Weather modification operations in California

f

(-

JUL 1 0 1^78

STATE OF CALIFORNIA
The Resources Agency

SCl£?«C!:."

cpartment of Wa ter Resources

iY30i[CO

BULLETIN No. 16-70

WEATHER MODIFICATION
OPERATIONS IN CALIFORNIA

October 1, 1969 - September 30, 1970

JULY 1971

NORMAN B. LIVERMORE, JR.
Secretary for Resources
The Resources Agency

RONALD REAGAN

Governor

Stole of Colifornio

WILLIAM R. GIANELLI

Direcfor

Department of Woter Resources

ABSTRACT

Within the reporting period, October 1, 1969> through September 30j
1970, nine licensees conducted ten weather modification projects
in California. No seeding occurred in one of the projects because
a no- seed chance decision was made for the season's only seedable
storm at that location. Except for one program for fog suppression,
all programs in which seeding did take place dispersed some form
of silver iodide as the active ingredient.

State of California

The Resources Agency

DEPARTMENT OF WATER RESOURCES

RONALD REAGAN, Governor, State of California

WILLIAM R. GIANELLI, Director, Department of Water Resoiirces

JOHN R. TEERINK, Deputy Director

DIVISION OF RESOURCES DEVELOHffiNT

Herbert W. Greydanus Division Engineer

James L. Welsh Chief, Environmental Q:uality Branch

This report was prepared by

Melvin M. Schwartz Chief, Impact Analysis Section

and
Joseph B. Powers Meteorologist III

-2-

CONTENTS

Weather Modification Operations 5

Project 1-70-1: Upper San Joaquin River Basin 5

Project 1-70-2: Upper Santa Ynez Valley 6

Project 12-70-1: Upper Kern River Basin 6

Project I8-7O-I: San Gabriel Mountains 7

Project 2I-7O-I: Upper Kings River Basin 8

Project 22-7O-I: Upper Santa Ana River Watershed 9

Project 23-7O-I: Lake Almanor

Project 3O-7O-I: Central Sierra Research

10

Project 29-7O-I: Fog Dispersal Program, Los Angeles ... H

Intemationeul Airport

Ik

Project 3I-7O-I: Upper American River I6

Tables

1 Historical Summary of Authorized Weather Modification. . 17

Operations

2 Historical. Summary, Licensed Weather Modification ... 17

Operations

3 Historical Summary of Regional Weather Modification . . 19

Projects

k Cloud Modification Projects 20

5 Active Agents and Dispersal Methods 20

Plates

1 Water Year Precipitation ^

2 Weather Modification Projects in California: 12

1970 Water Year

3 Regions of Weather Modification Since I9U7 I8

-3-

PLATE I

NORTH

COASTAL

/

WATER YEAR PRECIPITATION
OCTOBER I, 1969 - SEPTEMBER 30, 1970

SCALE OF MILES

LEGEND

120— Precipitation in Percent of Averoge fof

35 Yeor Period , October 1, 1931 -September 30,1965

ELEVATION IN FEET
1 500 ond Under

500 to 5000
I 5000 ond Over
N Hydrogrophic Area Boundary

CENT RAL
COAST A L

COASTAL^

NOTE: Bulletin No 120-70, "Water Conditions in Coiifornio: Foil Report"
Dated October 1970, Provides Detailed Precipitation Data
For The Water Yeor.

uuLiORADO
DES ERT

-4-

WEATHER MODIFICATION OPERATIONS

Weather modification operations were conducted in 10 areas in Cali-
fornia during the 1969-7O water year by 9 licensed operators. A project \mder-
taken to suppress fog at the Los Angeles International Airport made use of poly-
electrolytes and svirfactants. The rest of the projects used silver iodide in
various forms to induce precipitation and otherwise modify atmospheric condi-
tions. Four of the licensees acted on their own behalf; the remainder were
employed by governmental agencies and public utilities.

A long-term progrsun conducted by the Santa Clara County Flood Control
and Water District was suspended during the I969-7O water year because the water
supply carried over from the previous year was considered ample.

Project 1-70-1: UPPER SAN JOAQUIN RIVER BASIN

SUMMARY

Licensee; North American Weather Con-
sultants
Client: Southern California Edison

Company
Target Area

Upper San Joaquin River

and tributary streams above Power
House No. 3

Purpose; To increase snowpack in the
drainage area of the river

Active Agent; Silver iodide and sodium
iodide (in acetone)

Dispersal Method; Ground-based gener-
ators

T4RGCT ABEA BOUNOAR

A SDiEdATOn

Generator

Houri

of Operation

No.

Location

Oct.

Nov,

Dec.

Jan.

Feb.

Mar.

Apr.

May

June

Total

1

Florence

0

0

0

2U.00

0

0

31.00

0

0

55.00

2

Venanton

0

0

37.25

13.00

72,50

39.50

25.00

0

0

187.25

3

Chin* PeaX

0

0

0

"•6.75

U2.5O

0

U.75

0

0

103.00

U

Mt. Given

5.25

30.00

12.75

3.75

73.00

"17.00

16.75

0

6.50

195.00

5

Hiintln^on

5.25

30.00

1.6.75

U8.75

6I4.5O

1*7.00

16.25

0

12.25

270.75

6

MUDOth

0

30.00

11.00

32.25

6i..25

1*3.75

38.50

0

27.00

21*6.75

7

Shaver

5.25

30.00

U2.75

l.e.75

1*9.25

U2.25

8,00

0

21* .00

250.25

8

Pine Ridge

0

2U.25

9.75

52.75

1*1.25

21.00

0

0

0

11*9.00

9

Auberry

0

5.00

9.75

32.75

Ul.25

21.00

0

0

0

109.75

10

Toll House

0

21*. 25

23.75

33.50

30.25

31.75

0

0

0

11*3.50

U

South Fork

0

30.00

10.00

32.75

26.50

0

0

0

0

99.25

12

Baaa Lake

0

1.00

10.00

2''. 75

6.50

0

0

0

0

U2.25

Total

15.75

20J*,50

213.75

395.75

511.75

293.25

11*7,25

0

69.75

1,851.75

Number

of stormc

1

1

U

li

7

3

3

0

2

25

D«y* 0

r Beading

1

2

U

6

9

6

U

0

3

35

A«I u»

ed (graaa)

9".. 5

1227.0

1282.5

?37''.5

3070.5

1759.5

883.5

0

1*16.5

11,110.5

Rat« 0

f dispersal.

