Pete Wilson 

Governor 

State of California 



Douglas P. Wheeler 
Secretary for Resources 
The Resources Agency 



David N. Kennedy 
Director 
Department of 
Water Resources 




Department of Water Resources, Sacramento, 1994 



Copies of this bulletin may be purchased at $25.00 for Volumes 1 and 2 from: 

State of California Department of Water Resources 

P. O. Box 942836 

Sacramento, CA 94236-0001 

Make checks payable to: Department of Water Resources 

California residents add current sales tax. 



Executive Summary 



Foreword 



Over 35 years have passed since the California Water Plan was published in 
1957 to guide and coordinate beneficial use of California's water resources. In the 
ensuing years, our population has continued to grow, approaches to water resource 
management have changed, and water policies have become a complex mix of public 
input, legislation, litigation, and federal mandates. Bulletin 160-93, the California 
Water Plan Update, is a two-volume work that documents much of how population 
growth, land use, and water allocations for the environment are affecting water 
resource management. The bulletin discusses the effects of more stringent water 
quality standards, the Endangered Species acts, the Central Valley Project 
Improvement Act of 1992, and efforts to solve problems in the San Francisco 
Bay-Sacramento-San Joaquin River Delta estuary. Most importantly. Bulletin 
160-93 presents both statewide and regional water budgets and reveals the gap 
between supply and demand that must be filled if California is to have reliable water 
supplies. It differs from the five previous water plan updates by: 

O estimating environmental water needs separately and accounting for these needs 
along with urban and agricultural water demands; 

O presenting water demand management methods , including conservation and land 
retirement, as additional means of meeting water needs; and, 

O presenting two separate water balance scenarios for average and drought 
conditions. 

The bulletin was developed with extensive public involvement. An outreach 
advisory committee made up of representatives of urban, agricultural, and 
environmental interests was established in July 1992 to assist the Department of 
Water Resources in developing the bulletin. The committee met regularly to review 
and comment on the content and adequacy of work in progress. In addition, the 
California Water Commission held public hearings in each of the ten major hydrologic 
regions to receive comments from the public about the November 1993 draft of The 
California Water Plan Update. Summaries of the comments received during the public 
hearing and comment period are in Appendix B of the bulletin. 

This executive summary highlights the major points of Bulletin 160-93. 
Condensing over 700 pages of information into less than 50 requires that much of the 
background, figures, and data be generalized or excluded. Thus, this report is an 
overview of where California's water resource planning must focus to ensure reliable 
supplies. The data contained here and in Bulletin 160-93 are current as of 1993. 
However, a few events and agreements which occurred during the first part of 1994 
are briefly discussed in the report. Readers should turn to Bulletin 160-93 to answer 
questions that the executive summary might raise. 




David N. Kennedy 
Director 




Foreword 



The California Water Plan Update 



Foreword 



Executive Summary 



Contents 



Foreword iii 

Chapter 1 Introduction 1 

Background 1 

Recent Changes in the Institutional Framework 1 

Changing Conditions 4 

Chapter 2 Water Supplies 7 

Surface Water Supplies 7 

Ground Water 10 

Water Quality 13 

Chapter 3 Water Demands 17 

Urban Water Demand 17 

Agricultural Water Demand 19 

Environmental Water Demand 22 

California's Total Water Demand 25 

Chapter 4 Balancing Water Supply and Demand 27 

Options for Balancing Supply and Demand 27 

Local Water Management Issues 32 

Chapter 5 Conclusions and Recommendations 37 

Conclusions 37 

Recommendations 38 

Figures 

Figure ES- 1 . The Sacramento-San Joaquin Delta and San Francisco Bay 3 

Figure ES-2. Hydrologlc Regions of California 6 

Figure ES-3. Disposition of Average Annual Water Supply 7 

Figure ES-4. Major Water Project Facilities in California 8 

Figure ES-5. Components of Ground Water Use and Sources of Recharge 1 1 

Figure ES-6. Comparison of Population Projections 

Used in Bulletin 160 Analyses 17 

Figure ES-7. Irrigated Acreage in California 1870 - 2020 20 

Figure ES-8. Environmental Water Needs 22 

Figure ES-9. The California Water Balance 26 



Contents 



The Governor's Water Policy 2 

Water Transfer Criteria 4 

California's Water Supply Availability 9 

Definition of Terms 16 

Tables 

Table ES- 1 . California Water Supplies with 

Existing Facilities and Programs 10 

Table ES-2. Use of Ground Water by Hydrologic Region. 1990 12 

Table ES-3. Urban Water Demand by Hydrologic Region 18 

Table ES-4. Agricultural Water Demand by Hydrologic Region 21 

Table ES-5. Environmental Water Needs by Hydrologic Region 23 

Table ES-6. California Water Demand 25 

Table ES-7. California Water Budget 28 

Table ES-8. Level 1 Demand Management Options 30 

Table ES-9. Level I Water Supply Management Options 31 

Table ES-10. California Water Supply with 

Level 1 Water Management Programs 32 

Table ES- 1 1 . Level 11 Water Management Options 33 



vi Contents 



Executive Summary 



Chapter 1 



Several events with far-reaching consequences have altered water management IntrOdUCtiOn 
in California since 1987, the last year an update to the California Water Plan was 
published. A drought that lasted six years strained the State's water supply system. 
During the last year of drought, 1992, actions to protect threatened aquatic species 
changed the operations of California's two largest water projects, the State Water 
Project and the Central Valley Project. That same year, the Central Valley Project 
Improvement Act passed, reallocating CVP supplies to protect natural resources. With 
severely limited supplies and fewer demands fully met. California realized that its 
water management system was no longer providing adequately reliable service, and 
the reliability of future supplies was highly uncertain. 

In October 1991, amendments to California Water Code Sections 10004 and 
10005 passed, requiring that the State's water plan be updated every five years. The 
California Water Plan Update, Bulletin 160-93, is the first update to be issued 
according to these amendments. This executive summary condenses the major 
findings and conclusions in Bulletin 160-93. After a short background discussion and 
an abstract of how recent acts and laws are affecting California's water resource 
management, essential supply and demand figures are presented. Next, options for 
balancing water supply and demand are outlined. Finally, major conclusions and 
recommendations from the bulletin are recapped. Key findings of Bulletin 160-93 are: 

O During drought, present supplies are insufficient to meet present urban, 
agricultural, and environmental demands. 

O By 2020, without improved water management and additional facilities, annual 
shortages of 3.7 to 5.7 maf could occur in average water years. Annual drought 
year shortages could increase to 7.0 to 9.0 maf. 

Background 

In most areas of California, the 1987-92 drought caused a marked increase in 
urban water conservation, reduced surface water supplies for agriculture, and 
stressed environmental resources. Some urban areas resorted to mandatory 
rationing, farmers in several agricultural areas chose to leave part of their acreage 
fallow, and ecosystems in certain regions endured harsh impacts. Still, innovative 
water banking, water transfers, and changes in project operations helped reduce the 
harmful effects of drought. The six-year drought and the need for a comprehensive 
policy to guide California's water management and planning prompted the Governor 
to announce his water policy on April 6. 1992. The policy provided general guidance 
in developing the options in Bulletin 160-93. 

Recent Changes in the Institutional Framework 

For decades, the San Francisco Bay-Sacramento-San Joaquin River Delta 
estuary has been the focal point for a wide variety of water-related issues, generating 

Introduction 



The California Water Plan Update 




The Governor's Water Policy 

Here are key elements of ttie Governor's water policy as announced on Apri 
1992. Asthie Governor stressed, eacti of ttiese elements must be linked in suchi a wc 
1ho\ no single interest (urtxin, agricultural, or environmental) gains at ttie expense of 
anottier. 

□ Fixing ttie Delta □ Water Conservation 

□ Reduction of Ground Water □ Water Recycling 
O^^erd^on Q Desalination 

□ Water Marketing and Transfers ^ ^^^^^^^^ ^^ ^^^ ^^^^^^, ^^^^^^^ 

□ Additional Water for Fishi and Valley Project to State Control 
Wildlife 



□ Colorado River Water Banking 



□ Additional Storage Facilities 



more Investigations than any other waterway system in California. Major components 
of the complex Bay-Delta system include the Suisun Marsh. San Pablo Bay. and the 
Delta estuary. Two-thirds of the State's population and millions of acres of 
agricultural land receive part or all of their water supplies from the Bay-Delta. More 
than 100 species offish use the Bay- Delta system. The Suisun Marsh covers 80,000 
acres cind is the largest contiguous wetland remaining in California. The entire system 
provides habitat for hundreds of species offish, migratory waterfowl, mammals, and 
plants while also supporting extensive farming and recreational activities. The Delta 
and its tributaries, the Sacramento and San Joaquin rivers, are critical to California's 
water supply picture (see Figure ES-1). Water quality issues affecting these water 
bodies affect supplies from Ccdifomla's key water supply liub. 

In February 1993, the National Marine Fisheries Sei^ice issued its biological 
opinion for the threatened winter-run chinook salmon (and later changed its 
designation to endangered). In Mcirch 1993. the U.S. Fish and Wildlife Service issued 
its biological opinion for the threatened Delta smelt. Both species had been listed 
under the federal and State Endangered Species acts because of population declines. 
The biological opinions impose restrictions on exports from the Bay-Delta. In 
addition, the CVPIA reallocates over 1 million acre-feet of CVP supplies to the 
protection of fish, wildlife, and their habitat. In 1993, about 400.000 acre-feet of 
reallocated CVP supplies benefited winter-run salmon and Delta smelt. The act's 
ultimate effect on Delta exports and how the environmental water will be used for the 
long-term are yet to be determined. 

Other factors that will likely impose added restrictions on Delta exports are the 
State Water Resources Control Boards Bay-Delta proceedings and the U.S. 
Environmental Protection Agency's proposed Bay-Delta water quality standards. In 
response to the Governor's April 1992 water policy statement. SWRCB proceeded with 
a process to establish interim Bay-Delta standards (proposed Water Right Decision 
1630) to provide immediate protection for fish cmd wildlife. In April 1993, the 
Governor asked SWRCB to withdraw its proposed Decision 1630 and Instead focus 
efforts on establishing permanent standards since recent federal actions had 
effectively pre-empted State interim standards and provided interim protection for the 
Bay-Delta environment. By the end of 1993, EPA announced its proposed standards 
for the estuary in place of SWRCB water quality standards EPA had rejected in 1991. 

Introduction 



Executive Summary 



Figure ES-1. The Sacramento-San Joaquin Delta and San Francisco Bay 



Suisun Resource 
Conseivation District 



ShRM 



i 




SULE IN MILES 



Introduction 



The California Water Plan Update 



In April 1994, the SWRCB began a series of workshops to review Delta 
protection standards adopted in its 1991 Water Quality Control Plan for Salinity and 
to examine proposed federal EPA standards issued in December 1993. This process is 
intended to help establish a draft SWRCB Delta regulator>' plan acceptable to both the 
State and federal governments, to be released in December 1994. The plan will be 
developed in accordance with the Triennial Review requirements of the Clean Water 
Act. 

More recently, the California Water Policy Council, created to coordinate 
activities related to the State's long-term water policy, and the Federal Exosystem 
Directorate (sometimes referred to as ~Club Fed**), comprising representatives from 
the EPA. NMFS, USFWS. and the USBR. have developed and signed a framework 
agreement for the Bay-Delta Estuary. The agreement provides for improved 
coordination and communication among State and federal agencies with resource 
management responsibilities in the estuary. It covers the water quality standards 
setting process: coordinates water supply project operations with requirements of 
water quality standards, endangered species laws, and the CVPIA; and provides for 
cooperation in planning and developing long-term solutions to the problems affecting 
the estuarys major public values. Coordination of State-federal resource 
management and long-range planning in the Bay-Delta estuary is necessary to 
promote regulatory consistency and stability, and to address the estuary*s 
environmental problems, in a manner that minimizes economic and water costs to 
California. 

