Skip to main content

Full text of "Santa Clara Valley investigation"

See other formats


STATE OF CALIFORNIA 
GOODWIN J. KNIGHT 
GOVERNOR 

O 


PUBLICATION OF 

STATE WATER RESOURCES BOARD 


Bulletin No. 7 


SANTA CLARA VALLEY 
INVESTIGATION 




June, 1955 




Irrigated Orchard in Santa Clara Valley 


•T'£> ZZ.S Sssssa ^^sSc. I 


ilMTA CLARA VAllEY WATER DISTRICT 
uarfARY 

6750 Ai.iviAu£N EXPRESSWAY 
tftN jOSE, CALIFORNIA 91118 


STATE OF CALIFORNIA 
GOODWIN J. KNIGHT 
GOVERNOR 


PUBLICATION OF 

STATE WATER RESOURCES ROARD 


Rulletin No. 7 


SANTA CLARA VALLEY 
INVESTIGATION 



June, 1955 



TABLE OF CONTENTS 


Pag-e 

LETTER OF TRANSMITTAL, STATE WATER RESOURCES BOARD 9 

ACKNOWLEDGMENT 10 

ORGANIZATION, STATE AVATER RESOLTICES BOARD 11 

ORGANIZATION, STATE DEPARTMENT OF PUBLIC AVORKS, DIVISION OF WATER RESOURCES 12 
ORGANIZATION, COUNTY OF SANTA CLARA AND CITY OF SAN JOSE 13 


Page 


CHAPTER I. INTRODUCTION 15 

Autliorization for Investigation 15 

Related Investigations and Reports 15 

Scope of Investigation and Report 16 

Area Under Investigation 17 

Natural Features 17 

Drainage Basins 19 

Climate 20 

Geology 20 

Soils 1 20 

Present Development 20 

CHAPTER II. AYATER SUPPLY 23 

Precipitation 23 

Precipitation Stations and Records 23 

Precipitation Characteristics 1 25 

Quantity of Precipitation 27 

Runoff 27 

Stream Gaging Stations and Records 27 

Runoff Characteristics 27 

Quantity of Runoff 29 

Imported and Exported AV'ater 30 

Underground Hydrology 30 

Ground AVater Geology 31 

Ground AA^ater Basins 32 

Specific Yield and Ground AA^ater Storage 

Capacity 33 

Ground AA^ater Levels 33 

Change in Ground AA^ater Storage 35 

Land Subsidence 36 

Subsurface Inflow and Outflow 37 

High AA^ater Table Areas 38 

Safe Ground AA^ater Yield 39 

Porebay Zones 39 

Pressure Zones 40 

Quality of AYater 41 

Standards of Quality for AA^ater 42 

Quality of Smfface AYater_ 43 

Quality of Ground AA^ater_ 43 

CHAPTER III. AYATER UTILIZATION AND 

SUPPI.EAIENTAL REQUIREMENTS.. 47 

AA^ater Utilization 47 

Present AA^ater Supply Development 48 

Appropriation of AYater 51 

Dams Under State Supervision 51 


Page 


Land Use 53 

Past and Present Patterns of Land Use 53 

Probable Ultimate Land Use 53 

Unit Use of AA^ater 55 

Past and Present AA^ater Requirements 57 

Probable Ultimate AA^ater Requirement 58 

Nonconsumptive AA^ater Requirements 59 

Flood Control 59 

Recreation and Fish and AYildlife 61 

Factors of AA^ater Demand 61 

Irrigation Efficiency 61 

Monthly Demands for AA^ater 61 

Permissible Deficiencies in Application of 

AYater 62 

Supplemental AA^ater Requirements 62 

Present Supplemental AA^ater Requirement 62 

Probable Ultimate Supplemental AA^ater Re- 
quirement 63 

CHAPTER lA^. PLANS FOR AYATER DE- 
VELOPMENT 65 

The California AA^ater Plan 65 

Feather River Project 66 

Other Plans Lnder Consideration 67 

Plans for Initial Local DeA^elopment 68 

North Santa Clara A^allej^ 68 

Northern A^alley Project 69 

(1) Coyote A^alley AA^ell Field and Coyote 

A^alley-San Jose Pipe Line 73 

(2) Calero-Los Gatos Conduit 73 

Little Francis Project 74 

Zayante Project . 77 

Discussion of Plans for Initial Local Develop- 
ment for North Santa Clara Valley 79 

South Santa Clara A^alley 79 

Uvas and Llagas Creeks Project 79 

CHAPTER V. SUMMARY OF CONCLU- 
SIONS, AND RE COMMEND ATIONS._ 85 

Summary of Conclusions 85 

Recommendations 86 


(5) 



TABLE OF CONTENTS-Continued 


A, Agreenients Authorizing Investigation and 

Report 

B. Bibliography of Prior Reports-^ 

C. Geology of the Santa Clara Valley 

D, Records of Monthly Precipitation in Santa 

Clara Valley not Previously Published 

B. Records of Daily Runoff in Santa Clara Vah 
ley not Previously Published 

P, Records of Depth to Ground Water at Se- 
lected Wells in Santa Clara Valley 111 


Page 


G. Records of Partial Mineral Analyses of 

Ground Water in Santa Clara Valley 113 

H, Apnlications to Appropriate Water in Santa 

Clara Valley 121 

1-, Dams iJnder State Supervision in and Ad“ 

jacent to Santa Clara Valley, 1954 127 

J. Records of Application of Ground Water to 

Representative Crops in Santa Clara Val- 
ley 131 

K. Seasonal Summaries of Monthly Yield Stud- 

ies 139 

L. Estimates of Cost 145 


APPENDIXES 

Page 

87 
93 
97 

107 

109 


TABLES 


Number Page 

1. Mean, Maximum, and Minimum Seasonal 

Precipitation at Selected Stations in or 
Near Santa Clara Valley 24 

2. Recorded Seasonal Precipitation at San 

Jose and Gilro 3 =^_ 26 

3. Mean Monthly Distribution of Precipita- 

tion at San Jose and Gilroy 26 

4. Estimated Weighted Seasonal Depth and 

Total Quantity of Precipitation on Santa 
Clara Valley 27 

5. Stream Gaging Stations in Santa Clara 

Valley 28 

6. Recorded and Estimated Seasonal Natural 

Runoff of Coyote Creek Near Madrone 
and Uvas Creek Near Morgan Hill 29 

7. Estimated Seasonal Natural Flow of 

Streams Tributary to Santa Clara Valley 30 

8. Estimated Mean Monthly Distribution of 

Natural Plow of Coyote Creek Near 
Madrone and Uvas Creek Near Morgan 


Hill 30 

9. Estimated Seasonal Surface Inflow to and 
Outflow Prom Porebay Zones of Santa 
Clara Valley 31 

10. Seasonal Importation of Water to North 

Santa Clara Valley, 1935-36 Through 
1947-48 31 

11. Estimated Specific Yield and Ground Wa- 

ter Storage Capacity, Santa Clara Valley 34 

12. Measured Pall Depths to Ground Water at 

Representative Wells in Santa Clara 
Valley 35 

13. Estimated Average Pall Depths to Ground 

AVater in Porebay Zones of Santa Clara 
Vallej?^ 36 

14. Estimated Weighted Average Seasonal 

Changes in Pall Ground Water Eleva- 
tions in Porebay Zones of Santa Clara 
Valley 36 

15. Estimated Weighted Average Seasonal 

Changes in Ground Water Storage in 
Porebay Zones of Santa Clara Vallejo 36 


Number Page 


16. Estimated Subsurface Plow Prom Coyote 

Creek Cone to South Santa Clara Valley 38 

17. Estimated Average Seasonal Subsurface 

Inflow From Adjacent Hills in North 
and South Santa Clara Valleys During 
Respective Base Periods- 38 

18. Estimated Safe Ivlean Seasonal Groiiiid 

Water Yield of Porebay/ Zones of Santa 
Clara Valley 40 

19. Complete Mineral Analyses of Representa- 

tive Surface Waters in Santa Clara Val- 
ley 44 

20. Complete Mineral Analyses of Ground Wa- 

ters in Santa Clara Valley 45 

21. Ground Water Pumpage by Public Utilh 
ties Furnishing Domestic and Industrial 

Water in Santa Clara Valley 48 

22. Ground. Vv^ ater Pumpage by Publicly 

Owned Systems in Santa Clara Valley __ 48 

23. Areas Served by Water Districts and Mu- 

tual Water Companies in Santa Clara 
Valley 1 48 

24. Irrigated Lands in North and South Santa 

Clara Valleys, 1947-48 49 

25. Pattern of Land Use in North and South 

Santa Clara Valleys, 1948-49 53 

26. Summary of Average Pattern of Land Use 

During Base Periods in North and South 
Santa Clara Valleys 54 

27. Pattern of Urban Land Use in North Santa 

Clara Vallejo Under Probable Ultimate 
Development 54 

28. Estimated Probable Ultimate Pattern of 

Land Use in North and South Santa 
Clara Valleys 54 

29. Estimated Unit Values of Mean Seasonal 

Consumptive Use of Water in Porebay 
Zones of North and South Santa Clara 
Valleys 56 

30. Estimated Weighted Mean Seasonal Appli- 

cation of Ground Water to Principal 
Crops in Santa Clara Valley 56 


( 6 ) 



TABLE OF CONTENTS-Continued 

TABLES— Continued 


Number Page 

31. Estimated Present Unit Values of Urban 

Draft on Ground Water in Santa Clara 
Valley 57 

32. Estimated Past and Present Seasonal Wa- 

ter Requirements Met From Porebay 
Zone of North Santa Clara Valley 57 

33. Estimated Past and Present Seasonal Wa- 

ter Requirements Met From Forebay 
Zone of South Santa Clara Valley 58 

34. Estimated Average and Mean Seasonal 

Draft on Ground Water in North Santa 
Clara Valley 58 

35. Estimated Average and Mean Seasonal 

Draft on Ground AVater in South Santa 
Clara Yslley 58 

36. Probable Ultimate Mean Seasonal Abater 

Requirement in North Santa Clara A^al- 
le^^ 59 

37. Probable Ultimate Mean Seasonal AVater 

Requirement in South Santa Clara A^al- 
ley 59 


Number Page 

38. Estimated Average Monthly Distribution 

of Seasonal Demands for AA^ater in Santa 
Clara A^alley 62 

39. Probable Ultimate Mean Seasonal Supple- 

mental AA^ater Requirements in Santa 
Clara A^alley 63 

40. Estimated Ne\v Mean Seasonal Yield From 

Northern A^alley Project 70 

41. Estimated Percolation Rates in Streams of 

North Santa Clara A^alley 71 

42. General Features of Coyote A^alley AA^ell 

Field and Coyote A^alley-San Jose Pipe 
Line 73 

43. General Features of Calero-Los Gatos Con- 

duit 74 

44. Areas and Capacities of Little Francis 

Reservoir 75 

45. General Features of Little Francis Project 77 

46. Areas and Capacities of Zayante Reservoir 77 

47. General Features of Zayante Project 78 

48. Areas and Capacities of Uvas Reservoir 81 

49. General Features of Uvas and Llagas 

Creeks Project 82 


PLATES 

Plates Nos. 1-23 follow page 86 


Plate No. 

1. Hydrologic Zones and Organized AVater Con- 

servation Districts, 1954 

2. Lines of Equal Mean Seasonal Precipitation, 

1898-1947 

3. Recorded Seasonal Precipitation at San Jose 

and Gilroy 

4. Accumulated Departure From Mean Seasonal 

Precipitation at San Jose and Gilroy 

5. Recorded and Estimated Seasonal Natural Run- 

off of Coyote Creek Near Aladrone and Uvas 
Creek Near Alorgan Hill 

6. Accumulated Departure From Alean Seasonal 

Natural Runoff of Co^mte Creek Near Ala- 
drone and Uvas Creek Near Morgan Hill 

7. Lines of Equal Depth to Ground AA^ater, Fall of 

1953 

8. Diagrammatic Profiles of Pressure and Forebay 

Zones in North and South Santa Clara A^al- 
leys 

9. Lines of Equal Elevation of Ground AA^ater, 

Fall of 1953 

10. Aleasured Depth to AA^ater Level at Selected 

AVells 

11. Average Fall Depth to Ground AA^ater in Fore- 

bay Zones 

12. Lines of Equal Change in Ground AA^ater Ele- 

vations, Fall of 1948 to Fall of 1953 


Plate No. 

13. Lines of Equal Change in Ground AA^ater Ele- 

vations in North Santa Clara A^allev, Fall of 
1935 to Fall of 1948 

14. Lines of Equal Subsidence of Ground Surface 

in North Santa Clara A^alley for the Periods 
1934-1948 and 1948-1954 

15. Lines of Equal Elevation of Ground Water in 

North Santa Clara A^alley, September-0 eto- 
ber, 1953 

16. Land Use, 1955 

17. Existing AVater Conservation Works and AVorks 

Considered for Future Development, 1955 

18. The Alameda- Santa Clara-San Benito Branch 

of the Feather River Project Aqueduct, 1955 

19. Coyote A^alley AVell Field and Coyote Valley- 

San Jose Pipe Line, 1955 

20. Calero-Los Gatos Creek Conduit, 1955 

21. Little Francis Project, 1955 

22. Zayante Project, 1955 

23. Uvas and Llagas Creeks Project, 1955 

Plates Listed Below Follow Appendix C 

C-1 Areal Geology, 1955 
C-2 Index Alap 

C-3 Columnar Sections — Santa Clara County 
C-4 Geologic Sections, 1955 



TABLE OF CONTENTS-Continued 


ILLUSTRATIONS 


Page 

Irrigated Orchard in Santa Clara 

Valley Frontispiece 

Aerial View of Portion of North Santa Clara 

Valley 18 

Calero Dam and Reservoir on Arroyo Calero- 50 

Sprinkler Irrigation in Santa Clara Vallejo 52 

Orchards in Bloom, Santa Clara Valley 52 


Page 


Anderson Reservoir on Coyote Creek 60 

Anderson Dam on Coyote Creek 60 

Lexington Dam and Reservoir on Los Gatos 

Creek I 72 

Chesbro Dam on Llagas Creek, May 26, 1955_ 80 

Gilro}^ Water Works Dam at TTvas Dam Site 
on Uvas Creek 80 


( 8 ) 



LETTER OF TRANSMITTAL 


Goodwin J. Knight 

GOVERNOR 



STATE OF CALIFORNIA 

STATE WATER RESOURCES BOARD 

PUBLIC WORKS BUILDING 

SACRAMENTO 5, CALIFORNIA 


CL.AIR A. HILL, CHAIRMAN, REDDING 

R. V. MEIKLE, Vice chairman, Turlock 

A, D. EDMONSTON, ST AT E ENGl N E ER 
SECRETARY 


June 30, 1955 


A. FREW, king City 
C, A, GRIFFITH, AZUSA 
W. P. RICH, MARYSVILLE 
W. PENN ROWE, SAN BERNARDINO 
PHIL D. SWING, San DIEGO 


ADDRESS ALL COMMUNICATIONS TO THE SECRETARY 


Honorable Goodwin J. Knight, Governor^ and 

Members of the Legislattire of the 
State of California 

Gentlemen: I have the honor to transmit herewith Bulletin No. 7 of the 
State Water Resources Board, entitled Santa Clara Valley Investigation,^’ as 
authorized by Chapter 1514, Statutes of 1945, as amended. 

The Santa Clara Valley Investigation was conducted and Bulletin No. 7 was 
prepared by the Division of Water Resources of the Department of Public 
Works, under the direction of the State Water Resources Board. 

Bulletin No. 7 contains an inventory of the underground and surface water 
resources of Santa Clara Valley, estimates of present and probable ultimate 
water utilization, estimates of present and probable ultimate supplemental water 
requirements, and preliminary plans and cost estimates for water development 
works. 


Very trul}^ yours, 


Clair A. Hill 

Chairman 



ACKNOWLEDGMENT 

Valuable assistance and data used in the investig-ation were contributed by 
agencies of the Federal GoYernment, cities, Santa Clara County, public dis- 
tricts, and by private companies and individuals. This cooperation is gratefully 
acknowledged. 

Special mention is also made of the helpful cooperation of the Board of Super- 
visors of the County of Santa Clara, the Santa Clara County Planning Commis- 
sion, the City Council of the City of San Jose, the Santa Clara Valley Water 
Conservation District, the South Santa Clara Water Conservation District, the 
San Jose Water Works, the Geological Survey, United States Department of the 
Interior, Stanford University, the Coast Counties Gas and Electric Company, 
the Pacific Gas and Electric Company, and Blackie and Wood, Consulting 
Engineers. 



ORGANIZATION 

STATE WATER RESOURCES BOARD 

CLAIR A. HILL, Chairman^ Redding 
R. V. MEIKLE, Vice Chairman, Turlock 

A. FREW, King City W. PENN ROWE, San Bernardino 

C. A. GRIFFITH, Azusa PHIL D. SWING, San Diego 

W. P. RICH, Marysville 

A. D. EDMONSTON, State Engineer 
Secretary and Engineer 

SAM R. LEEDOM, Administrative Assistant 


( 11 ) 



ORGANIZATION 

STATE DEPARTMENT OF PUBLIC WORKS 
DIVISION OF WATER RESOURCES 

FRANK B. DURKEE Director of Public Works 

State Engineer 

Assistant State Engineer * 

This builefin was prepared under 
the direction of 
VV= L. BERRY 

Principal Hydraulic Engineer 

by 

J. M, HALEY 

Supervising Hydraulic Engineer 

and 

Senior Hydraulic Engineer 

Senior Hydraulic Engineer 

Associate Hydraulic Engineer 

Associate Engineering Geologist 

Assistant Hydraulic Engineer 

Assistant Hydraulic Engineer 


Assistance was furnished by 

W. MacROSTIE Supervising Hydraulic Engineer 

M* THIEBAUD Supervising Hydraulic Engineer 

A. J. DOLCIN! Senior Hydraulic Engineer 

M. G. FAIRCHILD Senior Hydraulic Engineer 

R. T. BEAN Senior Engineering Geologist 

C. F. KLEINE Associate Hydraulic Engineer 

J. H. LAWRENCE Associate Soil Technologist 

H, E, ANDRUS Photogrammetrist II 

J. E. EATON Assistant Hydraulic Engineer 

J. B. YORK .Assistant Civil Engineer 

J. D. GOODRiDGE Junior Civil Engineer 

G. E. JOHNSON- Junior Engineering Aid 

J. J. DONAHUE Under Engineering Aid 

E. W. FAUSSET Student Engineering Aid 

J. L. JAMES Supervisor of Drafting Services 

LENORE N. CASE Senior Stenographer-Clerk 

Ground water phases of this buHetin were reviewed 
by a staff committee composed of 

H. O. BANKS Assistant State Engineer 

L M. INGERSON Principal Hydraulic Engineer 

G, B. GLEASON Supervising Hydraulic Engineer 

E. C. MARLIAVE Supervising Engineering Geologist 


HENRY HOLSINGER, Principal Attorney 
T. R. MERRYWEATHER, Administrative Officer 
ISABEL C. NESSLER, Coordinator of Reports 

* P. H. VAN ETTEN, Assistant State Engineer, until June 15, 1951. 


D. F. DRESSELHAUS 
R, R. REYNOLDS __ 

W. B. SHAW 

R. G, THOMAS _____ 
J. W. McPARTLAND 
T. P. WOOTTON____ 


A. D. EDMONSTON 
T. B. WADDELL __ _____ 


( 12 ) 



WALTER CASPER 
ED. LEVIN 


ROBERT DOERR 
WILLIAM J. FOLEY 
JOE SANTORA 


ORGANIZATION 

COUNTY OF SANTA CLARA 

BOARD OF SUPERVISORS 

ARTHUR W. BROWN, Chairman 

SAM DELLA MAGGORI 
JOSEPH M. McKinnon 

E. T. McGEHEE, County Clerk 
HOWARD CAMPEN, County Counsel 
LEONARD BUSHNELL, County Surveyor 


CITY OF SAN JOSE 

PARKER L. HATHAWAY, Mayor 
ANTHONY P. HAMANN, City Manager 


COUNCILMEN 


DOROTHY COVILL, City Clerk 
ROBERT E. CASSIN, City Attorney 
H. J, FLANNERY, City Engineer 


LOUIS S. SOLARI 
GEORGE STARBIRD 
FRED WATSON 


{ la ) 



CHAPTER I 


INTRODUCTION 


The area in Santa Clara County under this investi- 
gation has in recent years experienced an increase in 
water utilization, and as a result is confronted with a 
need for more complete conservation of its local water 
resources, as well as for the consideration of importa- 
tion of supplemental supplies. Water demands have 
increased substantially in the Santa Clara Valley, 
keeping pace with the growth and development of the 
area. Although some water for early agricultural and 
urban developments was diverted from surface 
streams, ground water has long been the principal 
source of supply. Problems related to deficient ground 
water supplies have been recognized for a number of 
years and have brought about local concern. These 
difficulties have been manifested largely in progres- 
sive lowering of ground water levels. Public agencies, 
consulting engineers, and individuals have reported 
on the problems and have proposed plans for their 
solution. As a result, a number of important water 
conservation works have been locally financed and 
constructed to provide surface storage and to re- 
plenish the ground water basins of the Santa Clara 
Valley. 

Despite these steps toward solution of water prob- 
lems in the Santa Clara Valley, it has become in- 
creasingly apparent that additional conservation 
measures will be required to satisfy present water 
needs, and to provide for growth in the future. This 
was clearly emphasized in the decade from 1940 to 
1950, when recession of ground water levels was 
greatly accelerated in most areas of the Santa Clara 
Valley by increased pumping draft. 

AUTHORIZATION FOR INVESTIGATION 

In 1947, officials of the County of Santa Clara and 
of the City of San Jose, concerned about the increas- 
ing water problems confronting the area, requested 
the State Water Resources Board to undertake a 
cooperative survey of water conditions in the Santa 
Clara Valley. The Secretary of the Santa Clara 
County Planning Commission appeared before the 
Board on December 5, 1947, representing local inter- 
ests in this matter. The Board referred the request 
to the State Engineer for preliminary examination 
and report on the need for such an investigation, and 
an estimate of its scope, duration, and cost. 

The State Water Resources Board on January 16, 
1948, approved a recommendation by the State Engi- 
neer, based on findings of the preliminary examina- 
tion, for a cooperative investigation, and authorized 


negotiation of an agreement with local agencies. An 
agreement between the State Water Resources Board, 
the County of Santa Clara, the City of San Jose, and 
the Department of Public Works, acting through the 
agency of the State Engineer, was executed on April 
1, 1948. This agreement provided that the work to 
be performed shall ^'consist of investigation and re- 
port on the underground water supply in the County 
of Santa Clara, including quality, replenishment and 
utilization thereof, and, if possible, a method or 
methods of solving the water problems involved.’’ 
This agreement authorized the provision of funds to 
meet the costs of investigation for one year. A sup- 
plemental agreement executed hy the same parties on 
February 18, 1949, authorized funds to complete the 
investigation and bulletin. 

Funds to meet the costs of the investigation and 
bulletin to the extent of $44,000 were provided as 
follows: State of California (State Water Resources 
Board), $22,000; City of San Jose, $11,000; and 
County of Santa Clara, $11,000. Additional funds 
have been expended in investigation of the Santa 
Clara Valley by the State Water Resources Board in 
connection with the current State-wide Water Re- 
sources Investigation, certain results of which have 
been used in connection with the Santa Clara Valley 
Investigation. 

Copies of the two agreements between the State 
Water Resources Board, the County of Santa Clara, 
the City of San Jose, and the Department of Public 
Works are included as Appendix A. 

RELATED INVESTIGATIONS AND REPORTS 

Reports on prior investigations, containing infor- 
mation pertinent to the evaluation of water problems 
in the Santa Clara Valley have been reviewed in con- 
nection with the current investigation. These reports, 
listed in Appendix B, cover most phases of the water 
problems in the Santa Clara Valley. State Division 
of Water Resources Bulletin No. 42, published in 1933, 
reported on historic ground water level recession in 
northern Santa Clara Valley, the amount of ground 
water depletion so represented, and the quantity of 
replenishment from surface streams tributary to the 
northern part of the valley. Similar information, as 
well as geologic details, specific yield of the alluvium, 
and quality of water are included in reports by the 
United States Geological Survey, and in reports by 
consulting engineers. Ground water pollution by sea- 
water intrusion, and ground surface subsidence, have 


( 15 ) 



16 


SANTA CLAEA VALLEY INVESTIGATION 


been discussed in a technical paper by C. F. Tolman 
and J. F. Poland, and published in the July, 1940, 
Transactions of the American Geophysical Union. The 
United States Department of Agriculture and the 
University of California have published reports deal- 
ing with the soils of the area. Investigation of water 
problems, and designs of reservoirs and percolation 
works for their solution have been reported on by 
consulting engineers. 