6

grmn«

per hour per

gener

•tor

-5-

Project 1-70-2:

UPPER SANTA YNEZ VALLEY

SUMMARY

Licensee: North American Wea-

ther Consultants
Client: Naval Weapons Center,

China Lake

Target Area; San Rafael Moun-
tains and Santa Inez Valley
above Solvang

Purpose: To test ground- based
pyrotechnic devices for cloud
seeding

Active Agent; Silver iodide

Dispersal Method; LW-83 fusees

EL CAP1TAN
M.LES LODGE

Sunaary

Nov.

Dec.

Jan.

Feb.

Mar.

Total

Hoiirs of operation

1.25

0

U.50

U.25

8.25

18.25

Number of storms

1

0

k

3

2

10

Days of seeding

1

0

k

k

2

11

Fusees used

6

0

21

21

37

85

A«I used (grams)

2l400

0

81tOO

8U00

lit, 800

SU.OOO

Rate of dispersal,
grams per fusee

uoo

Length of bum,
minutes

3.2

Project 12-70-lt UPPER KERN RIVER BASIN

SUMMARY

Licensee; Precipitation Con-
trol Company of California

Client; Kern County Board of
Supervisors

Target Area; Kern River water-
shed

Purpose: To increase precipi-
tation and streamflow

Active Agent: Silver iodide

Dispersal Method; Silver iodide
introduced into an electric
sure to produce smoke

— ^ TARGET AREA BOUNDARY
SueBASIN BOUNDARY

Suamary

Nov.

Dec.

Jan.

Feb.

Mar.

f Apr.

Total

Hours of flight ^iae

5:35

114:05

21:00

14:00 5:25

10:55

71:00

Number of storms

1

5

5

3 2

U

21

Flights

2

5

8

I* 2

5

26

Agl used (grans)

27.3

596.5

892.5

595.0 230.2

I.6U.0

3017.5

Rate of dispersal,
per hour

li ou
(U2.

Qces

5 grams)

-6-

Project 18-70-1: SAN GABRIEL MOUNTAINS

SUMMAJOf

Licensee: Los Angeles County Flood Control District

Client; Same

Target Area: Southerly slopes of the San Gabriel Mountains in the San Gabriel
River, Big Tujunga Creek, and Pacoiina Creek drainage basins
tributary to the District's reservoirs

Purpose; Water supply increase

Active Agent; Silver iodide

Dispersal Method; Two percent solution of silver iodide and sodiua iodide (in
acetone) burned in a propane f^Laae, producing 10-^ to iO-'-J
nuclei per second {ICr- to 10 nuclei per gram of silver
iodide) .

TARGET 4RE4 BOUNOART

▲ GENERATOR

Generator

No.

Location

Hours of Operation

Jam.

Feb.

Mbt,

Total

1 Pacolma Spreading Grounds

2 LaTuna Debris Basin

3 Pickens Patrol Station
U Devil's Gate Dam

5 Eaton Spreading Basin

9 Thompson Creek Dam

10 Baldy Notch

11 Mt. Baldy Guard Station

12 Tanbark Flat

13 Pine Mountain
lU Spring Camp

15 Mount Wilson

16 Red Box Ranger Station

17 Big Tujunga Dam

18 Cogswell Dan

19 East Pork Ranger Station

Total

Number of storms
Days of Seeding
Agl used (grams)
Rate of dispersal, grams per
hour per generator

0

0

0

0

0

0

0

0

0

0

0
12.25
15.25
12.75
12.75
15.25

0

2.25
12.00
13.00

0

0

17.50

9.00

0
28.25
23.25
12.75
33.50
2U.50
37.50
12.75

0

6.75

17.00

18.50

12.25

0

0

0

19.25

6.25

6.25

0

0

6.25

19.00

0

0

9.00
29.00
31.50
12.25

0
17.50

9.00
19.25
3'«.50
29.50
25.00
U8.75
'♦3.50
69.25
28.00

68.25 226.25 111.50 i«06.0O

1

3

2

6

2

U

2

8

'409.5

1357.5

669.0

2U36.0

6

-7-

Project 21-70-1: UPPER KINGS RIVER BASIN

SUMMARY

Licensee: Atmospherics Incorporated

Client: Kings River Conservation District

Target Area: Upper Kings River Basin

Purpose: To increase precipitation

Active Agent: Solution of silver iodide and sodium iodide (in acetone) biimed in a propane
flame.

Dispersal Method: Ground-based generators and pyrote

chnic devices (aircraft)

.^-^"^ X^Courtr/g/lt^ u jj-
.'^^ ^^ Reservoir V /qy — s<„.

V.-/>xi

1 ^ '^A4l|^,sw-w/i- \

} \iy 1

\ <*^rpir,i, Flat ^^r^^ Si*^ ^

I ^ R»urvoir ^^^^^

/r^ (^\

Oranoa Co* .
O 8-^9

A GENERATOR (ACTIVE)

MILES

GENERATOR (INACTIVE)

FLIGHT AREA

Generator

Elev.
Ft.

Hours of Operation

No. 1 Location

Nov, I Dec, 1 Jan.