Changing Conditions 

Regulatory consistency and stability in the Bay- Delta estuary are also crucial to 
facilitating water transfers. Water transfers and marketing are integral components of 
California's water supply network. With appropriate safeguards against adverse 
environmental cmd third party effects, water transfers are an important tool for 

Water Transfer Criteria 

In his water policy statement of April 6, 1992, the Governor stated that the following five 
criteria must be met in developing a fair and effective water transfer policy. 

O Water trar«fers must be voluntary, and they must result in 
transfers that are real, not paper water. Above all, water 
rights of sellers must not be impaired. 

O Water transfers must not harm fish and wildlife resources or 
their habitats. 

Q There needs to be assurances that transfers will not cause 
overdraft or degradation of ground water basins. 

Q Entities receiving transferred water should be required to 
show that they are making efficient use of existing water 
supplies, including carrying out urban Best Management 
Practices or agricultural Efficient Water Management 
Practices. 

O Water districts and agencies that hold water rights or 
contracts to transferred water should have a strong role in 
deciding how transfers are carried out. Impacts on the fiscal 
integrity of the districts and on the economies of small 
agricultural communities must be considered. 





Introduction 



Executive Summary 



solving some of California's supply and allocation problems. There are generally fewer 
environmental impacts associated with transfers than with construction of 
conventional projects, and although often difficult to implement, transfers can be 
carried out more quickly and usually at less cost than construction of additional 
facilities. 

During the 1987-92 drought, many water transfers took place between areas 
that could temporarily reduce usage and areas with water shortages. Some of these 
transfers were part of the State Drought Water Bank, which was designed to move 
water from areas of greatest availability to areas of greatest need. There were three 
sources of water for the 1991 State Drought Water Bank: temporary surplus in 
reservoirs, surface supplies freed up by the use of ground water, and surface supplies 
freed up by fallowing farm land. (The 1992 State Drought Water Bank did not 
purchase surface supplies freed up by fallowing.) Transfers of water outside the 
State-sponsored Drought Water Bank have also become more prevalent; many of 
these transfers involve the Department of Water Resources because they require 
conveyance of the transferred water through SWP facilities. 

At the same time. California's water supply infrastructure is limited in its ability 
to transfer marketed water due to constraints placed on export pumping from the 
Delta (what some people refer to as "the institutional drought"). For example, in 
1993, an above norhial runoff year, environmental restrictions limited CVP deliveries 
to 50 percent of contracted supply for all federal water service contractors in the area 
from Tracy to Kettleman City. Such limitations will exacerbate ground water 
overdraft in the San Joaquin River and Tulare Lake regions (Figure ES-2) because 
surface supplies in wet years will not be available to recharge ground water that was 
used during dry years to replace the shortfall in surface supplies. 

It may take a decade or more to fully assess the cumulative effects of the 
biological opinions, the CVPIA, more stringent water quality standards, and increased 
water transfers. In that time, the effects will be somewhat offset because adjustments 
to water demand patterns will probably lead to more efficient use of water, and 
options for improving the supply system's reliability and fiexibility will probably be 
implemented. In the short-term, however, those areas of California relying on the 
Delta for all or part of their water face great uncertainty about supply reliability. Until 
solutions to complex Delta problems are identified and put in place, many 
Californians will experience more frequent and severe shortages. Without solutions to 
key Bay-Delta problems, many of the major proposed water supply programs north 
and south of the Delta are not feasible. 



i 



Introduction 



The California Water Plan Update 



Figure ES-2. Hydrologic Regions of California 



North 
Coast 




N 

i 






San Joaquin 
River 



Tulare Lake 



Central 
Coast 



^ 



South 
Lahontan 



South 
Coast 



Colorado 

River 



Water Supplies 



Executive Summary 



Chapter 2 



i 



In analyses used to develop Bulletin 160-93, a normalized 1990 was used as the WotGr SuppMeS 
base year. (Normalization is the process of adjusting actual water use or supply in a 
given year to account for unusual events such as dry weather conditions, government 
interventions for agriculture, rationing programs, or other irregularities.) In 1990, 
California generally had adequately reliable supplies that met average annual urban, 
agricultural, and environmental water demands. However, the 1987-92 drought 
caused shortages in some California communities, such as Santa Barbara County, 
and impacted environmental resources, such as Central Valley wetland habitat. 

Prior California Water Plan updates determined the existing base case for water 
supply and demand then balanced forecasted future demand against existing supply 
and against future supply and demand management options. To better illustrate 
overall supply availability, Bulletin 1 60-93 presents two water supply and demand 
scenarios, an average year and a drought year, for the 1990 level of development and 
for forecasts to 2020. What follows is an overview of California's surface and ground 
water supplies and of water quality problems that affect the availability of supply. At 
the close of each section are Bulletin 160-93 recommendations for improving water 
management planning and addressing water quality issues. Figure ES-3 shows the 
disposition of California's average annual total water supply. 



Surface Water Supplies 

The Sacramento and San Joaquin rivers have provided an average of nearly 15.5 
million acre-feet annually for urban and agricultural uses. The supply for these uses 



Figure ES-3. 
Disposition of 
Average Annual 
Water Supply 




Instream ^f°"'^' 

(1%) '''^"l 

Wild & Scenic 
Rivers 

(21%) 



Delta Oufflow 
D1485 

(5%) 




Water Supplies 



The California Water Plan Update 



Figure ES-4. Major Water Project Facilities in California 



Mth Bay 
Aqueduct' 




San Francisco 



South Ba 
Aqueduc 



San Felipe 
Unit 

Monterey 



San 
Obispo 



— State Water Project Fadiities 

— Federal Water Project Facilities 

— Local Water Project Facilities 



San Diego ^ 
\^ Aqueducts' 
San 
Diego 



Water Supplies 



Executive Summary 



could decrease by roughly 1 to 3 maf because of potential operational and institu- 
tional changes discussed in Chapter 1 . 

As Arizona and Nevada continue to use more of their allocated Colorado River 
supplies, imports to the South Coast Region for urban and agricultural uses could 
eventually decline from about 5.2 to 4.4 maf annually, which is California's allocated 
Colorado River supply. (See Figure ES-4 for locations of major water project facilities 
in California.) In past years. Arizona and Nevada had been using less than their share 
of Colorado River water, and their unused supply was made available to California. 
Southern California was spared from severe rationing during most of the 1987-92 
drought primarily because of the 600,000 af annually of unused Colorado River water 
made available to the Metropolitan Water District of Southern California. Even with 
this supply, however, much of Southern California experienced significant rationing in 
199 1 . Supplemental Colorado River water cannot be counted on to meet needs in the 
future as Arizona and Nevada continue to use more of their Colorado River 
allocations. 

The 1987-92 drought induced many creative approaches for coping with water 
shortages throughout California, including construction of more interconnections 
between local. State, and federal water delivery facilities. The City of San Francisco's 
connection to the State Water Project's South Bay Aqueduct allowed emergency 
drought supplies to be conveyed into the city's system. Toward the end of the 
drought, the City of Santa Barbara constructed a sea water desalting facility and 
received limited SWP supplies through an emergency interconnection and a series of 
exchanges with other water agencies. Throughout California, water agencies were 
buying and exchanging water to meet critical needs. The State Drought Water Bank 
played a vital role in meeting some of those critical needs. 

Prior to changes in water allocations from the Sacramento-San Joaquin and 
Colorado river systems, California had roughly enough water to meet average annual 
urban and agricultural water demands at the 1990 level while complying with existing 
SWRCB standards, as specified in D-1485. Table ES- 1 shows California's water sup- 
ply with existing facilities and programs as operated in accordance with D-1485. 

Average annual supplies at the 1990 level of development are about 63.5 maf (in- 
cludes natural flows dedicated for instream use and ground water overdraft) and could 
decrease to 63 maf by 2020 without any additional facilities or programs. A possible 

California's Water Supply Availability 

^P Average year supply is the average annual supply of a water development 

system over a long period. For this report the SWP and CVP average year supply is the 
average annual delivery capability of the projects over a 70-year study period 
( ] 922-9 1 ). For a local project without long-term data , it is the annual average deliver- 
ies of the project during the 1984-1986 period. For dedicated natural flow, it is the 
long-term average natural flow for wild and scenic rivers, or it is environmental flows 
as required for an average year under specific agreements, water rights, court deci- 
sions, and congressional directives. 

^w Drought year supply is the average annual supply of a water development sys- 

1^ tern during a defined drought period. For this report, the drought period is the average 
of water years 1990 and 1991 . For dedicated natural flow, it is the average of water 
years 1990 and 1991 for wild and scenic rivers, or it is environmental flows as required 
under specific agreements, water rights, court decisions, and congressional direc- 
tives. 



Water Supplies 



The California Water Plan Update 



10.1 


8.1 


1.0 


0.7 


5.2 


5.1 


7.5 


5.0 


1.2 


0.8 


2.8 


2.1 


0.2 


0.2 


7.1 


11.8 



4.4 


4.4 


4.4 


4.4 


4.4 


4.4 


7.7 


5.1 


7.7 


5.2 


7.7 


5.2 


1.3 


0.8 


1.3 


0.8 


1.3 


0.8 


3.2 


2.0 


3.3 


2.0 


3.3 


2.0 


0.2 


0.2 


0.2 


0.2 


0.2 


0.2 


7.1 


12.0 


7.2 


12.1 


7.4 


12.2 



Table ES-1. California Water Supplies with Existing Facilities and Programs 

(Decision 1485 Operating Criteria for Delta Supplies) 
(millions of acre-feet) 

Supply 7990 2000 2070 2020 

average drought average drought average drought average drought 

Surface 

Local 10.1 8.1 10.1^ ^8.1 10.2 8.3 10.3 8.4 

Local imports'!' 1.0 0.7 1.0 0.7 1.0 0.7 1.0 0.7 

Colorado River 

CVP 

Other federal 

SWP'^' 
Reclaimed 
Ground water'^' 
Ground water overdraft'^' 1.3 1.3 — — — — — — 

Dedicated natural flow 27.2 15.3 27.4 15.4 27.4 15.4 27.4 15.4 

TOTAL 63.5 50.4 62.4 48.9 62.7 49.1 63.0 49.4 

(1) 1990 SWP supplies are normalized and do not reflect additional supplies delivered to offset the reduction of supplies from the Mono and Owens basins to the South Coast 
hydrologic region. 

(2) Average ground water use is prime supply of ground water basins and does not include use of ground water which is artificially recharged from surface sources into the ground 
water basins. 

(3) The degree future shortages are met by increased overdraft is unknown. Since overdraft is not sustainable, it is not included as a future supply. 



800,000-af reduction in Colorado River supplies could be offset by short-term 
transfers and increased SWP Delta diversions, in addition to water management pro- 
grams of the MWDSC. The 1990 level drought year supplies are about 50.4 maf and 
could decrease about 1 maf by 2020 without additional storage and water management 
options. However, until solutions to complex Delta problems are identified and imple- 
mented. Delta diversions will continue to be impaired. 

Annual reductions in total water supply for urban and agricultural uses could 
be in the range of 500,000 af to 1 maf in average years and 2 to 3 maf in drought 
years. These reductions result mainly from compliance with the ESA biological opin- 
ions and proposed EPA Bay-Delta standards. Until a Delta solution that meets the 
needs of urban, agricultural, and environmental interests is identified and implement- 
ed, there likely will be water supply shortages in both dry and average years. 

Bulletin 160-93 analyses found that baseline hydrologic and water development 
data used in preparing statewide supply and demand balances need to be updated. 
The last major inventory of such conditions was Bulletin 1, Water Resources of 
California, published in 1951. Bulletin 160-93 thus recommends that DWR should 
initiate work to update and maintain this resource document to incorporate more re- 
cent hydrologic data, including 40 more years of runoff data. 

Ground Water 

California's ground water storage in some 450 ground water basins statewide is 
about 850 maf, roughly 100 times the State's annual net ground water use. Probably 
less than half of the ground water is usable because of quality considerations and the 
cost of extraction. However, the large quantity of good quality ground water in storage 
makes it a crucial component of California's total water supply. Ground water played 
a vital role in helping the State through the 1987-92 drought. 