The Division of Water Resources is presently con- 
ducting survej^^s and studies as a part of the State- 
wide Water Resources Investigation, authorized by 
Chapter 1541, Statutes of 1947. This investigation, 
under direction of the State Water Resources Board, 
has as its objective the formulation of The California 
V7ater Plan, for full conservation, control, protection, 
and utilization of the Statens water resources, to meet 
present and future water needs for all beneficial pur- 
poses and uses in all parts of the State, insofar as 


3tlCo 


ie. 


u vv ^ ‘ ■ 


the Division of AVater Resources for the AA^ater 
Project Authority in connection with the proposed 
Feather River Project which was described in detail 


rrojeet wnien 
in a publication of the State AYater Resources Board, 
entitled Report on Feasibility of Feather River 
Project and Saeramento-San Joaquin Delta Diver- 
sion Projects Proposed as Features of The California 
AYater Plan, dated May, 1951, and which was au- 
thorized and adopted by the 1951 Legislature. Results 
of these investigations have a direct bearing on solu- 
tions to the water problems of the Santa Clara A^al- 
ley, particularty with regard to plans to meet supple- 
mental w^ater requirements of the area under ultimate 
conditions of development. Tnese mvestigations are 
described in a publication of the Division of W ater 
Resources, entitled Program for Financing and 
Constructing the Feather River Project as the Initial 
Unit of The California Water Plan,’’ dated Febru- 
ary, 1955. 


SCOPE OF iNVESTiGATION AND REPORT 

It has been stated that under provisions of the 
authorizing agreements the general objectives of the 
Santa Clara A^alley Investigation included investi- 
gation and study of the underground water supply of 
lands in the investigational area, including quality, 
replenishment and utilization thereof, and, if pos- 
sible, a method or methods of solving the water prob- 
lems involved. In attaining these objectives it was 
necessary that the scope of the investigation include 
full consideration of surface as well as ground water 
supplies, and that it involve determination of present 
and ultimate water utilization and supplemental 
water requirements. 

The area of comprehensive investigation was gen- 
erally limited to valley floor lands underlain by 
ground water in the County of Santa Clara, and 


encompassed about 217,000 acres. However, certain 
areas outside and adjacent to the valley floor were 
considered in determination of probable ultimate 
water requirements, and conservation works extend- 
ing beyond the boundaries of Santa Clara County 
were included in the surveys and studies. Since minor 
underground v^ater supplies lying outside the floor 
of Santa Clara A^alley were not studied, the investi- 
gation was not county -wide in its scope. 

Field 'work in the investigational area, and office 
studies, as authorized by the initial and supplemeri- 
\ tal cooperative agreements, commenced in March. 
1 1948, and continued into 1954. 

In the course of the investigation, available pre- 
cipitation and stream flow records were collected and 
compiled, in order to evaluate water supplies avail- 
able to the investigational area. Four new stream 
gaging stations were installed and maintaiiied to 
supplement the available h 3 Mrographic data. These 
stations were on Little Arthur Creek near Adams 
School, Bodfish Creek near Gilroy, Llagas Creek at 
Pacheco Pass Road, and Carnadero Creek at Bloom- 
field Avenue. 

In order to determine ground water storage capac- 
ity and afield, and to assist in the determination of 
areas of free and confined ground water, geologic fea- 
tures of the ground water basin undertying the 
investigational area were investigated. This stmty 
included the collection and study of about 1,100 well 
logs throughout the area. A geologic report on Santa 
Clara A^alle^^ is included as Appendix C to this 
bulletin. 

The effects of draft on and replenishment of the 
ground water basin were determined from measure- 
ments of static ground water levels made at about 
800 wells each spring and fall during the period of 
investigation. These wells formed a comprehensive 
measuring grid over the entire area. In addition, 
measurements to determine monthty fluctuations of 
water levels were made at approximatety 100 control 
wells. 

Present land use was determined hy a complete 
BUTYej of all lands in the investigational area. This 
stmty was conducted in 1948 and 1949. The total 
area surveyed was about 217,000 acres. The land, 
use survey data were used in conjunction with avail- 
able data on unit water use to estimate total present 
water utilization in the investigational area. 

Current irrigation practices in the investigational 
area were siirvej^ed in order to determine unit appli- 
cation of water to important crops on lands of various 
soil types. During the 1948 irrigation season, records 
of application of water were collected at 110 plots, 
and during the following season at 42 plots. The data 
collected included records of pump discharge, acreage 
served, crops irrigated, number and period of irriga- 
tions, and amount of water applied. 



INTRODUCTION 


17 


Studies were made of the mineral quality of sur- 
face and ground waters, in order to evaluate their 
suitability for irrigation and municipal use, and to 
determine the cause of degradation in mineral quality 
in local areas during recent years. Data used in these 
studies included some 783 partial and 59 complete 
mineral analyses of ground water from wells. Anal- 
yses of surface water samples were 19 in number. 

Field reconnaissance surveys, including geologic 
examinations, were made to locate and evaluate pos- 
sible dam and reservoir sites for conservation of sur- 
face runoff. Reconnaissance surveys were also made 
of possible routes for conversance of water to areas 
of use. For the more favorable and strategicalty lo- 
cated sites, topographic surveys were made and maps 
prepared or obtained from other sources. 

Results of the Santa Clara Valley Investigation are 
presented in this bulletin in the four ensuing chap- 
ters. Chapter II, ‘AVater Supply,’^ contains evalua- 
tions of precipitation, surface and subsurface inflow 
and outflow, and imports of water. It also includes 
results of investigation and stud^^ of the ground 
water basins, and contains data regarding mineral 
quality of surface and ground water supplies. Chap- 
ter III, Water Utilization and Supplemental Re- 
quirements,’’ includes data and estimates of present 
and probable ultimate land use and water utilization, 
and contains estimates of present and probable ulti- 
mate supplemental water requirements. It also in- 
cludes available data on factors of water demand, 
with respect to rates, times, and places of delivery. 
Chapter lY, Plans for Water Development,” de- 
scribes preliminary plans for conservation and utiliza- 
tion of available water supplies to meet supplemental 
water requirements, including operation and yield 
studies, design considerations and criteria, and cost 
estimates. Chapter V, Summary of Conclusions, and 
Recommendations,” comprises a summary statement 
of conclusions resulting from the investigation and 
studies, together with recommendations for action re- 
lating to solution of water problems. 

AREA UNDER INVESTIGATION 

The Santa Clara Valley is an intermediate valley 
in the Coastal Range, between the Santa Cruz Moun- 
tains and the Gabilan Range on the west and the 
Diablo Range on the east. The valley extends in a 
southeasterly direction from San Francisco Bay to 
near Hollister. 

The portion of the Santa Clara Valley under in- 
vestigation, and to which all subsequent reference 
is limited, lies entirely in Santa Clara County, and 
extends from San Francisco Bay to the Pajaro River, 
a distance of about 50 miles. The valley varies in 
width from about fourteen miles in the northern por- 
tion to less than a mile near the midpoint, and to 
approximately five miles in the southern portion. 


Most of the cultivated land in Santa Clara County 
is contained within the Santa Clara Valley. 

The Santa Clara Valley is separated into two main 
drainage areas by a low divide in the alluvium near 
Morgan Hill, about 25 miles south of the northern 
boundary of the area of investigation. For purposes 
of this bulletin, the portion lying north of the divide, 
with drainage into San Francisco Bay, is designated 
North Santa Clara Valley,” and the remaining por- 
tion with drainage south to the Pajaro River is called 
''South Santa Clara Valley.” The location of the 
area of investigation is indicated on Plate 1, entitled 
"Hydrologic Zones and Organized Water Conserva- 
tion Districts, 1954.” For purposes of hydrologic 
analysis. North and South Santa Clara Valleys were 
further divided into zones comprising in each valley 
a "Forebay Zone” and a "Pressure Zone.” These 
subdivisions are shown on Plate 1. 

Natural Features 

The Santa Clara Valley occupies an elongated 
trough betAveen the Diablo Range on the east and 
the Santa Cruz Mountains on the Avest. The valley 
and each of these ranges trend in southeast and 
northw^est directions. OAAung to ample precipitation, 
nattye vegetation in the Santa Cruz Mountains is 
dense, ranging from redAA^oods, firs, oaks, and other 
typically associated trees, to chaparral on the higher 
ridges. Lesser amounts of precipitation in the Diablo 
Range result in less timber groAvth than in the Santa 
Cruz Mountains. A moderate to heaA^y growth of 
wild grasses is found in the Diablo Range. Climat- 
ically, the lower reaches of the Santa Cruz Mountains 
tying adjacent to the floor of the valley are attracttye 
for residential purposes, and for agriculture AAhere 
soils and topography are faAnrable. Virtually all of 
the highly deA^eloped agricultural lands, hoAA^CA^er, lie 
on the valley floor. 

The east slope of the Santa Cruz Mountains tribu- 
tary to the Santa Clara Valley is relattyely narroAV, 
and someAA^hat steeper than its AA^estern slope. Width 
of the east slope varies from a minimum of about 
three miles to a maximum of approximately eight 
miles. The highest point reached in this portion of 
the Santa Cruz Mountains is Loma Prieta, with an 
eleAmtion of 3,798 feet, about 11 miles AA^est of 
Morgan Hill. 

The Diablo Range, paralleling the Santa Clara 
Valley on the east, varies in Avidth from 20 miles 
opposite the northern portion of the Amlley, to about 
10 miles opposite San Martin, and to about 17 miles 
at the southern extremity of South Santa Clara 
Valley. A substantial portion of the Diablo Range in 
Santa Clara County is within the Alameda Creek 
drainage area and, therefore, is not tributary to the 
Santa Clara Valley. Another part of the Diablo 
Range, tying in southeastern Santa Clara County, 
drains to Pacheco Creek, then to the Pajaro River, 




Courtesy State Division of Highways 

Aerial View of Portion of North Santo Clara Valley 




INTKODUCTION 


19 


and thence to Monterey Bay. The remainder of the 
Diablo Range in Santa Clara County drains westerly 
to the area under investigation. Copernicus Peak, 
with an elevation of 4,372 feet, and Mount Isabel, 
with an elevation of 4,223 feet, are the highest points 
on the Diablo Range in Santa Clara County. 

The portion of the Santa Clara Valley under in- 
vestigation has an irregular outline, defined on the 
northwest by tidelands along the shore of San Fran- 
cisco Bay, on the southeast by the Pajaro River, and 
on the southwest and northeast by foothills of the 
Santa Cruz Mountains and Diablo Range, respectively. 
Alluvial fans emanating from these foothills slope 
toward the central part of the valley, with gradients 
ranging from 500 to 20 feet per mile. The general 
slope of North Santa Clara Valley is in a northwest- 
erly direction, and varies from 25 feet per mile near 
Morgan Hill to about 5 feet per mile near San Fran- 
cisco Ba}^. South Santa Clara Valley slopes in a south- 
erly direction, with an average gradient of approxi- 
mately 15 feet per mile. 

Several low bedrock hills rise from the floor of 
North Santa Clara Valley from four to six miles 
southeast of the City of San Jose. Other rock masses 
protrude from the alluvium two to five miles north- 
west of Gilroy, in South Santa Clara Valley. Aside 
from these features, the surface of the valley floor has 
few notable irregularities. 

Drainage Basins 

Streams tributary to the Santa Clara Valley are 
typical of those draining the Coast Range in the cen- 
tral part of California. By far the greater portion of 
runoff occurs after storms during the winter months. 
Although some streams continue to flow in the moun- 
tains during the summer, most are dry during this 
season on the valley floor, except where replenished 
by effluent seepage from ground water or return water 
from irrigation. 

The stream system of North Santa Clara Valley 
consists of the Coyote Creek and Guadalupe River 
groups, and of Stevens, Permanente, San Antonio, 
Matadero, and San Francisquito Creeks. Coyote Creek 
originates in the Diablo Range east of the Santa Clara 
Valley. After entering the valley floor area near 
Morgan Hill, Coyote Creek flows northwesterly near 
the eastern edge of the valley to The Narrows, seven 
miles southeast of San Jose. At this point, the stream 
flows over bedrock at the northwest tip of Eden vale 
Hills. Below The Narrows the valley broadens, and the 
Coyote Creek channel runs parallel to and about four 
miles southwest of the eastern boundary of the valley, 
discharging into San Francisco Bay near Alviso. Dry 
and Silver Creeks are tributary to Coyote Creek on 
the east side of the valley, and join about one mile 
below Evergreen, flowing northwesterly to the vicinity 
of Alum Rock, and thence westerly to join Coyote 


Creek immediately north of San Jose. Several small 
streams tributary to Dry Creek drain the east side 
of the valley between Evergreen and Alum Rock. 
Farther north, Penitencia Creek, draining the water- 
shed east of Alum Rock, flows southwesterly, joining 
Cojmte Creek north of San Jose. The former channel 
of Penitencia Creek, paralleling and then joining 
Coyote Creek near the county line, now carries only 
local surface runoff and waters of Berryessa Creek, 
tributary from the east. Scott Creek flows along the 
northern boundary of the investigational area to join 
Coyote Creek near San Francisco Bay. 

The Guadalupe River group consists of those 
streams rising on the eastern slope of the Santa Cruz 
Mountains tributary to the Guadalupe River. Los 
Alamitos, Guadalupe, and Los Gatos Creeks originate 
on the northern and northwestern slope of Loma 
Prieta. Los Alamitos and Guadalupe Creeks join on 
the valley floor at the northwest extremity of the 
Santa Teresa Hills, and then, as the Guadalupe River, 
flow northwesterh^ through San Jose to San Francisco 
Bay near Alviso. Los Gatos Creek leaves the Santa 
Cruz Mountains at Los Gatos, and flows northeast- 
erly about nine miles to join the Guadalupe River in 
San Jose. Saratoga, San Tomas Aquinas, and Cala- 
bazas Creeks enter the valley floor north of Los Gatos, 
and flow northerly across the valley, joining near 
Agnew. The combined stream then flows northerly to 
join the Guadalupe River west of Alviso, 

Watercourses draining the eastern slope of the 
Santa Cruz Mountains north of the Guadalupe River 
group are, from south to north: Stevens, Permanente, 
San Antonio, Matadero, and San Francisquito Creeks. 
San Francisquito Creek and its tributary, Los Tran- 
cos, drain the area lying generally southwest of Palo 
Alto. Their courses coincide with a portion of the 
northern boundary of the investigational area. 

The stream system of South Santa Clara Valley is 
comprised of Llagas Creek and the Carnadero Creek 
group, both of which are tributary to the Pajaro 
River, Llagas Creek originates on the eastern slope 
of Loma Prieta, flows northeasterly for a short dis- 
tance, thence southeasterly, flowing onto the valley 
floor near Morgan Hill. Small streams flowing from 
the Diablo Range on the eastern side of the valley 
are tributary to Llagas Creek along its southeasterly 
course to the Pajaro River, 

Tributaries of Carnadero Creek are Uvas, Little 
Arthur, and Bodfish Creeks, originating on the east 
slope of the Santa Cruz Mountains. Uvas Creek rises 
on the southeastern slope of Loma Prieta and flows 
approximately southeasterly, reaching the valley floor 
four miles southwest of San Martin. From that point, 
Uvas Creek flows southerly two miles to the point 
where Little Arthur Creek enters from the west, 
thence southeasterly about two miles to its confluence 
with Bodfish Creek. From that point, as Carnadero 



20 


SANTA CLAEA VALLiiiY INVESTIGATION 


Creek, the combined now trends generally southeast- 
erly, but in its final three miles swings southward 
to join the Pajaro River. 


Climate 

The climate of the Santa Clara Valley is generally 
mild, and is characterized by dry summers v/ith mod- 
erate to high daytime temperatures and cool nights, 
and wet winters with moderate temperature. More 
than 80 per cent of the precipitation occurs during 
the five-month period from November through March. 
The growing season is long, the 30-year recorded av- 
erage for San Jose, centrally located in North Santa 
Clara Valley, being 305 days between killing frosts, 
and the ll~year recorded average for Gilroy, centrally 
located in South Santa Clara Valley, being 273 days 
between killing frosts. Temperatures at San Jose have 
ranged from 20° P. to 106° F., and the monthly av- 
erage for the period from 1906 to 1952 ranged from 

. I ll p_J I y ia; ui i’ . iix w Lli v . 

tures in Gilroy have ranged, from 20° F. to 116° F., 
and the monthly average for the period from 1874 to 
1915 ranged from 46.5° F. in January to 68.8° F. 


Geology 

The geologic formations of the Santa Clara Valley 
region may be divided into water-bearing and non- 
water-bearing series. Nonwater-bearing rocks form the 
highlands bordering the Santa Clara Valle}^, and 
underlie water-bearing sediments oi the vali 67 y itself. 
The nonwater-bearing rocks range in age from iiptier 
Jurassic to middle Pliocene. Marine sandstones and 
shales are most common but conglomerates, cherts, 
marls, and several varieties of basic igneous rocks 
also occur. 


Structure of the nonwater-bearing rocks is complex, 
consisting* of faults and folds striking* generally in a 
northwesterly direction. The most lorominent faults 
in the region are the San Andreas fault in the Santa 
Cruz Mountains west of the valley, and the Calaveras- 
llayward fault system in the Diablo Range east of 
the valley, both having a northwesterly trend. Faults 
ill the southern part of Santa Clara County extend 
between the San Andreas and Calaveras-Hayward 
fault systems. The Santa Clara Valley is essentially a 
down-d.ropped block between the Santa Cruz Moun- 
tains and the Diablo Range. 


The water-bearing sediments are of Plio-Pleistocene 
and upper Quaternary age. Plio-Pleistocene sediments 
outcrop in hills immediately adjacent to the valley 
floor, and probably underlie most of the upper Quat- 
ernary sediments comprising the valley/ fill. The upper 


Quaternary sediments, composed of up to 1,000 feet 
of poorly sorted gravel, sand, and clay, contain most 
of the ground water in the Santa Clara Valley. 


Soils 


Soils of the Santa Clara Valley vary in their chem- 
ical and physical properties in accordance with differ- 
ences in parent material, drainage, and age and degree 
of development since their deposition. The soils may 
be divided into two broad groups: (1) those derived 
from recent alluvial depositions, and (2) those de- 
rived from old alluvial fans or terraces. The first 
group may be further divided into alluvial land soils 
and basin land soils, and the second group may be 
divided into low terrace land soils and high terrace 
land soils. 

Alluvial fan soils occupy the flood plains immedi- 
ately adjacent to stream channels generalh^ through- 
out the valley. They consist of unmodified to slightly 
modified alluvial deposits, and are usually medium 
to fine textured, having deep permeable to moderately 
dense subsoils. These soils are highly productive and 

suited to a wide variety of crops, and have the highest 

1 1 ,, „ 

cl gi'iC 111 L lli'iiX V cli Ut*. 


Basin land soils occux3y large flat basin-like areas 
in North Santa Clara Valley. In South Santa Clara 
Valley the basin land soils occup}/ an area generally 


T 

LU COAV Ci/llL-1- LXIC j- CLJCllV^ J JflOXll 

land soils are fine textured, and are characterized by 
dense subsoil, or hardpan, and poor drainage. These 
soils are best suited for shallow-rooted field crops. 

Low terrace land soils are generally found in 
smooth elevated areas around the edge of the valley. 
These soils are gravelly to medium textured, having 
slightly to moderately dense subsoil, and are mostly 
devoted to nonirrigated orchard crops. 

High terrace land soils are smooth to rolling higher 
areas of alluvial or older vallev fill materials. These 


soils vary from fine to medium textured, with moder- 
ately dense to dense clay subsoils, and are not gen- 
erally suited to irrigation. 


Present Development 

The Santa Clara Valley derives its name from 
Mission Santa Clara, found.ed by the Francisea,n 
padres in 1777 on Guadalupe Creek at the northern 
edge of the present City of Santa Clara. Follovdng 
the founding of the Mission, the Pueblo de San Jose 
de Guadalupe, now San Jose, was established. 

Land use in the Santa Clara Vallejo has developed 
from nonirrigated pasture and hay lands, through an 
era of grain growing, to the present period of inten- 
sive production of deciduous fruits and truck and 
row crops. Fruit and vegetable processing and pack- 
ing plants have expanded with agricultural devel- 
opment. 

There has been considerable recent industrial de- 
velopment in the vicinities of San Jose, Sunnyvale, 
Mountain View, and Milpitas. Favorable climate, in- 
creasing markets, and availability of adequate trans- 
portation facilities will undoubt edh^ attract more 
industry to the area in the future. 



INTRODUCTION 


21 


World War II brought a large influx of military 
personnel and civilians to the area. After the end of 
the war many persons in both groups remained in 
the county because of the pleasant living conditions. 
The total population, which had grown from 12,000 
in 1860 to 175,000 in 1940, surged to about 291,000 
in 1950. In San Jose, the principal city of the Santa 
Clara Valley, the population expanded from 68,500 
in 1940 to an estimated 95,600 in 1950. The majority 
of people in the Santa Clara Valley live in urban 
areas. About 55 per cent are residents of large in- 
corporated cities, while many others live in smaller 
incorporated communities. The rural population rep- 
resents less than half of the total population. 

The principal industries in the area are the can- 
neries and packing plants associated with the process- 
ing of agricultural products. Other industries include 
assembling of automobiles, steel fabrication, chem- 
ical and cement production, and manufacture of 
clothing, electrical equipment, pumps, food machin- 
ery, and construction equipment. 

Adequate rail, motor truck, and air facilities serve 
the residential areas, factories, and farms in the 


Santa Clara Valley. The main coastal line of the 
Southern Pacific Railroad from San Francisco to 
Los Angeles passes through the valley. At San Jose, 
a branch of this railroad from Oakland joins the main 
line. The Western Pacific Railroad also x)rovides i-ail 
transportation to the valle^^ Santa Clara County is 
also served by a large number of trucking concerns, 
including common carriers and contract haulers. 

A survey conducted in 1949 as a part of the cur- 
rent investigation indicated that irrigated lands in 
the Santa Clara Valley totaled about 130,000 acres, 
while approximately 35,000 acres were diw-farmed. 
Of the irrigated acreage, deciduous orchards and 
vineyards occupied about 72 per cent of the land, 
truck vegetables approximately 18 per cent, and field 
crops about 10 per cent. The deciduous orchard lands 
are devoted chiefly to prunes, apricots, pears, cher- 
ries, and walnuts. Approximately one-third of the 
supply of prunes grown in the world is produced in 
the Santa Clara Valley. Truck and row crops, includ- 
ing beans, sugar beets, broccoli, cauliflower, celery, 
lettuce, and tomatoes, are also grown on the valley 
floor, but are of lesser importance than orchards. 



CHAPTER II 


WATER SUPPLY 


Virtually all surface and ground water supplies in 
the Santa Clara Valley are derived from precipita- 
tion on lands overlying the ground water basin, tribu- 
tary surface inflow, and subsurface inflow. However, 
a small amount of water is imported through the 
water supply system of the City of San Francisco to 
a portion of North Santa Clara Valley. Percolation of 
stream flow on the valley floor is an important source 
of ground water replenishment. Sewage and waste 
waters from principal urban areas in North Santa 
Clara Valley are carried to San Francisco Bay. Sew- 
age and waste waters from other communities are 
disposed of within the area. The water supply of the 
area is considered and evaluated in this chapter un- 
der the general headings ‘‘Precipitation,” ‘‘Kunoff,’’ 
“Imported and Exported Water,” “Underground 
Hydrology,” and “Quality of Water.” 

The following terms are used as defined in connec- 
tion with the discussion of water supply in this 
bulletin : 

Annual — This refers to the 12-month period from 
January 1st of a given year through December 31st 
of the same year, sometimes termed the “calendar 
year.” 

Seasonal — This refers to any 12-month period other 
than the calendar year. 

PrecApitation Season — The 12-month period from July 
1st of a given year through June 30th of the fol- 
lowing year. 

Runoff Season— The 12-month period from October 
1st of a given year through September 30th of the 
following year. 

Investigational Seasons — The two runoff seasons of 
1948-49 and 1949-50, during which most of the 
field work on the Santa Clara Valley Investigation 
was performed. 

Mean Period — A period chosen to represent condi- 
tions of water supply and climate over a long series 
of years. 

Base Period — A period chosen for detailed hydrologic 
analysis because prevailing conditions of water 
supply and climate were approximately equivalent 
to mean conditions, and because adequate data for 
such hydrologic analysis were available. 