1 Feb, 1 Mar, | Apr, ] Total

1 Mmrlev 1900

2 Helo Pad Ujoo

3 Sequoia Lake 5200
It Cherry Gap 69OO

5 Quail Flat 7000

6 Kings Canyon

Overlook 7100

7 Plnehurat UIOO

8 Badger itH 3OOO

9 Badger #2 30OO
10 Hackett Ranch 500
n Trlnmer #1 1000

12 Trlimier #2 1000

13 Balch Camp 0
lU Wlahon Dam #1 7200

15 Wishon Dam #2 7200

16 Radar 350

Subtotal
Aircraft

Total

0 0 0

2.0 0 10.7

2U.0 26.3 39.6

27.6 27.2 5l<.l

27.5 0 31.5

0 27.0 57.7
0 28.1 0
0 26.U 26.6

15.7 38.7 0 5I1.I1
15.5 38.2 0 66.1*
23.3 l^.li 0 159.6
32.3 53.0 0 19l'.2
21*. 7 28.5 0 U2.2

23.1* 28.8 0 136.9
0 25.5 18.2 71.8
0 311.0 0 87.0

C 0 15.7
0 0 0

0 0 0 15.7
25.0 33.0 17.2 75.2

0 5.3 8.7
0 8.3 16.6

0 3.3 12.0

17.0 21.0 50.5 102.5
5.3 0 2l*.l* ^.6
0 0 0 15.3

81.1 153.9 273.2
1.2 5.6 8.6

182,2 31*5,1 110.3 1,11*5.8
10.8 5.6 0.0 31.0

82.3 159.5 281.8

193.0 350.7 U0.3 1,177.6

NuTber of storms 2 U 6
Days of seeding 3 5 7
Number of flights 12 3

5 3 3 23
5 6 5 31
5 1* 0 15

Agl used (grams)

Generator 1216.5 2308.5 l«)98.0
Aircraft gO.O 1*20.0 6U5,0

Total I3O6.5 272b. 5 "713.0

2733.0 5176.5 I65I1.5 17,197.0
810.0 1*20.0 0.0 2,385.0

3513.0 5596.5 165^.5 19,572.0

Rate of dispersal, grams per
hour

Generator 15
Aircraft 7'

-8-

Project 22-70-1: UPPER SANTA ANA RIVER WATERSHED

SUMMARY

Licensee; San Bernardino Valley Municipal Water District

Client; Same

Target Area; Upper Sajita Ana River Watershed

Purpose; Randomized test to increase precipitation*

Active Agent; Solution of silver iodide and sodium iodide (in acetone) burned
in a propane flame

Dispersal Method; Ground-based generators

* No seeding operations took place during this water year because few storms were
deemed seedable and random decisions to not seed were made for those considered
seedable. Only about haJLf the storms were to have been selected for seeding on
a random basis. Unseeded storms were to have been used for comparison.

▲ GENERATOR
TARGET AREA BOUNDARY

MILES

Generator; No. Location

Generator; No. Location

1 Big Bear Lake

2 Running Springs

3 Seven Oaks

k Camp Angelus

5 Mill Creek

6 Forest Home

-9-

Project 23-70-1: LAKE ALMANOR

3UM4ARI

Licensee: Psciflc Gag and Electric Ccspany

Client: Sane

Target Area: North Fork Feather River drainage baaln near Lake Aiaanor and the Butt Valley and (lountaln Meadows reierroir* 1

Purpose; To Increase high-level snovpack and subsequent dry season runoff and to detemine the effectiveness

of Cloud seeding

Active A«ent: Silver iodide and sodiua iodide (in acetone)

Dispersal Method: Hlgh-elevatlon, radlo-contro

Lied ground generators*

est. The south group was randomlKed in 12-hour periods during

"cold southerlj"

•Generator operation was grouped as south and w

storms. If seeding did occxir, It occurred during the first 11 hours. Ko seeding took place in the

12th hour.

Then the

chance decision on the next 12-hour period was nade. Handooiltatlon was based on the overall expectation that

50 percent of

the 12-hour periods would b« seeded and 'yO percent would not. The west group was not rarulnalxed.
varied between generators because certain of then were not always operable.

Total hourl

of operation

^'/ A (\ ^^^

r-^5va.^oA \ ^A \ \ ]

^*.,^7~^-AJ \^ \ \ I

^^ 5 '^Vv 3^ — A 1 \ Mountain M90dows\
\ ^>5tf/- 1 J Reservoir \

I u>K£ ^^ m.r ^^^L J

/ iUtANOfI ^^^^ ^HL ^^^ /

/ ^^H^^^ ^* y^

/ az ^y0^ ^*^^^^ /" ""^"^^

(^'''^'^f^iT^'^\\ ^▼Z

^_^^^^^^ TAO^CT AQCA omiunADV m ^^ 0\

A GENERATOR eu/l fff//«r^ V 0 ""'"

a

'^,.r^.,.r ^, 1 1

J I

^,- '

South Generator Group

_,._ .; :T_.,..;r

So. Generator

1 1 1 I 1 r

Location

Dec. Jan. Feb. Mar. Apr. May

Total

2 Butt Mountain 77:1*3 61:53 3:00 8:00 0 11:05

161:1*1

3 stover Mountain 0 22:5^ 0 0 0 U:05

33:59

1* Ohio Pidge 77:'*3 61:53 3:00 8:00 0 11:05

161:1*1

5 Keefer Bicige 77:l<3 61:53 3:00 8:00 0 U:05

161:1*1

6 Dyer Mountain 77:1»3 61:53 3:00 6:00 0 U:05

161:1*1

7 Feather River Meadon 77:1*3 61:53 15:00 8:00 0 11:05

161:1*1

Total 388:35 332:19 15:00 Ii0:00 0 66:30

81.2:21.

West Generator Group

Hours of Operation

No. Generator
Location

Dec. 1 Jan. | Feb. | Mar | Apr. | May |

Total

1 Christie HiU 0 0 0 0 56:28 '•'■:05

102:33

2 Butt Mountain 12:Ul 36:to 0 0 147:11 l4li:05

11*0:37

3 stover Mountain 0 0 0 0 0 U*:05

l.l.:05

5 Keefer Bidge 12:1.1 36:1« 0 0 76:51 l''':05

170:17

7 Feather River Meadows 12:1*1 36:1« 0 0 38:1*0 l*il:05

132:06

e Mud Greek Butte

Total

7:51' 36:1*0 0 0 0 0

l*J*:3l.