10 Water Supplies 



Executive Summary 




Overdraft: 

Depletion of groum 
water storage over a 
long period of time 




Prime Supply: 

aturol percolation of 
II and seepage 
from stffeonibeds 



Net Ground Water Use = 

Prime supply + overdraft 

Perennial Yield = 

Extraction - overdraft 



Deep percolation of 
applied surface and 
ground water 



Figure ES-5. 
Components of 
Ground Water Use 
and Sources of Recharge 



In a year of average precipitation and runoff, an estimated 1 5 maf of ground 
water is extracted and applied for agricultural, municipal, and industrial use. There is 
a substantial amount of ground water recharge from surface water and ground water 
used to irrigate agricultural crops. Some of the irrigation water flowing in unlined 
ditches and some of the water that is applied to irrigate crops infiltrates into the soil, 
percolates through the root zone and recharges the ground water basins (see 
Figure ES-5). 

The annual net use of ground water is ground water extraction minus deep 
percolation of applied water. The 1990 statewide average annual net ground water use 
was about 8.4 maf. The use of prime supply from ground water basins for 1990 was 
about 7.1 maf. and the remaining 1.3 maf was overdrafted from the basins. (Ground 
water prime supply is the long-term average annual percolation into major ground 
water basins from precipitation and from flows in rivers and streams.) Table ES-2 
shows 1990 level use of ground water and overdraft by hydrologic region. The 
amounts shown include an estimated 200.000 af of overdraft resulting from possible 
degradation of ground water quality in adjacent basins located in the trough of the 
San Joaquin Valley. Poor quality ground water moves eastward, displacing good quali- 
ty ground water in the trough of the valley. The concentration of total dissolved solids 
in the valley "s west side ground water generally ranges from 2,000 to 7,000 milli- 



Water Supplies 



11 



The California Water Plan Update 



Table ES-2. Use of Ground Water by Hydrologic Region, 1990 

(thousands of acre-feet) 



Hydrologic Region 



Ground Water Use 

average drought 



Ground Water 
Overdraft 



North Coast 
San Francisco Bay 
Central Coast 
South Coast 
Sacramento River 
San Joaquin River 
Tulare Lake 
North Lahontan 
South Lahontan 
Colorado River 



263 

IOC 

688 

,083 

,496 

,098 

915 

121 

221 

80 



ay 100 


139 





688 


762 


240 


1,083 


1,306 


20 


ST 2,496 


2,865 


30 


er 1,098 


2,145 


210 


915 


3,773 


650 


121 


146 






283 
139 
762 
306 
865 
145 
773 
146 
252 
80 





iO 
20 
30 
10 
50 

70 
80 



STATEWIDE 



7,100 



11,800 



1,300 



grams per liter: TDS In the valley's east side basin ranges from 300 to 700 milligrams 
per liter. 

Annual ground water overdraft has diminished to about two-thirds of what it 
was in 1980 (when ground water overdraft was last studied), from roughly 2 maf in 
1980 to about 1.3 maf in 1990. This reduction has mainly occurred in the San 
Joaquin Valley and is due to the benefits of imported supplies to the San Joaquin Riv- 
er and Tulare Lake regions: construction and operation of new reservoirs in the San 
Joaquin River Region during the 1960s and 1970s: and prudent surface and ground 
water management, including conjunctive use of these supplies. However, until key 
Delta issues are resolved and additional water management programs are implement- 
ed, the reductions in overdraft seen in the San Joaquin Valley during the last decade 
will reverse as more ground water is pumped to make up for lost surface water sup- 
plies, some of which formerly came from the Delta. In the long-term, continued 
overdraft is not sustainable. As such, overdraft is not included as a future supply. 

Conjunctive use operations, which helped reduce ground water overdraft, will 
continue to be refined and made more effective in the future. Efficient use of surface 
and ground water through conjunctive use programs has become an extremely impor- 
tant water management tool. Such programs are generally less costly and cause fewer 
adverse environmental impacts than traditional surface water projects because they 
increase the efficiency of existing supply systems without requiring major facility 
additions. However, conjunctive use programs must address potentially undesirable 
results such as loss of native vegetation and wetland habitat, adverse effects on third 
parties and fish and wildlife, land subsidence, and degradation of water quality in the 
aquifer. 

Bulletin 160-93 recommends that the State encourage efforts to develop ground 
water management programs at the local and regional levels and to remove legal, 
institutional, financial, and other barriers that limit conjunctive use of ground water 
basins. The programs should be focused on solutions to clearly identified problems, 
such as overdraft, and natural and human-caused contamination so as to optimize 



12 



Water Supplies 



Executive Summary 



the use of surface and ground water resources. Specific recommendations are as 
follows: 

1 . Local agencies should adopt programs for ground water management with the 
following goals: 

a. Identity and protect major natural recharge areas. Devel- 

op managed recharge programs where feasible. 

b. Optimize use of ground water storage conjunctively with 

surface water, including storage of recycled water and 
imported sources. 

c. Increase monitoring of ground water quality to improve 

the ability to assess and respond to water degradation 
problems. Report trends in the chemical contents of 
ground water. 

d. Develop ground water basin management plans that not 

only manage supply, but also address overdraft, in- 
creasing salinity, chemical contamination, and 
subsidence. 

e. Adopt and implement a public education program to 

ensure that citizens understand the importance of 
ground water and steps they can take to protect and 
enhance their water supply. 

2. Continuing use of overdraft as a source of supply is not sustainable and thus 
must be addressed in State and local water management plans. Options for 
addressing the management of overdraft will be strongly influenced by the 
availability of supplies and economic factors that must be considered in such 
plans. 

Water Quality 

Water quality directly affects the quantities of water available for use in 
California. Poor water quality has inherent costs, such as treatment and storage costs 
for drinking water, reduced crop yields, higher handling costs, and damage to fish and 
wildlife. Avoiding these costs by protecting water sources from degradation in the first 
place is one of California's more pressing water management problems. 

Of critical importance to many Californians is the water quality of the 
Sacramento-San Joaquin Delta. Water soluble minerals, municipal and industrial 
waste discharges, and agricultural drainage increase the salt content of water as it 
flows from higher elevations to the Delta. Sea water intrusion is a major source of 
salts in Delta water supplies. Bromides from sea water are of particular concern be- 
cause in combination with dissolved organic compounds present in soil, bromides 
contribute to the formation of harmful disinfection byproducts during water treat- 
ment processes. On average. Delta inOuences are responsible for elevating the salt 
concentration at Banks Pumping Plant to about 150 milligrams per liter above that of 
the fresh water inflows to the Delta. Most of the Delta water quality objectives relate 
to salinity. The SWP and CVP are required to release sufficient fresh water to meet 
Delta salinity standards. 

Numerous aspects of water quality can affect fish and wildlife habitat and result 
in monetary or environmental costs. An example is selenium in agricultural drainage 

Water Supplies 13 



The California Water Plan Update 



from the San Joaquin Valley which was used to supply wetland habitat in the valley. 
In this case, elevated selenium concentrations caused severe reproductive damage to 
fish and wildlife species, particularly to birds using the wetlands. 

Human activities introduce a variety of pollutants that contribute to degrada- 
tion of water quality. Mining can be a major source of acids and toxic metals. 
Agricultural drainage may contain chemical residues, toxic elements, salts, nutrients, 
and elevated concentrations of chemicals that cause harmful disinfection byproducts. 
Municipal and industrial discharges, including storm runoff, are regulated by State 
and federal environmental protection laws and policies. Waste water must be treated 
to render it free of certain disease-carrying organisms and reduce its environmental 
impact. Unfortunately, normal waste water treatment plant processes may not com- 
pletely remove all water-borne synthetic chemicals. Increasingly, more stringent and 
costly water quality standards for public health are affecting the continued reliability 
and costs of water supplies. 

Disease-causing organisms and other harmful microorganisms found in 
untreated water can pose serious health risks. Federal and State drinking water stan- 
dards have been adopted to protect the health of consumers. The California 
Department of Health Services, Office of Drinking Water, promulgates and enforces 
State standards and enforces federal standards. Most drinking water quality stan- 
dards are met by California's municipal drinking water utilities. However, some 
drinking water regulatory activities may conflict. For example, concern over surviving 
pathogens spurred a rule requiring more rigorous disinfection. At the same time, 
there is considerable regulatory concern over trihalomethanes and other disinfection 
byproducts, resulting from disinfection of drinking water with chlorine. The problem 
is that if disinfection is made more rigorous, disinfection byproduct formation is 
increased. Additionally, poorer quality source waters wit^i elevated concentrations of 
organic precursors and bromides further complicate the problem of reliably meeting 
standards for disinfection while meeting standards for disinfection byproducts. 

New and more costly federal and State surface water treatment rules (effective in 
June 1993) require that all surface water supplied for drinking receive filtration, high 
level disinfection, or both. The cost of constructing new filtration facilities to meet 
new regulations can be quite high. The U.S. Environmental Protection Agency esti- 
mates the annual nationwide cost of treating drinking water to meet existing and new 
standards will be $36 million a year in the early 1990s, $539 million annually by 
1994, and will rise to $830 million, as a result of the need to make long-term capital 
investments, before stabilizing at $500 million a year by the year 2000. These esti- 
mates demonstrate that major costs will result from meeting the new standards. The 
regulatory community will have to carefully balance the benefits and risks associated 
with pursuing the goals of efficient disinfection and reduced disinfection byproducts. 
One essential corollary action will be to make any source water quality improvements 
that are feasible. 

There are many water quality problems which can result in cost, either direct or 
environmental. In turn, these impacts reduce flexibility in water supply planning and 
management. California's record has been a good one, for an industrialized state. 
Most of our waters remain fit for fish and wildlife, and for multiple uses by people. 
However, the rapidly growing population and continued industrialization will continue 
to greatly challenge our ability to maintain and improve water quality. If we are to 
meet this challenge successfully, it will require the best efforts of government. 



14 Water Supplies 



Executive Summary 



industry, and. most of all. concerned citizens. Bulletin 160-93 put forth the following 
recommendations about solving water quality problems: 

1 . Increasingly stringent and costly drinking water quality standards for public 
health protection will affect the continued availability and cost of water 
supplies. More effort must be made by State and federal agencies to balance the 
cost with public health and other benefits of such standards. 

2 . Research into relationships and effects of water quality degradation on fish and 
wildlife should continue. In particular, more information is needed on acute 
and chronic effects of low level toxicants on the health and reproductive 
capacity of aquatic organisms. (Research should be a cooperative effort by State 
and federal agencies.) 

3 . Urban water supplies diverted from the South Delta face the threat of increasing 
water quality degradation from both salinity intrusion and organic substances 
originating In Delta Island drainage . Factors responsible for quality degradation 
from Delta Island drainage should be investigated by State agencies, cind 
potential means of mitigating problems identified. 

4. Reuse of adequately treated waste water can. In some areas, provide alternative 
sources of supply as well as benefit fish and wildlife resources, particularly in 
arid portions of the State. Efforts by State agencies should be continued to 
define the conditions and degree of treatment needed to allow use of treated 
waste water for beneficial uses and discharge of effluents to water courses so 
that these benefits can be realized. 



Water Supplies 15 



The California Water Plan Update 



Definition of Terms 

O Applied water: The amount of water from any source needed to meet the demand of the user. It is the 
quantity of water delivered to any of the following locations; 

□ the intake to a city water system or factory. 

□ the farm headgate. 

□ a marsh or wetland, either directly or by incidental drainage flows; this is water for wildlife areas. 

□ For existing instream use, applied water demand is the portion of the stream flow dedicated to in- 
stream use or reserved under the federal or State Wild and Scenic Rivers acts or the flow needed to 
meet salinity standards in the Sacramento-San Joaquin Delta under SWRCB standards. 

O Evapotranspiration: The quantity of water transpired (given off) and evaporated from plant tissues and 
surrounding soil surfaces. Quantitatively, it is expressed in terms of volume of water per unit acre of depth 
of water during a specified period of time. Abbreviation: ET. 

O Evapotranspiration of applied water: The portion of the total evapotranspiration which is provided by 
irrigation. Abbreviation: ETAW. 

O Irrecoverable losses: The water lost to a salt sink or water lost by evaporation or evapotranspiration from 
conveyance facilities or drainage canals. 