Mean — This is used in reference to arithmetical aver- 
ages relating to mean periods. 


Average — This is used in reference to arithmetical 
averages relating to periods other than mean 
periods. 

In studies for the current State-wide Water Re- 
sources Investigation, it was determined that the 50 
years from 1897-98 through 1946-47 constituted the 
most satisfactory period for estimating mean sea- 
sonal precipitation generally throughout California. 
Similarly, the 53-year period from 1894-95 through 
1946-47 was selected for determining mean seasonal 
runoff. In studies of the Santa Clara Valley, condi- 
tions during these periods were considered representa- 
tiYe of mean conditions of water suppl}^ and climate. 

Studies were made to select base periods for hydro- 
logic analysis of the Santa Clara Valley during which 
conditions of water supply and climate would ap- 
proximate mean conditions, and for w^hich adequate 
data on inflow, outflow, and ground water levels 
would be available. It was determined that the 13- 
year period from 1935-36 through 1947-48 was satis- 
factory in this respect for North Santa Clara Valley. 
Furthermore, during this period there was only a 
small change in ground water storage. For like rea- 
sons, a base period embracing the 16 years from 
1932-33 through 1947-48 was selected for hydrologic 
analysis in South Santa Clara Valley. Conditions 
during these chosen base periods closely approached 
conditions prevailing during the mean period, and 
were considered to be equivalent. For this reason, 
determined relationships between base period water 
supply and present and probable ultimate water 
utilization w^ere assumed to be equivalent to corre- 
sponding relationships which might be expected un- 
der mean conditions of water supply and climate. 

PRECIPITATION 

The Santa Clara Valley lies within the path of 
storms which periodically sweep inland from the 
North Pacific during Avinter months. Rainfall result- 
ing from these storms ranges from moderate to 
heaA^y, and direct precipitation provides a substantial 
portion of the water supply of the area. 

Precipitation Stations and Records 

Forty-one precipitation stations in or near the 
Santa Clara Valley have unbroken records of 10 
years ^ duration or longer. These stations are fairly 
well distributed arealty, and their records are suffi- 


( 23 ) 



24 


SANTA CLAEA VALLEY INVESTIGATION 


TABLE 1 


MEAN, MAXIMUM, AND MINIMUM SEASONAL PRECIPITATION AT SELECTED 
STATIONS IN OR NEAR SANTA CLARA VALLEY 


Map reference 
number 

Station 

Elevation, 
in feet 

Period of 
record 

Source of 
record 

Mean 
seasonal 
precipitation, 
in inches 
of depth 

Maximum and minimum 
seasonal precipitation 


Season 

Inches of depth 

SC-1 


640 

1936-53** 

SCVWCD 

29.78* 

1951 -.52 

50.58 

17.70 



1946-47 

SC-2 


8 

1941-53** 

Private 

14.37* 

1951-52 

1946-47 

20.21 

9.03 



SC-3 


255 

1921-53** 

Private 

16.63* 

1951 -.52 

25.40 



1923-24 

7.95 

2-90 

Campbell _ _ 

Ol *7 

1 897_27 

USWB 

14.85* 

1906 07 







1912-13 

5.29 

SC-4 


192 

1935-53 

Private 

15.77* 

1940-41 

1946-47 

28 17 



10.23 

SC-5 


800 

1937-53** 

SCVWCD 

20.57 

1Q40-41 

34 46 



1938-39 

14.28 

3-10 


460 

1907-51** 

Private 

29.43 

1913 




1923-24 

9.61 

SC-6 


215 

1896-1953 

Private 

15.68 

1940-41 

31.46 



1912-13 

5.82 

3-11 _ 


375 

1928-49 

Private 

30.21* 

1Q40 41 

49 60 



1930-31 

14.56 

SC-7 


135 

1935-53 

UC 

15.08* 

1940 41 

26.50 



1938-39 

8.63 

SC-8 


340 

1942-53 

Private 

16.16* 

1951-52 

24.09 



1946-47 

10.00 

3-14 


193 

1874-1915 

USWB 

19.10* 

1 889 90 

37 75 



1876-77 

6.53 

3-13 

Oilroy Wentz 

204 

1873-1953 

Private 

19.92 

1 889 90 

48.04 



1876-77 

7.66 

SC-9 

Gilroy, 6W 

355 

1937-49 

Private 

28.58* 

1940-41 

1938-39 

50 . 50 
17.76 


SC-10____ 

Guadalupe Reservoir 

450 

1936-53** 

SCVWCD 

27.55* 

At 

1946-47 

43.94 


16.30 

2-86 

TTfLwell Reservoir fT,M.Ke TCit.trerlp'e'^ 

1 ,400 

1915-53 i 

SJWWKS 

40 . 05* 

1 1940-41 

1923-24 

71.38 



i 14.94 

2-84 

Lake Ranch Reservoir (Lake McKenzie) 

1.809 

1926-53 

SJWWKS 

43.83* 

1940-41 

1938-39 

1 74.48 

25.09 


2-80 _ 

Lick Observatory (Mt, rTamilton)-. 

4,209 

1881-1953 

USWB 

27.31 

1883-84 

58.09 



1923-24 

11.56 

3-0111 __ 

Little XJvas 

625 

1929-39** 

Private 

34.22* 

1937-38 

63.87 



1943-50 

1932-33 

21.00 

SC-11 

Liagas Creek 

620 

1931-50 

Private 

25 . 58* 

1937-38 

46.91 



1932-33 

12.65 

2-88 ___ 

T,rm 0»tos 

500 

1885-1953 

■ 

USWB 

28.94 

1889-90 

67.22 



1923-24 

11.41 

2-89 

Los Gatos Reservoir 

560 

1915-53 ' 

SJWWKS 

28.68* 

1940-41 

53.14 



1923-24 

11.11 

2-92 

Los Gatos Summit 

1,800 

1922-38 

Private 

43 . 57* 

1937-38 

67.50 



1923-24 

14.45 

2-87 

Madera Colorado (Montevina Road Reservoir) 

696 

1915-53 

SJWWKS 

31.86* 

1951-52 

54 . 51 



1923-24 

11.78 

2-60 

Main Station 

91 

1914-53 

SJWWKS 

13.61* 

1914-15 

22.67 



1923-24 

6.24 




WATER SUPPLY 


25 


TABLE 1 — Continued 


MEAN, MAXIMUM, AND MINIMUM SEASONAL PRECIPITATION AT SELECTED 
STATIONS IN OR NEAR SANTA CLARA VALLEY 


Map reference 
number 

Station 

Elevation, 
in feet 

Period of 
record 

Source of 
record 

Mean 
seasonal 
precipitation, 
in inches 
of depth 

Maximum and minimum 
seasonal precipitation 

Season 

Inches of depth 

2-74 


79 

1885-1953 

Private 

14.21 

1889-90 

31.15 







1912-13 

6.04 

3-12 


392 

1924-38 

Private 

19.90* 

1937-38 

34.55 







1930-31 

11.70 

2-71 -- - -- 

Palo Alto _ - _ . - 

57 

1910-53 

USWB 

15.93* 

1914-15 

26.64 







1923-24 

7.06 

SC-12 


425 

1897-1953 


24.09 

1913-14 

46.76 







1923-24 

8.45 

SC-13 ... 


500 

1931-53 


17.96* 

1940-41 

32.12 







1933-34 

11.19 

SC-14 


470 

1929-53 

SJWWKS 

16.57* 

1951-52 

23.58 







1946-47 

10.33 

2-78 - . _ 


141 

1874-1953 

USWB 

13.72 

1889-90 

30,30 







1876-77 

4.83 

2-76 

Santa Clara ----- 

90 

1881-1953 

uswm 

14.86 

1889-90 

31.23 







1912-13 

6.57 

2-85--- - 

Saratoga Reservoir (Big Basin Way) - _ 

577 

1915-53 

SJWWKS 

31.46* 

1940-41 

55.48 







1923-24 

11.01 

2-91--- 

Seven Mile Reservoir _ - - _ - _ 

322 

1915-53 

SJWWKS 

19.79* 

1940-41 

33.71 







1923-24 

7.01 

2-72- _ . . _ 

Stanford Corporation Yard - _ 

118 

1930-53 

'Stan. Univ. 

16.81* 

1940-41 

27.99 







1930-31 

9.36 

SC-15 - 

Stevens Creek Reservoir - - - _ 

600 

1937-53** 

SCVIVCD 

24 . 60* 

1951-52 

44.95 







1946-47 

15.64 

2-75 

Sunnyvale - _ - 

97 

1926-42 

USWB 

14 . 76* 

1940-41 

27.24 







1928-29 

8.63 

2-94 

Williams Reservoir (Wrights Station) 

1,222 

1912-53** 

SJWW^KS 

43 . 79* 

1937-38 

73.96 



(900) 




1917-18 

19.32 

SC-16 

TViilow Glen - 

135 

1933-53 

Private 

15.32* 

1940-41 

24.50 







1949-50 

9.52 

2-93 

Wrights - 

1,600 

1918-53 

USWB 

49 . 43* 

1920-21 

84.43 




1 


1923-24 

16.75 


Estimated. 

** Broken record. 

SCVVVCD — Santa Clara Valiev Water Conservation District. 
SJWWKS— San Jose Water Works. 


Stan. Univ. — Stanford University. 
USWB— United States Weather Bureau. 
UC — ^University of California. 


cient to provide an adequate representation of the 
pattern of precipitation. Most of the records of pre- 
cipitation of these stations have been published in 
bulletins of the United States Weather Bureau. Un- 
published records were obtained from local agencies 
and individuals, and are included in Appendix D. 
Locations of the stations are shown on Plate 2, en- 
titled Lines of Equal Mean Seasonal Precipitation, 
1898-1947.^^ The stations and map reference numbers 
are listed in Table 1, together with elevations of the 
stations, periods and sources of record, and mean, 
maximum, and minimum seasonal precipitation. The 
map reference numbers for twenty -five of the stations 
correspond to those utilized in State Water Eesources 
Board Bulletin No. 1, ^AYater Resources of Cali- 


fornia.’^ New map reference numbers were assigned 
to the remaining stations listed and are designated 
by the prefix '^SC.” In those instances where it w^as 
necessary, the available records were extended to 
cover the 50-year mean period by comparison with 
records of nearby stations having records covering 
this period. 

Precipitation Characteristics 

Because of the uniformity of the general precipi- 
tation in North Santa Clara Valley and South Santa 
Clara Valley, as indicated on Plate 2, precipitation 
at San Jose and Gilro}?' was considered to be fairly 
representatwe of rainfall over each of the two sub- 
areas, respectively. A record of precipitation at San 



26 


SANTA CLAEA VALLEY INVESTIGATION 


Jose was available from a United States AVeatber 
Bureau station maintained since 1874-75/ and a rec- 
ord of precipitation at Gilroy since 1873-74 was avail- 
able from Mr. Carrol AA^entz of Gilroy. Eecorded 
seasonal precipitation at these two stations during 
the periods of record are given in Table 2, and are 
shown on Plate 3, entitled Recorded Seasonal Pre- 
cipitation at San Jose and Gilroy.’’ 

Precipitation in the Santa Clara A^alley occurs 
aliiiosL entirely as rainfall, although snow occasion- 
ally occurs on the higher surrounding mountains. 


TABLE 2 


RECORDED SEASONAL PRECIPITATION AT 
SAN JOSE AND GiLROY 


(In inches of depth) 


Season 

San 

Jose 

Gilroy 

Season 

San 

Jose 

Gilroy 

1873-74^ 


24.17 

1913-14 „ 

19.45 

34.71 

74-75 

7.90 

20.19 

14-15 

22.71 

26.22 

75-76 __ 

19.48 

32.79 

15-16- ___ 

16.31 

23.96 

76-77 

4.83 

7.66 

16-17- --- 

12.63 

21.88 

77-78 _ „ _ 

19.28 

29.43 

17-18 

9.36 

10.28 

78-79 

16,40 

17.90 

18-19 

18.87 

22,33 

1879-80 

13.80 

23.73 

1919-20- 

8.81 

14.81 

80-81 

12.45 

24.44 

20-21 

15,02 

18.92 

81 8^^ 

11.75 

11,39 

20.08 

14.98 

16.10 

26.12 

21 22 

14.77 

22 . 82 

82- 83_„„_ 

83- 84 

29 23 

13.85 

6.55 

18.73 

7.91 

23-24- 

1884-85 

11.27 


1924-25 - _ 

14.24 

16.90 

85-86 

20.63 

23.68 

25-26 _ _ 

14.47 

14.24 

86-87 

11.36 

31.85 

26-27- _ _ 

13.88 

22.71 

87-88 

12.17 

17.63 

27-28 

10.11 

15.97 

88-89 

15.71 

15.47 

28-29 

10.14 

12.96 

1889-90.. 

30.30 

48.04 

1929-30- 

10.83 

15.70 

90-91 

12.88 

16.51 

17.50 

30-31 

8.36 

12.29 

91-92 

15.22 

31-32 

13.40 

24.59 

Q‘?-Q8 

93-94 

og 17 

28.89 

12.28 

32 33 

8.89 

8.75 

13-61 

12.92 

33-34 _ - 

12.13 

1894-95 

23.32 

27.67 

1934-35 

16.18 

21.38 

95-96 

13.69 

19.87 

35-36 

12.41 

21.44 

96-97 

16.56 

19.70 

36-37 

16.93 

25.56 

97-98 

6.87 

10.02 

9.92 

37-38 

18.57 

31.39 

98-99 - 

19.85 

38-39- . _ 

1G.67 

12.15 

1899-1900 - 

13.87 

15,96 

1939-40- --- 

16.45 

24.21 

00-01 

19.88 

24.72 

40-41. 

21 . 42 

34.85 

01-02 

02-03 

12.98 

13.89 

19.02 

18.73 

41-42 

16.50 

23.34 

42-43-- 

13.20 

20.84 

03-04 

10.47 

19.41 

43-44 __ 

11.47 

19.49 

1904-05 

17.96 

24.93 

1944-45 

12.43 

22.02 

05-06 

15.09 

32.51 

45-46 

11.23 

1 18.13 

06-07 

22.71 

30.38 

40-47 

9.04 

15.94 

07-08 

11.96 

13.97 

47-48 

9.89 

1 15.63 

08-09- - 

18,31 

27 . 50 

48-49 

11.48 

14.72 

1909-10--- 

14.56 

18.47 

1949-50 - - 

8,31 

16.71 

10-11- - 

22.65 

22.54 

50-51 

14.01 

27.04 

11-12 --- 

10.59 

13.62 

51-52 

19.75 

31.81 

12-13 

6.35 

10.14 

52-53 

9.62 

1 19.97 

Mean for 50-year period, 1897-98 through 1946-47 

13.72 

19.92 




14.16 

20.41 

Average for 

13-year bas 

3 period, 1935-36 through 


1947-48 





13.86 


Average for 

: 6-year base period, 1932-33 through 


1047-48 





20.76 

1 




Mean seasonal depth of precipitation from north to 
south ranges from 15.93 inches at Palo Alto to 13.72 
inches at San Jose, to 19.90 inches at Morgan Hill, 
and 19.92 inches at Gilroy. Similarly, from west to 
east, it ranges from 43.57 inches at Los Gatos Sum- 
mit, to 28.94 inches at Los Gatos, and 27.31 inches 
at Lick Observatory on Mount Hamilton. In the 
Santa Cruz Mountains, the mean seasonal depth of 
precipitation exceeds 50 inches in some small areas, 
but decreases in an easterly direction with distance 
from the mountain crest to a minimum near the center 
of the valley. In the eastern portions of the Santa 
Clara Valley, and in the Diablo Range, increasing 
elevations bring greater seasonal precipitation. How- 
ever, it does not reach the high mean values found 
in the Santa Cruz Mountains. 

Precipitation in the Santa Clara A^alley varies over 
wide limits from season to season, having ranged 
from less than 40 per cent of the seasonal mean to 
more than 200 per cent. The maximum seasonal depth 
of precipitation at San Jose and Gilroy occurred in 
1889-90 when 30.30 inches and 48.04 inches of rainfall 
were recorded, respectively. In 1876-77, the minimum 
season at these stations, the depth of precipitation was 
only 4.83 inches and 7.66 inches, respectively. Long- 
term trends in precipitation for the Santa Clara 
A^alley are indicated on Plate 4, entitled “ Aecmiiii- 
lated Departure Prom Mean Seasonal Precipitation at 
San Jose and Gilroy.” 

More than 80 per cent of the seasonal precipitation 
in the Santa Clara A^alley occurs during the five 
months from November through March. The remain- 
ing months of the y^ear are correspondingly dry', and. 
only traces of rainfall occur in July and August. 
Mean monthly distribution of precipitation as re= 
corded at San aose and Gilroy^ is preseiited^ in Table 3. 

TABLE 3 

MEAN MONTHLY DISTRIBUTION OF PRECIPITATION 
AT SAN JOSE AND GILROY 


Month 

San Jose 

Gilroy 

IR inches 
of depth 

In percent 
of 

seasonal 

total 

In inches 
of depth 

In percent 
of 

seasonal 

total 

July 

0.00 

0.0 

0.01 

0.0 

August - - — — - 

0.02 

0.2 

o.Oi 

0,0 

September - 

0.30 

2.2 

0.22 

1.1 

October __ 

0.65 

4.7 

0.74 

3.7 

November 

1.21 

8.8 

1.89 

9.5 

December ______ — 

2.30 

16.8 

3,60 

18.1 

January.. _ — — 

2.84 

20.7 

4.36 

21.9 

February- — — 

2.65 

19.3 

3.89 

19.5 

March __ _ 

2.27 

16.6 

3.36 

16.9 

April - 

0.91 

6.6 

1.21 

6.1 

May 

0.47 

3.4 

0.63 

2.7 

June- - 

0.10 

0.7 

0.10 

0.5 

TOTALS 

13.72 

100.0 

19.92 

100.0 



A¥ATER SUPPLY 


27 


TABLE 4 


ESTIMATED WEIGHTED SEASONAL DEPTH AND TOTAL QUANTITY OF 
PRECIPITATION ON SANTA CLARA VALLEY 


Season 

North Santa Clara Valley 

South Santa Clara Valley 

Precipita- 

tion 

index 

Forebay Zone 

Pressure Zone 

Precipita- 

tion 

index 

Forebay Zone 

Pressure Zone 

Depth, 

in 

inches 

Quantity, 

in 

acre-feet 

Depth, 

in 

inches 

Quantity, 

in 

acre-feet 

Depth, 

in 

inches 

Quantity, 

in 

acre-feet 

Depth, 

in 

inches 

Quantity, 

in 

acre-feet 

Average for 13-j'^ear base period, 1935-36 

101 

20.2 

145,600 

15.2 

99,600 






Average for IG-jj'ear base period, 1932-33 
f.lirni^gh 1Q47-4S 

104 

100 

22.8 

21.9 

60,400 

58,000 

19.8 

19.0 

33,700 

32,300 

Mean for 50-year period, 1897-98 through 
1946-47 

100 

20.0 

144,200 

15.1 i 

99,000 


Quantify of Precipifofion 

The mean seasonal quantity of precipitation in the 
Santa Clara Valley was estimated by plotting re- 
corded or estimated mean seasonal depth of precipi- 
tation at stations in or near the area on a map. Lines 
of equal mean seasonal precipitation, or isohyets, were 
then drawn, as are shown on Plate 2. By planimeter- 
ing the areas between these isohyets, the weighted 
mean seasonal depth and total quantity of precipita- 
tion were estimated for North and South Santa Clara 
Valleys, and for the segregation of these two subareas 
into forebay and pressure zones, which segregation is 
discussed in the ensuing section on ^^Underground 
Hydrology. ’ ’ 

In order to determine seasonal depth and quantity 
of precipitation during the respective base periods, 
the foregoing estimates for the mean period were ad- 
justed on the basis of recorded precipitation at San 
Jose and Gilroy. The results of the estimates are pre- 
sented in Table 4, which also shows the precipitation 
index for the base periods. The term ‘^precipitation 
index” refers to the ratio of the amount of precipita- 
tion during a given season to the mean seasonal 
amount, and is expressed as a percentage. 

RUNOFF 

Eunoff from the tributary watersheds of the Santa 
Clara Valley constitutes the major source of water 
available to replenish the ground water basin. The two 
most important streams contributing surface inflow to 
North Santa Clara Valley are Coyote and Los Gatos 
Creeks. Runoff in these streams comprises about 30 
and 18 per cent, respectively, of the tributary surface 
inflow, while the many smaller streams discharge the 
remaining 52 per cent. A large part of the surface 
inflow tributary to South Santa Clara Valley is con- 
tributed hj Uvas and Llagas Creeks, which supply 41 
per cent and 27 per cent, respectively, of the total 
surface inflow to that valley. 


Stream Gaging Stations and Records 

Available records of runoff of principal streams in 
the Santa Clara Valley were sufficient in number, 
length, and reliability for purposes of required hydro- 
graphic studies. With respect to certain of the smaller 
streams, however, records of runoff were nonexistent 
or confined principally to measurements made during 
the investigational season of 1948-49. By comparison 
with records of nearby stations on major streams, 
adequate estimates Tvere made of runoff of these 
smaller streams. 

Table 5 lists those stream gaging stations pertinent 
to the hydrography of the investigational area, to- 
gether with their map reference numbers, drainage 
areas above stations where significant, and periods and 
sources of records. These stations are also shown on 
Plate 2. The map reference numbers for the first seven 
stations listed under “Northern Inflow,” the first two 
listed under “Northern Outflow,” and that for Uvas 
Creek near Morgan Hill, correspond to those used in 
State W^ater Resources Board Bulletin No. 1, “Water 
Resources of California.” New map reference num- 
bers were assigned to the remaining stations listed 
and are designated by the prefix “SC.” The last four 
stations listed in Table 5 were installed, operated, and 
maintained as a part of the Santa Clara Valley In- 
vestigation. 

Runoff records of stations maintained by the United 
States Geological Survey have been published in its 
Water-Supply Papers. The records of stations main- 
tained by the Santa Clara Valley Water Conservation 
District, the South Santa Clara Valley Water Conser- 
vation District, and the Division of Water Resources 
not previously published are included in Appendix E. 

Runoff Characteristics 

An excellent continuous record of the flow of 
Coyote Creek near Madrone is available for the period 
since December, 1916, when a stream gaging station 
was established by the United States Geological Sur- 
vey. This record provides a measure of flow of Coyote 



28 


SANTA CLARA VALLEY INVESTIGATION 


TABLE 5 

STREAM GAGING STATIONS IN SANTA CLARA VALLEY 


Map 

reference 

number 

Stream 

Station 

Drainage 
area, in 
square 
miles 

Period of record 

Source of record 

X^orthern 

Inflow 





2-39 



193.0 

1902-1912, 

USGS 





1916-1953 


2-45 



35.0 

1930-1953 

USGS, DWR 

2-4fi 

Los Capitancillos ('Guadalupe) Creek 

at Guadalupe . — — .. 

12.6 

1930-1943, 

USGS, DWR 





1945-1953 


2-48 



40.0 

1930-1944 

USGS. DWR 

2-49 

Los Gatos Creek „ _ „ 


43.6 

1944-1953 

USGS 

2-50 



8.8 

1938-1953 

USGS 

2-9 

Stevens Creek - _ „ _ „ ^ _ 


18. 1 

1930-1953 

USGS. DWR 

SC-1 

Penitencia Creek- 


23.4 

1934-1946 

SCVWGD 



at Mitchell’s Dam _ 


1946-1953 


SC-IA 




1934-1953 

SCVW^CD 

SC-4 



9.5 

1932-1944 

SCVWCD 

SC-5 



5.3 

1934-1944 

SCVWCD 

SC-6 

Fisher Creek 

au KJ, J-W-I. 

9.4 

1934-1053 

grjywQV) 

SC-7 



6.2 

1942-1945 

SCVWCD 

SC-7A 



4.3 

1932-194‘^ 

SCVWCD, DWR 



at Southern Pacific Railroad . 


1945-1951 

SC-7B 



3.7 

1939-1942, 

SCVWCD 



at Southern Pacific Railroad 


1945-1951' 


SC-7C 



2.3 

1938-1945, 

SCVWCD 



Smiths Dam near Elam Road 


1945-1951 


SC-10 

Calabazas Creek ^ ^ „ 

at Sunnyvale- Saratoga Road _ . . - 

4.1 

1932-1945 

SCVWCD, DWR 



at Southern Pacific Railroad near Azule Station. 



1945-1951 


SC- 13 

Permanente Creek-. 

near Loyola. . 