1*5:57 11*6:1*0 0 0 221:10 220:25

631* :1^

Total Hours l*3l*:32 1*76:59 15:00 1*0:00 221:10 286:55

1,1.76:36

South and West

Gener»tor Groups

no. or Storm. 1. 1* 1 1 1. 2

16

Days of Seeding 10 6 1 1 6 6

31*

AgJ used (GraM) 8393.1*0 7178.01* 321*.00 86U.OO 0 11*36.1*0 16,195.81.

South Generator Group

Agl used (Grans) W2.52 3166.00 0 0 1*777.20 U76I.OO 13,696.72

West Generator Gitjup

Total Agl used (Grsjss) 9385.92 103l*<.01* 321*.00 flfili.OO U7T7.20 6197.1*0 31,891*. 56

South and West Generator

Croups

Rate of dispersal (all 21.6

genermtors), grama per

hour

-10-

Project 29-70-1: FOG DISPERSAL PROGRAM,
LOS ANGELES INTERNATIONAL AIRPORT

SUMMARY

Licensee: World Weather, Inc.

Client; Department of Airports, City of Los Angeles

Target Area; Runway and approach, Los Angeles International Airport

Purpose; To disperse fog during period from December I969 through April 1970

Active Agent; Polyelectrolytes and surfactants

Dispersal Method; Dispersed from a C-U7 aircraft

O

34°00

Santo Monica
Municipal Airport

Los Angeles
JntefnotionaT Airport

W

- 33° 50

<!^

-t-

-+■

O Hawthorne

Municipal Airport

Long Beoch

Municipal Airport

O

O
Torronce
Municipal Airport

Fullerton
Municipal Airport
O

^ Los Alomitos
^ Naval Air Station

-(-

il8° 40

_i I I I 1

II8''30

IIS-ZO

II8°I0

MILES

118'" 00

FLIGHT COURSE

TARGET AREA

Siiinmary

Dec.

Jsm.

Feb.

Mar.

Total

Hours operated 19.5 27,1 1.0 6.8

Days operated 6 5 12

Pounds of polyelectrolytes 2kk 339 27 96
and s\irfactaiits dispersed

Rate of dispersal, pounds 1
per mile

5h.k

lU

706

-11-

0 R ^E G 0 |i

- p ,

."o" t SISKIYOU I I

I— -N MOOOC !

/^^ / — r — 1

* \ / SH«>T> 1 L/kSSEN

Itiiihity; I

! <^- ^^

LOCATION

OF

TARGET AREAS

— L-J """V>>^^— -^ "-70-1

> — -^' \ /> a

*>,«LtNN' BUTTE if SIEHK» I

I OB SNOWFALL PROJECT

9 FOG DISPERSAL PROJECT

30-70-1

SAN FNANCISC'
"O »A«

1-70-1

SANTA CRUZ

1-70-2

29-70-1

18-70-1

SCALE OF MIL£S
40 0 40 BO

PLATE

PROJECT
No

LICENSE

YEAR

1969 1970

LICEiE

1-70-1 1

1-70-2 1

5

North American Weathf

Consultants
Santa Barbara Municip A
Goleta, California 93C'

North American Weath^

1

12-70-1 12

18-70-1 18

21-70-1 21

22-70-1 22

23-70-1 23

24

25

Water Resources Deve )n

Corporati on
Weather Modification P t
611 South Palm Canyoi)|
Suite 216
Palm Springs, Californi '

Precipitotion Control Cn
of Ca lifornia '

105 Pierce Street
Taft, California 93268

Los Angeles County F

Control District
P.O. Box 2418, Termin
Los Angeles, Californi<

Atmospherics Incorporcd
4981 Eost Dakota Aven
Fresno, Colifornia 937'

Son Bernardino Valley

Municipal Water DistrL
1350 South E Street |
P.O. Box 5906 I

San Bernardino, Califorl

Pacific Gos ond Electr (

245 Market Street

San Francisco, Califorrf

Intemotionol Weather Cil

Incorporated
40 West First Street, Si«
Reno, Nevada 89501

KRC Service Corporatio

2956 C Street

San Diiego, California SI

I

DAy:i

PROJECT NUMBER

§

OCT

10 1

OBER

5 20 25 31

) 1

^40VEMBER

0 15 20 25 30 5

DECEMBER

10 15 20 25 31 t

JANUARY FEBRUARY
10 15 20 25 31 5 10 15 20 25 28

MARC
5 10 15 \

1-70-1

A

""I""

Mil

1 1 I M

"T"'

""['J

' ' ' ' '

1

1

JM

1

T

1

H

■

1 -70-2

P

1

TTi

J

.

12-70-1

G

1

1

M '

1

1

\zy^

11 1

1

18-70-1

A

1

I ,

■

21-70-1

A

1

1

m ■

J

f Ji

Jliriu

P

1

f 1 ^

1

Irf

22-70-1

23-70-1

A5

III

1

A.W

I

1

■1

29-70-1

U

-S;-

II

1

1 1

30-70-1

A

1

1

1

TIJ

1

III

P

1

1

1

■1

1

JJ

P

1

j"

M

31-70-1

A

1

■

■ 1

1

M ^

1 1 1 1

1 1 1 1

1 1 1 1

Mill

MM

MM

1 1 1 1

Mil

Mil

MM

Ml |]> ' 1 '

1 M 1 1

MM

MM

MM

Mill

MM

MM

1 M 1

MM

,,■,"„■,,„

1 1

19

69

B.