O Net water demand: The amount of water needed in a water service area to meet all the water service 
requirements. It is the sum of evapotranspiration of applied water in an area, the irrecoverable losses from 
the distribution system, and the outflow leaving the service area, including treated municipal outflow. 

O Depletion: The water consumed within a service area and no longer available as a source of water supply. 
For agriculture and wetlands it is ETAW plus irrecoverable losses. For urban areas it is the exterior ETAW, 
sewage effluent that flows to a salt sink, and incidental ET losses. For instream needs it is the dedicated flow 
that proceeds to a salt sink. 

O Average year demand: The demand for water under average weather conditions for a defined level of 
development. 

O Drought year demand: The demand for water during a drought period for a defined level of development. 
It is the sum of average year demand and water needed for any additional irrigation of farms and 
landscapes due to the lack of precipitation or increase in evapotranspiration during drought. 

O Normalized demand: The result of adjusting actual water use in a given year to account for unusual events 
such as dry weather conditions, government interventions for agriculture, rationing programs, etc. 



16 Water Demands 



Executive Summary 



Chapter 3 



Extensive evaluation and analyses of water demands were conducted to com- Woter DemondS 
plete Bulletin 160-93. These analyses recognize the water demands of all beneficial 
uses: urban, agricultural, environmental, and other uses including water based rec- 
reation and power generation. An overview of these demands follows. 

Urban Water Demand 

Urban water demand forecasts are primarily based on statewide population pro- 
jections that show an increase of almost 19 million people from 1990 to 2020, from 
roughly 30 million to 49 million people. About half the projected population increase 
will happen in the South Coast Region. Population projections for the California Water 
Plan Update are based on the Department of Finance baseline series. The DOF popu- 
lation estimates are taken from the 1 990 census as the base year. Figure ES-6 shows 
projections of population. 

Urban annual net water demand could increase from 6,800,000 af in 1990 to 
10,500,000 af by 2020, after accounting for implementation of conservation measures 
that are expected to reduce urban annual net water demand by about 900.000 af. 
Urban water demand forecasts are based on: population projections, unit urban water 
use values — considering probable effects of future water conservation measures, and 
housing trends, such as increases in multi-family housing and greater growth in 
warmer inland areas of the State. Table ES-3 shows urban water demand forecasts by 
hydrologic region. 




Figure ES-6. 
Comparison of 
Population Projections 
Used in Bulletin 160 
Analyses 



Water Demands 



17 



The California Water Plan Update 



Table ES-3. Urban Water Demand by Hydrologic Region 

(thousands of acre-feet) 

1990 2000 2010 2020 

average drought average drought average drought average drought 



Hydrologic Region 



North Coast 


Applied water demand 


168 


177 


186 


195 


204 


214 


219 


230 


Net water demand 


168 


177 


186 


195 


204 


214 


219 


230 


Depletion 


no 


112 


119 


122 


127 


132 


136 


142 


San Francisco Bay 


Applied water demand 


1,186 


1,287 


1,298 


1,390 


1,365 


1,486 


1,406 


1,530 


Net water demand 


1,186 


1,287 


1,298 


1,390 


1,365 


1,486 


1,406 


1,530 


Depletion 


1,079 


1,175 


1,185 


1,271 


1,247 


1,362 


1,287 


1,403 


Central Coast 


Applied water demand 


273 


277 


315 


321 


365 


373 


420 


429 


Net water demand 


229 


233 


263 


268 


304 


311 


349 


357 


Depletion 


203 


206 


235 


239 


272 


278 


315 


321 


South Coast 


Applied water demand 


3,851 


3,997 


4,446 


4,617 


5,180 


5,381 


6,008 


6,244 


Net water demand 


3,511 


3,641 


4,010 


4,161 


4,623 


4,799 


5,309 


5,514 


Depletion 


3,341 


3,463 


3,536 


3,677 


3,993 


4,158 


4,596 


4,785 


Sacramento River 


Applied water demand 


744 


807 


911 


989 


1,076 


1,167 


1,231 


1,335 


Net water demand 


744 


807 


911 


989 


1,076 


1,167 


1,231 


1,335 


Depletion 


236 


257 


293 


318 


349 


378 


400 


434 


Son Joaquin River 


Applied water demand 


495 


507 


663 


684 


839 


867 


1,029 


1,063 


Net water demand 


353 


366 


468 


490 


587 


616 


717 


752 


Depletion 


192 


194 


258 


265 


332 


340 


410 


420 


Tulare Lake 


Applied water demand 


523 


523 


716 


716 


892 


892 


1,116 


1,116 


Net water demand 


214 


214 


292 


292 


364 


364 


454 


454 


Depletion 


214 


214 


292 


292 


364 


364 


454 


454 


North Lahontan 


Applied water demand 


37 


38 


43 


44 


46 


48 


51 


52 


Net water demand 


37 


38 


43 


44 


46 


48 


51 


52 


Depletion 


14 


15 


17 


18 


19 


20 


21 


21 


South Lahontan 


Applied water demand 


187 


193 


292 


302 


409 


423 


550 


565 


Net water demand 


123 


125 


191 


198 


269 


277 


360 


372 


Depletion 


123 


125 


191 


198 


269 


277 


360 


372 


Colorado River 


Applied water demand 


301 


301 


399 


399 


512 


512 


621 


621 


Net water demand 


204 


204 


272 


272 


349 


349 


424 


424 


Depletion 


204 


204 


272 


272 


349 


349 


424 


424 





TOTAL 

Applied water demand 7,800 8,100 9,300 9,700 10,900 11,400 12,700 13,200 

Net water demand 6,800 7,100 7,900 8,300 9,200 9,600 10,500 11,000 

Depletion 5,700 6,000 6,400 6,700 7,300 7,700 8,400 8,800 



Water Demands 



Executive Summary 



Urban water agencies recognize the need for better demand forecasting methods 
to estimate water use. Some water agencies are moving toward a more disaggregated 
approach, similar to that of energy utilities. DWR and the University of California at 
Los Angeles have evaluated forecasting methods and developed procedures to esti- 
mate conservation from Best Management Practices. In this approach, data about the 
end uses of water are analyzed individually and then aggregated together to forecast 
overall water use. The benefits from implementing BMPs were evaluated and included 
in Bulletin 160 estimates of future urban water use. Statewide, implementation of 
BMPs could reduce urban annual applied water demand by about 1 .300,000 af by 
2020. The annual net water use and depletion reduction from BMPs could amount to 
900,000 af and is included in the urban water demand forecasts shown in Table ES-3. 
The 900.000 af is in addition to 400,000 af of annual net savings resulting from con- 
servation measures put in place between 1980 and 1990. However, more water use 
information must be gathered to further refine urban demand forecasting and evalua- 
tion of BMP effects on future water demand. Specific recommendations presented in 
Bulletin 160-93 are: 

1 . Urban water use forecasts require annual reporting of data to accurately estimate 
urban water use for residential, industrial, commercial and governmental sectors. 
Water use data reported to the State Controller's Office and the Department of 
Health Services, Office of Drinking Water, are currently insufficient to meet in- 
creasingly more complex forecasting needs. DWR should implement new report- 
ing mechanisms for urban water use data. 

2. LxDcal land use planning and resulting General Plans should be coordinated with 
water resources planning agencies to insure compatibility between land use plans 
and water supply plans to make optimum use of the State's water resources. 

3. DWR, in cooperation with the Urban Water Conservation Council, should deter- 
mine cost-effectiveness and water savings (reduced depletions) resulting from the 
various urban Best Management Practices and identify additional urban practices 
for use in statewide and regional planning. 

4. Urban ''water price" effects and their relationship to conservation practices are 
not well understood and require further data collection and analysis to ascertain 
their effects on demand. It is recommended that efforts of the Urban Water Con- 
servation Council and others be combined with an expanded program in DWR to 
address the issue. 

Agricultural Water Demand 

To compute agricultural water demand. Bulletin 160-93 analyses integrated the 
results of three forecasting methods used to estimate irrigated acreage and crop type: 

O Review of local historical crop acreage along with the availability of water and 
impacts of urban encroachment 

O Crop Market Outlook 

O Central Valley Production Model 

Every five to seven years since 1948, DWR has physically surveyed agricultural 
land use to help assess the locations and amounts of irrigated crops. Acreages of 
crops grown are estimated on a yearly basis, using the annual crop data produced by 
county Agricultural Commissioners, adjusted on the basis of DWR land use surveys, 
and estimates of urban expansion onto irrigated agricultural land (see Figure ES-7). 

The Crop Market Outlook is an economic model that uses data based on the 
expert opinion of bankers, farm advisors, commodity marketing specialists, and oth- 



t 



Water Demands 19 



The California Water Plan Update 



Figure ES-7. 

Irrigated 

Acreage in 

California 

1870-2020 

Nolc: Tlw decline in 1983 was 

caused primarily by wel 

conditions and the federal 

agricullural paymetU in kind 

(PIK) program. Vie decline in 

1987-90 was due to drought. 




ers regarding trends in factors affecting crop production in California. Several factors 
are evaluated, but the four primary ones are: (1) the current and future demand for 
food and fiber by the world's consumers; (2) the shares of the national and interna- 
tional markets for agricultural productions that are met by California's farmers and 
livestock producers; (3) technical factors, such as crop yields, pasture carrying capa- 
cities, and livestock feed conversion ratios; and (4) competing output from dryland 
(non-irrigated) acres in other states. The results determine the forecasted future po- 
tential California production of various crops. 

The Central Valley Production model is an economic model that accounts for 
crop production costs in different areas of the Sacramento and San Joaquin valleys in 
conjunction with the effect of overall production levels on the market prices for 
California crops. This helps to estimate how the total California production will be 
distributed among counties. 

Some crop shifts are expected to happen as growers move from low price to high 
price crops. Alfalfa and pasture lands are forecasted to decrease by about 331,000 
acres mostly in the San Joaquin and Tulare Lake regions. Crop acreages expected to 
increase include vegetables, nuts (almonds and pistachios), and grapes. While the 
acreage of low-quality (bulk) wine-grape acreage is decreasing in the San Joaquin 
Valley, the acreage of high-quality table wine grapes is increasing in other regions. 

The 1990 level crop acreage and crop types are based on agricultural land use 
surveys which were normalized to take into account the impact of the 1987-92 
drought, government set aside programs, and other annual crop acreage fluctuations. 
Forecasts of agricultural water needs are based on; ( 1 ) agricultural acreage forecasts, 
(2) crop type forecasts, (3) crop unit applied water and unit evapotranspiration of ap- 
plied water values (in acre-feet for each crop acre), and (4) estimates of future water 
conservation. 