8.0 

1932-1945 

SCVWCD, DWR 



at Holly Ranch 



1945-1951 


SC-13A 

Magdalena Creek _ . . . 

at Fremont Road . . 

2,8 

1938-1946 

SCVWCD 



near Magdalena Road . 


1946-1951 


2-11 

San Francisquito Creek 

at Stanford University . = _ = = . .. 

37.7 

1931-1941, 

USGS, DWR 





1949-1953 


Northern Outflow 





2-43 

Coyote Creek . . . . 

near Edenvale. 

229.0 

1916-1953 

USGS 

2-47 

Guadalupe River (Creek). 

at San Jose 

131.0 

1930-1953 

USGS, DWR 

SC-2 


near Ring Road 

25.7 

1932-1953 

SCVWGD, DWR 

SC-3 


at Capitol Avenue _ . 

33.8 

1932-1948 

SCVWCD, DWR 

SC-8 

San Tomas Aqtunas Creek 

at U. S. Highwav 101. 

17.4 

1932-1945 

SCVWCD, DWR 



at Homestead Road 


1945-1953 


SC-9 

Campbell Creek (Saratoga Creek) . _ 

at U= S. Highway 101. . . . 

16.2 

1932-1949 

SCVWGD, DWR 



at Stevens Creek Road ... 

11.9 

1949-1953 


SC-11 


at U. S. Highw'ay 101 . . 

7.8 

1932-1945 

SCVWCD, DWR 



at Pomeroy Avenue _ _ 


1945-1953 

SC-12 

Stevens Creek .. , 

at Southern Pacific Railroad, Mountain View 

23.7 

1932-1953 

SCVWCD, DWR 



Southern Pacific Railroad 



1938-1942 


SC-14 

Permanente Creek „ _ . _ 

at California Street, Mountain View 

12.7 

1942-1953 

Suv Wuu 

2-15 

San Francisquito Creek 

at Palo Alto 

38.6 

1931-1940 

USGS 

Southern Inflow 





SC 15 

Llagas Creek 

T.auc Avomie Rridge 

19.6 

1942-1953 

SSCVWCD, DWR, 






Ysgs 

3-9 

Uvas Creek . . .. . . 

near Morgan Hill. 

30.2 

1930-1953 

USGS 

SC-16 

Little Arthur Creek 

near Adams School 

9.6 

1948-1949 

DWR 

SC-17 


near Gilroy . . 

12.4 

1948-1949 

DWR 

Southern Outflow 





SC- 18 


at Pacheco Pass Road-- ... = 

66.5 

1948-1949 

DWR 

SC-19 

Carnadero Creek . 

at Bloomfield Avenue — 

85.2 

1948-1949 

DWR 


USGS — ^United States Geological Survey. 

DWIi — State Division of Water Hesources. 

SrVW'CD — Santa Clara Valley Water Conservation District. 

SSCVW'CD — South Santa Clara Valley Water Conservation District. 

Creek into North Santa Clara Valley, A good record 
of flow of this stream at about the same location exists 
for the period from October, 1902, to September, 1912, 
Since Coyote Creek is by far the largest tributary 
stream, and because of its length of record, it was com 
sidered that its record of flow more nearly reflects 
characteristics of tributary runoff to North Santa 
Clara Valley than do records of flow of other trib- 
utary streams. 

The flow of Coyote Creek near Madrone is impaired 
by operation of Coyote and Anderson Reservoirs, lo- 


cated upstream from this station. An estimate of the 
natural runoff of Coyote Creek near Madrone, as it 
would be if unaltered upstream diversion, storage, 
importation, or exportation, is included in State 
Water Resources Board Bulletin No. 1, ''Water Re- 
sources of California. This estimate, as revised and 
extended, is presented in Table 6. The estimate of 
natural flow is also shown graphically on Plate 5, en- 
titled "Recorded and Estimated Seasonal Natural 
Runoff of Coyote Creek Near Madrone and Uvas 
Creek Near Morgan IlillC^ 



WATER SUPPLY 


29 


An excellent continuous record of flow of Uvas 
Creek near Morgan Hill is available for the period 
since December, 1930, when a stream gaging station 
was established at the present location by the United 
States Geological Survey. This record provides a 
measure of the natural flow of Uvas Creek into South 
Santa Clara Valley, since impairment of flow up- 
stream from the station is small. This estimate is pre- 
sented in Table 6 and shown graphically on Plate 5. 

Estimates of natural flow of streams tributary to 
the Santa Clara Valley indicate that average seasonal 
runoff during the 13-year base period for North Santa 
Clara Valley, and the 16-year base period for South 
Santa Clara Vallejo, approximated the seasonal mean 
during the 53-year period. These estimates, obtained 
from State Water Resources Board Bulletin No. 1 and 
revised and extended, are presented in Table 7, to- 
gether with runoff indices for the combined natural 
flow. The term ^Yunoff index refers to the ratio of 


TABLE 6 


RECORDED AND ESTIMATED SEASONAL NATURAL RUN- 
OFF OF COYOTE CREEK NEAR MADRONE AND 
UVAS CREEK NEAR MORGAN HILL 


Season 


1894 - 95 - - 

95 - 96 „_ 

96 - 97 -- 

97 - 98 - - 

98 - 99 -- 

1899-1900 
00-01 -- 
01 - 02 -_ 

02 - 03 _- 

03- 04__ 

1904-05 __ 

05 - 06 -- 

06 - 07 -- 

07- 08_- 

08 - 09 - - 

1909 - 10 _- 
10 - 11 -- 

11- 12-_ 

12 - 13 - - 

13 - 14 .- 

1914 - 15 - - 

15 - 16 -_ 

16 - 17 - - 

17 - 18 -- 

18 - 19 -- 

1919 - 20 - - 
20 - 21 __ 
21 - 22 -- 

22 - 23 -- 

23 - 24 __ 

1924 - 25 -. 

25 - 26 - _ 

26- 27-- 

27 - 28 -- 

28 - 29 - _ 


(In acre-feet) 


Coyote 

Creek 

Uvas 

Creek 

near 

Season 

Coyote 

Creek 

Uvas 

Creek 

near 

near 

Madrone 

Morgan 

Hill 


near 

Madrone 

Morgan 

Hiil 

161,300* 

67,200* 

57,300* 

1929-30 

20,100 

1,670 

6,800* 

1,400* 

48,500* 

30-31 

123,500* 

34,600* 

31-32 

69,800 

32,700 

1,700* 

2,400* 

32-33. 

8,110 

5,600 

31,300* 

11,700* 

33-34 

10,700 

10,100 

23,200* 

19,100* 

1934-35 

32,000 

15,500 

67,200* 

44,400* 

83,200 

50,000* 

19,100* 

21,100* 

35- 36 

36- 37 

54,300 

72,200 

155,700 

25,300 

31,400 

68,000 

37-38 

35,800 

27,900 

38-39 

10,800 

4,600 

31,800 

21,000 

1939-40 

76,700 

44,500 

117,000 

42,200 

40-41 

146,900 

57,500 

204,000 

42,900 

41-42. 

76,900 

38,800 

47,200 

13,400* 

42-43 

68,700 

27,800 

176,000 

51,500* 

43-44 

50,000 

17,300 

51,100 

16,100* 

i 1944-45 

53,700 

25,000 

126,000 1 
6,380 
3,850* 
189,000* 

121,000* 

57,900* 

45-46 . . 

29,600 

15,200 

10,000 

6,000 

4,900* 

1,500* 

54,500* 

46,400* 

46-47 

9,000 i 

47-48 . . 

4,800 

19,100 

14,000 

48-49 

13,800 

1949-50 

10,800 

39,200 

153,000* 

54,300* 

50-51 : 

60,400 

70,200 

13,400 

40,200* 

51-52 

113,700 

54,900 

13,700* 


47,500 

11,800* 

53-year mean. 





1894-95 



14,000 

8,000* 

through 



56,800 

15,900* 

1946-47 

61.700 

26,500 

69,100 

48,300* 

13-year aver- 
age, 1935-36 
through 



50,700 

880 

26,900* 

1,900* 



13,200 

8,100* 

1947-48 

62,300 




40,300 

35,100* 

16-year aver- 



53,300 

22,500 

7,250 

40,200* 

13,500* 

7,700* 

age, 1932-33 
through 
1947-48 - 


25,200 




the amount of runoff during a given season to the 
mean seasonal amount, and is expressed as a per- 
centage. 

Discharge of streams tributaiw to the Santa Clara 
Valley vary between wide limits from season to sea- 
son, and within the season. This is indicated by the 
flow of Cojmte Creek near Madrone and Uvas Creek 
near Morgan Hill. The maximum recorded seasonal 
runoff of Coyote Creek occurred in 1906-07 and 
amounted to 204,000 acre-feet, while the maximum 
for LTvas Creek occurred in 1937-38 and amounted to 
68,000 acre-feet. The minimum seasonal runoffs re- 
corded at both stations occurred in 1930-31, and 
amounted to 1,670 acre-feet and 1,400 acre-feet, re- 
spectively. Maximum recorded instantaneous dis- 
charge on Coyote Creek was about 25,000 second-feet, 
which probabU occurred on March 7, 1911, and max- 
imum recorded instantaneous discharge on Uvas 
Creek was about 8,600 second-feet on December 11, 
1937, Both creeks have been dry at times. Esti- 
mated mean monthly distribution of natural flow of 
Coyote Creek near Madrone and Uvas Creek near 
Morgan Hill is presented in Table 8. Long-term trends 
in runoff of these streams are indicated on Plate 6, 
entitled ^‘Accumulated Departure From Mean Sea- 
sonal Natural Runoff of Coyote Creek Near Madrone 
and Uvas Creek Near Morgan HilL’^ 

Quantify of Runoff 

Available records of stream flow, including those 
obtained from measurements made in connection with 
the investigation, were sufficient to permit reliable 
determination of surface inflow to and outflow from 
the area of investigation during the respective base 
periods for North Santa Clara Valley and South 
Santa Clara Valley. 

Inflow to the Forebay Zone of North Santa Clara 
Valley was measured at the stations listed under 
“Northern Inflow’’ in Table 5. Inflow to the Forebay 
Zone of South Santa Clara Valley was measured at 
the stations listed under ‘ ‘ Southern Inflow. ’ ’ The esti- 
mated inflow from unmeasured watersheds was de- 
rived from estimated unit values of runoff per square 
mile multiplied by the areas of the watersheds. The 
unit values of runoff Avere determined by comparison 
with that from nearby measured watersheds with sim- 
ilar watershed and runoff characteristics. Records of 
runoff of short duration were extended to cover each 
season of the 53 -year mean period by correlation with 
flow at nearby stations having a long record. 

Surface outflow from the Forebay Zone of North 
Santa Clara Valley was measured at the stations listed 
under “Northern Outflow’’ in Table 5. Unmeasured 
surface outflow during the 13-year base period was 
estimated from correlation with recorded outflow in a 
manner similar to that used in estimating surface in- 
flow. In South Santa Clara Vallejq the base period 
surface outflow from the Forebay Zone was estimated 


* Estimated, 



30 


SANTA CLARA VALLEY INVESTIGATION 


TABLE 7 

ESTIMATED SEASONAL NATURAL FLOW OF STREAMS TRIBUTARY TO SANTA CLARA VALLEY 

(In acre-feet) 


I North Santa Clara Valley 


South Santa Clara Valley 


Season 

Runoff 

index 

Coyote 

Creek 

near 

Madrone 

Minor 

east- 

side 

streams 

Los 
Capi- 
tan- 
cillos 
Creek 
at Gua- 
dalupe 

Alamitos 

Creek 

near 

Eden- 

vale 

Los 
Gatos 
Creek 
at Los 
Gatos 

Stevens 

Creek 

near 

Cuper- 

tino 

Minor 

west- 

side 

streams 

1 

San 

Francis- 

quito 

Creek 

at 

Stanford 

Com- 

bined 

flow 

Runoff 

index 

Llagas 

Creek 

near 

Morgan 

Hili 

Uvas 

Creek 

near 

Morgan 

Hili 

Com- 

bined 

flow 

1932-33 _ 











19 

2,300 

5,600 

7,900 

33-34 











46 

9,200 

10,100 

19^300 

1934-35 











63 

11,000 

15,500 

26,500 

35-36 _ 

82 

54,600 

24,100 

6,500 

9,800 

28,600 

6,900 

21,400 

12,800 

164,600 

97 

15,300 

25,300 

40,600 

36-37- _ „ _ -- 

114 

72,200 

30,300 

9,800 

17,700 

37,000 

9,400 

32,900 

20,300 

229,600 

117 

17,800 

31,400 

49,200 

37-38 

250 

155,700 

64,100 

22,600 

48,100 

82,200 

23,100 

72,100 

34,300 

502,200 

254 

38,600 

68,000 

106,600 

R«_RQ 

16 

10,800 

4,700 

2,000 

700 

6 200 

2 100 

3,800 

1,500 

31,800 

20 

3,800 

4,000 

8,400 

1939-40 __ - 

146 

76,700 

30,800 

12,700 

23,900 

59,700 

18,500 

46,900 

25,300 

294,500 

159 

22,100 

44,500 

66,600 

40-41 „ --- 

247 

146,900 

64,800 

17,200 

38,700 

81,400 

28,300 

89,100 

31,500 

497,900 

246 

45,500 

57,500 

103,000 

41-42 

144 

1 76,900 

33,600 

13,100 

24,500 

53,900 

17,800 

46,100 

24,100 

290,000 

147 

23,000 

38,800 

61,800 

42-43 

107 

68,700 

26,000 

1 8,300 

17,900 

36,300 

11,900 

28,500 

17,100 

214,700 

99 

13,500 

27,800 

41,300 

43-44 

62 

50,000 

20,400 

5,400 

7,200 

19,000 

4,200 

14,300 

4,800 

125,300 

60 

8,000 

17,300 

25,300 

1944-45 _ _ . 

84 

1 53,700 

21,800 

7,300 

11,900 

32,900 

7,500 

21,100 

11,900 

168,100 

81 

9,100 

25,000 

34,100 


56 

29,600 

11,400 

5,300 

7,400 

26.100 

7.900 

16,900 

8,200 

1 12,800 

GO 

10,000 

15,200 

25,200 

46-47 

17 

9,000 

2,500 

2,100 

1,400 

9,300 

3,600 

5,100 

1,400 

34,400 

38 

6,000 

10,000 

16,000 

47-48 

16 

4,800 

1,700 

3,100 

2,300 

12,300 

2,000 

4,200 

2,500 

32,900 

21 

2,900 

6,000 

8,900 

Average for 13-year base 















period 

103 

62,300 

25,900 

8,900 

16,300 

37,300 

11,000 

30,900 

15,100 

207,700 





Average for 16-year base 















period 











96 

14,900 

25,200 

40,100 

53-year mean 

100 

61,700 

25,600 

8,700 

16,100 

35,800 

9,800 

29,200 

14,300 

201,200 

100 

15,400 

26,500 

41,900 


TABLE 8 


ESTIMATED MEAN MONTHLY DISTRIBUTION OF NATURAL 
FLOW OF COYOTE CREEK NEAR MADRONE AND 
UVAS CREEK NEAR MORGAN HILL 


Month 

Coyote Creek 

Uvas Creek 

Runo^, in | 
acre-feet 

1 

Percent of 
seasonal ; 
total 

Runoff, in 
a,cre-feet 

Percent of 
seasonal 
totaJ 

October ___ 

200 

0.3 

40 

0.2 

November- 

500 

0.8 

300 

1.1 

December 

3,700 

6.0 

2^500 

9 4 

January „ 

9,300 

15.1 

4,200 

15.9 

February 

21,000 

34.0 

9,000 1 

34.0 

Alarch - 

15,700 

25.5 

5,900 ! 

22.2 

April - _ 

7.400 

12.0 

3,300 

12.4 

May 

2,500 

4.1 

800 

3.0 

June __ 

600 

1.0 

300 i 

1.1 

July _ 

400 

0.6 

100 

0.4 

August — 

200 

0.3 

40 

0.2 

September 

200 

0.3 

20 

0.1 

TOTALS 

61,700 

100.0 

26,500 

j 

100,0 


from seasonal inflow to the valley floor, and from 
stream percolation measurements made in 1948-49 at 
the stations listed in Table 5 under ’‘Southern Out- 
flow. ’ ^ 

Measured and estimated seasonal surface inflow to 
and outflow from the Forebay Zones of North and 
South Santa Clara Valleys during the mean and base 
periods are presented in Table 9. 


Imported and Exported Water 

Water is imported to North Santa Clara Valley 
for municipal use in the Cities of Palo Alto, Sunny- 
vale, and Milpitas, and for use at Moffett Field by the 
United States Navy. The imported water supplies are 
purchased from the City of San Francisco. A portion 
of the imported water originates on the west slope of 
the Sierra Nevada in the Tuolumne River watershed, 
and the remainder on the Diablo Range in the Ala- 
meda Creek watershed. No water is imported to South 
Santa Clara Valley. 

Seasonal importations to North Santa Clara Valley 
averaged about 2,000 acre-feet during the 13-year 
base period from 1935-36 through 1947-48. Present 
average seasonal importation, assumed to be some- 
what greater than the 1947-48 value, is about 4,000 
acre-feet. Table 10 indicates the amounts of importa- 
tion of water to North Santa Clara Valley for each 
season of the 13-year period. So far as v/as deter- 
mined during the investigation, there were no ex- 
ports of water from Santa Clara Valley. 

UNDERGROUND HYDROLOGY 

Water pumped fom the ground water basins of 
the Santa Clara Valley meets nearly all of the irriga- 
tion, domestic, and industrial demands of individuals 
and organizations in the valley. Percolation of rain- 
fall, stream flow, drainage from adjacent hills, sub- 



WATER SUPPLY 


31 


TABLE 9 

ESTIMATED SEASONAL SURFACE INFLOW TO AND OUTFLOW FROM 
FOREBAY ZONES OF SANTA CLARA VALLEY 


(In acre-feet) 


Subarea and stream 

Surface inflow 

Surface outflow 

53-year mean, 
1894-95 through 
1946-47 

13-year average, 
1935-36 through 
1947-48 

16-year average, 
1932-33 through 
1947-48 

53-year mean, 
1894-95 through 
1946-47 

13-year average, 
1935-36 through 
1947-48 

16-year average, 
1932-33 through 
1947-48 

North Santa Clara Valley 

14,300 

3,100 

9,800 

2,200 

6,500 

3,600 

35,800 

ns, 100 

8,700 

15,100 

3,200 

10,800 

1.500 

7.500 
4,100 

37,300 

n7,700 

8,800 


12,200 

2,400 

3,700 

1,100 

4,000 

1,900 

12,300 

2,300 

3,700 

1,100 

4,000 

1,900 





Stevens Creek _ _ _ „ 















Los Alamitos Creek _ _ 




— 

Guadalupe Creek .. 




Guadalupe River ... 


32,300 

32,600 


Fisher Creek 

4.600 
61,700 

3.600 
0,000 

25,200 

4,700 

60,900 

3.900 

5.900 
26,100 



Coyote Creek 


m,ioo 

700 

2,400 

8,200 

m,400 

700 

2,500 

8,800 


Silver and Dry Creeks 



Penitencia Creek 



Unmeasured ^ _ _ 


— 

TOTALS 

14,900 

25,200 

17,000 

203,000 

15,400 

26,500 

18,700 

207,500 

110,000 

9,500 

31,200 

9,300 

111,300 

South Santa Clara Valley 

Llagas Creek 

9,300 

30,500 

9,200 

Uvas Creek 



Unmeasured 



TOTALS 



60,600 

57,100 

50,000 

49,000 





® Includes an estimated 2,000 acre-feet that percolates above the gaging station. 
Includes outflow from Los Gatos, Guadalupe, and Los Alamitos Creeks. 

Includes outflow from Fisher Creek. 


TABLE 10 

SEASONAL IMPORTATION OF WATER 
TO NORTH SANTA CLARA VALLEY, 
1935-36 THROUGH 1947-48 


(In acre-feet) 


Season 

Importation 

1935-36 

0 

36-37 

0 

37-38 

0 

38-39 

860 

1939-40 

1,990 

40-41 

2,140 

41-42 

2,080 

42-43 

2,450 

43-44 

2,470 

1944-45 

2,650 

45-46 - 

2,760 

46-47 

3,050 

47-48 

3,600 

AVERAGE 

1,850 


surface inflow, and the unconsumed portion of ap- 
plied irrigation water, are the most important sources 
of ground water replenishment. 

The term ‘‘free ground water, as used in this 
bulletin, generally refers to a body of ground water 
not overlain by impervious materials and moving 
under control of the water table slope. “Confined 


ground water ’ ’ refers to a body of ground Avater OA^er- 
lain by material sufficiently impervious to scA^er free 
h3^draulic connection with overlying Avater, and mov- 
ing under pressure caused by the difference in head 
between intake and discharge areas of the confined 
AA'ater body. In areas of free ground water, the ground 
Avater basin proAudes regulatorj^ storage to smooth 
out fluctuations in available AA^ater supplies, and 
changes in ground water storage are indicated by 
changes in ground water levels. 

Data and information collected during the Santa 
Clara Valley Investigation indicate that both free 
ground water and confined ground water bodies exist 
in present zones of pumping. Study of historic fluctua- 
tions of water levels in the Santa Clara Valley, under 
varying conditions of draft and replenishment, per- 
mitted a determination of changes in ground water 
storage in the basins, and their safe ^deld of water 
under stated conditions. 

Ground Wafer Geology 

Geologic features of the ground AA'ater basin under- 
lying the Santa Clara Vallejo AA^ere iiwestigated by 
the Division of Water Resources in connection with 
the current iiwestigation. Appendix C comprises a 
someAvhat detailed report covering geologic features 
of the Santa Clara Valle3^ Included with the report 



32 


SANTA CLAEA VALLEY INVESTIGATION 


are a g'eneral geologic map, columnar sections, and 
geologic sections. 

The water-bearing sediments of the Santa Clara 
Valley occupy the valley proper and some adjacent 
areas. At depth these sediments are underlain by 
older nonwater^bearing rocks, which also flank the 
water-bearing materials around the margin of the 
valley. 

The age of the water-bearing sediments is Plio- 
Pleistocene and upper Quaternary. The Plio-Pleisto- 
eene sediments consist of up to 4,000 feet of conti- 
nental sand, gravel, and clay, and locally include some 
carbonate, lignite, and basalt. These deposits have 
been faulted and folded by the middle Pleistocene 
disturbance which affected the entire California Coast 
Ranges. The Plio-Pleistocene sediments suppl^^ water 
to deep wells in areas VvTiere the upper Quaternary 
sediments are thin, and to small domestic wells in the 
hills surrounding the valley. 

Upper Quaternary sediments are the main source 
of ground water in the Santa Clara Valley. These 
sediments consist of flood plain deposits, alluvial 
fan deposits, and tideland or marine swamp deposits, 
of which the alluvial fan and tideland deposits form 
the largest part. The sediments include up to 1,000 
feet of poorly sorted gravel, sand, and clay. Various 
mixtures of these sedimentary types are comnnon, 
and the coaser sediments in particular generally oc- 
cur as lenses and stringers, rather than as wide- 
spread layers of homogeneous material. 

Gravels are the main aquifers in the upper Quater- 
nary sediments. Water-yielding sands are also pres- 
ent, but wells in this area are not generally perfo- 
rated in sand strata. The tideland deposits consist of 
fairly continuous blue claj^s, which cap the pressure 
area of North Santa Clara Valley, The blue clays have 
their greatest thickness in the area around the south- 
errnost portion of San Francisco Bay, and thin out 
toward Milpitas, San Jose, Sunnyvale, and Palo Alto. 
The blue elays dip gently toward San Francisco Bay, 
the dip probably being in part the original attitude 
of the sediments and in part due to greater compac- 
tion of the sediments in the central part of the valley. 

The blue clays in South Santa Clara Valley dip 
gently southward, and increase in thickness from San 
Martin toward the Pajaro River. These blue clays 
were originally deposited in fresh-water lakes and 
swumps, and now form the capping beds of a pres- 
sure area. 

No definite evidence was found during this investi- 
gation that faulting has disturbed the upper Quater- 
nary^ sediments in the Santa Clara Valley, although 
fault barriers in alluvium do exist in Alameda County^ 
to the north and San Benito County- to the south. If 
faulted upper Quaternary sediments do exist in Santa 
Clara County, the faults apparently do not form 
barriers to ground water movement. 


Ground Wafer Basins 

During the current and previous investigations, two 
major ground water basins in the Santa Clara Valley 
have been identified. These ground water basins are 
separated by a low divide near Morgan Hill and 
underlie North and South Santa Clara Valley^s, re- 
spectively. 