GROUND BASED GENERATORS

AIRCRAFT BASED GENERATORS

A Acetone solution of Agl used
6 A9I used

-12-

THER MODIFICATION PROJECTS IN CALIFORNIA: 1970 WATER YEAR

CLIENT

PROJECT
No

LICENSE

CLIENT

No

YEAR

LICENSEE

1969 1 1970

Southorn California
Edison Company

26 X X

Sonto Clara County Flood Control

and Woter District
15420 AUadan Road
Son JoJ», California 95118

ts Naval Weapons Cent«r,
China Loke

27 X X

Vijfa Irrigotion District

P.O. Box 1088

Visto, Colifornio 92083

28 X X

Weather Science Incorporoted

P.O. Box FF

Normon, Oklohomo 73069

Kern County Board of

29-70-1 29 X X

World Weather Incorporoted
620 Commercial Bank Tower
Midland, Texos 79701

Department of Airports
City of Los Angeles

Supervisors

Los Angeles County
Flood Control District

30-70-1 30 X X
31-70-1 31 X X

Fresno Sfote College Foundation
Atmospheric Water Resources Research
4831 East Shields Avenue
Fresno, Colifornio 93726

Weofher Measure Corporation

P.O. Box 41257

Sacramento, Colifornio 95841

Fresno State College

Foundotion
Atmospheric Water

Resources Reseorch

Socramento Municipol
Utility District

Kings River Conservation
District

32 X X

Desert Reseorch Institute
University of Nevodo System
Reno, Nevodo 89507

Son Bernardino Valley
Municipal Water
District

33 X

EG 8. G, Incorporated
Environmental Services Operation
P.O. Box 1022
Boulder, Colorado 80302

t Pociffc Gos and Electric
Company

34 X

Sacramento Municipal Utility District

P.O. Box 15830

Socramento, Colifornio 95813

35 X

Sonfiogo Engineering, Inc.
1540 Eost Edinger Street
Suite E
Sonto Ana, Colifornio 92705

36 X

Wem-Cor, Inc.
390 Gfond Avenue
Ooklond, Colifornio 95610

• Licensee Inactive

this water year.

.OUD SEEDING

4PRIL MAY JUNE JULY AUGUST SEPTEMBER

Jl ^ O 15 20 » JO 5 IQ 15 20 » 31 5 10 IS 20 25 30 S K) 15 20 2S 31 5 IQ IS 20 ?5 SI 5 10 IS 20 25 iO

:'"

""!""

rrrr

Ml,

MM

III 1

MM

Ml 1

rrrr

""

nrr

, . . .

III 1

, ,. ,

1

1

I

1

r

, 1 I ■

1 1

I

1 1

I

■r FT"

■ ■

■

i"

r

-Ui.

1

1

lUl.

lliJ.

UU

ULL

ijja

Uil

nil

liii

uii

UJLk

UUL

JXLL

UU

uu

ILUL

JJXbJ

iLLU

^rottchnc* uMd

PohrtiKtrotvtw artd h#foctonii jm<j

1970

S South GtnvolOr ^roup

W Wwl G«n«rotor group

-13-

Project 30-70-1: CENTRAL SIERRA RESEARCH

SUMMAHY
Licensee: Fresno State CoUege Foundation, Atmospheric Water Resources Research
Client: Sane

Target Area: Watersheds of the Stanislaus and Mokelimne Rivers above an elevation of 5,000 feet

Purpose: Experlnental weather modification for precipitation increase. (Program receives continuing financial support
of U.S. Bureau of Reclamation and research assistance from various other organizations.)

Active Agent; Silver iodide

Dispersal Method: Various

Generator

Hours of Ope rati

on

No.

Location

Dec.

Jan.

Feb.

Mar.

Apr.

Total

Acetone Generators, Fixed, Ground

Al Dodge Ridge

26:30

10:30

15:30

7:1.5

U:08

61.:23

A2 Eagle Peak

11:00

2:1.5

11:1.5

3:15

0

28:1.5

A3 Big Meadow

20:30

7:1.5

6:U5

l.:30

17:55

57:25

AU Lake Alpine

5:00

0

2:15

0

13: ''7

21:02

A5 Sapps Hill

20:30

7:U5

7:30

l.:30

17:55

58:10

Subtotal

83:30

28:U5

1.3:1.5

20:00

53:1.5

229:1.5

Fyrotechnic Generators

Fixed, Ground (Flares)

PI Angels Camp (Frogtown)

9:00

7:00

5:00

2:00

7:00

30:00

P2 Sonora IISSW (Cox Ranch)

1:1.5

9:1*5

2:00

7:30

0

21:00

P3 Sneliing 3N

0

0

0

0

0

0

pli Coulterville

0

3:00

0

1:00

0

l.:00

P5 Groveland (Priest Reservoir)

0

3:15

3:00

8:15

0

ll.:30

P6 Cherry Valley Dan

3:00

3:00

6:15

3:00

0

15:15

Mobile Generator

Vallecito to Columbia

0

2:00

0

0

0

2:00

Columbia to Yankee Hill

0

2:15

0

0

0

2:15

San Andreas Airport

0

0

0

0

3:20

3:20

Pioneer

0

0

0

0

2:00

2:00

Jackson

0

0

0

0

1:00

1:00

Aircraft (Fusees)

0

0

2:00

l.:50

2:to

9:30

Total

97:15

59:00

62:00

1.6:35

69:U5

331.: 35

Number of flares, fixed generators

9".

177

151

255

55

732

Number of flares, mobile generator

s 0

lU

0

0

38

52

Number of fusees, aircraft

0

0

36

60

30

126

Agl used (grams)

U385.O

1.682.5

5052.5

6900.0

to72.5 25,092.5 1

Number of storms seeded

3

3

2

2

1

11

Number of storms not seeded

0

2

1

0

0

3

Days of seeding

1*

6

3

3*

2

18

* One day of seeding for storm continuing from previous month

Generators

Bum rate
generator
grsun.s per

per

in

hour

Bum time,
in seconds

Silver iodide,
in grams pro-
duced per unit

Nuclei produced

at - 12*C, per

gram of silver

iodide

Elapsed inter-
val between
pyrotechnic
bums

Ground-based, fixed
Acetone*
Pyrotechnic (flares)

30
30

'^5

20

2 X 10^
2 X 10^3
1 X 10^3

8 min. (approx.)