Agricultural water needs were evaluated by determining crop t5T3es and acreages 
for each region. Forecasts indicate that irrigated agricultural acreage will decline by 
about 378,000 acres between 1990 and 2020. from 9,178,000 acres to about 



20 



Water Demands 



Executive Summary 



Table ES-4. Agricultural Water Demand by Hydrologic Region 

(thousands of acre- feet) 



Hydrologic Region 



1990 

average drought 



2000 

average drought 



2010 

average drought 



2020 

average drought 



North Coast 


Applied water demand 


HR 33^ 


915 


868 


948 


891 


972 


907 


989 


Net water demand 


744 


760 


748 


764 


761 


776 


771 


787 


Depletion i..i^»^^||||||^ 


■■i^iiw^ 


647 


611 


669 


627 


686 


637 


698 


San Francisco Bay 


Applied water demand 


SiV ^^ 


103 


94 


104 


94 


104 


94 


103 


Net water demand 


88 


99 


90 


100 


90 


100 


90 


99 


Depletion 'Bi 


HHB 30 


89 


82 


90 


82 


90 


82 


89 


Central Coast 


Applied water demand 




1,178 


1,166 


1,206 


1,182 


1,220 


1,189 


1,233 


Net water demand 


893 


961 


910 


982 


920 


991 


921 


1,003 


Depletion JBHn| 


■■■^ ^^^ 


950 


901 


971 


911 


980 


911 


992 


South Coast 


Applied water demand 


■HHHI^P 


753 


632 


655 


499 


518 


382 


396 


Net water demand 


644 


668 


569 


592 


458 


474 


356 


370 


Depletion .^p^Bgai 


flBB^i^i^ 


668 


569 


592 


458 


474 


356 


370 


Sacramento River 


Applied water demand 


lBII^7MB 


8,645 


7,698 


8,517 


7,592 


8,475 


7,558 


8,333 


Net water demand 


6,788 


7,394 


6,602 


7,222 


6,506 


7,184 


6,497 


7,049 


Depletion ^H 


■■P^TZ 


6,123 


5,426 


6,149 


5,439 


6,151 


5,437 


6,151 


San Joaquin River 


Applied water demand 


mm^^K 


6,757 


6,052 


6,500 


5,817 


6,227 


5,665 


6,080 ■■ 


Net water demand 


5,778_^^ 


6,217 


5,561 


5,967 


5,346 


5,695 


5,215 


5,572 


Depletion ^^^^gjj^ 


■■■■■HM|MW 


5,064 


4,605 


4,909 


4,490 


4,/// 


4,383 


4,678 


Tulare Lake 


Applied water demand 


'^HB^'^^3 


9,849 


9,306 


9,518 


9,075 


9,281 


8,833 


9,038 


Net water demand 


7,723 


7,895 


7,518 


7,685 


7,347 


7,505 


7,169 


7,320 


Depletion '^KsgEsaii 


flHB^^^^ 


7,876 


7,499 


7,666 


7,328 


7,486 


7,150 


7,301 


North Lohonton 


Applied water demand 


WKm ^22 


587 


523 


589 


525 


591 


536 


602 


Net water demand 


460 


511 


458 


510 


457 


508 


469 


521 


Depletion W9i 


HHK 378 


426 


385 


433 


393 


442 


399 


449 


South Lahontan 


Applied water demand 


mmpp^f^^ 


321 


266 


270 


258 


262 


253 


257 


Net water demand 


290 


293 


242 


245 


235 


238 


231 


234 


Depletion WKKttM 


HHI 290 


293 


242 


245 


235 


238 


231 


234 


Colorado River 


Applied water demand 


■■V'^05 


3,705 


3,598 


3,598 


3,453 


3,453 


3,363 


3,363 


Net water demand 


3,439 


3,439 


3,362 


3,362 


3,262 


3,262 


3,181 


3,181 


Depletion 


^Bmmam: 3^439 


3,439 


3,362 


3,362 


3,262 


3,262 


3,181 


3,181 





TOTAL 

Applied water demand 31,100 32,800 30,200 31,900 29,400 31,100 28,800 30,400 

Net v^ater demand 26,800 28,200 26,100 27,400 25,400 26,700 24,900 26,100 

Depletion 24,200 25,600 23,700 25,100 23,200 24,600 22,800 24,100 



Water Demands 



21 



The California Water Plan Update 



8,800.000 acres. This decline represents a 700,000-acre reduction from a pccik in 
1980. 

Many of agriculture's unit applied water values have decreased during the past 
decade. For the State as a whole, agricultural annual net water demand will decrease 
by about 1.9 maf, from 26.8 maf in 1990 to 24.9 maf in 2020. Part of this decrease is 
due to improvements in irrigation efficiency and increased emphasis on water con- 
servation since the 1976-77 drought. Table ES-4 shows the 1990 level and future 
agricultural water demands by hydrologic region. Bulletin 160-93 put forth the fol- 
lowing recommendations for better assessing agricultural water demand: 

1 . State agencies should encourage and provide technical assistance to agricultural 
water suppliers in preparation and implementation of water management plans. 

2. DWR needs to develop additional, more precise, on-farm applied-water data by 
crop to more accurately estimate agricultural applied water use efficiency in cer- 
tain areas. 

3. Studies need to be carried out by the State to determine the effect of increasing 
population on overall food production needs (in California and the nation) and 
their relationship to California's agricultural industry. 



Figure ES-8. 
Environmental 

Water Needs 
(Average Year) 



Environmental Water Demand 

Estimates of environmental water demand are based on: water needs of man- 
aged fresh water wetlands and the Suisun Marsh, environmental instream fiow needs. 
Delta outflow, and wild and scenic rivers. Wetlands water needs were tabulated from: 
(1) investigations of existing public and private wildlife refuges; and (2) additional wa- 
ter for wetlands as required by the CVPIA. Environmental instream flow 
needs were compiled by reviewing existing fishery agreements, water rights, and court 

decisions pertaining 
to water needs of 
aquatic resources of 
streams. Additional 
flows in the Trinity 
River, as noted in the 
CVPIA, are also in- 
cluded in forecasts of 
environmental in- 
stream demand. 

Environmental wa- 
ter needs in drought 
years are considerably 
lower than in average 
years, reflecting the 
variability of the natu- 
ral flows of rivers and 
lower fishery flow re- 
quirements, suchasin 
D-1485 for the Bay- 
Delta. Table ES-5 
shows California's re- 
gional environmental 
net water demands. 




22 



Water Demands 



Executive Summary 



Table ES-5. Environmental Water Needs by Hydrologic Region 

(thousands of acre-feet) 



Hydrologic Region 



1990 2000 2010 2020 

average drought average drought average drought average drought 



North Coast 


Applied water demand'" 


19,199 


9,299 


19,326 


9,426 


19,326 


9,426 


19,326 


9,426 


Net water demand'" 


19,087 


9,187 


19,212 


9,312 


19,212 


9,312 


19,212 


9,312 


Depletion'" 


19,085 


9,185 


19,210 


9,310 


19,210 


9,310 


19,210 


9,310 


Son Francisco Bay 


Applied water demand 


4,775 


3,245 


4,775 


3,245 


4,775 


3,245 


4,775 


3,245 


Net water demand 


4,775 


3,245 


4,775 


3,245 


4,775 


3,245 


4,775 


3,245 


Depletion 


4,775 


3,245 


4,775 


3,245 


4,775 


3,245 


4,775 


3,245 


Central Coast 


Applied water demand 


4 


2 


4 


2 


4 


2 


4 


2 


Net water demand 


1 





1 





1 





1 





Depletion 


1 





1 





1 





1 





South Coast 


Applied water demand 


2 


2 


6 


6 


6 


6 


6 


6 


Net water demand 


2 


2 


6 


6 


6 


6 


6 


6 


Depletion 


2 


2 


6 


6 


6 


6 


6 


6 


Sacramento River 


Applied water demaftdF ' " - 


3,927 


3,493 


4,117 


3,638 


4,117 


3,638 


4,117 


3,638 


Net water demand 


3,717 


3,299 


3,860 


3,442 


3,860 


3,442 


3,860 


3,443 


Depletion flHMHHHv 


168 


168 


207 


207 


207 


207 


207 


208 


San Joaquin River 


Applied water demand 


599 


511 


744 


656 


744 


656 


744 


656 


Net water demand 


554 


466 


670 


582 


670 


582 


670 


582 


Depletion JlHHHHHft_ 


■ 190 


190 


306 


306 


306 


306 


306 


306 


Tulare Lake 


Applied water demand 


82 


82 


136 


136 


136 


136 


136 


136 


Net water demand 


34 


34 


56 


56 


56 


56 


56 


56 


Depletion 


34 


34 


56 


56 


56 


56 


56 


56 


North Lohontan 


Applied water demand 


17 


17 


M 


17 


17 


17 


17 


17 


Net water demand 


17 


17 


17 


17 


17 


17 


17 


17 


Depletion 


\7 


17 


17 


17 


17 


17 


17 


17 


South Lahontan 


Applied water demand 


128 


122 


128 


122 


128 


122 


128 


122 


Net water demand 


128 


122 


128 


122 


128 


122 


128 


122 


Depletion JHHJiiHiHHL^ 


H. 73 


67 


73 


67 


73 


67 


73 


67 


Colorado River 


Applied water demand 


39 


39 


44 


44 


44 


44 


44 


44 


Net water demand 


39 


39 


44 


44 


44 


44 


44 


44 


Depletion ^Ht 


39 


39 


44 


44 


44 


44 


44 


44 





TOTAL 


















Applied water demand 


28,800 


16,800 


29,300 


17,300 


29,300 


17,300 


29,300 


17,300 


Net water demand 


28,400 


16,400 


28,800 


16,800 


28,800 


16,800 


28,800 


16,800 


Depletion 


24,400 


12,900 


24,700 


13,300 


24,700 


13,300 


24,700 


13,300 



(1 ) Includes 1 7.8 MAF and 7.9 MAF flows for Norlfi Coast Wild and Scenic Rivers for average and drought years, respectively. 



Water Demands 



23 



The California Water Plan Update 



Regulatory agencies have proposed a number of changes in instream flow needs 
for major rivers, including the Sacramento and San Joaquin. These proposed flow re- 
quirements are not necessarily additive; however, an increase ranging from 1 to 3 maf 
is presented to envelop potential environmental water needs that could result from 
proposed additional instream flows and actions under way by regulatory agencies (see 
Figure ES-8). Bulletin 160-93 recommends the following to better assess environmen- 
tal water needs: 

1 . Current methodologies for identifying cause and effect relationships for habitat 
and fishery populations need to be improved and new techniques developed and 
implemented by the State to better define environmental water needs. 

2. DWR Bulletin 216, Inventory of Instream Flow Requirements related to stream 
diversions was last updated in 1982. An up-to-date inventory of flow require- 
ments should be completed and maintained. 

3. Water resources management for protection of fish and wildlife species should be 
planned and performed under a multi-species approach. 



I 



24 Water Demands 



Executive Summary 



California's Total Water Demand 

Table ES-6 shows California's net water demands; these include reductions in 
demand due to long-term conservation measures for both urban and agricultural 
users and reductions due to land retirement in San Joaquin Valley areas with poor 
drainage. A majority of the environmental net water demand occurs in the North 
Coast hydrologic region, indicating the large dedicated natural flows of the North 
Coast wild and scenic rivers system, about 17.8 maf in an average year. Dedicated 
instream flow under D-1485 makes up the largest portion of the San Francisco Bay 
Region's net water demand, about 4.6 maf, while urban and agricultural net water 
demands for the region amount to 1.3 maf. The South Coast Region has the highest 
net water demand for urban use, about 3.5 maf in an average year, and the Tulare 
Lake Region has the largest net water demand for agriculture, about 7.7 maf in an 
average year. 



Table ES-6. California Water Demand 

(millions of acre-feet) 



Category of Use 


1990 

average drought 


2000 

average drought 


2070 

average drought 


2020 

average drought 


Urban 












11.4 
9.6 
7.7 

31.1 
26.7 
24.6 

17.3 
16.8 
13.3 

0.3 


12.7 

10.5 

8.4 

28.8 
24.9 
22.8 

29.3 
28.8 
24.7 

0.3 
1.5 
1.0 




Applied water demand 


7.8 


8.1 


9.3 


9.7 


10.9 


13.2 


Net water demand 


6.8 


7.1 


7.9 


8.3 


9.2 


11.0 


Depletion 


5.7 


6.0 


6.4 


6.7 


7.3 


8.8 


Agricultural 














Applied water demand 


31.1 


32.8 


30.2 


31.9 


29.4 


30.4 


Net water demand 


26.8 


28.2 


26.1 


27.4 


25.4 


26.1 


Depletion 


24.2 


25.6 


23.7 


25.1 


23.2 


24.1 


Environmental 














Applied water demand 


28.8 


16.8 


29.3 


17.3 


29.3 


17.3 


Net water demand 


28.4 


16.4 


28.8 


16.8 


28.8 


16.8 


Depletion 


24.4 


12.9 


24.7 


13.3 


24.7 


13.3 


Other'^' 














Applied water demand 


0.3 


0.3 


0.3 


0.3 


0.3 


0.3 


Net water demand 


1.5 


1.5 


1.5 


1.4 


1.5 


1.4 
1.0 


1.4 


Depletion 


1.0 


1.0 


1.0 


1.0 


1.0 


1.0 
















TOTAL 












60.1 
54.5 
46.6 


71.1 
65.7 
56.9 




Applied wafer demand 


68.0 


58.0 


69.1 


59.2 


69.9 


61.2 


Net water demand 


63.5 


53.2 


64.3 


53.9 


64.9 


55.3 


Depletion 


55.3 


45.5 


55.8 


46.1 


56.2 


47.2 













(1) Includes major conveyance facility losses, recreation uses, and energy production. 