The geologic and hydrologic studies made of the 
valley fill in the Santa Clara Valley indicated that, 
over portions of the valley^ relatively impervious and 
generally^ continuous strata exist between the ground 
surface and the principal pumping aquifers. Such 
strata appear to prevent significant quantities of rain- 
fall, stream flow, or unconsnmed water applied to 
irrigation from percolating to the deeper water- 
bearing strata. Consequently, the principal pumping 
aquifers, overlain by the relative^ impervious strata, 
coiitain confined water exhibiting pressure character- 
istics. Conversely^, free ground water or forebay zones, 
found generally upstream from the pressure zones, 
contain unconfined ground water, and are replenished 
by percolating rainfall, percolating irrigation water, 
percolating surface stream flow, percolation from 
ponds, and sub-surface inflow. In addition to suppH- 
ing water for use on overhang lands, these nnconfined 
ground water bodies act as forebay^s, supplydng the 
pressure zones by^ underflow. 

The pressure zone in North Santa Clara Valleys 
covers an area extending from about four miles south- 
east of the CityT- of San Jose to San Francisco 
Bay on the north, and from near Palo Alto on the 
west to near Milpitas on the east. The pressure zone 
in South Santa Clara Valley’^ covers an area ex- 
tending from about two miles southeast of San Martin 
to the Pajaro River on the south, and along the Pajaro 
River from near Sargent on the west to near San 
Felipe Lake on the east. The forebay^ zone in North 
Santa Clara Valley lies upstream and adjacent to the 
pressure zone, and generally extends to the valleys 
floorJoothill line on the west and east, and to the 
south boundary^ of North Santa Clara Valley near 
Morgan Hill. The forebay^ zone in South Santa Clara 
Valley" lies between the boundary^ of the pressure zone 
in that valley" and the valley floor-foothill line on the 
west and east, and extends northwest to the north 
boundary/ of South Santa Clara Valleys near Morgan 
HilL The forebay^ zones in North and South Santa 
Clara Valleys comprise about 8^51)0 and 26,600 acres, 
respeetivelya The pressure zones comprise about 
78,600 and 20,400 acres, respectivelya The locations of 
zones of free and confined ground waters are shown 
on Plate 7, entitled Lines of Equal Depth to Ground 
Water, Pall of 1953.’^ Plate 8, entitled. ‘^Diagram- 
matic Profiles of Pressure and Porebay Zones in 
North and South Santa Clara Valleys,'^ shows the 
relative positions of the forebay and pressure zones, 
as well as the relative positions of water table and 
piezometric surfaces at the time of the investigation. 



WATER SUPPLY 


33 


Methods of confirming the presence of and delimit- 
ing the boundaries between forebay and pressure 
zones in the two major divisions of the Santa Clara 
Valley were primarily geologic and hydrologic. In 
connection with the geologic studies, 1,100 well logs 
were obtained from local well drillers and other 
sources, and the well locations were indicated on maps. 
Logs indicating the presence of blue clay were noted, 
and lines drawn on a map showing upstream limits of 
the blue clay capping strata provided one criterion 
for locating pressure zone boundaries. 

A hydrologic method utilized for differentiating be- 
tween pressure and free ground water bodies was 
based upon the characteristics exhibited by these 
bodies under conditions of change in rate of pumping 
draft. Over a period of several days, water stage 
recorders were installed on abandoned wells to differ- 
entiate the high amplitude and cyclic piezometric sur- 
face fluctuation of ground water under pressure from 
the gradual water table elevation changes in free 
ground water zones. Another method utilized con- 
sisted of the preparation of a ground water map show- 
ing lines of equal change in ground water elevation 
for the period from summer to fall in 1949, which map 
differentiated characteristic positive changes in levels 
of confined ground water from characteristic negative 
changes in the free ground water zones. 

In addition to the foregoing criteria for deter- 
mining pressure zone boundaries, the limits of the area 
within which artesian wells were once found in North 
and South Santa Clara Valleys, as reported in United 
States Geological Survey Water-Supply Paper No. 
519, were noted. Artesian flow of water from wells is 
indicative of ground water under pressure. 

For North Santa Clara Valley only, the area over 
which land surface subsidence occurred between 1933 
and 1948 was considered. The area of subsidence is 
related to the zone of confined ground water, since it 
is believed that ground surface lowering has resulted 
from compaction of the capping clay strata under re- 
duced hydrostatic pressures. 

The foregoing considerations resulted in several 
lines of demarcation between pressure and forebay 
zones in North and South Santa Clara Valleys, which 
agTeed within reasonable limits. 

Evidence indicates that the pressure zones of both 
North and South Santa Clara Valleys extend beyond 
the limits defined in this investigation. The zone of 
confinement in North Santa Clara Valley extends 
northward both under San Francisco Bay and under 
lands east and west and adjacent to this body of 
water. The pressure zone in South Santa Clara Valley 
continues southward beyond the Pajaro River into 
San Benito County. 

Aquifers beneath the aforementioned capping clay 
beds are the principal sources of ground water util- 
ized in these pressure zones. Perched ground waters 
exist in both North and South Santa Clara Valleys 


above these beds, but are not used extensively because 
of their poor quality or insufficiency of yield of wells. 

Specific Yield and Ground 
Wafer Storage Capacity 

The term specific yield, when used in connection 
with ground water, refers to the ratio of the volume 
of water a saturated soil will yield by gravity to its 
own volume, and is commonly expressed as a per- 
centage. Ground water storage is estimated as the 
product of the specific yield and the volume of 
material in the depth intervals considered. 

As has been stated, during the investigation some 
1,100 well logs were collected, identified, and located 
on a map. Sources of the well logs included private 
owners, well drillers, public agencies, and private 
organizations. Average values of specific yield for the 
forebay zones in North and South Santa Clara Val- 
leys were computed for each 25 -foot depth interval 
from the ground surface to 300 feet below the surface, 
in the manner described in Division of Water Re- 
sources Bulletin No. 45. 

The weighted average specific yield of sediments 
of the valley fill for the depth interval from 25 to 300 
feet below the ground surface in the North Santa 
Clara Valley forebay zone was estimated to be 7.4 
per cent. In the forebay zone of South Santa Clara 
Valley, the average specific yield of the alluvium in 
the depth interval from 25 to 300 feet below the 
ground surface was estimated to be about 6.5 per cent. 

Ground water storage capacity Avas estimated as 
the product of the weighted specific yield of the 
zones, and the volume of material in the depth inter 
vals considered. For the ^ne from 0 to 300 feet 
below the surface in North and Sou^ Santa Clara 
Valleys, the total ground * wate^^ capacities 

were estimated to be approximately 1,900,000 acre- 
feet and 510,000 acre-feet, respectively. Of this total 
capacity, only that between the limits of 25 and 200 
feet below the ground surface w^as considered to be 
usable. Total usable storage volumes in these depth 
zones for North and South Santa Clara Valleys were 
estimated to be about 1,250,000 and 300,000 acre-feet, 
respectively. 

Table 11 presents estimated weighted average spe- 
cific yields and ground water storage capacities for 
25-foot depth intervals in North and South Santa 
Clara Valleys. 

Ground Wafer Levels 

Records of ground water level measurements 
are available for an extended period for both 
North and South Santa Clara Valleys. The Santa 
Clara Valley Water Conservation District, encom- 
passing most of the northern valley, has measured 
depth to ground water at about 250 wells each year 
since 1933. Earlier records of well measurements in 


2—19273 



34 


SANTA CLARA VALLEY INVESTIGATION 


TABLE 11 

ESTIMATED SPECIFIC YIELD AND GROUND WATER 
STORAGE CAPACITY, SANTA CLARA VALLEY 


Depth 
interval, 
in feet 
below 
ground 
surface 

North Santa Clara Valley 

South Santa Clara Valley 

Weighted 
average 
specific 
yield, 
in per cent 

Ground 
water 
storage 
capacity, 
in acre-feet 

Weighted 

average 

specific 

yield, 

in per cent 

Ground 
water 
storage 
capacity, 
in acre-feet 

0- 25 

6.2 

134,000 

5.7 

38,000 

-.25- .50 

8.7 

188,000 

6.1 

41,000 

50- 75 

8.4 

183,000 

7.1 

47,000 

75-100 

8.7 

188,000 

5.9 

39,000 

100-125 

8.3 

179,000 

7.6 

51,000 

125-150 

7.8 

168,000 

6.8 

45,000 

150-175- - 

S. 1 

176,000 

6 . 7 

45,000 

175-200 

7.9 

171,000 

5.4 

36,000 

200-225 

7.0 

1.52,000 

6.7 

45,000 

9!95-95n 

6.0 

131,000 

7.4 

49,000 

250-275 

5.7 

123,000 

6.8 

45,000 

275-.300 

5.2 

112,000 

4.7 

32,000 

TOTALS __ 


1,905,000 


513,000 


North Santa Clara Valley may be found in a report 
to the Santa Clara Valley Water Conservation Dis- 
trict Committee Tibbetts and Kieffer^ dated March, 
1921, in Division of Water Resources Bulletin No. 
42, and in United States Geological Survey Water- 
Supply Papers 400 and 519. 

In connection with the current investigation, the 
Division of Water Resources measured depth to 
ground water at about 500 wells in North Santa 
Clara Valley in the spring and fall seasons of 1948, 
1949, and 1950, and made monthly well measure- 
ments at 35 key wells during 1948 and 1949. In South 
Santa Clara Valley measurements of depth to ground 
water were made at about 290 wells in the spring and 
tall seasons of 1948, 1949, and 1950, and monthly 
measurements were made at 65 key wells in 1948 
and 1949. The wells were chosen to form a compre- 
hensive grid covering the entire area. Measurements 
made by the Division of Water Resources during the 
current investigation, and records of depth to ground 
water at selected wells in the Santa Clara Valley for 
years prior to the investigation, are included as Ap- 
pendix P to this bulletin. 

Depths to ground water in the Santa Clara Valley/ 
as measured each fall from 1948 through 1953 were 
plotted on maps and lines of equal depth to ground 
water were drawn. An example of these maps is 
shown on Plate 7. Plate 9, entitled Lines of Equal 
Elevation of Ground Water, Fall of 1953,'' was pre- 
pared from the data used for Plate 7, depths to 
ground water being subtracted from elevations of 
the measuring points above seadevel to obtain eleva- 
tions of the ground water level. 

Table 12 shows depths from the ground surface 
to water levels at selected representative wells in 
the Santa Clara Valley during the fall of most years 


from 1914 to 1953. Fluctuations in depth to ground 
water at certain of these wells are depicted graphi- 
caHy on Plate 10, entitled ^‘Measured Depths to 
Water Level at Selected Wells." 

The wells are numbered by the system utilized 
by the United States Geological Survey, according^ 
to township, range, and section. Under this system 
each section is divided into 40 -acre plots which are 
lettered as follows : 


D 

C 

B 

A 

T? 

T? 

n. 

XT 


-L' 

VJI 

XJ. 

M 

L 

K 

J 

N 

P 

Q 

E 


Wells are numbered within each of these 40-acre 
plots according to the order in which they are lo- 
cated. For example, a well having a number 7S/1W- 
13 H2 woiild be found in Township 7 South, Range 
1 West, and in Section 13. It would be further identi 
fied as the second well located in the 40-acre plot 
lettered H. 

From study of all available well measurements, esti- 
mates were made of the approximate average depth 
to ground water in the forebay zones of the Santa 
Clara Valley in the fall of each year from 1932 
through 1953. These values, which constitute arith- 
metical averages of available measurements, and 
weighted averages for years for which maps showing 
ground water depths were draw^ii, are presented in 
Table 13, and are illustrated graphically on Plate 
11, entitled Average Fall Depth to Groiiiid Water 
in Forebay Zones." 

It is indicated in Table 13 that a moderate rise of 
ground water levels in North Santa Clara Valley oc- 
curred from 1935 to 1938, followed by a lowering in 
1939, and a rise again to a maximum in 1942. In that 
year the estimated average depth to ground water 
was the least during the period from 1932 through 
1953. Following 1942, coincidental with dry years 
and an increase in water utilization, a continuous 
lowering of water levels occurred, reaching its great- 
est average depth in the fall of 1950. There was some 
recovery of water levels in 1951, and recent data in- 
dicates that additional recovery in the Forebay Zone 
occurred in 1952 and 1953. Although there has been 
a rise in ground water levels in the Forebay Zone of 
North Santa Clara Valley, there has not been a cor- 
responding rise of water levels in the Pressure Zone 
of the northern valley. This is shown on Plate 12, 




WATER SUPPLY 


35 


TABLE 12 

MEASURED FALL DEPTHS TO GROUND WATER AT REPRESENTATIVE WELLS IN SANTA CLARA VALLEY 


(In feet) 



North Santa Clara Valley 

South Santa Clara Valley 

A 

Year 

Pressure Zone 

Forebay Zone 

Pressure Zone 

Forebay Zone 


6S/1W^- 

6S/1E- 

7S/1W- 

7S/1W^- 

7S/2W^- 

7S/2E- 

88/ IE- 

10S/3E- 

11S/4E- 

9S/3E- 

10S/3E- 

11S/3E- 


32Q1 

30M1 

2G1 

35C1 

3K1 

17M1 

5N1 

13R1 

OBI 

27C2 

INI 

1A2 

1914_ 



















43.6 

25.0 

— 

1915 

— 

— 

— 

107.0 

— 

— 

— 

— 

— 

— 

— 

— 

17 










50.8 



18 





122.0 







■ 




19 

--- 

---- 

--- 

---- 

145.2 

--- 

---- 

-- 

-- 

65 . 0 

---- 

— 

1920 



21.7 

141.6 

159.0 


81.8 






21 







156.0 












22 





159.7 












23 





161.8 











24 

---- 

---- 

---- 

---- 

184.0 

--- 

---- 



-- 

---- 

---- 

1925 . 





193.6 








26 

— 

---- 

--- 

--- 

192.5 

---- 

---- 

---- 

---- 

---- 

---- 

---- 

28 





196.5 








29 

--- 

--- 

--- 

-- 

217,0 

---- 


--- 

---- 


---- 

— 

1930 

77.4 

37.0 

61.5 

182.0 

229.0 

128.8 

118.3 






31 

102.2 

46.8 

84.9 

203.0 

236.0 

151.6 

149.4 








32 

90.0 

47.1 

71.8 

194.0 

238.0 

137,6 

120.2 








33 

96.7 

54.2 

78.9 

208.0 

249.5 

143.3 

138.7 


42.0 





34 

104.8 

62.4 

86.2 

212.0 

245.9 

157.2 

139.1 

---- 

37.0 

--- 


--- 

1935 

113.4 

70.2 

86.2 

194.0 

249 .1 

160.6 

103.9 


36.0 

105.0 



36 

127,0 

78.9 

90.2 

200.0 

246.5 

170.5 

104.5 


30.0 

100.0 





37 

108.3 

50.2 

82.5 

186.0 

231.2 

181.0 

53.7 


31.0 





38 

87.1 

37.1 

52.4 

155.0 

197.5 

138.2 

40.6 


24.0 

50.0 





39 

102.5 

39.3 

69.3 

185.0 

222.8 

160.0 

103.8 


--- 

81.0 

---- 

---- 

1940 

88.6 

25.3 

55 . 6 

157.0 

201.2 

156.2 

48.7 

40.9 


63.0 


48.0 

41 

54.1 

5.4 

31.8 

136.0 

170.0 

154.9 

32.6 

30.0 


43.0 

28.0 

45.0 

42 



15.9 

120.0 




31.1 



32.0 

42.0 

43 

33.6 

^.3* 

20.9 

138.0 

162.7 

141.7 

37.5 




38.0 



44 

48.0 

4.5 

35.4 

151.0 

182.0 

149.9 

42.9 

42,7 

31.0 

— 

50.0 

60.0 

1945 „ 

87.0 

27.0 

45.9 

158.0 

193.2 

152.3 

63.0 

47.0 


77.0 ; 

57.0 

70.0 

46 

70.0 

17.2 

58.2 

171.0 

203.5 

169.0 

93.0 

58.8 


87.5 i 

70.0 

95.0 

47 

55.0 

62.0 

74.0 

198.0 

228.0 

169.0 

117.7 

68.0 


101.5 I 

86.0 



48 

110.4 

82.0 

102.1 

229.0 


220.5 

139.6 

84.2 


125.6 

93.0 

65.0 

49 

103.0 

102.0 

109.8 

224.0 

261.7 

220.0 

111.0 

88,8 

— 

134.5 

107.0 

73.0 

1950 

142.1 


122.9 

243.0 

252.7 

235.6 

151.8 

104.0 

68.0 

142.0 

113.0 

80.0 

51 „ _ ^ 

134.7 

117.5 

138.8 

236.0 



111.6 

90.0 


128.4 




52 




216.0 




65.4 



72.0 

54.0 

53 

140.3 

87.4 

110.9 

216.0 

— 

— 

102.4 

— 

--- 

107.4 

— 

— 


* Flowing. 


entitled Lines of Equal Change in Ground Water 
Elevations, Fall of 1948 to Fall of 1953/’ 

In South Santa Clara Valley ground water levels 
rose to a high point in 1938, declined in 1939, and 
again rose to a maximum in 1943. In that year the 
estimated average depth to ground water was the 
least during the period from 1932 through 1953. Fol- 
lowing 1943, coincidental with dr^^ years and an in- 
crease in w^ater utilization, a continuous lowering of 
w^ater levels occurred, reaching its greatest average 
depth in the fall of 1950. 

In order to estimate w^eighted average changes in 
ground water elevations in the Santa Clara Valley 
during the selected base periods and each investiga- 
tional season, maps w^ere drawui showing lines of equal 


change in ground water elevations during these pe- 
riods. An example of these maps is presented as 
Plate 13, entitled Lines of Equal Change in 
Ground Water Elevations in North Santa Clara Val- 
ley, Fall of 1935 to Fall of 1948.” By planimetering'^ 
the areas between lines of equal change, the weighted 
average change in elevation of ground water levels 
was estimated. The results of these estimates are pre- 
sented in Table 14. 

Change in Ground Wafer Storage 

In an area of free ground w^ater, the volume of soil 
unw^atered or resaturated over a period of time, when 
multiplied by its specific yield, measures the change 
in ground w^ater storage during that time. Available 



36 


SANTA CLARA VALLEY INVESTIGATION 


TABLE 13 

ESTIMATED AVERAGE FALL DEPTHS TO GROUND WATER 
IN FOREBAY ZONES OF SANTA CLARA VALLEY 


{!n feet) 


Year 

North 

Santa 

Clara 

Valley 

South 

Santa 

Clara 

Valley 

Year 

North 

Santa 

Clara 

Valley 

South 

Santa 

Clara 

V alley 




1941 

64 

37 




42 

56 

34 

1932.__„ 

102 

67 

43 

60 

32 

33 

108 

72 

44 

72 

40 

34 

109 

74 







1945 

84 

48 

1935 

105 

68 

46 

95 

58 

36. 

103 

68 

47 

107.1 i 

68.0 

37___. . 

94 

60 

48 

114.4 

75.3 

38 

79 

42 

49 

123.3 

81 . S 

39 

91 

52 







1950 .. 

139.6 ^ 

92.5 

1Q40 

79 

47 

51 

123.9 i 

79,9 




52 .. 

113.0 ; 

73.2 




53 

101.8 

64.9 


Rata on fluctuations of water levels at wells in forebaj^ 
zones of the Santa Clara Valley were sufficient to 
estimate the volunie of soil un watered or resaturated 
during the base periods, and during the investiga- 
tional and following seasons. Changes in ground water 
storage were estimated for each of the foreba}^ zones 
by multiplying changes in elevations of ground water, 
presented in Table 14, by the area of each of the 
zones and bj^ the average values of specific yield de- 
termined for each of the zones. The results of these 
estimates are presented in Table 15. 


f The estimates presented in Table 15 indicate that 
an average seasonal decrease in ground water storage 
in North Santa Clara Valley of about 4,500 acre-feet 
occurred during the 13-year base period, in which 
conditions of water supply and climate were approx- 
imately equivalent to conditions during the mean pe- 
riod. The estimated decrease in ground water storage 
during the period from 1947-48 through 1949-50 
totaled approximately 208,000 acre-feet. However, for 
the period from 1950-51 through 1952-53 there was a 
recovery of about 242,000 acre-feet. An average sea- 
sonal decrease in ground water storage in South Santa 
Clara Valley of about 900 acre-feet occurred during 
the 16 -year base period, in which conditions of water 
supply and climate were approximately equal to con- 
ditions during the mean period. The estimated de- 
crease in ground water storage during the period 
from 1947-48 through 1949-50 totaled^ approximately 
42,000 acre-feet. However, for the period from 1950-51 
through 1952-53 there was a recovery of about 47,800 
acre-feet. 

Land Subsidence 

The Ground Water Branch of the United States 
Geological Survey is making a continuing study of the 
rate, magnitude, and causes of land surface subsid- 
ence in North Santa Clara Valle}^ This study was 
initiated during the early 1930s by C. P. Tolman, 
since deceased, and J. P. Poland of Stanford Univer- 
sity, presently with the United States Geological 
Survey. 


TABLE 14 


ESTIMATED WEIGHTED AVERAGE SEASONAL CHANGES IN FALL GROUND WATER 
ELEVATIONS IN FOREBAY ZONES OF SANTA CLARA VALLEY 

(In feet) 



1935-36 

1932-33 







Division 

to 

1947-48 

to 

1947-48 

1947-48 

1948-49 

1949-50 

1950-51 

1951-52 

1952-53 

North Santa Clara Valley | 

—0.7 



—7.3 

—8.9 

—16.3 

-hl5.7 

-rlO.9 

+ 11.2 

South Santa Clara Valley — . _ . j 


—0.5 

—7.3 

— 6.5 

—10.7 

+ 12.6 

^ +6.7 

+ 8.3 


TABLE 15 


ESTIMATED WEIGHTED AVERAGE SEASONAL CHANGES IN GROUND WATER 
STORAGE IN FOREBAY ZONES OF SANTA CLARA VALLEY 

(In acre-feet) 


Division 

Area 

in 

acres 

1935-36 

to 

1947-48 

1932-33 

to 

1947-48 

1947-48 

1948-49 

1949-50 

1950-51 

1951-52 

1952-53 

North Santa Clara Valley 

86,500 

—4,500 

— 

—46,700 

—57,000 

—104,300 

+ 100,500 

+69,800 

+71,700 

South Santa Clara Valley 

26,600 


—900 

—12,600 

—11,200 

—18,500 

+21,800 

+ 11,600 

+ 14,400 



WATER SUPPLY 


37 


A bench mark network was laid out in 1933, in co- 
operation with the United States Coast and Geodetic 
Survey, to determine the extent and amount of sub- 
sidence in the vicinity of San Jose. Between 1933 and 
the spring of 1940, the network was releveled ten 
times by the Coast and Geodetic Survey, and was re- 
leveled again in the winter of 1948 and in the sum- 
mer of 1954, 

The rate of land subsidence was not uniform over 
the area. In Sunnjwale, which was the point of great- 
est subsidence during the base period, the decrease 
in ground surface elevation was about 0.9 foot from 
the spring of 1935 to December, 1937, and only 0.16 
foot from December, 1937 to December, 1939. The in- 
dicated subsidence from December, 1939 to February, 
1948 was 0.42 foot. 

The Geological Survey has made a study for de- 
termination of the magnitude of subsidence that oc- 
curred from the spring of 1935 to the winter of 1948. 
Observed elevations of the Coast and Geodetic Sur- 
vey were utilized to estimate subsidence. Contours of 
equal subsidence were drawn, and the volume lying 
between the ground surface in 1935 and that in 1948 
was ascertained. The volume so determined was esti- 
mated at 52,000 acre-feet. Thus, the average rate of 
subsidence during the period was about 4,000 acre- 
feet per year. 

The hydrostatic pressure on aquifers overlain by 
clays was substantially reduced during the base 
period. It has been suggested that, with reduced hy- 
drostatic pressure and large weight of overlying ma- 
terial, these clays were reduced in volume, which in 
turn was reflected in land subsidence. It has been 
assumed that this reduction in volume of the clays 
was accompanied b}^ yield of the water of compac- 
tion which filled the interstices between particles of 
elsLjy equal in volume to that of the land subsidence. 
Thus, the average rate of yield of the water of com- 
paction during the base period was about 4,000 acre- 
feet per year. 