Ground, mobile

Pyrotechnic (flares)

—

k5

20

1 X 10^3

Variable

Aircraft**

Pyrotechnic (fusees)

—

150

20

1.25 X lO^'*

Variable

♦ Five generators supplied and operated by the Pacific Gas and Electric Company under the direction of
the Fresno State College Foundation burned a solution of silver iodide and sodium iodide (in acetone).
♦•Aircraft follonred a closed flight pattern within the flight area.

-14-

Ebbetfs
Pass

Plymouth

Lake
Eleanor
Res.

6

I t.

MILES

Mocco»in P5 Second Gorrole Hill

PI

TARGET AREA BOUNDARY

.P3

SU8BASIN BOUNDARY

A PYROTECHNIC GENERATOR

• ACETONE GENERATOR

■■■ FLIGHT AREA

-15-

Project 31-70-1: UPPER AMERICAN RIVER

SUMMARY

Licensee: Weather Measure Corporation

Client: Sacramento Municipal Utility District

Target Area: Upper American River

Basin in

eastern El Dorado

County, north of U.

S. Highway 50

Purpose: To increase water supply

Active Agent: Silver icxiide

Dispersal Method

: Grcjund-based generators*

e located in the scune positions as in the I968-69 season, except generator Ho. 6 at
h was moved to Robbs Saddle, about one-half mile north of Robbs Power House. Gener-
erly called Fresh Pond, was renamed Pacific House.

* Generators wer
Strawberry, whic
ator No? 3» form

i / I

/

A GENERATOR

^

L

/■

^^^■

0 J

^ — ^

junionveileyf /
meservoirjt ^y /

MILES

5

10
1

Echo^J

2

1 _

\Sfoflur let House ^
^ . ffsservar

y^iri^«^Cc

^

^5

0

"

Generator

Dec.

Jan.

Feb.

Mar.

Apr.

Total

No.

Location

1 Big Hill

2 Camino

3 Pacific House
1+ Logdeck

5 KybuTZ

6 Robbs Saddle

Total

57:1+5
57:30
57:20
57:20
57:30
57:25

2U:00 2P:00
37:1+5 31:30
39:10 29:1+5
37:10 27:55
39:30 31:30
23:55 29:35

25:00
U8:00
l+lt:55
1+7:30
1+8:00
22:1*0

2l»:00
23:55
1+8:30
1+8:00
1+8:15
U9:10

+

159:1+5
198:1*0
219:1+0
217:55
22U:U5
182 :U5

3l+l+:50

201:30 179:15

236:05

21+1:50

1203:30

Number of storms
Days of Seeding
Agl used (grams)
Rate of dispersal,
grauns per hour

3

6

8621

25

2 1

1+ 2
5037 1+Wl

3

5

5902

2

1+
601+6

30,087

-16-

HISTORICAL SUMMARY OF WEATHER MODIFICATION
OPERATIONS IN CALIFORNIA

Tables 1 through k present an over-
view of the history of seeding
activities in California from 19^7,
when early weather modification
operations were carried out in sev-
ered widely separated regions of
the State. This work was an out-
growth of cloud seeding experiments
performed in the mid-19^'s that
were forerunners of present-day
weather modification.

Operators listed in Table 1 func-
tioned prior to uniform licensing
by the Department of Water Resources.
Licensing of operators shown in
Table 2 began in 1951, after enact-

ment of regulatory legislation. Means of
modifying the weather that have been used in
California appear in Table 5. Other means
available for such work have not yet been
used in the State.

Tobl. 1. WEATHER MODIFICATION OPERATIONS PRIOR TO LICENSING (k,

litcgl ft.

1

Oj*rmtor»

Identi-
fication
Nuffitieri

Yean of Operation [

i^>udi/

l*6.4<li/

19^9-50

19^-51

1951-5^

Atvcxxj Crop Dusterl,

101

bkersfleld

L. Lasner, Pmsadena

102

X

B. L. Medllcott.Elclnore

103

X

Clnore Rudnick

10^

X

BUcrsfleld

A. L, Hannah, Heiaet

105 X

U. S. Weather Burfau

110

X

Teneacal Water Coapany,

Ul

X

Corona

Weather Control, Hedford,

112

X

Oregon

1/ Three additional programs are luiovn to have been carried out during tnli period.
They were not reported directly to the Department and tdentliiei of the operatori
are ujiiuiown.

Table 2. LICENSED WEATHER MODIFICATION OPERATIONS

Ucenseee'

License
No.

1951

1952

1953

195^

1:'5'-'

l''^7

1)^^

1959

IJfcC

1 1

1961

1',*? 1»3

196t

1965

1966

1967

1968

1969

1970

■a. or

Teara

A-tlve

Ilorth American Weather Conjultant* 1
Santa Ana Weather Cootrtil 2
John A. Battle 3
California Kleetric Power Co^iany ^
Water Betource. Developoent 5

Corporation
Weather •todlflcatlon Corporation 6
Precipitation Control CoopMy 7
P. J. Murray B
placer County Fa™ lAbor Cooperative, 9

XXXXX

X X

XXX

XXXXX

XXXXX

XXXXX
X X
X X

X X

XXXXX

XXX
XXXXX

XXXXX

XXXXX

XXXXX
XXXXX

XXXXX

XXXXX

X

20
2

3
6
20

16
2
2
2

Inc.
Pole to Pole Weatlwr lonitlgatlon 10
Kenneth H. Perry 11
precipitation Control Coqany of 12

Call forala
Bo Fog Corporation 13
North Aaerican Weather Conjultantt lU

of California
Walter Floyd Jonea IS
Qz CatUe COBpany 16

XXXX

XXXX

XXX

X X
X

X

X X
XXXXX

X X
XXXXX

X

X X

XXXXX
XXXXX

XXXXX

X

6

18

k
12

2

2

California State Dlvlilon of Foreatry 17
Loa An«ele« Comty Flood Control 16

Dlatrlct
Weather en«lneera Incorporated 19
International Weather Control, Inc. 20
Ataoapherlct Incorporated 21
San Bernardino Valley xunlclpal Water 22