Water Demands 



25 



The California Water Plan Update 



Figure ES-9. 
The California 
Water Balance 




26 



Balancing Water Supply and Demand 



Executive Summary 



Chapter 4 



California's average annual water supplies are generally adequate for today's 
average annual demands. However, during drought, present supplies are insufficient 
to meet present demands, as illustrated by the 2.7-maf shortage shown in the 1990 
level drought scenario under D-1485 criteria for Delta supplies. In the 1991 and 1992 
drought years, shortages caused urban mandatory water conservation (rationing), 
agricultural land fallowing and crop shifts, reductions in environmental flows, and 
short-term water transfers. As shown in the California Water Budget, Table ES-7, 
and in the California Water Balance, Figure ES-9, water shortages exist today. 

As a result of altered water project operations to comply with biological opinions 
and the CVPIA, supplies for areas of the State relying on Delta exports are becoming 
more unreliable. EPA's (and other) proposed water quality standards could also 
reduce total water supply for urban and agricultural use by a range of 500,000 af to 1 
maf in average years and 2 to 3 maf in drought years. While these amounts do not 
include potential reductions in Delta exports due to "take limits" under the biological 
opinions, they basically fall within the l-to-3-maf range for proposed additional 
environmental demands. Such uncertainty of water supply delivery and reliability will 
continue until issues involving the Delta and other long-term environmental water 
management concerns are resolved. 

Water managers are looking into a wide variety of management actions to 
supplement, improve, and make better use of existing resources. The single most 
important one will be solving key issues in the Delta. Some options for addressing the 
shortages and improving California's supply reliability are summarized here. After 
presenting the options, some local water supply and management issues (detailed in 
Volume 11 of the bulletin) are highlighted. 

Options for Balancing Supply and Demand 

Bulletin 160-93 presents both long-term and short-term supply augmentation 
and demand management options for meeting future needs. Included are short-term 
drought management options (demand reduction through urban rationing programs 
or water transfers that reallocate existing supplies through use of reserve supplies 
and agricultural land fallowing programs) and long-term demand management and 
supply augmentation options (increased water conservation, agricultural land 
retirement, additional waste water recycling, benefits of a long-term Delta solution, 
more conjunctive use programs, and additional south-of-the-Delta storage facilities). 
Future water management options are presented in two levels to better reflect the 
status of investigations required to implement them. Table ES-8 shows Level I 
demand management options, and Table ES-9 lists Level I water supply options. 

O Level I options are those programs that have undergone extensive investigation and 
environmental analyses and are judged to have a higher likelihood of being 
implemented by 2020. 



Balancing Water 
Supply and Demand 



Balancing Water Supply and Demand 



27 



The California Water Plan Update 



Table ES-7. California Water Budget 

(millions of acre-feet) 

Water Dentand/Suppfy 7 990 

average drought 



Net Demand 


Urtxm — with 1 990 level of conservation 


6.8 


7.1 


— reductions due to long-term conservation measures (Level 1) 








Agricultural — with 1 990 level of conservation 


26.8 


28.2 


— reductions due to long-term conservation measures (Level 1) 

— land retirement in poor drainage areas of San Joaquin Valley (Level 1) 








Environmental 


28.4 


16.4 


Otfier^'i 


1.5 


1.5 


SuhMni 


63.5 


53.2 


Proposed Additional Environmental Water Demands'^ 

Case 1 - Hypotfiehcal 1 MAP ^^^ 






Case II - Hypotfieticai 2 MAP IH 


IHHIHHP 


r — 


Case 111 - Hypothetical 3 MAP 


— 


— 




Total Net Demand 


63.5 


53.2 


Cose! 


— 


— 


Case II 


— 


— 


Case III 


— 


— 


Wafer Supplies w/Existing Facilities Under D- 1485 for Delta Supplies 

Developed Supplies 


Surface Water<3' 


27.9 


22.1 


Ground Water 


7.1 


11.8 


Ground Water OverdraP' !■ 


mmiiiiiii^ 


1.3 


Subtotal ..____^^_ 


36.3 


35.2 


Dedicated Natural Plow sH^^H^^I 


■§27.2 


15.3 




TOTAL Water Supplies 


63.5 


50.5 




Demand/Supply Balance 


0.0 


-2.7 


Casel 


— 


— 


Casell 


— 


— 


Case III 


— 


— 


leve/ 1 Water Management Programs'' 

Long-term Supply Augmentation 


Reclaimed 


— 


— 


Local 


— 


— 


Central Valley Project 


— 


— 


State Water Project 
Short-Term Drought Management 


— 


— 


Potential Demand AAanogement 


— 


1.0 


Drought Water Transfers 


— 


0.8 


Subtotal - Level 1 Wafer Management Programs 


— 


7.a 


Islet Ground Water or Surface Water Use Reduction 
Resulting from Level 1 Programs 


— 


0.0 


NET T01AL Demand Reduction/Suppiy Augmentation 


0.0 


7.8 


Remaining Demand/Supply Balance Requiring Level II Options 


0.0 


-0.9 


Casel 


— 


— 


Casell 


— 


— 


Cow III 


— 


— 





(1) Includes major conveyance facility losses, recreation uses, and energy production. 

(2) (Voposed Environmental Water Demands — Case l-lll envelop potential and uncertain demands and hove immediate and future 

consequences on supplies from the Deha, beginning with actions in 1 992 and 1 993 ta protect winter run salmon and delta smeh (actions 
which could also protect other fish species). 



28 Balancing Water Supply and Demand 



Executive Summary 



2000 

average drought 



Table ES-7. California Water Budget 

(millions of ocre-feet) 

2010 

average drought 



2020 

average drought 





£" f8.3'_j3BiiBaig 


8.7 


9.9 


10.3 


11.4 


11.9 


-0.4 


-0.4 


-0.7 


-0.7 


-0.9 


-0.9 


^■^■■■127-7 


25.8 


27.1 


25.4 


26.6 


-0.2 
-0.1 


-0.2 
-0.1 


-0.3 
-0.1 


-0.3 
-0.1 


-0.4 
-0.1 


-0.4 
-0.1 


^aHHHHIi6.8 


28.8 


16.8 


28.8 


16.8 


1.5 


1.4 


1.5 


1.4 


1.5 


1.4 


^^HflHHB<^-^ 


64.9 


54.5 


65.7 


55.3 


1.0 


1.0 


1.0 


1.0 


1.0 


1.0 


2.0 


2.0 


2.0 


2.0 


2.0 


2.0 


3.0 


3.0 


3.0 


3.0 


3.0 


3.0 




ta- - 


— 


— 


— 


— 


— 


65.3 


54.9 


65.9 


55.5 


66.7 


56.3 


66.3 


55.9 


66.9 


56.5 


67.7 


57.3 


67.3 


56.9 


67.9 


57.5 


68.7 


58.3 




2778 


21.5 


28.1 


21.6 


28.2 


21.7 


7.1 


12.0 


7.2 


12.1 


7.4 


12.2 


— 


— 


— 


— 


— 


— 


34.9 


33.5 


35.3 


33.7 


35.6 


33.9 


27.4 


15.4 


27.4 


15.4 


27.4 


15.4 




62.3 


48.9 


62.7 


49.1 


63.0 


49.3 




■ — 


— 


— 


— 


— 


— 


-3.0 


-6.0 


-3.2 


-6.4 


-3.7 


-7.0 


-4.0 


-7.0 


-4.2 


-7.4 


-4.7 


-8.0 


-5.0 


-8.0 


-5.2 


-8.4 


-57 


-9.0 




0.5 


0.5 


0.6 


0.6 


0.8 


0.8 


0.0 


0.1 


0.0 


0.3 


0.0 


0.3 




0.0 


0.0 


0.0 


0.0 


^OjO „..^ 


0.2 


0.1 


0.6 


1.0 


0.7 


1.0 


— 


1.0 


— 


1.0 


— 


1.0 


— 


0.8 


— 


0.8 


— 


0.8 


0.7 


2.5 


1.3 


3.8 


1.5 


3.9 


0.1 


0.0 


0.1 


0.2 


0.1 


0.2 


0.7 


2.5 


1.4 


4.0 


1.6 


4.1 














— 


— 


W -2.3 


-3.5 


-1.8 


-2.4 


-2.1 


-2.9 


-3.3 


-4.5 


-2.8 


-3.4 


-3.1 


-3.9 


-4.3 


-5.5 


-3.8 


-4.4 


-4.1 


-4.9 





(3) The degree future shortages are met by increased overdraft is unknown. Since overdraft is not sustainable, it is not included as a future suppJy. 

(4) Protection of fish and v/ildlife and a long-term solution to complex Delta problems will determine the feasibility of several v/ater supply 
augmentation proposals and their wafer supply benefits. 



Balancing Water Supply and Demand 



29 



The California Water Plan Update 



Table ES-8. Level I Demand Management Options 



Program 


Applied Water 


Net Water Demand 


Economic 


Comments 




Reduction 


Reduction 


Unit Cost 






(1,000 AF) 


(1000 AF) 


(S/AFY"^ 








average 


drought 






Long-term Demand Management: 












Urban Water Conservation 


1,300 


900 


900 


315-390"'' 


Urban BMPs 


Agricultural Water 


1,700 


300 


300 


Not 


Increased irrigation 


Conservation 








Available 


efficiency 


Land Retirement ' 


130 


130 


130 


60 


Retirement of land v/ith 
drainage problems in west 
San Joaquin Valley; cost is at 
the Delta. 


All American Canal Lining 


68 


68 


68 




Water conservation project; 
increases supply to South 
Coast Region 


Short-term Demand Management: 












Demand Reduction 


1,300 





1,000 


Not 


Drought year supply 
Available 


Land Fallowing/Short-term 


800 





800 


125 


Drought year supply; cost is 


Water Transfers 










at the Delta. 



(a) Economic costs include capital and OMP&R costs discounted over a 50-year period at 6 percent discount rate. These costs do not include applicable transportation and treatment costs. 

(b) Gssts ore for the ultra-low-flush toilet retrofit and residential water audit programs. 

O Level II options are those programs that could fill the remaining gap shown in the 
balance between supply and urban, agricultural, and environmental water 
demands. These options require more extensive investigation and alternative 
analyses. 

If all Level I options were implemented, there would still be a potential shortfall 
in annual supplies of about 2.1 to 4. 1 maf in average years and 2.9 to 4.9 maf in 
drought years by 2020 that must be made up by Level II water supply augmentation 
and demand management programs. Table ES-10 shows California's water supplies 
with Level 1 water management programs. Table ES- 1 1 lists Level II water 
management options. 

After accounting for future reductions of 1 .3 maf in net water demand resulting 
from implementation of urban Best Management Practices, agricultural Efficient 
Water Management Practices, and after accounting for another 1 00, 000-af reduction 
due to future land retirement, forecasted 2020 net demand totals roughly 65.7 maf in 
average years and 55.3 maf in drought years. These demand amounts could increase 
by 1 to 3 maf, depending on the ultimate outcome of the CVPLA, the biological 
opinions, and other actions being taken to protect Delta water quality or threatened 
species. 

By 2020, without additional facilities and improved water management, annual 
shortages of 3.7 to 5.7 maf could occur during average years, again depending on the 
outcome of various actions discussed in Chapter 1. Average year shortages are 
considered chronic and indicate the need for implementing long-term water supply 
augmentation and demand management measures to improve water service 
reliability. Similarly, by year 2020, annual drought year shortages could increase to 
7.0 to 9.0 maf under D-1485 criteria, also indicating the need for long-term measures 
in addition to short-term drought management measures. 

30 Balancing Water Supply and Demand 



Executive Summary 



Program 



Table ES-9. Level I Water Supply Management Options 
lype 



Capacity 

(hOOOAF) 



Annual 
Supply 

(1000 AF) 



Economic 
Unit Cost 

($/AF)i'i 



Comments 



average 



drought 



Statewide Water Management: 

Long-term Delta Delta Water 

Solution Management Program 



200 



400 Not Under study by Bay/Delta 

Available Oversight Council; water supply 

benefit is elimination of carriage 
water under D-1 485. 