The releveling in the summer of 1954 by the 
United States Coast and Geodetic Survey showed 
that the maximum subsidence had amounted to as 
much as 2.5 feet since 1948. This, when compared 
with the maximum subsidence of 1.7 feet during the 
base period, indicated that subsidence is continuing 
at an accelerated rate. The subsidence occurring dur- 
ing the two periods from 1935 to 1948 and from 1948 
to 1954, is shown on Plate 14, entitled Lines of 
Equal Subsidence of Ground Surface in North Santa 
Clara Valley for the Periods 1934-1948 and 1948- 
1954. This plate was plotted from U. S. Coast and 
Geodetic Survey data. 

Subsurface Inflow and Outflow 

Subsurface inflow constitutes a part of the water 
supplies utilized in both North and South Santa 
Clara Valleys. Ground water inflow to North Santa 


Clara Vallejo enters through pressure aquifers from 
beneath San Francisco Bay and from hills adjacent 
to the valley floor. South Santa Clara Valley re- 
ceives small quantities of ground water inflow from 
adjacent hills, and from the northern end of the val- 
ley through sediments of the Coyote Creek alluvial 
cone. 

The portion of the average seasonal subsurface in- 
flow from beneath San Francisco Bay to the pressure 
zone of North Santa Clara Valley in 1946-47, 1947- 
48, 1948-49, and 1949-50, was estimated from the con- 
figuration of the piezometric surface of ground water 
in that zone, and from estimates of ground water ex- 
tractions. During those seasons it was found that a 
trough existed in the piezometric surface of the 
ground Avater near the shore of San Francisco Bay. 
This trough condition is indicated on Plate 15, enti- 
tled ‘Ujines of Equal Elevation of Ground Water in 
North Santa Clara Valley, September-October, 1953.^’ 
Prom the basic hydraulic principle that flow of water 
occurs in the downward direction of the slope of the 
hydraulic gradient, it folloAA^s that all pumping on the 
bay side of the trough is supplied by infloAv from the 
direction of the bay. A^^erage seasonal pumping draft 
during the aforementioned three seasons Avas esti- 
mated from the area of irrigated crops, urban area, 
and miscellaneous areas in the pressure zone lying 
betAA^een the mean position of the ground Avater trough 
and San Francisco Bay, and from aA^erage applica- 
tion of AA^ater to these areas, determined from studies 
conducted during the investigation. The aA^erage sea- 
sonal subsurface infloAV so determined from 1947-48 
through 1949-50 AA^as about 9,200 acre-feet. During 
the base period, beginning in 1934-35 and ending in 
1947-48, seasonal subsurface infloAv from under San 
Francisco Bay probably A^aried in amount and direc- 
tion of fioAA% depending upon ground AA^ater elcA^ations 
in the forebay zone, pattern and amount of pumping, 
and other A^ariables. The estimated aA^erage subsurface 
infloAv from beneath San Francisco Bay during the 
13-year base period was about 8,000 acre-feet per sea- 
son. This estimate was made by applying the ratio of 
the aA^erage ground Avater OA^erdraft in the pressure 
zone during the base period, and the oA^erdraft in the 
pressure zone in 1947-48, both of AA^hich are discussed 
later, to average subsurface infloAv from beneath the 
bay during the period from 1947-48 through 1949-50. 

Subsurface outflow from North Santa Clara Valley 
occurs through sediments of the Coyote Creek cone to 
South Santa Clara Valley, as hereinafter discussed. 
The 13 -year base period seasonal average of subsur- 
face outflow from the northern valley from the Coyote 
Creek cone Avas estimated to liaA^e been about 2,400 
acre-feet, and the mean seasonal value about 2,700 
acre-feet. 

Lines of equal elevation of ground Avater shoAAUi on 
Plate 10 indicate that subsurface infloAv to South 
Santa Clara Valley occurs from the Coyote Creek 



38 


SANTA CLAEA VALLEY INVESTIGATION 


cone. The amount of this inflow was estimated from 
total percolation occnring in the nine-mile reach of 
Coyote Creek from the Upper to the Lower Gorge. 
Prom the shape of ground water contours on the 
Coyote Creek cone, it was estimated that about 1.8 
miles of the nine-mile reach supplies percolating 
w^aters to South Santa Clara Valley. Assuming per- 
colation over the nine-mile reach is constant, about 
20 per cent of the total percolation is tributary to the 
southern valley". Presented in Table 16 are seasonal 
quantities of estimated inflow to South Santa Clara 
Valley for the 16-3^ear period from 1932-33 to 1947-48, 
inclusive. The average seasonal subsurface inflow for 
this period was about 2,400 acre-feet. Mean subsur- 
face inflow w^as estimated b^^ multiplying the base 
period average by the ratio of the 53-3^ear mean to 
the 16-3^ear average surface inflow in Coyote Creek, 
and amounted to about 2,700 acre-feet per season. 


ESTIMATED SUBSURFACE FLOW FROM COYOTE CREEK 
CONE TO SOUTH SANTA CLARA VALLEY 

(Sn acre-feet) 


Season 

Percolation loss, 
Upper to Lower 
Gorpce 

Subsurface 

flow 

1932-33 

5,120 

1,020 

33-34 

6,900 

1,380 

1934-.35 

15,700 

3,140 

35-36 

24,150 

4,830 

36-37 

12,630 

2,530 

37-38 

16,130 

3,230 

38-39 

6,170 

1,230 

1939-40 

1 1,010 

2,200 

40-41 

6,960 

1,390 

41-42 

13,140 

2,630 

42-43 - 

15 950 

3,190 

43-44 _ __ _ _ 

15,850 

3,170 

1944-45 ______ 

18,870 

3,770 

45-46 

11.700 

2.340 

46-47 1 

6,000 

1,200 

47-48 

3,600 

720 

TOTALS 

189,880 

37,970 

AVERAGES-- 

11,900 

2,400 


Piezometric ground water contours indicate that 
subsurface outflow from South Santa Clara Valley 
across its southern boundarj^, the Pajaro Elver, is 
small. This value, therefore, was neglected in the 
Iwdrologie studies. Ground water overhung the pres- 
sure zone at the louver end of the southern valle^^ 
probably rises in the channel of the Pajaro Elver and 
leaves the valle}^ as surface outflow. 

Base period subsurface inflow from hills of the 
pervious Santa Clara formation, adjacent to the floor 
of the Santa Clara Valley, w^as estimated b^^ an in- 
direct method. This involved evaluation of subsurface 
inflow^ from adjacent hills as the item necessary to 
effect a balance between water suppU and disposal. 

r\-P T + r^r\Tnr%irkT^ic*^irtfv ■flna •xTJdi'Cty* 

-1. J.V\-J.AXO t'XXV. V > IXJ V X 


a given hydrologic unit or area must be equal to the 
sum of the items of water disposal. In the Santa Clara 
Vallejo values of water suppl}^ and disposal, other 
than subsurface inflow from adjacent hills, were 
quantitative!}" measured or estimated. Subsurface in- 
flov/ from the adjacent hills ^vas the remaining un- 
known quantity to balance suppty and disposal. 
Table 17 sets forth this equation during the respec- 
tive base periods for North and South Santa Clara 
Valle^^s. Determination of the values of use of water 
shown in Table 17 is explained in Chapter III. 

TABLE 17 

ESTIMATED AVERAGE SEASONAL SUBSURFACE INFLONV 
FROM ADJACENT HILLS IN NORTH AND SOUTH SANTA 
CLARA VALLEYS DURING RESPECTIVE BASE PERIODS 


(In acre-feet) 


Item 

North 

Santa 

Clara 

Valley 

South 

Santa 

Clara 

Valley 

Water Supply 

Precipitation on Porebay Zone 

Surface inflow to Forebay Zone_. 

Decrease in ground water storage 

145,600 

207,500 

4,500 

4.000 

8.000 
2,000 

60,400 

57,100 

900 

Subsurface inflow other than from adjacent hills 

2,400 



TOTALS----. 

371,600 

120,800 

Water Disposal 

Surface outflow from Forebay Zone 

Subsurface outflow 

111,300 

2,400 

183,900 

90,200 

49,000 

Consumptive use of water in Forebav Zone - 
Applied water in Pressure Zone 

58,400 

23,900 

TOTALS 

387,800 

131,300 

REMAINDER-SUBSURFACE INFLOW FROM 
ADJACENT HILLS 

16,200 

10,500 


The estimates of seasonal subsurface inflow from 
hills adjacent to the Santa Clara Valle}^ shown in 
Table 17 were also utilized as mean seasonal values, 
since the water supplies available during the selected 
base periods closety approached mean seasonal values 
of water suppty. 

High Wafer Table Areas 

During the investigational seasons it w^as found 
that drainage was not a serious problem in the Santa 
Clara Valley, except on lands adjacent to the tidal 
marshes of San Francisco Baj" in North Santa Clara 
Valle}^, and near the Pajaro Elver in South Santa 
Clara Valley. The drainage problems experienced in 
prior 3^ears have improved, probabty due to lowering 
of ground water levels and to the series of dry 3^ears 
following 1942. 

United States Geological Survey Water-Suppty 
Paper 519, published in 1924, reported the existence 
of a swamp east of San Jose, which ^tyrobably owes 
its origin to the building of the alluvial fans of 

r^mT-nfA PlrAAlr anrl pAni+AnAia PlyooV ait + a oi/Taq 



WATEE SUPPLY 


39 


of it. The finer materials deposited on the margan of 
the Penitencia fan probably tend to obstruct the 
movement of the ground water percolating from Dry 
Creek and thus bring it to the surface in the swamp. ’ ^ 
Improved drainage, resulting from the straightening 
and improvement of the Silver Creek channel, has 
since made possible the reclamation of this swamp, 

Water-Supply Paper 519 also reported on the ex- 
isting Lake Laguna Seco and adjoining swampy lands 
at the northern end of Coyote Valley and stated 
that they ^‘owe their origin to the fact that the area 
occupied by them is lower than the land nearer 
Coyote Creek and to the fact that the projection of 
hard rock nearly across the valley west of them 
stops the progress of ground water and forces it 
to rise. A small intermittent stream (Fisher Creek) 
discharges into this swampy tract, but its flow is 
probably not sufficient during the dry season to sup- 
ply more than part of the water that evaporates 
from the lake and swamp ... it is believed that 
most of the water of the lake and swamp is ground 
water supplied by percolation from Co^nte Creek 
farther up the fan. Construction of a drainage 
canal has improved this condition, and the construc- 
tion of the Coyote Canal has further helped to re- 
lieA^e it by reducing percolation on the Co\mte Creek 
cone. 

The Morgan Hill and San Juan Bautista Quad- 
rangles of the United States Geological Survey, sur- 
veyed in 1915, show a fresh-water marsh of consider- 
able extent along Llagas Creek, beginning east of 
Gilroy and extending south to Bloomfield Avenue, 
and a smaller fresh-water marsh about two miles 
north of Sargent. Although drainage of these areas 
has been improved in recent years by construction 
of drainage works, there is evidence that high water 
levels occasionally prevail. This is evidenced by small 
patches of tules, water grass, low water use b}^ crops 
indicating sub irrigation, and areas where water 
stands for some time following irrigation, floods, or 
rains. The constriction of the Pajaro Eiver near 
Sargent by impervious formations of the Santa Cruz 
Range restricts drainage in the southernmost portion 
of Santa Clara Count 3 ^ Thus, the area lying between 
Llagas Creek and the foothills of the Santa Cruz 
Range, and between Gilroy and Sargent, is subject 
to high ground water, the source of which may con- 
sist of one or more of the following ; percolation of 
rainfall on the area, natural percolation from Llagas 
and Carnadero Creeks which occurs over the pressure 
zone, flooding from Llagas and Carnadero Creeks, sub- 
surface inflow from the free ground water zone at 
times when the water surface in that zone is above 
the confining aquifers, deep percolation from irriga- 
tion in the area, and contributions from the pressure 
aquifers through old casings perforated in both the 
pressure aquifers and overljdng ground water zones. 


Safe Ground Wafer Yield 

The term ^^safe ground water jdeld^’ refers to the 
maximum rate of extraction of water from a ground 
water bod}- which, if continued over an indefinitely 
long period of 3 ^ears, would result in the maintenance 
of certain desirable fixed conditions. Commonly, safe 
ground water ^deld is determine(|^jDy one or more of 
the following criteria : 

1. AVater levels are not so lowered as to imperil the 
econom\^ of ground water users b}^ excessive costs of 
pumping from the ground water basin, or hy exclusion 
of users from a suppty therefrom. 

2. Mean geasonal extraction of Avj;ter from the 
ground water basin does not exceed mean seasonal 
replenishment to the basin. 

3. AV'ater lei^els are not so lowered as to cause 
harmful impairment of the quality" of ground water 
b,y intrusion of other water of undesirable quality, 
nor hy accumulation and concentration of degradants 
or pollutants. 

Under the present pattern of water use in the 
Santa Clara A^alle^^, average pumping lifts, while 
large in certain areas, have resulted in no widespread 
local concern regarding costs of pumping. The lack of 
aiw special concern probably" arises from the fact 
that, at least in North Santa Clara A^alle}^, much of 
the recent development has been urban in nature 
and able to carr^^ larger pumping costs than if such 
development had been mostU agricultural. For this 
reason it was considered that onh^ the second and 
third of the foregoing criteria were of significance in 
this instance. The second criterion was considered ap- 
plicable to determination of safe yield in the forebay 
zones of North and South Santa Clara A^alle^^ while 
the third criterion was utilized for determination 
of safe yield in the pressure zones. 

Forebay Zones. Safe ground water yield of the 
foreba^" zones of North and South Santa Clara A^al- 
le 3 ", as derived in this bulletin, was measured b^^ net 
extraction of water from the ground water basins, 
as differentiated from total pumpage from these 
basins. From irrigated lands overlying the free 
ground water bodies of the Santa Clara ValleA^, most 
of the unconsumed portion of the total pumpage of 
water returns to the ground water body and becomes 
available for re-use. HoAvever, such unconsumed por- 
tion in the pressure zones wastes from the valle^^ and 
is not available for re-use. The net rate of extraction 
of ground water, therefore, was considered to be 
the total pumpage in the pressure zones plus that 
portion of the pumpage from the ground water basin 
in the forebay zones which was consumptively used. 

LTnder natural conditions, ground water is expended 
hy consumptive use from seep lands and from lands 
where the water table is close to the ground surface, 
b}^ effluent stream flow, and by subsurface outflow. 



40 


SANTA CLARA VALLEY INVESTIGATION 


Artificial development and utilization of groiind 
water salvages all or a portion of such natural dis- 
posal, lowering ground water levels. As wells are 
drilled and pumped, unconfined ground Avater leA^els 
are loAvered, salvaging water lost in uneconomic con- 
sumption, and providing storage space to conserve 
surplus waters. 

Under present i5nditions of water utilization in 
North and South Santa Clara Valleys, the extraction 
of water from the ground water basins in both these 
areas exceeds the safe yields therein. This condition 
also prevailed during the respective base periods. 

Estimates of the net seasonal draft on ground 
water during the respective base period for North 
and South Santa Clara Valleys are presented iii 
Chapter III. After correction of these estimates for 
differ piiees between mean and base period A^alues for 
percolation, precipitation, change in ground water 
storage, yield of ^YSiter of compaction, and subsurface 
inflow from beneath San Eraneisco Ray, the seasonal 
safe ground w^ater yield w^as estimated. These esti- 
mates are presented in Table 18. 


TABLE 18 

ESTIMATED SAFE MEAN SEASONAL GROUND WATER 
YIELD OF FOREBAY ZONES OF SANTA 
CLARA VALLEY 

(In acre-feet) 


Item 

North 

Santa 

Clara 

Valley 

South 

Santa 

Clara 

Valley 

Average net draft on ground water during base period- 

154,800 

41,600 

Difference between average base period percolation 



and mean percolation - - _ - 

— i,300 

1,000 

Difference between average base period precipitation 



and mean precipitation _ _ _ 

—1,400 

—2,400 

Average base period change in ground water storage __ 

—4,500 

—900 

Average base period yield of water of compaction 

-4,000 

0 

Average base period subsurface inflow from beneath 



San Francisco Bay 

1 —8,000 


Difference between average base period and present 



subsurface inflow from beneath San Francisco Bay. 

—1,200 


SAFE SEASONAL GROUND AVATER YIELD, 

134,400 

39,300 


Pressure Zones. With regard to the third of the 
stated criteria for determination of safe yield, it was 
found that in the Pressure Zone of North Santa Clara 
Valley a rate of ground AA^ater extraction from the 
confined aquifers has been reached sufficient to induce 
intrusion of A^/ater from beneath San Francisco Bay. 
During periods of heaA^^j^ pumping draft in summer 
months, the elevation of the hydraulic gradient in the 
confined aquifers is depressed beloAv sea level near the 
baA^, resulting in a threat of degradation of the water 
supply by sea-AA^ater intrusion from the bay. This 
trough condition results from the inadequacy of the 
confined aquifers in the Pressure Zone to convey 
AA'ater from the Forebay Zone at rates sufficient to 
meet the rate of draft in the Pressure Zone. For this 


reason the third of the foregoing criteria AA^as adopted 
for determination of safe ground AA^ater yield in the 
Pressure Zone of North Santa Clara Valley. The 
limit of safe ground Avater yield AA^as defined as that 
maximum rate of pumping extraction from the Pres- 
sure Zone beyond AAffiich the hydraulic gradient in 
the confined aquifers Avould not be depressed beloAA’ 
mean sea level. 

Fluctuations in AA^ater leA^els in a free ground 
AA^ater body indicate changes in ground water storage, 
since these levels represent the true ground AA^ater 
surface. In contrast, fluctuations of w-ater levels in a 
confined ground water body reflect only A^ariations 
in the piezometric surface elcA^ation, or pressure head, 
and do not indicate chang’es in g'round AA^ater storage 
unless the AA^ater surface drops beloAA?^ the impervious 
strata OA^erlying the aquifers. In the Pressure Zone 
of North Santa Clara. Valley the piezometric surface 
elcA^ation remained abov^e the confining clays through- 
out the period of iiwestigation. 

The yield of Avater-b earing formations in a con- 
fined ground w^ater body is dependent both on the 
capacity of the aquifers to conduct Avater from the 
forebay, and on the hydraulic gradient from the fore- 
bay through the confined ground water body. The 
hydraulic gradient, in turn, is influenced by the areal 
extent, storage capacity, and seasonal recharge of 
the forebay, and by draft from aquifers in the con- 
fined ground AA^ater body. 

Based on Avell measurements made during the sea- 
son of 1946-47, it was found that a trough condition, 
in Avhich the elevation of the hydraulic grade line 
Avas depressed beloAV sea level, occurred in the Pres- 
sure Zone of North Santa Clara Valley during the 
summer months. In 1946-47 the trough first appeared 
near the bay about June 1st, moAung slightly inland 
and deepening as the pumping season progressed. The 
trough receded as pumping draft decreased in the 
fall, but, based on aA^ailable measurements of depth to 
ground Avater, it has failed to disappear up to the pres- 
ent time. Prior to 1946-47, and during the base period, 
data indicate that in each year a trough condition ex- 
isted at the height of the season of heavy draft. Hoav- 
eA^er, as the draft decreased the trough wnuld disap- 
pear. During each season of the period from 1946-47 
through 1953-54, the most inland position of the trough 
Avas generally in the same location. The trough gener- 
ally extended inland from the bay to Palo Alto, Moun- 
tain VieAV, Sunnyvale, and between Milpitas and 
Alviso. In connection wath a Avater resource iiwestiga- 
tioii being conducted in Alameda County by the 
Division of Water Resources, it AAms found that the 
trough continued in the fall of 1953 from North Santa 
Clara Valley into Alameda County as far north as San 
Lorenzo. In 1947-48, the maximum depth of the 
trough in North Santa Clara Valley was 70 feet be- 
loAA^ mean sea leA^el. In April and September of 1953, 
the trough had reached a depth of 60 and 100 feet 



WATEE SUPPLY 


41 


below sea level, respectively. A grouiid water map 
was prepared showing elevations of the pressure sur- 
face in the Pressure Zone of North Santa Clara 
Valley, near the time of the maximum trough condi- 
tion. This map is included as Plate 15, entitled Lines 
of Equal Elevation of Ground Water in North Santa 
Clara Valley, September-October, 1953.^’ 

A typical trough condition in the Pressure Zone 
of North Santa Clara Valley is also illustrated on 
Plate 8, which shows the indicated relationships of 
the Porebay Zone and San Francisco Bay to the 
confined aquifers of the Pressure Zone. Formation of 
the trough in the Pressure Zone indicates that the 
rate of pumping extraction from the confined aqui- 
fers, during the months of heavy draft, exceeds the 
rate at which the aquifers could convey water from 
the Porebay Zone under conditions of safe yield as 
previously defined. Also, intrusion of water from 
beneath San Francisco Bay in the confined aquifers 
is indicated by the hydraulic gradient from the bay 
inland to the trough. Since ground water flows in 
the direction of the hydraulic gradient, it is evident 
that pumping draft between the bay and the trough 
must be supplied by flow of water through the con- 
fined aquifers from the direction of San Francisco 
Bay. Similarly, pumping draft on the inland side of 
the trough must be furnished by flow down the aqui- 
fers from the direction of the Porebay Zone. 

It will be noted that Plate 8 also illustrates a posi- 
tion of the h^^draulic grade line with rate of pumping 
draft equal to or less than the safe yield of the con- 
fined aquifers. Under this safe yield condition, the 
elevation of the hydraulic grade line would never 
be depressed below mean sea level, and the only 
source of flow in the confined aquifers would be from 
the Porebay Zone. 

In light of the foregoing, the rate of safe ground 
water yield in the Pressure Zone of North Santa 
Clara Valley was derived by estimating the rate of 
flow from the Porebay Zone through the confined 
aquifers immediately prior to existence of a trough. 
Since the Porebay Zone is the only source of ground 
water to the confined aquifers under conditions of 
safe yield, the rate of pumping draft from the aqui- 
fers under these conditions would equal the flow in 
the aquifers. As was stated, during the 1946-47 season 
a ground water trough first appeared about June 1st. 
Thus, the draft prior to June 1st was met entirely 
by water supplied from the forebay. It was estimated 
that the monthly draft on ground water at that time 
was about 11,000 acre -feet, or a continuous flow at 
the rate of about 182 second-feet. 

Based on the previously cited studies of application 
of water in the Pressure Zone of North Santa Clara 
Valley, it was estimated that the rate of pumping 
draft at the peak of the 1948 season was about 286 
second-feet. Bates of pumping draft during the 1948 


season, therefore, were substantially greater than the 
estimated safe yield of 182 second-feet. It is indicated 
that the portion of pumping draft in excess of safe 
yield is supplied by flow from beneath San Francisco 
Bay and by the increased flow from the Porebay Zone 
induced by the steepening of the hydraulic gradient 
be^mnd that prevailing under conditions of safe yield. 

Studies indicated that the rate of pumping draft 
at the peak of the 1948 pumping season exceeded that 
for safe yield by about 104 second-feet. In terms of 
quantity, and based on these rates, it was estimated 
that the total draft exceeded safe yield by about 
20,000 acre-feet in 1947-48. Of this value it was esti- 
mated that about 9,200 acre-feet constituted intrusion 
of water from beneath San Francisco Bay, and about 
10,800 acre-feet was furnished by increased inflow 
down the aquifers from the Porebay Zone, induced 
by the steepened hydraulic gradient beyond the safe 
yield gradient. 

On the basis of studies of application of water, as 
derived in Chapter III, the estimated total pumpage 
from the confined aquifers of the Pressure Zone of 
North Santa Clara Valle}^ was about 104,300 acre- 
feet in 1947-48. Based on derived rates of flow in 
the confined aquifers, pumping draft exceeded safe 
ground water yield by an estimated 20,000 acre-feet 
in 1947-48. Therefore,^ under the present pattern of 
draft, safe ground water yield_qf tUe. jeonfined^ 
fers serving the Pressure Zone of North Santa Clara 
Valley was estimated to be about 84,300 acre-feet 
p er season._ 

Piezometric ground water measurements made in 
the Pressure Zone of South Santa Clara Valley near 
the Pajaro Elver during the investigation indicated 
that no ground water troughs w^ere formed during 
periods of maximum pumping draft. However, the 
measurements showed that hydraulic gradients during 
such periods were fairly fiat, indicating that the safe 
yield of the confined aquifers may have been nearly 
reached. As derived in Chapter III on the basis of 
studies of application of water, the estimated maxi- 
mum monthly pumpage from the confined aquifers 
of the Pressure Zone of South Santa Clara Valley 
was about 5,100 acre-feet, or a continuous flow equiv- 
alent to about 85 second-feet. This rate was considered 
to approximate the safe ground water yield of the 
Pressure Zone of South Santa Clara Valley. The safe 
yield of the Pressure Zone, on a quantitative basis, 
and under the present pattern of draft, was, there- 
fore, considered to equal the 1947-48 pumping draft 
of 26,600 acre-feet per season. 