Biatrlct
Pacific Gai and Electric Ccapany 23
International Weather Control, 21i

XXXXX
XXXX

X

X
X
X

X

X
XXXXX

XXXXX
XXXXX

XXXXX
XXXXX

XXXXX

XXXXX
XXXXX

XXXXX
XXXXX

t

Ik

1

1

11

u
11

10

Incorporated
KBC Service Corporation 25
Santa Clara County Flood Control 26

and Water Diatrict
Viota Irri((atlon Diatrict 27
WMther Science IncorporaUd 28
World Weather Incorporated 29
Freano State CoUegc Foundation 30

Atanaphcrica Water Reaourc.a

Raaaarch

XXX
X

X

I X I I X
XXXXX

XXXXX

XXX

XXXX

XXX

e

6

6
3
it

3

Weather Heaaure Corporation 31
Deaert Reaearch Inatitute 32
t. :. i r,.. Incorporated: Eiperl- 33

aental Senricea Operation
Sacraoento Municipal LTtlllty Diatrict 3i*
Santiago tngineerloc. Inc. 35
W«a-Cor, Inc. 36

X X X
XXX
X X

5

3

2

1

1
1

Total llcenaea active per year

1

8 U 9 8 10

U U H B U

U 10 11 U 13

13 1-' 17 17 11

Uaifora llc«a«in< of watrwr ■c«dir:^tt.Lon operator* t>«san in 19)1 foLlovlnc «nact«»nt of l««l«latlon r«gxU.atln< lucti ftctivltl«i

-17-

PLATE 3

Jr^

C-

J REGIONS OF WEATHER MODIFICATION
! SINCE 1947

Keyed to Table I

,<^ J-y^l-E'''^._BU'''TE ^SIERRA I

LEGEND

- — " COMBINED OPERATIONS AND TARGET
AREAS.

/^x^^ OPERATIONS AREA ONLY

•lb

SAN FRANCISCO!
t) SAN MATEO

SANTA CRU

X

SAN BERNARDINO >-' V

:>

SCALE OF MILES
40 0 40 80

-18-

Table 3. REGIONAL WEATHER MODIFICATION PROJECTS

h*§^arch (flr« «uppr«iilon)

PrW ^'T»clFl^«tlo^. lr.cre«.«r

PIH Fr«clpit*tlor lncre»««

PIR pp«elplt4it,loo locr«»«e

pry Precipitation !ncr«Me

KydTMlact-rlc g«n«r»tloa
ftccr*fttlon (wftt«r, inow)
Flr« Bupprvcalon

PIE
LS
H8

Precl p 1 t*t 1 on Ir.cr*»»e:
Ll«ittaiQC 8uppr«i«;oc
Hall Bup|ir«ialoci
Poc Stippnttioa

f-£i:iO!»

^
^

1

9
1

1

\

J,

Si

■r

5,

1

I

s

1

1

\

X

1

>

1

5

I

?

e
i

Ho.

Htx

I Upptr KlMKth DnloftC" for
ftocu* Rlwr Valler (Oracon)

KS HS

J

RS

5
KS

5

HS

II HMboldt County ftod Vicinity

U2

rs

10
PI7

III » Trinity County Mtd Vicinity

17
IE

in b Uusen County %ad Vlclolty

11
I£

17
LS

17
LS

17
LS

17
12

1

1

lU
PIH

Ik
PIH

11.
PIH

Ik
PIH

Ik
HH

23
PIH

23

PIH

23
PIH

23
PIH

23

PIH

23
PIR

23
PIH

23

PIH

23
PIR

23
PIH

V a Aaertcu River Dr&lnM*

uo

PIV

9
HS

9
KS

9

HS

5
HS

5
KS

5
HE

5
IE

5

le

5
KS

5
HS

5
HS

5
HS

5

31
pre

31

pre

Vb Tructee Rlwr Draioa^

5
PIB

VI Delt*: Portion* irtthln Marin
to Saenarnto County

5
HS

5
HS

20
PS

29
PS

33
PS

Vn ItokeluHM Rlv«i^3tAnlslaus
River Dr«lna«e

1
PIH

1
PIH

1
PIH

lU
PIH

11.
PIH

11.
PIH

11.
PIH

Ik

PIH

23
PIH

30

pn

30
PH

VUI 8«nt« Cl»r« County

PIV

3

PIV

e

PIW

6

PIV

11
PIV

6
PIV

6
PIW

6
PIW

6
PIV

6

PIW

6
PIW

6

PIV

6

PIV

26
PIW

26
PIV

26

pre

26

pre

IX 8«a Benito County and
SftUnM River

PIV

6
PIV

ID

nw

X Crwe VaUey

1
PIH

1
PIH

li<

PIH

lU
PIH

111

PIH

Ik
PIR

XI irpper S«n Joaquin River

1
PIH

1

PIH

1

nH

1
PIH

1
PIH

lU
PIH

ll<
PIH

11.
PIH

Ik
PIH

Ik
PIH

Ik
PIR

Ik

PIR

Ik
PIH

Ik
PIR

Ik

Ik

nR

1
PIR

1

PIR

1

PIR

1

PIH

m Southern Sierra (Spring and
StaaMr Research Project)

21
PIX

21

ph

21
PIE

nil IClns* River Drainage

6

PIV

6
PIV

6

PIV

6

PIV

6
PIW

6
PIV

21
PIV

21
PIV

21

PIV

21
PIV

21
PIV

21
PIW

21
PIW

21

pre

21

pre

21

pre

XTT ■ Biebop Creek Area

U \* k
PW PXH PIH

PU

PIH

l4

PIH

PIH

ii

PIH

6

pm

6
PIH

1.

PIH

XIV b Mwotb Mountain kn*.