Interim Soutfi Delta 
Water Management 
Program 


Soutfi Delta 
Improvement 




60 


60 


60 


Final draft is scheduled to 
be released in late 1 994 


Los Bonos Grondes 
Reservoir^^*^ 


Offstream Storage 


1,730"! 


250-300 


260 


260 


Schedule now coincides with 
BCXDC process 


Kern Water Banki^' 














Kern Fan Element 


Ground Water Storage 


1,000 


90 


140 


105-155 


Evaluation under way 


Local Elements 


Ground Water Storage 


2,000 


90 


290 


180-460 


Schedule now coincides with 
BDOC process 


Coastal Broncfi- 
Phase II (Santa Ynez 
Extension) 


SWP Conveyance 
Facility 


57 


N/A 


N/A 


630-1,110 


Notice of Determination was 
filed in July 1 992; construction 
began in late 1 993. 


American River 
Flood Controli"! 


Flood Control Storage 


545131 


" 


" 


" 


Feasibility report and 
environmental documentation 
completed in 1991. 


Local Water Management: 

Water Recycling 


Reclamation 


1,321 


923 


923 


125-840 


New water supply 


Ground Water 
Reclamation 


Reclamation 


200 


100 


100 


350-900 


Primarily in South CousI 


El Dorado County 
Water Agency 
Water Program 


Diversion from Soutfi 
Fork American River 




24 


23(51 


280 


Certified final ProgramnKitic 
EIR identifying preferred 
alternative; water rights hearings, 
new CVP contract following 
EIR/EIS preparation 


Los Vaqueros 
Reservoir-Contra-Costra 
Water District 


Offstream Storage 

Emergency Supply 

Water Quality 


100 


N/A 


N/A 


320-950 


EIR certified in October 1 993, 
404 permit issued in April 1 994. 


EBMUD 


Conjunctive Use and 
Other Options 




N/A 


43 


370 


Final EIR certified in October 
1993 


New Los Padres 
Reservoir-MPWMD 


Enlarging existing 
reservoir 


24 


22 


18 


410 


T&E species, steelheod resources, 
cultural resources in Carmel River 


Domenigoni Valley 
Reservoir-MWDSC 


Offstream storage of 

SWP and Colorado 

River water, drought year 

supply 


800 





264 


410 


Final EIR certified 


Inland Feeder-MWDSC 


Conveyance Facilities 


— 


— 


— 


— 




San Felipe Extension- 
PVWA 


CVP Conveyance 
Facility 




N/A 


N/AI5) 


140 


Capital costs only; convey 
1 8,000 AF annually 


City of San Luis 
Obispo-Salinas Reservoir 


Enlarging existing 
reservoir 


18 


— 


1.6 


" 


Final EIR is expected to be 
certified in 1994. 



(1 ) Economic costs include capital and OMP&R costs discounted over a 50-year period at 6 percent discount rote. These costs do not include applicaljle transportation ond 

(2) Annual supply and unit cost figures are based on Delta water supply availability under D- 1 485 with on Interim South Delta Water Management Program in pkice. 

(3) Reservoir capacity. 

(4) Folsom Lake flood control reservation woukJ retum to original 0.4 MAP. 

(5) Yield of this project is in part or fully comes from the CVP 

(6) N/A: Not Applicable 

(7) These programs are only feasible if a Delta Water AAanagement Program is implemented. 



treatment costs. 



Balancing Water Supply and Demand 



31 



The California Water Plan Update 



1.0 


0.7 


5.2 


5.1 


7.5 


5.0 


1.2 


0.8 


2.8 


2.1 


0.2 


0.2 


7.1 


11.8 


1.3 


1.3 



10.2 


8.2 


10.2 


8.3 


10.3 


8.4 


1.0 


0.8 


1.0 


1.0 


1.0 


1.0 


4.4 


4.4 


4.4 


4.4 


4.4 


4.4 


7.7 


5.2 


7.7 


5.2 


7.7 


5.2 


1.3 


0.8 


1.3 


0.8 


1.3 


0.8 


3.4 


2.1 


3.9 


3.0 


4.0 


3.0 


0.7 


0.7 


0.8 


0.8 


0.9 


0.9 



Table ES-10. California Water Supplies with Level I Water Management Programs 

(Decision 1485 Operating Criteria for Delta Supplies) 
(millions of acre-feet) 

Supply 1990 2000 2010 2020 

average drought average drought average drought average drought 

Surface 

Local ld.T 8.f 

Local imports'^' 

Colorado River 

CVP 

Other federal 

SWF' 
Reclaimed 
Ground water'^' 
Ground water overdrgft<^> 
Dedicated natural flow 27.2 15.3 27.5 15.4 27.5 15.4 27.5 15.4 

TOTAL 63.5 50.4 63.3 49.5 64.0 51.2 64.5 51.6 

(1) 1990 SWP supplies are normalized and do not reflect additional supplies delivered to offset the reduction of supplies from the Mono and Owens basins to the South Coast 
hydrologic region. 

(2) Average ground water use is prime supply of ground water basins and does not include use of ground water which is artificially recharged from surface sources into the ground 
water basins. 

(3) The degree future shortages ore met by increased overdraft is unknown. Since overdraft is not sustainable, it is not included as a future supply. 

Water shortages would vary from region to region and sector to sector. For 
example, the South Coast Region's population is expected to increase to over 25 
million people by 2020, requiring an additional 1 .8 maf of water each year. Population 
growth and increased demand, combined with a possibility of reduced supplies from 
the Colorado River, mean that the South Coast Region's annual shortages for 2020 
could amount to 400,000 af in average years and 1 maf in drought years. All told, 
forecasted shortages will be larger if solutions to complex Delta problems are not 
found, proposed local water management programs are not implemented, and 
additional facilities for the SWP are not constructed. 

Local Water Management Issues 

Local surface water development includes direct stream diversions as well as 
supplies in local storage facilities. As a result of economic, environmental, cind 
regulatory obstacles, local agencies are finding it difficult to undertake new water 
projects to meet their needs where supply shortfalls exist or are forecasted. Thus, 
many local and regional water agencies are advocating or implementing incentive 
programs for water conservation to reduce demand where such programs are cost 
effective. Implementation of urban Best Management Practices and agricultural 
Efficient Water Management Practices will reduce demands in the future, and 
reductions caused by these practices were incorporated into Bulletin 160-93 water 
demand forecasts to 2020. Following are highlights of some local water supply issues 
covered in Volume 11 of the bulletin. 

In the North Coast Region, a number of smaller communities have continuing 
water supply reliability problems, often related to the lack of economic base to 
support water management and development costs. Small communities along the 
coast, such as Moonstone, Smith River, and Klamath, either experience chronic water 
shortages or have supplies inadequate to meet projected growth. Water use is already 

32 Balancing Water Supply and Demand 



Executive Summary 



Table ES-1 1 . Level II Water Management Options 



Program 



Type Supply Augmentation 
or Demand Reduction 

(1,000 AF) 



Comments, Concerns, 
Problems 



Demand Management: 

Agricultural Water Conservation 
Urban Water Conservation 
Land Retirement 

Water Transfer 



Demand Reduction 300'°' Increased agricultural water use efficiency 

Demand Reduction 220'°' Increased urban water use efficiency 

Demand Reduction 477'°' Retirement of land witfi poor drainage disposal In 

west side San Joaquin Valley 

— 800""' Institutional constraints 



wide Supply Management: 

Stanislaus-Calaveras River 
Water Use Program 


Conjunctive Use 


801^1 


Sacramento Valley Conjunctive 
Use Program 


Conjunctive Use 


100'^' 


Red Bank Project 


Storage 


40(0 


Shasta Lake Enlargement 


Storage 


1,450'^' 


Clair Engle Lake Enlargement 


Storage 


700'^' 


Westside Sacramento Valley Project 


Conveyance 


— 


Westside Reservoirs 


Storage 


up to 2,000'^' 


Mid-Valley Canal 


Conveyance 


— 


Folsom South Canal Extension 


Conveyance 


— 


American River Water 


Storage 


— 



DWR, USBR, and local agencies are conducting 
studies. 

Initial studies under way by DWR and local 
agencies. 



Resources Investigation 



Local Water Management: 

Use of Gray Water 


Reclamation 


180'^' 


Water Recycling 


Reclamation 


370'=' 


Water Desalting 


Reclamation 


390'=' 


Reuse of Agricultural Brackish Water 


Reclamation 


— 


San Diego County Water Authority 
Water Resources Plan 


Variety of Programs 


85'=' 


Santa Clara Valley Water 
Management 


— 


— 


Delta Storage 


Storage 


— 


Watershed Management 


— 


100'=' 



Requires investment in separate plumbing; health 
concerns. 

Estimated ultimate potential 



High salt accumulation in soil 

Plan includes water recycling, ground water 
development, and desalination of brackish water. 

Studies by district in progress; will need 1 00,000- 
1 50,000 AF additional supplies by 2020. 

Water quality, THM concerns 

Increases runoff from the watershed, environmental 
concerns. 



(a) Reduction in applied water. 

(b) Reallocation or supply for short- or long-ternn transfers. 

(c) Average annual supply. 

low due to conservation, so most of these problems will have to be solved by either 
constructing or upgrading community water systems. 

In the San Francisco Bay Region, Marin Municipal Water District has relied, in 
part, on imported supply from Sonoma County Water Agency and extensive 
conservation efforts by its customers to ensure adequate supplies throughout the 



Balancing Water Supply and Demand 



33 



The California Water Plan Update 



recent drought. Under 2025 demand conditions, without supplemental supplies, the 
district estimates a 40-percent deficiency once every 10 years. To improve reliability. 
MMWD has negotiated an agreement with SCWA to import an additional 10,000 af. 
This supplemental supply, in conjunction with the district's water conservation and 
water management plans, should limit water shortages to about 10 percent once every 
10 years. 

Imported supplies by the City of Scm Francisco, Santa Clara Valley Water 
District, and East Bay Municipal Utilities District also suffered deficiencies during the 
recent drought. During 1991. the City of San Francisco was able to reduce expected 
rationing from 45 to 25 percent through purchases of 50.000 af from the 1991 State 
Drought Water Bank and 20.000 af from Placer County Water Agency. Customers 
were still required to reduce indoor use by 10 percent cind outdoor use by 60 percent. 
During 1989-91, Santa Clara Valley Water District was able to get through with 25 
percent rationing by purchasing 69,000 af from Yuba County, 14,000 af from Placer 
County and 20,000 af from the State Drought Water Bank. 

Water supplies in much of the Central Coast Region are greatly dependent upon 
the region's ground water basins; the storage in these basins is small and fluctuates 
from year to year. Since ground water and limited local surface supplies are its 
primary source of water, the region is vulnerable to droughts. As ground water 
extractions exceed ground water replenishment, several of the region's coastal 
aquifers are in overdraft, allowing sea water intrusion. The recent drought required 
mciny communities in the region to implement stringent water conservation programs. 
The cities of Santa Barbara and Morro Bay constructed sea water desalination plants 
to improve their water service reliability. 

The South Coast Region is home to more than one half of the State's population. 
16 million people. The region's population is expected to increase to more than 25 
million people by 2020. Such growth poses several critical water supply difficulties, 
most notably increased demand with limited ability to increase supply. Further, 
imports from Mono Lake tributaries. Owens Valley, and the Colorado River will be 
reduced and limits placed on Delta exports could further reduce water service 
reliability in the South Coast Region. MWDSC has several programs in progress to 
improve its water delivery and supply capability, including the construction of 
Domenigoni Valley Reservoir, and supports improved Delta transfer capabilities to 
improve reliability of its SWP supplies. 

Court ordered restrictions on diversion fi-om the Mono Basin and Owens Valley 
in the South Lahontan Region have reduced the amount of water the City of Los 
Angeles can receive. These restrictions affect South Coast Region supplies while 
improving the reliability of supplies for meeting environmental needs in the South 
Lahontan Region. 