QUALITY OF WATER 

The surface and ground water supplies of the Santa 
Clara Valley are generally of excellent mineral qual- 
ity, and well suited from this standpoint for irriga- 
tion and other beneficial uses. However, in certain 



42 


SANTA CLARA VALLEY INVESTIGATION 


limited areas in the eastern portion of North Santa 
Clara Valley the ground water is unfit for prolonged 
irrigation use because of its high concentration of 
certain mineral constitutents. Ground water of ques- 
tionable quality also occurs on the fringe of the tide- 
land area adjacent to San Francisco Bay. The prin- 
cipal objectives of the water quality investigation, 
therefore, were to evaluate these conditions, and to 
determine the extent of the area presently affected by 
poor quality water and the source or sources of such 
water. 

It is desirable to define certain terms commonly 
used in connection with discussion of quality of water : 

Quality of Water — Those characteristics of water af- 
fecting its suitability for beneficial uses. 

Mineral Analysis — The quantitative determination of 

1 n I's-virMTr'i'fTOQ r\in‘ U-ic<c<rkliT/i/~l c'f t 4-ii 

Jl.-tAV-'A CJ-JL J. \J 1- V Ci-L V/ iX 1.3 L' i 1/ L,i “ 

eiits in water. 

Degradation — Impairment of the quality of water due 
to causes other than disposal of sewage and indus- 
trial wastes. 

Contamination — Impairment of the quality of water 
by sewage or industrial waste to a degree which 
creates a hazard to public health through poisoning 
or spread of disease. 

Pollution — Impairment of the quality of water by 
sewage or industrial waste to a degree which does 
not create a hazard to public health, but which ad- 
versely and unreasonably affects such water for 
beneficial uses. 

Hardness — The characteristic of water which causes 
curdling of soap, increased consumption of soa^p, 
deposition of scale on boilers, injurious effects in 
some industrial processes, and sometimes objec- 
tionable taste, and which is due in large part to the 
presence of salts of calcium, iron, and magnesium. 


Complete mineral analysis included a determination 
of three cations, consisting of calcium, magnesium, 
and sodium ; four anions, consisting of bicarbonate, 
chloride, sulphate, and nitrate ^ total soluble salts ^ 
boron; and computation of per cent sodium. Partial 
analysis included determination of chlorides and total 
mineral solubles only. 

With the exception of boron, the concentrations of 
cations and anions in a water sample are expressed in 
this bulletin in terms of equivalents per minion. 
This was done because ions combine with each other 
on an equivalent basis, rather than on a basis of 
weight, and a chemical equivalent unit of measure- 
ment provides a better and more convenient expres- 
sion of concentration. This is especially true when it 
is desired to compare the composition of waters having 
variable concentrations of mineral solubles. In the case 
of boron, concentrations are expressed on^ a weight 
basis of ^tyarts per million’’ of water. In order to 

-W ▼ ^ 1 rN ^ ^ ^ ■i ' -m 1 1 t 

V 3 ^j.iv cx V ^m.11 vaxciiLCi xiixxxxuix tu jjai to pcx xxxxxxxvix^ 


the concentration, expressed in equivalents per mil- 
lion, should be multiplied by the equivalent weight of 
the cation or the anion in question. Equivalent 
weights of the common cation and anions are pre- 
sented in the following tabulation : 


Equivalent 


Cation iveight 

Calcium 20.0 

Magnesium 12.2 

Sodium 23.0' 


Equivalent 
Anion weight 

Bicarbonate 61.0 

Chloride 35.5 

Sulphate 48.0 

Nitrate 62.0 


Data used to determine the quality of water in 
the Santa Clara Valley included complete mineral 
analyses of 19 surface water samples, and complete 
mineral analyses of ground water samples collected 
from 59 wells. The data also included partial mineral 
analysis of water samples collected from 297 wells 
during the investigation. Results of these partial 
analyses are presented in Appendix G. Other data 
used during the course of the investigation included 
chloride anatyses of water samples collected from 337 
wells in 1938-39. These analyses were furnished by 
J. F. Poland of the United States Geological Survey. 


Standards of Qualify for Wafer 


Investigation and study of the quality of surface 
and ground waters of the Santa Clara Valley, as re- 
ported herein, Vvere largely limited to consideration 
of mineral constitutents of the waters, with particular 
reference to their suitability for irrigation use. How- 
ever, it may be noted that, within the limits of 
analyses herein reported, a water which is determined 
to be suitable for irrigation may also be considered 
as being either generally suitable for municipal and 
domestic use, or susceptible to such treatmerit as will 
render it suitable for that purpose. 

The major criteria which were used as a guide to 
judgment in determining suitabilitv of water for irri- 
gation use comprised the following: (1) chloride con- 
ceiitratioii, (2) total soluble salts, (3) boron eonceii- 
tration, and (4) per cent sodium. 


1. The chloride anion is usually the most trouble- 
some element in irrigation waters. It is not eonsid.ered 
essential to plant growth, and excessive conceiitra- 
tions will inhibit growth. 

2. Total soluble salts furnishes an approximate in- 
dication of tile over-all miiieral quality of water. It 
may be approximated by multiplying specific electrical 
conductance (Ec x 10^ at 25 C.) by 0.7. The pres- 
ence of excessive amounts of dissolved salts in irriga- 
tion water will result in reduced crop yields. 

3. Crops are sensitive to boron concentration, but 
require a small amount, less than 0.1 part per million, 
for growth. They will usually not tolerate more than 
0.5 to 2 parts per million, depending on the crop in 
question. 

4. Per cent sodium reported in the analyses is the 
proportion of the sodium cation to the sum of all 

o 4 T 'irs /*\ /I t i i ^ /I 4 ^ 

ctxxi^t xo uv U-X v xuixxxg i5>UU.xuill uy 



WATEK SUPPLY 


43 


sum of calcium, magnesium, and sodium, all expressed 
in equivalents per million, and multiplying 100. 
Water containing a high per cent sodium has an ad- 
verse effect upon the physical structure of the soil 
by dispersing the soil colloids and making the soil 
^ ^ tight, ’’ thus retarding movement of water through 
the soil, retarding the leaching of salts, and making 
the soil difficult to work. 

The following excerpts from a paper by Dr. L. D. 
Doneen, of the Division of Irrigation of the Uni- 
versity of California at Davis, may assist in inter- 
preting water analyses from the standpoint of their 
suitability for irrigation : 

Because of diverse climatological conditions, 
crops, and soils in California, it has not been pos- 
sible to establish rigid limits for all conditions 
involved. Instead, irrigation waters are divided 
into three broad classes based upon work done at 
the University of California, and at the Rubidoux, 
and Regional Salinity Laboratories of the LTnited 
States Department of Agriculture. 

Class 1. Excellent to Good — Regarded as safe 
and suitable for most plants under any condition 
of soil or climate. 

Class 2. Good to Injurious— Regarded as pos- 
sibly harmful for certain crops under certain 
conditions of soil or climate, particularly in the 
higher ranges of this class. 

Class 3. Injurious to Unsatisfactory — Regarded 
as probably harmful to most crops and unsatis- 
factory for all but the most tolerant. 


Tentative standards for irrigation waters have 
taken into account four factors or constituents, as 
listed below. 



Class 1 

Glass 2 

Class S 


Fwcellent 

Good to 

In jurious to 

F actor 

Conductance 
(Ec X 10® @ 

to Good 

Injurious 

Unsatisfactory 

25° C.) 

Less than 1000 

1000-3000 

More than 3000 

Boron, ppm 

Less than 0.5 

0.5-2.0 

More than 2.0 

Per cent sodium 

Less than 60 

60-75 

More than 75 

Chloride, epm 

Less than 5 

5-10 

More than 10 


(end of quotation) 



Hardness of water is caused principally by com- 
pounds of calcium and magnesium, although other 
mineral constituents such as iron, manganese, alum- 
inum, barium, silica, and strontium, may contribute to 
the hardness. In this bulletin total hardness is expressed 
in parts per million in terms of calcium carbonate 
hardness. It was computed by adding calcium and 
magnesium, expressed in equivalents per million, and 
multiplying this sum by 50. AYater haAdng a total 
hardness of less than 50 parts per million is rated as 
soft w^ater for nearly all purposes except the most ex- 
acting of industrial uses, and seldom requires treat- 
ment for reduction or elimination of hardness. AYater 
having a range of total hardness up to 150 parts per 


million is suitable for most household uses. However, 
in the case of such water, reduction of hardness by 
softening processes would reduce soap consumption 
and deposits of scale in plumbing systems, thus en- 
hancing the suitability of the water for laundries and 
other industrial purposes. AA^here total hardness in 
water exceeds from 150 to 200 parts per million, water 
softening processes are usually resorted to in order to 
render the water more acceptable for domestic, mu- 
nicipal, and industrial uses. However, objections to 
hardness in water may depend on local opinion, and 
a water considered too hard in certain localities might 
be considered satisfactory in others. 

Quality of Surface Wafer 

Surface inflow to the Santa Clara A^alley is gener- 
ally of excellent mineral quality, and is well suited to 
irrigation and other uses. Surface waters are charac- 
terized by low concentrations of mineral solubles, low 
per cent sodium, and, with the exception of Penitencia 
Creek, low boron content. Penitencia Creek is the 
only stream of importance whose waters sometimes 
contain quantities of boron deleterious to plant 
growth. Boron in this stream originates principally 
from mineral springs in the vicinity of Alum Rock 
Park. 

AYater in streams draining the Santa Cruz Aloun- 
tains on the west side of the Santa Clara A^alley gen- 
erally contain lower concentrations of mineral sol- 
ubles than water in streams emanating from the 
Diablo Range on the east. Concentrations of total 
solubles in streams entering the valley floor from the 
west are in the order of about 200 parts per million, 
whereas those in east-side streams approximate 350 
parts per million. This difference is due largely to 
greater dilution by higher runoff in west-side streams, 
and to the dissimilar composition of rocks in the two 
mountainous areas. 

Analyses of representative surface waters collected 
from major surface streams entering the Santa Clara 
A^alley are presented in Table 19. Results of deter- 
mination of total hardness in water samples collected 
from representative streams of the Santa Clara A^alley 
during 1949 are also presented in Table 19. 

Qualify of Ground Wafer 

Mineral analyses of ground waters in the Santa 
Clara A^alley indicate that such water supplies near 
the Santa Cruz Mountains are less saline than those 
near the Diablo Range, reflecting the aforementioned 
qualities of surface inflow. On the w^est side of North 
Santa Clara A^alley, concentrations of mineral solu- 
bles in ground water are from about 300 to 400 parts 
per million, while on the east side concentrations are 
from about 700 to 800 parts per million. AYells near 
the Santa Cruz Mountains in South Santa Clara Val- 
ley yield water containing total solubles of about 275 
parts per million, whereas those near mountains to 



44 


SANTA CLARA VALLEY INVESTIGATION 


TABLE 19 

COMPLETE MINERAL ANALYSES OF REPRESENTATIVE SURFACE WATERS IN SANTA CLARA VALLEY 


Station 

Date 

of 

sample 

Total 
hard- 
ness, in 

Con- 

duct- 

Boron, 

Per 



Mineral constituents, 
in equivalents per million 



ppm 

of 

CaCOa 

ance, 
EcX10« 
at 25° C. 

in 

ppm 

cent 

sodium 

Ca 

Mg 

Na 

HCOa 

-fCOa 

Cl 

SO4 

NOa 

North Santa Clara Valley 

Penitencia Creek at Santa Clara Valley 

/ 2/11/49 

100 

448 

1.45 

40 

1.80 

1.49 

2.19 

3.61 

0.88 

1.09 

0.06 

Water Conservation District diversion. _ 

\ 3/ 5/19 

120 

366 

0.S2 

11 

1.30 

l.OS 

1.68 

2.38 

0.59 

0.64 

0.09 

Dry Creek, 2.5 miles upstream from Ever- 
green SchooE „ 

3/24/49 

310 

641 

0.08 

23 

2.29 

3.88 

1.81 

5.14 

1.16 

1.74 

0.09 

Silver Creek, 1 mile above ga^e 

3/ 5/49 

340 

058 

0.07 

21 

0.98 

5.83 

1.83 

6.04 

1.51 

0.62 

0.13 

Coyote Creek at Cochran Road 

2/16/49 

160 

366 

0.22 

21 

1.85 

1.37 

0.85 

2.45 

0.33 

1.07 

0.21 

Coyote Creek at Alviso-Milpitas Road* 

9/19/49 

250 

535 

0.10 

24 

3.2i 

1.79 

1.61 

4.78 

0,15 

0.82 

trace 

Aimaden Creek at McKean Road 

2/ 8/49 

160 

288 

0.07 

15 

1.20 

2.05 

0.56 

2.84 

0.19 

0.42 

trace 

Guadalupe Creek at United States Geo- 
logical Survey gage _ „ . . „ . 

2/ 8/49 

140 

261 

0.12 

13 

1.25 

1.52 

0.40 

2.39 

0.22 

0.48 

trace 

San Tomas Aquinas Creek at San Tomas-.. 

3/ 7/49 

160 

348 

0.00 

1 19 

1.48 

1.64 

0.75 

2.47 

0.46 

i 0.66 

0.11 

Los Gatos Creek, 0.4 mile upstream from 
Los Gatos 

3/ 9/49 

160 

315 

0.11 

21 

1.89 

1.34 

0.84 

2.40 

0.26 

1.17 

trace 

Los Gatos Greek at Vasona Dam 

3/ 7/49 

140 

310 

0.05 

21 

1.55 

1.27 

0.75 

2. 12 

0.29 

O.QO 

0.09 

Campbell Creek at Saratoga 

3/ 9/49 

150 

320 

0.16 

19 

2.03 

1.08 

0.73 

2.44 

0.35 

0.92 

trace 

Stevens Creek at United States Geological 
Survey gage_ 

3/ 9/49 

200 

376 

0.13 

16 

2.57 

1.36 

0.77 

3.34 

0.43 

O.SO 

trace 

Permanente Creek at Loyola 

3/ 9/49 

430 

807 

0.00 

18 

4.99 

3.64 

1.91 

6,48 

1.93 

1.79 

0.10 

San Francisquito Creek at Stanford golf 
course 

2/16/49 

no 

286 

0.09 

38 

1.24 

0.97 

1.34 

1.34 

0.04 

0.95 

0.26 

South Santa Clara Valley 

Llagas Creek at Llagas Road ^ ^ ^ 

2/ 7/49 

140 

262 

0.21 

14 

1.14 

1.67 

0.40 

2.33 

0.26 

0.52 

trace 

Uvas Creek at V/atsonville Road _ 

2/ 7/49 

100 

192 

0.00 

18 

0.93 

0.98 

0.42 

1.58 

0.20 

0.44 

trace 

Carnadero Creek at Bloomfield Road^ 

2/ 7/49 

80 

150 

G.05 

24 

0.74 

0.85 

0.49 

1.18 

0.20 

0.40 

trace 

Carnadero Creek at Sargents Ranch* 

1 9/21/49 

320 

855 

0.37 

43 

2.92 

3.40 

4.77 

7.05 

1.20 

1.98 

trace 


- Ir ligation drainage waters. 


the east produce water having mineral constituents 
aniOLiiiting to approximately 350 parts per million. 
It should be noted, however^ that waters having the 
higher concentrations of dissolved solids are well 
within limits prescribed for good quality irrigation 
water. 

It is apparent that mineral constituents present in 
ground waters of the Santa Clara Valley are depend- 
ent ill part on constituents of the surface water sup- 
plies. Those originating from percolation of surface 
runoff from the Santa Cruz Mountains are predomi- 
nantly of the calcie-bicarbonate type, and have rela- 
tively low concentrations of boron and per cent 
sodium. They are suitable for unrestricted irrigation 
use. Mineral properties of ground waters originating 
in tile Diablo Eange runoff vary more widely than 
those derived from west-side streams. These east-side 
waters are also chieflv of the calcic-bicarbonate type 
and are suitable for irrigation use. However^ rela- 
tively high concentrations of boron in some ground 
waters of the Penitencia Creek cone, and high mag- 
nesium content of waters in a portion of the Silver 
and Dry Creek cones, render these ground waters in 
certain localities unfit for prolonged irrigation use. 
Ground waters of questionable quality also occur on 
the fringes of the ti deland area adjacent to San Fran- 
cisco Bay, 

As described heretofore, the normal slope of the 
ground water hydraulic gradient in the North Santa 
Clara Valley pressure zone toward San Francisco 


Bay has been reversed due to excessive lowering of 
ground water levels. Ground water supplying pump- 
ing draft in the pressure zone between the previously 
described ground water trough and the shore of San 
Francisco Bay flows through gravel deposits under- 
Bdng the bay. Potential intrusion of saline water 
from the bay may be a threat to the quality of ground 
water in the Pressure Zone of North Santa Clara 
Valley, if the bay waters have access to the under- 
hdng pressure aquifers. 

Under original conditions, ground water movement 
occurred from the free ground v/ater bodies around 
the edges of the San Francisco Bay depression into 
the pressure aquifers winch extended under the allu- 
viated areas and finally under San Francisco Bay. 
Ground water movement was generally toward the 
bay from all its sides. The discharge of fresh water 
from the pressure aquifers beneath San Francisco 
Bay under original conditions must have been from 
these aquifers directly into the sea water of the bay. 
The points of discharge included all points where the 
aquifers were not protected by confining beds and 
were in direct contact wdth sea water of the bay. 
Early reports of boilr of fresh water in San Francisco 
Bay were undoubtedly attributable to discharge of 
fresh water at such points. 

The present situation of a ground water trough in 
the pressure zone of North Santa Clara Valley at an 
elevation considerably below sea level, indicates that 
the extension of the pressure surface beneath San 



WATER SUPPLY 


45 


TABLE 20 

COMPLETE MINERAL ANALYSES OF GROUND WATERS IN SANTA CLARA VALLEY 


Well number 


Depth, 

in 

feet 


NORTH SANTA CLARA 
VALLEY 


Pressure Zone 

5S/1W-36J1 

5S/3W-35G1 

6S/1W-1P1 

6S/1W-10P3 

6S/1W-UA1 

6S/1W-12A1 

6S/1W-15C2 

6S/1W-15F2 

6S/1W-17K1 

6S/1W-18L1 

6S/1W-22J1 

6S/1W-23J1 i 

6S/1W-25D1 

6S/1W-34P1 

6S/2W-7J1 

6S/2W-9L1 

6S/2W-12P1__. 

6S/2W-14M2 

6S/2W-15D1 

6S/2W-16H1 

W 6S/2W-29D2 

6S/3W-3L1.-. 

6S/1E-30N1 

6S/1E-33H1 

6S/1E-34Q1 

7S/1W-3G1 

7S/1W-18N1 

7S/2W-12K1 

7S/1E-15B1 

7S/1E-25E4 


815 

174 

360 


800 

700 

600 

350 

316 


525 

510 

268 


Average 


Forebay Zone 

5S/1E-32P1 

6S/1E-5G1 

6S/1E-6A1 

6S/1E-22B1 

6S/1E-22E2 

7S/1E-32R1 

8S/1W-3D1 

8S/1E-8R1 

8S/1E-10J2 

8S/1E-26H1 

8S/2E-7A3 

8S/2E-34R1 

9S/3E-7C1 


250 

278 


818 

183 

25 

203 

150 

170 


Average 


SOUTH SANTA CLARA 
VALLEY 


Pressure Zone 
10S/4E-28N2 
11S/4E-4P2- 
11S/4E-10L1 
11S/4E-11C1 
11S/4E-13B1 
11S/4E-14D1 
11S/4E-17A1 
11S/4E-29G1 


322 

220 

673 

280 

120 


Use 

Date 

of 

sample 

Hard- 

ness, 

ex- 

pressed 

in 

ppm 
of Ca 
COs 

Con- 
duct- 
ance, 
Ec X 
10® at 

25^ C. 

Boron, 

in 

ppm 

Per 

cent 

so- 

dium 

Ca 

in 

Mg 

Miner 

equiva 

Na 

al cons 
lents pe 

HCOs 

+ 

CO 3 

ituents 
jr millio 

Cl 

n 

SO 4 

NOs 


9/20/49 

270 

562 

0.16 

23 

3.66 

1.75 

1.59 

4.83 

0.76 

1.04 

Tr 

Municipal 

9/20/49 

200 

714 

0.17 

53 

2.65 

1.34 

4.46 

4.25 

2.82 

0.87 

Tr 

Irrigation 

9/19/49 

282 

592 

0.16 

20 

3.71 

1.93 

1.42 

5,22 

0.72 

0.91 

Tr 

Irrigation _ _ _ . 

6/24/49 

471 

1123 

0.09 

31 

4.40 

5.02 

4.31 

6.62 

3.66 

3.37 

Tr 

Irrigation 

6/ 2/49 

242 

637 

0.09 

34 

3.00 

1.85 

2.53 

5 . 45 

1.31 

0.61 

Tr 

Irrigation 

6/ 8/49 

289 

621 

0.06 

22 

3.71 

2.07 

1.65 

5.67 

0.75 

0.93 

Tr 

Irrigation and domestic 

6/24/49 

968 

2355 

0.07 

33 

9.28 

10.08 

9.42 

7.69 

13.05 

7.50 

Tr 

Irrigation 

5/23/49 

938 

2325 

0.17 

34 

9.14 

9.61 

9.53 

8.82 

11.38 

7.15 

Tr 


9/19/49 

436 

1177 

0.96 

44 

2.20 

6.53 

6.77 

11.91 

1.63 

1.64 

Tr 

Irrigation 

9/20/49 

634 

1563 

1.04 

37 

5.60 

7.07 

7.54 

10.45 

3.19 

3.78 

1.54 

Domestic 

6/24/49 

66 

461 

0.03 

74 

0.81 

0.52 

3.81 

3.72 

1.10 

0.34 

Tr 

Irrigation _ _ 

6/24/49 

211 

481 

0.00 

28 

2.86 

1.36 

1.66 

4.13 

0.64 

0.95 

0.06 

Irrigation. 

9/ 7/49 

542 

1020 

0.08 

16 

7.02 

3.81 

2.07 

6.16 

1.22 

5.17 

0.10 

Irrigation 

7/14/49 

232 

481 

0.10 

21 

3.23 

1.42 

1.25 

4.02 

0.44 

1.08 

0.10 

Irrigation and domestic 

7/18/49 

716 

1340 

0.18 

19 

6.69 

7.63 

3.32 

8.25 

4.15 

2.63 

1.31 


5/26/49 

712 

1258 

0.00 

11 

7.64 

6 . 59 

1.81 

7.27 

1,77 

6.64 

0.11 

Stock . . . 

5/26/49 

567 

1250 

0.13 

22 

5.10 

6.24 

3.27 

8.80 

3.34 

1.46 

0.49 

Municipal 

5/26/49 

120 

1099 

0.28 

79 

1.57 

0.83 

8.99 

5.08 

6.06 

0.21 

0.00 

Irrigation 

7/14/49 

158 

483 

0.17 

48 

1.91 

1.24 

2.94 

4.46 

0.54 

0.65 

Tr 

Irrigation 

7/14/49 

332 

694 

0.09 

24 

4.44 

2.21 

2,12 

5.15 

1.07 

2.06 

Tr 

Irrigation 

8/31/49 

- 296 

637 

0.05 

27 

3.64 

2.28 

2.24 

6.07 

0.86 

0.42 

0.21 

Municipal 

8/29/49 

229 

662 

0.27 

42 

3.01 

1.57 

3.25 

4.34 

1.93 

1.25 

0.04 

Irrigation and domestic 

5/23/49 

664 

1299 

0.00 

19 

7.04 

6.24 

3.11 

10.06 

2.56 

3.76 

0,00 

Irrigation _ 

8/ 8/49 

316 

680 

0.00 

24 

4.25 

2.06 

2.01 

5.28 

1.64 

1.09 

Tr 

Irrigation _ . . . 

5/24/49 

1716 

4120 

0.25 

33 

19.24 

15.08 

17.13 

9.14 

22.50 

19.43 

Tr 


9/20/49 

233 

i 483 

i 0.11 

19 

3.11 

: 1.55 

1.09 

3.79 

0.47 

1.30 

0.09 

Irrigation . . _ 

9/12/49 

234 

516 

0.21 

28 

2.86 

i 1.81 

1.77 

3.99 

0.94 

0.62 

0.11 

Irrigation 

9/20/49 

257 

565 

0.17 

24 

2.77 

i 2.37 

1.62 

4.81 

1.10 

0.44 

0.14 

Irrigation and domestic 

5/27/49 

374 

735 

0.00 

17 

3.41 

: 4.06 

1.52 

6.33 

0.70 

1.79 

0.07 

Irrigation „ . 