6
PIR

PIB

V« Kern and Tule River
Uatersheds

7
PIW

7
PIW

12

PIV

12
PIV

15
PIV

It)

PIV

XV b TUlar* County

11

21
PIW

21
PIV

21
PIV

21
PIW

XV c Kern River Drainage

12
PIV

12
PIW

12
PIW

12
PIV

12
PIV

12
PIV

12
PIV

12
PIW

12
PIW

12
PIV

12
PW

12

pre

12

pre

XVI • Veatem Kern Cowity and
Carrlzo Plain

1/ 7
PIV PIV

7
PIV

7
PIV

12
PIV

12
PIV

12
PIV

12
PIW

12
PIW

12
PIV

12
PIW

12
PIV

XVI b Southani Kmi County

PIV

7
PIV

7
PIV

1
PIV

XVII ■ Santa Barbara County

PIV

1

PIV

1

PIW

1
PIV

Ik
PIW

Ik
PIW

Ik
PIV

Ik
PIV

1

PU

1
pn

1
pii

XVH b Ventura County

PIV

e

PIV

Ik
PIW

Ik
PIV

Ik
PIW

XVin • Sierra Hadre Hountalna

102
PIV

XVrn b Antelope Valley

mn c Laafalr VaUcy umt Headlea

5
PIV

1

PIV

l£

PIW

XVIII d San Gabriel Hountaina

IS
PIW

18
PIV

le

PIV

le

PIV

18
PIV

18
PIW

18
PIV

la

PIW

16
pre

le
nw

18

pre

18

pre

18
PIW

XVIII • Loa Aacelaa InUmatlonal
Airport

XlXa San Jacinto River Drainage

103
105
PIV

33

rs

29

rs

XlZb Santa Aim River Drainage

7 LU
PIW PIV

3.7
PIV

3
PIV

6
PIV

6
PIV

6
PIW

6
PIV

•>

PIW

5
PIW

Ik
PIV

Ik
PIW

22
PIV

22
PIV

22
PIV

22

PIV

PIW

22

PIV

22

pre

22

pre

22,

Pivi/

XX a 3an Diego County

2/
PIV

1

PIV

3
PIV

6
PIV

6

nv

XX t Lake Henahaw Area

5
PIV

25
PIV

25
PIW

27
PIW

27
PIV

27

pre

1/ Licanae maber or pre-llrenalog Identification nuaber (aee Tablra 1 and ?).
3/ Identity of operator unknoMi. Operation not reported to the Departaent.

No operatlona were actually conducted.

-19-

Table 4. WEATHER MODIFICATION PROJECTS

Purpose

Water Year |

CO

J-

H

ON

-J

H

r-i
1

R

a.

H

H

LP.

0^

m

CM
ON

J-

lA

c^

H

ON
.H

lA

C7N
H

lA
Ni

lA

ON

H

ON

s

On

H

^0

1
H

J-

NO

1

lA

ND

n£)

Ni,

H

ON
NO

H

Jn

Water Supply

8

5

3

8

9

h

u

6

6

8

8 9

7

5

5

7

7

8

7

6

5

It

Ij

Hydroelectric Generation

1

1

1

2

2

3

5

5

5

5

5 It

3

3

2

2

2

2

2

2

2

3

3

Recreation

Water

»

«

«

#

»

#

♦

«

Snow

1

2

Fire Suppression

1

Research

1

2

3

2

2

Lightning Suppression

3

1

2

1 1

Hail Suppression

1

1

1

2*^

«-

' 2** 2** 3** 2

1

1

1

1

Fog Suppression

1

1

1

2

1

Total

9

6

h

11

13

12

11

13

ll»

17

17 17

13

10

8

10

9

10

10

10

U

11

10

One project was operated for both water supply and recreation and wa.s counted as part of the water supply programs.

One project actually operated for hail suppression for the Rogue River area, Oregon, but many of the generators
were in California,

Table 5. ACTIVE AGENTS AND DISPERSAL METHODS

AGENT

METHOD

PURPOSE

Silver iodide

Burning a solution of silver iodide (Agl)
and sodium iodide (Nal) , and acetone in a
propane or butane flame

Burning coke impregnated with an Agl-Nal—
Acetone solution

Producing silver iodide smoke by introduc-
ing Agl into an electric arc

Pyrotechnic materials

X

X
X
X

X

X

Water drops

Dispersed from an aircraft

X

Solid carbon dioxide
(CO2)

Scattering particles from an aircraft

X

Sulfur trioxide (SO^)

Dispersed from an aircraft

X

Metallic halloid5*i/

Dispersed from an aircraft

X

Titanium tetrachloride
(TiCl^)

Dispersed from an aircraft

X

Sodixim chloride (NaCl)

Dispersing particles from aircraft

X

X

Carbon black

Scattering from aircraft

^

Polyelectrolytes and
surfactants

Dispersing particles or spray from aircraft

X

Negative ions

Discharged from pole-strung wires which were
under a high negative potential

X

1/ Any compound of a metal, as titanium, silver, sodium, calcium, etc. with a halogen, most probably

chlorine, bromine, or iodine.
2/ Trial basis

-20-

Copies of this bulletin at $1.00 each moy be ordered from:

State of Colifornlo

DOCUMENTS SECTION

P.O. Box 20191

Sacramento, California 95620
Make checks payable lo STATE OF CALIFORNIA.
California residents add 5 percent soles tax.

9>

THIS BOOK IS DUE ON THE LAST DATE
STAMPED BELOW

BOOKS REQUESTED BY ANOTHER BORROWER
ARE SUBJECT TO RECALL AFTER ONE WEEK.
RENEWED BOOKS ARE SUBJECT TO
p IMMEDIATE RECALL

^*=ge=

MAR 2 0 mz

LIBRARY, UNIVERSITY OF CALIFORNIA, DAVIS

D4613 (12/76)

uNrvERSriT fif r*! ifoo»(i* r*. ■

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California.
Bulletin.

TC

82U

C2

PHYSiCAt
SCIENCES

Dept. of Water Resources.

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