Sacramento River Region water users are concerned about protecting their 
area's ground water resources from export. Organized ground water management 
efforts in the region are currently under way in Butte, Colusa, Glenn, Shasta, 
Tehcmia, and Yolo counties. Also, several foothill areas that rely heavily on ground 
water are finding those supplies limited. With many people relocating to these areas, 
concern about ground water availability and the potential for its contamination is 
increasing. 

Flood protection is another major concern for the region, especially along the 
Sacramento and American rivers near Sacramento. In 1991. the U.S. Army Corps of 
Engineers completed a feasibility report and environmental documentation for a flood 



34 Balancing Water Supply and Demand 



Executive Summary 



detention dam at the Auburn site in combination with levee modification along the 
lower American River to increase flood protection for the Sacramento area. The report, 
however, generated much controversy over whether Auburn Dam should be a flood 
detention only (dry dam) or multipurpose dam. 

Foothill areas of both the San Joaquin River and Tulare Lake regions share the 
Sacramento River Region's problem of limited water supplies. Major concerns for this 
region's agricultural community are agricultural drainage disposal and treatment 
costs and potential reduction of imported supplies. CVP supplies will be reduced by 
the CVPIA. and both the CVP and SWP supplies are affected by ESA biological 
opinions and other actions proposed to protect Delta water quality and fisheries. 
Ground water overdraft in these regions will most likely increase because 
formerly-available surface supplies that recharged ground water basins may not 
return to former amounts. 

In the North Lahontan Region years of disputes over the waters of the Truckee 
and Carson rivers led to the 1990 enactment of the Truckee-Carson-Pyramid Lake 
Water Rights Settlement Act. This federal act makes an interstate allocation of the 
rivers between California and Nevada, provides for the settlement of certain Native 
American water rights claims, and provides for water supplies for specified 
environmental purposes in Nevada. The act allocates to California: 23.000 af annually 
in the Lake Tahoe Basin. 32.000 af annually in the Truckee River Basin below Lake 
Tahoe. and allocations corresponding to existing water uses in the Carson River 
Basin. Provisions of the Settlement Act. including the interstate water allocations, will 
not take effect until several conditions are met. including negotiation of the Truckee 
River Operating Agreement required by the act. 

Water exports from the South Lahontan Region have been the subject of 
litigation since the early 1970s. In 1972. the County of Inyo sued the City of Los 
Angeles claiming that increased ground water pumping for export was harming the 
Owens Valley. Consequently, the City of Los Angeles and Inyo County implemented 
enhancement projects to mitigate the impacts of ground water pumping. In 1989. the 
parties reached agreement on the long-term ground water management plan for 
Owens Valley and the EIR was accepted by the court. 

Another long standing issue is the Los Angeles Department of Water and Power 
diversions from Mono Lake tributaries and the impact of these diversions on the lake 
level. As a result of extensive litigation between the City of Los Angeles and a number 
of environmental groups. LADWP is now prohibited by court order from diverting from 
the tributaries until the lake level stabilizes. SWRCB concluded Mono lake water 
rights hearings in February 1994. A draft decision regarding lake levels and stream 
flows on the four tributaries is expected in late 1994. The Mono-Owens system 
provided 17 percent of LADWP's water supply and 1.5 percent of its hydroelectric 
energy supply. Replacement water and energy are being sought. One source of 
replacement water will be four water reclamation projects to be funded by the 
Environmental Water Fund, which was created by the Legislature in 1989 to fund 
projects mutually agreed upon by LADWP and the Mono Lake Committee. 

The Colorado River Region faces increasingly difficult issues involving water 
quality. In the late 1960s. 1970s, and early 1980s, the Salton Sea suffered from high 
water levels caused by increased agricultural runoff, treated urban waste water, and 
above average rainfall. In 1984. the State Water Resources Control Board adopted 
Water Right Decision 1600. which required Imperial Irrigation District to prepare a 
conservation plan and take other steps to improve its delivery system. Following a 



Balancing Water Supply and Demand 35 



The California Water Plan Update 



1988 SWRCB order. IID implemented a program with funds provided by MWDSC to 
conserve water. The sea level has stabilized somewhat during recent years, due in 
part, to llD's conservation measures. The Salton Sea dilemma illustrates the 
complexity and opportunities for cooperative solutions of water management issues in 
California. 



36 Balancing Water Supply and Demand 



Executive Summary 



Chapter 5 



Considering that much of the hypothetical range for additional environmental 
water has now been mandated by the biological opinions and CVPIA. or formally 
proposed in EPA Bay-Delta water quality standards, California faces more frequent 
and severe water supply shortages for the year 2000 and beyond. In 1993, an above 
normal water year, some CVP contractors had their supplies cut by 50 percent. These 
unanticipated shortages point to the need for a quick resolution of Delta problems 
through federal cooperation and participation. They also emphasize the need to move 
forward with demand management and supply augmentation programs at both 
statewide and local levels. The major conclusions and recommendations in Bulletin 
160-93 follow. 



Conclusions and 
Recommendations 



Conclusions 

O California's population is projected to increase to 49 million people by 2020 (from 
about 30 million in 1990). Even with extensive water conservation, urban annual 
net water demand will Increase by about 3.8 maf to 10.5 maf by 2020. Nearly half 
of the Increased population is expected to occur in the South Coast Region, 
increasing that region's annual water demand by 1.5 maf. 

O Irrigated agricultural acreage is expected to decline by nearly 400,000 acres, from 
the 1990 level of 9.2 million acres to a 2020 level of 8.8 million acres, 
representing a 700,000-acre reduction from the 1980 level. Reductions in 
projected irrigated acreage are due primarily to urban encroachment onto 
agricultural land and land retirement in the western San Joaquin Valley, where 
poor drainage conditions exist. Increases in agricultural water use efficiency, 
combined with reductions in agricultural acreage and shifts to growing 
high-value, lower-water-use crops, are expected to reduce agricultural annual 
net water demand by about 2 maf by 2020. 

O The 1990 level and projections of environmental water needs to 2020 Include 
water needs of managed fresh water wetlands (Including Increases in supplies for 
refuges resulting from implementation of the CVPIA), Instream fishery 
requirements. Delta outflow, and wild and scenic rivers. Environmental water 
needs during drought years are considerably lower than average years reflecting 
principally the variability of natural flows in the North Coast wild and scenic 
rivers. Average annual net water demand for existing environmental needs is 
expected to Increase by 0.8 maf by 2020. Furthermore, regulatory agencies have 
proposed a number of changes in instream flow needs for major rivers including 
the Sacramento and San Joaquin. These proposed flow requirements are not 
necessarily additive; however, an Increase from 1 to 3 maf is presented to envelop 
potential environmental water needs as a result of proposed additional instream 



Conclusions and Recommendations 



37 



The California Water Plan Update 



needs and actions under way by regulatory agencies, both of which benefit 
fisheries. 
O With California's increasing population and higher levels of affluence, water based 
recreation has become an integral part of satisfying urban society's desire to 
escape from crowded cities. State, federal, and local public water supply projects 
have helped provide recreation areas in addition to those already provided by 
natural lakes and streams. In some cases, these projects have enhanced 
downstream flows during times of year when natural flows are low, thus creating 
Whitewater rafting opportunities that were not possible before reservoir operation. 
Often there are conflicting values and needs for the same river system. Recreation 
at reservoirs, natural lakes, and streams must be managed to prevent overuse 
and degradation. 

Recommendations 

The Delta is the hub of California's water supply infrastructure; key problems in 
the Delta must be addressed before several of the Level I options can be carried out. 
The framework agreement recently signed by the Governor's Water Policy Council and 
the Federal Ecosystem Directorate will provide an avenue for finding solutions to those 
problems. The agreement provides for improved coordination and communication 
among State and federal agencies with resource management responsibilities in the 
estuary. It covers the water quality standards setting process; coordinates water 
supply project operations with requirements of water quality standards, endangered 
species laws, and the CVPIA; and provides for cooperation in planning and developing 
long-term solutions to the problems affecting the estuary's major public values. 

Also, a proactive approach to improving fishery conditions — such as better water 
temperature control for spawning, better screening of diversions in the river system to 
reduce incidental take, and better timing of reservoir releases to improve fishery 
habitat — must be taken so that solutions to the Delta problems mesh with basin-wide 
actions taken for improving fishery conditions. To that end, many of the restoration 
actions identified in the CVPIA for cost sharing with the State can improve conditions 
for aquatic species. Once a Delta solution is in place and measures for recovery of 
listed species have been initiated, many options requiring improved Delta export 
capability could become feasible. 

Following are the major Level 1 options recommended to help meet California's 
water supply needs to 2020. Their potential benefits are also presented. Many of these 
options still require additional environmental documentation and permitting, and in 
some instances, alternative analyses. Before several of these programs can be 
implemented, identification and prioritization of environmental water needs, and 
funding issues must be addressed. 

Demand Management 

O Water conservation: By 2020, implementation of urban BMPs could reduce 
annual urban applied water demand by 1.3 maf , and net water demand by 0.9 
maf, after accounting for reuse. Implementation of agricultural EWMPs, which 
increase agricultural irrigation efficiencies, could reduce agricultural applied 
water demands by 1 .7 maf and net water demand by 0.3 maf, after accounting for 
reuse. In addition, lining of the Ail-American Canal and Coachella Canals will 
reduce net water demand by 68,000 af. 

O L£md fallowing and water bank programs during droughts: Temporary, 
compensated reductions of agricultural net water demands and purchases of 
surplus water supplies could reallocate at least 0.6 maf of drought year supply. 

38 Conclusions and Recommendations 



Executive Summary 



O Drought demand management: Voluntary rationing averaging 10 percent 
statewide during drought could reduce annual urban applied and net water 
demand by 1.0 maf in 2020. 

O Land retirement: Retirement of 45,000 acres of land with poor subsurface 
drainage and disposal in the western San Joaquin Valley could reduce annual 
applied and net water demand by 100.000 af by 2020. 

Supply Augmentation 

O Water reclamation: Plans for an additional 1 .2 maf of water recycling and ground 
water reclamation by 2020 could provide annual net water supplies of nearly 0.8 
maf after accounting for reuse. 

O Solutions to Delta water management problems: Improved water service reliability 
and increased protection for aquatic species in the Delta could provide 0.2 to 0.4 
maf annually of net water supplies (under D-1485) and make many other water 
management options feasible, including water transfers. 

O Conjunctive use: More efficient use of major ground water basins through 
programs such as the Kern Water Bank could provide 0.4 maf of drought year net 
water supplies (under D-1485). 

Q Additional storage facilities: Lx)s Banos Grandes (SWP) could provide 0.3 maf of 
average and drought year net water supplies (under D-1485), and Domenigoni 
Valley Reservoir (MWDSC) could provide 0.3 maf of drought year net water 
supplies. 

In the short-term, those areas of California rel)ang on the Delta for all or a 
portion of their supplies face uncertain water supply reliability due to the 
unpredictable outcome of actions being taken to protect aquatic species and water 
quality. At the same time, California's water supply infrastructure is severely limited in 
its capacity to transfer marketed water through the Delta due to those same operating 
constraints. Until solutions to complex Delta problems are identified and put in place, 
and demand management and supply augmentation options are Implemented, many 
Californians will experience more frequent and severe water supply shortages. 
Limitations of surface water deliveries will exacerbate ground water overdraft in the 
San Joaquin River and Tulare Lake regions because ground water Is used to replace 
much of the shortfall In surface water supplies. 

Finally, it is recommended that Level II options be evaluated, expanded to 
Include other sdternatives (such as additional long-term carryover storage in both 
surface reservoirs and in conjunctive operation of ground water basins), and planned 
for meeting the potential range of average year shortages of 2. 1 to 4. 1 maf and the 
potential range of drought year shortages of 2.9 to 4.9 maf. Level II options include 
demand management and supply augmentation measures such as additional 
conservation, land retirement, increased water recycling and desalting, and surface 
water development. Several mixes of State and local Level II options should be 
Investigated and their economic feasibility ascertained to address the range of 
uncertainty of demand and supply illustrated in the California Water Budget. 



Conclusions and Recommendations 39 



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