5/27/49 

303 

610 

0.00 

19 

1.44 

1 4.62 

1.42 

5.63 

0.70 

0.93 

0.06 



434 

1181 

0.17 

31 

4.65 

4.02 

3.85 

6.25 

3.10 

2.63 

.15 

Irrigation 

5/24/49 

193 

1205 

0.59 

70 

2.11 

1 1.75 

9.05 

6.92 

3.23 

2.63 

0.07 

Irrigation 

9/ 7/49 

292 

926 

0.44 

48 

3.39 

i 2.44 

5.27 

6.70 

2.62 

1.06 

0.26 

Irrigation and domestic 

6/ 8/49 

83 

565 

0.27 

75 

0.88 

i 0.78 

4.88 

5.00 

0.60 

0.99 

Tr 

Irrigation . _ _ . . 

5/24/49 

244 

1012 

1.88 

62 

2.64 

i 2.24 

7.81 

6.65 

2.63 

3.33 

Tr 

Irrigation 

6/22/49 

173 

733 

1.01 

61 

2.43 

i 1.03 

5.35 

5.81 

1.36 

1.54 

0.10 

Irrigation 

7/16/49 

233 

454 

0.15 

15 

2.04 

2,62 

0.84 

4.23 

0.32 

0.53 

0.10 


9/22/49 

198 

488 

0.05 

30 

2.14 

1,83 

1.66 

3.46 

1.19 

0.60 

Tr 

Irrigation _ . 

8/ 8/49 

199 

373 

0.17 

15 

1.88 

2.10 

0.70 

3.43 

0.32 

0.57 

0.03 

Irrigation 

8/ 8/49 

366 

758 

0.16 

24 

3.37 

3.96 

2.29 

5.73 

1.89 

1.63 

0.07 

Irrigation .... 

8/ 8/49 

278 

498 

0.16 

14 1 

1.35 

4.21 

0.91 

4.70 

0.70 

0.71 

0.04 

Irrigation 

8/ 8/49 

238 i 

451 

0.11 

19 ^ 

2.11 

2.66 

1.09 

4,24 

0.41 

0.90 

0.04 

Irrigation „ „ 

8/ 8/49 

256 

680 

0.12 

21 

2.73 

2.39 

1.36 

4.58 

0.53 

0.90 

0.13 

Irrigation _ . 

8/ 8/49 : 

242 

474 

0.16 ; 

19 

2.62 

2.21 

1.11 

3.91 

0.45 

1.18 

0.11 



230 

663 

0.41 

36 

2.28 

2,32 

3.26 

5.03 

1.25 

1.27 

0.07 

Irrigation 

8/ 3/49 

193 

431 

0.09 

28 

2,06 

1.80 

1.53 

3.75 

0.53 

0.57 

0.09 

Irrigation __ 

7/27/49 

236 

476 

0.10 

18 

2.28 

2.45 

1.05 

4.38 

0.42 

0.44 

0.24 

Irrigation. 

7/27/49 

434 

820 

0.16 

17 

3.88 

4.80 

1.72 

6.94 

1.02 

1.84 

0.13 

Irrigation and domestic 

7/27/49 

260 

608 

0.10 

27 

2.62 

2.59 

1.94 

5.92 

0.87 

0.15 

0.09 

Irrigation .. 

7/27/49 

110 

788 

0.42 

77 

1.41 

0.80 

7.30 

5.45 

2.25 

1.15 

Tr 

Irrigation and stock 

8/31/49 

175 

556 

0.17 

49 

1.93 

1.57 

3.42 

5.09 

0.94 

0.63 

Tr 

Irrigation 

7/27/49 

216 

444 

0.10 

21 

2.30 

2.01 

1.17 

3.86 

0.44 

0.70 

0.11 

Irrigation. 

8/30/49 

231 

467 

0.13 

20 

2.18 

2.44 

1.12 

3.91 

0.70 

0.74 

0.10 



232 

573 

0.16 

32 

2.33 

2.31 

2,41 

4.91 

0.89 

0.78 

0.10 


Average. 



46 


SANTA CLARA VALLEY INVESTIGATION 


TABLE 20— Continued 

COMPLETE MINERAL ANALYSES OF GROUND WATERS IN SANTA CLARA VALLEY 


Weil number 

Depth, 

in 

feet 

Use 

Date 

of 

sample 

Hard- 

ness, 

ex- 

pressed 

in 

ppm 
of Ca 
CO 3 

Con- 
duct- 
ance, 
Ec X 
106 at 
25° C. 

Boron, 

in 

ppm 

Per 

cent 

so- 

dium 

Mineral constituents, 
in equivalents per million 

Ca 

Mg 

Na 

HCO 3 

-r 

CO 3 

Cl 

SO 4 

NO 3 

SOUTH SANTA CLARA 
VALLEY — Continued 

Eorebay Zone 

9S/3E-22R2 

9S/3E-28B2 

9S/3E-35M1 

10S/3T^-4A2 

10S/3E-25K1 

10S/3E-34L1 

10S/3E-35J1 

iOS/4E-27Bl 

Average... 

240 

225 

141 

289 

412 

Irrigation and domestic 

Irrigation 

Irrigation 

Irrigation _ . 

Irrigation and domestic 

Irrigation 

7/29/49 

I 7/29/49 
^ 8/31/49 

7/29/49 
8/30/49 
9/20/49 
9/20/49 
8/ 3/49 

457 

505 

182 

1142 

210 

188 

455 

220 

1243 

1390 

354 

2470 

412 

368 

909 

690 

0.23 

0.27 

0.09 

0.17 

0.04 

0.09 

0.00 

0.14 

35 

34 

17 
15 
20 

18 
21 
48 

4.25 

4.32 

1.55 

11.30 

1.84 

1,95 

7.59 

2.36 

4.89 
5.78 
2.09 
11.53 ■ 
2.37 
1.82 
1.51 
2.05 

4.95 

5.20 

0.74 

4.06 

1.03 

0.85 

2.41 

3.98 

3.43 

3.99 

3.01 

4.60 

3.70 

3.17 

7.52 

6.74 

6.95 
9.41 
0.40 

19.62 

0.58 

0.32 

1.95 
0.94 

2.44 
1.40 
; 0.36 
2.10 
j 0.30 
0.79 

1 1.60 
0.57 

0.43 

0,10 

0.24 

0.10 

0.23 

Tr 

Tr 

Tr 

420 

980 

0.13 

26 

4.40 

4.01 

2.90 

4.52 

5.02 

1,20 

0.14 

i 


Francisco Bay has undoubtedly been reduced below 
sea level. The salt water of the bay thus has a 
higher head than the fresh water in the pressure aqui- 
fers in such places, and is entering the pressure aqui- 
fers at their points of free contact with sea water. 
Dredging taking place on the floor of San Francisco 
Ba^y in recent years has tended to further remove cap- 
ping beds, and may have exposed the aquifers to an 
extent as yet unkown. Thus, if draft on ground water 
in the pressure zone of North Santa Clara Valley con- 
tinues as at present, salt water can be expected to 
move into the pressure aquifers beneath San Fran- 
cisco Bay and from thence into the pressure zone. 
Indeed, intrusion of sea water from San Francisco 
Bay into aquifers in the Niles Cone area of Alameda 
County has already occurred, and degradation of 
qualit^f of the ground vvater in adjacent areas by 
spreading of the poor quality vvater is novv occurring. 

Studies made by Tolman and Poland in 1940 
showed the existence of a fringe of pollution from 
saline water near San Francisco Bay. These investi- 
gations indicated that the pollution was caused 
chiefly by movement of saline perched ground water 
through defective and abandoned w^ells, and through 
gravel deposits of active streams discharging into 
the bay. 

In 1940, pollution of ground water in the tideland 
area was primarily restricted to gravels within 100 


feet of the ground surface. Relatively impervious 
layers of blue clay prevented percolation of the pol- 
luted water below this depth, except in areas where 
the clay layers had been punctured. Many wells for- 
merly piercing the blue clay in the tideland area near 
Palo Alto and in the vicinity of Alviso have been 
plugged to prevent percolation of salt water to the 
principal pumping zone. 

Waters in 27 of the wells used in 1940 by Tolman 
and Poland to locate the fringe of pollution were re- 
sampled in 1949 and tested for chloride content. Com- 
parison of the recent and antecedent analyses showed 
no appreciable change in chloride concentration at 
these wells during the nine years. This indicated that 
pollution of deeper pressure aquifers by perched 
ground water had not generally increased, with the 
exception of possible pollution of ground water in the 
Palo Alto area. 

Mineral anatyses of water samples representative 
of ground waters in the Santa Clara Valley are pre- 
sented in Table 20. Results of determination of total 
hardness in water samples collected from ground 
water in the Santa Clara Valley are also presented 
in Table 20. Partial mineral analyses of water sam- 
ples collected from wells in the Santa Clara Valley 
are presented in Appendix G. 



CHAPTER III 


WATER UTILIZATION AND SUPPLEMENTAL REQUIREMENTS 


The nature and extent of water utilization and of 
requirements for supplemental water in the Santa 
Clara Valley, both at the present time and under 
probable conditions of ultimate development, are 
considered in this chapter. In connection with the 
discussion, the following terms are used as defined: 

Water Utilization — This term is used in a broad sense 
to include all employments of water by nature or 
man, whether consumptive or nonconsumptive, as 
well as irrecoverable losses of water incidental to 
such employment, and is synonymous with the 
term 'Cvater use.’’ 

Factors of Water Demand — Those factors pertaining 
to specific rates, times, and places of delivery of 
water, losses of water, quality of water, etc., im- 
posed by the control, development, and use of 
water for beneficial purposes. 

Water Eeqnirement — The amount of water needed 
to provide for all beneficial uses of water and for 
irrecoverable losses incidental to such uses. As used 
in this bulletin, the term refers to consumptive 
use of water in forebay zones plus pumpage in 
pressure zones. 

Snpplemental Water Eeqnirement — The water re- 
quirement over and above the sum of safe ground 
water yield and safe surface water jdeld. 

Consumptive Use of Water — This refers to water con- 
sumed by vegetative growth in transpiration and 
building of plant tissue, and to water evaporated 
from adjacent soil, from water surfaces, and from 
foliage. It also refers to water similarly consumed 
and evaporated by urban and nonvegetative types 
of land use, 

.Applied Water — The water delivered to a farmer’s 
headgate in the case of irrigation use, or to an in- 
dividual’s meter in the ease of urban use, or its 
equivalent. It does not include direct precipitation. 

Ultimate — This refers to conditions after an unspeci- 
fied but long period of years in the future when 
land use and water supph" development will be at 
a maximum and essentially^ stabilized. It is realized 
that any present forecasts of the nature and extent 
of such ultimate development, and resultant water 
utilization, are inherently subject to possible large 
errors in detail and appreciable error in the aggre- 
gate. However, such forecasts, when based upon 
best available data and present judgment, are of 


value in establishing long-range objectives for de- 
velopment of water resources. They are so used 
herein, with full knowledge that their re-evaluation 
after the experience of a period of years may re- 
sult in considerable revision. 

The present water requirement in the Santa Clara 
Valley was determined from both records and esti- 
mates. Estimates of consumptive use of water were 
made by the application of appropriate unit use 
factors to actual or estimated land use patterns. Esti- 
mates of applied water were made from records of 
pumping applications to selected plots of principal 
irrigated crops, and from records of delivery of 
water obtained in connection with this and other 
investigations. 

The probable ultimate water requirement was esti- 
mated by multiplying acreages of the estimated ulti- 
mate land use pattern by appropriate mean unit 
values of water requirement. Supplemental require- 
ments for water were estimated as the differences 
between derived values of safe yield and require- 
ment under both present and ultimate conditions of 
development. 

Water utilization is considered and evaluated in 
this chapter under the general headings, ‘‘Present 
AVater Supply Development,” “Land Use,” “Unit 
Use of Water,” “Past and Present AA^ater Require- 
ments,” “Probable Ultimate Water Requirement,” 
“Nonconsumptive A¥ater Requirements,” and “Fac- 
tors of Abater Demand.” Supplemental water require- 
ments are similarly treated under the two general 
headings, “Present Supplemental Requirement” and 
“Probable Ultimate Supplemental Requirement.” 

WATER UTILIZATION 

The Santa Clara Valley has long been one of the 
most important agricultural areas in the State. Early 
agricultural efforts were limited to the growing of 
grains and other dry-farmed crops. Although exten- 
sive plantings of orchards were made during the 19th 
century, for many years these were not generally irri- 
gated. A series of dry years in the latter part of that 
century resulted in damage to many of the valley 
orchards, and indicated the necessity for providing 
a firm irrigation water supply to supplement the 
variable annual precipitation. The increased yields 
and improved qualit}^ of fruit produced from irri- 
gated orchards offered further stimulus to the trend 
toward more irrigation. 


( 47 ) 



48 


SANTA CLARA VALLEY INVESTIGATION 


Inasmuch as the Santa Clara Valley streams are 
intermittent, having little or no flow during the 
summer season, irrigators found it more expedient 
to utilize water available in underground storage 
than to provide for artificial retention of tributary 
runoff in surface storage reservoirs. Utilization of 
ground water increased rapidly after the turn of the 
century to meet not only irrigation requirements, 
but also the ever increasing municipal and industrial 
water needs of metropolitan San Jose and suburban 
communities. 

Of the total amount of water presently utilized in 
Santa Clara Valley, approximately 73 per cent is 
consumed in the production of irrigated crops, while 
the remainder is consumed- by dry-farmed- crops and 
native vegetation, urban areas, farmsteads, and 
miscellaneous types of land use. It is considered 
urobable that the predominant importance of irri- 
gated agriculture, as related to utilization of water, 
will continue to prevail in South Santa Clara Valley, 
while in North Santa Clara Valley the future develop- 
ment will largely be urban. 

Present Wafer Supply Development 

Approximately 96 per cent of all water require- 
ments in the Santa Clara Valley are presently met by 
water pumped from underlying ground water basins. 
Irrigated lands utilizing ground water are generally 
served by individually owned and operated pumps. 
It has been estimated that in 1948 there were about 
3,700 irrigation wells in the valley. Water supplied in 
the Santa Clara Valle}^ for other than agricultural 
uses is furnished by municipal systems, water dis- 
tricts, and private and mutual companies. 

Public utilities serving v;ater in the Santa Clara 
Valley for domestic and industrial use, together with 


TABLE 21 

GROUND WATER PUMPAGE BY PUBLIC UTILITIES FUR- 
NISHING DOMESTIC AND INDUSTRIAL WATER 
IN SANTA CLARA VALLEY 


Organization 

Area 

served 

Ground water 
pumpage, 
in acre-feet 



1948 

1953 

Agnew Water Works _ - 

Agnew 

30 1 

30 



770 

1,190 

Campbell Water Co. — . ■ 

Campbell _ 

700 

1,020 

San Jose Water Works . 

Campbell 

Cupertino _ - 

Saratoga 

Los Gatos 

San Jose 

12,600 

15,500 

San Martin Water Works — 

San Martin 

30 

t30 

Suburban Water Co. of Loyola- _ 

Cupertino - _ 

1,490 

c3,420 

Water Works of Monte Vista, Ltd 

Monte Vista 

190 

1 390 

Total- 


15,810 

21,580 


» Also diverted 5,040 acre-feet of water in 194S and 12,500 acre-feet in 1953, from 
Los Gatos and Saratoga Creeks. 

Estimated. 

Owned by California Water Service Company. 


the total ground Avater pumpage by each in 1948 
and 1953, are listed in Table 21. 

Cities and communities within Santa Clara County 
having iiublicly owned water systems, and their 
pumpage of ground water in 1948 and 1953, are 
shown in Table 22. 

TABLE 22 

GROUND WATER PUMPAGE BY PUBLICLY OWNED 
SYSTEMS IN SANTA CLARA VALLEY 


City or community 

Ground water pumpage, in acre-feet 

1948 

1953 

! 

Gilroy 

470 

1,030 

Morgan Hill 

220 

260 

Mountain View - _ - - 

1,040 

1,910 

Palo Alto - -- - 

750 

4,250 

Santa Clara _ - _ - „ - i 

2,130 

2,890 

Suburban service .. . _ J 

930 

« 1,000 

Sunnyvale - - - - 

1,450 

2,120 

TOTAL - 

6,990 

13,460 


a Also diverted 120 acre-feet of water from TJvas Creek in 1948. 

Also obtained 3,600 acre-feet of water in 1948, and 2,740 acre-feet in 1953, from 
Hetch Hetchy Aqueduct. 

Estimated. 

In addition to the public utilities and privately 
owned systems, there are several smaller communi- 
ties, and numerous commercial and industrial enter- 
prises, which pump from private wells. The total 
draft on ground water these users was estimated 
to be approximately 9,000 acre-feet in 1948, and 
13,000 acre-feet in 1953. In Table 23 are listed water 
districts and mutual water companies that provide 
service in the Santa Clara Valle^^ Pumpage of ground 
water by these companies and districts is included 
in the foregoing estimates of 9,000 acre-feet and 
13,000 acre-feet for 1948 and 1953, respectively. 

TABLE 23 


AREAS SERVED BY WATER DISTRICTS AND MUTUAL 
WATER COMPANIES IN SANTA CLARA VALLEY 


District or company 

Area served 

Los Robies Mutual Water Company 

Redwood Mutual Water Company 

Stanford Water Company 

Palo Alto 

Los Gatos 

Palo Alto and Stanford Uni- 
versity 


The total draft on ground water by all the fore- 
going water service agencies was approximately 31,- 
800 acre-feet in 1947-48, and 48,000 acre-feet in 
1952-53. It was estimated that farmstead draft in 
both 1947-48 and 1952-53 was approximately 2,300 
acre-feet. The estimated total nonagricultural pump- 
ing draft on ground water in the Santa Clara Valley 
was, therefore, 34,100 acre-feet in 1947-48, and 50,- 
300 acre-feet in 1952-53. 

The area of lands in the Santa Clara Valley served 
by water diverted from surface streams was once 
appreciable but is now insignificant. It lias been 



WATER UTILIZATION AND SUPPLEMENTAL REQUIREMENTS 


49 


reported that the maximum use of surface diverted 
waters occurred between 1904 and 1906, when ap” 
proximately 13,000 acres were irrigated in this man- 
ner. In 1921 the area so irrigated amounted to less 
than 3,000 acres. At present there are a few diversions 
from Los Gatos Creek. However, subdivisions and 
highway construction have made service of these 
surface waters increasingly difficult. 

AVith the foregoing minor exceptions, irrigation 
water service in the Santa Clara Valley is from 
ground water. Lands which were under irrigation 
in 1947-48 in water service areas of North and South 
Santa Clara Valleys are indicated in Table 24. 

TABLE 24 


IRRIGATED LANDS IN NORTH AND SOUTH 
SANTA CLARA VALLEYS, 1947-48 


Division 

Acreage 

North Santa Clara Valley 


Forebay Zone - „ _ _ - 

58,500 

Pressure Zone. ^ 

41.900 

Subtotal -- -- 

100,400 

South Santa Clara Valley 


Forebay Zone . _ „ 

15,400 

Pressure Zone . _ _ 

14,300 

Subtotal -- - - - _ 

29,700 

TOTAL 

130,100 



Water conservation works in North Santa Clara 
Valley retain a portion of the winter runoff that 
would otherwise waste to San Francisco Bay. Waters 
stored in surface reservoirs, constructed and main- 
tained by the Santa Clara A^alley Water Conservation 
District, are released and percolated in stream chan- 
nels for storage underground. Conservation works 
constructed and maintained by the San Jose Water 
AVorks store waters for municipal use. In addition, 
numerous small conservation dams have been built 
by the Soil Conservation Service of the United States 
Department of Agriculture. Location of the major 
existing conservation works, described hereinafter, 
are shown on Plate 17, entitled ‘^Existing Water Con- 
servation Works and Works Considered for Future 
Development, 1955,^^ 

Major conservation works constructed and main- 
tained by the Santa Clara Valley Water Conservation 
District and pertinent data relating thereto, are 
presented in the following tabulation : 


Dam 

Stream bed 
elevation, 

Location in feet 

Reservoir 

storage 

capacity, 

in 

acre-feet 

Coyote 

-Coyote Creek 1,640 

25,000 

Anderson 

-Coyote Creek 405 

75,000 

Calero 

-Arroyo Calero 896 

9.200 

Alma den 

-Alamitos Creek 505 

2,000 

Guadalupe 

-Guadalupe Creek — 481 

8,500 

Lexington 

-Los Gatos Creek 460 

25,000 

Stevens Creek „ 

-Stevens Creek 425 

4.000 


Percolation works have been constructed by the 
Santa Clara Valley Water Conservation District on 
all but one of the major streams. The Penitencia 
Creek percolation ponds, constructed along an aban- 
doned railroad right of way and paralleling Peni- 
tencia Creek, consists of a line of ponds totaling 8,000 
feet in length and having a total area of 4.1 acres. 
The percolation capacity of these ponds is a rate of 
about 15 second-feet. The Coyote Creek percolating 
pond is located in the stream bed of Coyote Creek, 
just below the Lower Gorge and about one mile north 
of Coyote Station. It is formed by an 8-foot-high re- 
movable flashboard dam with reinforced-concrete floor 
and abutments. The area of the pond is 32 acres, and 
its average capacity for percolation in 1947 was a rate 
of about 20 second-feet. 

The Alamitos Creek percolation ponds are located 
at the junction of Alamitos and Guadalupe Creeks, 
and are formed by long low wire-enclosed gravel 
'^sausages^’ across the stream beds. A 6-foot-high re- 
movable fiashboard dam, with reinforced-concrete 
abutments and stilling basin, is located at the down- 
stream end of the percolation area. The percolation 
area totals about 17 acres. 

Percolation works on Los Gatos Creek are limited 
to small diversions for off -stream percolation and 
flooding of highly porous gravel areas. Vasona Dam 
on Los Gatos Creek is located about 2 miles below Los 
Gatos. The dam is constructed of two rolled-earth em- 
bankments, each 30 feet in height, and with a cen- 
trally placed reinforced-concrete spillway 210 feet in 
width. Storage capacity of Vasona Reservoir is 412 
acre-feet, and the reservoir covers an area of about 59 
acres. Water from the reservoir is diverted to the 
unlined Vasona Canal, which has a capacity of 75 
second-feet. The canal generally runs through porous 
ground for about 2.6 miles to San Tomas Aquinas 
Creek, where the diverted water is spread for perco- 
lation upon adjacent orchard land, and in San Tomas 
Aquinas Creek when percolation capacity above the 
natural flow in that creek allows. The Vasona Canal 
Extension, comprising a pumping plant and pipe line, 
has a capacity of 15 second-feet. Water is conveyed in 
it a distance of 1.65 miles from the Vasona Canal to 
Saratoga Creek for percolation in that creek. The 
Upper Page Ditch diverts water from Los Gatos 
Creek, about 1.5 miles beloAv Vasona Dam. The diver- 
sion is made by means of a low concrete and flash- 
board dam, and the diverted water is conveyed a dis- 
tance of 1.8 miles to San Tomas Aquinas Creek. 
Percolation of the diverted water is accomplished by 
spreading the water on orchard land, and by making 
use of the percolating capacity of San Tomas Aquinas 
Creek. The ditch also supplies water to three perco- 
lating ponds having a total area of 3.3 acres. Lower 
Page Dam, located about 1.5 miles below the Upper 
Page Dam on Los Gatos Creek, is a reinforced-con- 
crete diversion dam with low removable dashboards. 
The dam ponds water back over a very porous section 






Courtesy San Jose Chamber of Commerce 


Calero Dam and Reservoir on Arroyo Calero 


WATER UTILIZATION AND SUPPLEMENTAL REQUIREMENTS 


51 


of the stream bed of Los Gatos Creek for about 
one-half mile. Water is diverted at the dam to the 
Lower Pag^e Ditch, for irrigation and percolation on 
orchard land in the vicinity of Campbell. 

In addition to the foregoing works, the Santa Clara 
Yalley Water Conservation District has constructed a 
number of conduits to conve}^ waters from areas of 
surplus to areas of deficiency. The Coyote Canal, 
about 8.9 miles in length, has a capacity of 100 second- 
feet. The canal conveys water conserved in Coyote and 
Anderson Reservoirs to the Coyote Canal Extension, 
to Coyote Creek, and to the Coyote percolation pond. 
The Coyote Canal Extension has a total length of 
about 9 miles. It has a capacity of 65 second-feet to 
Metcalf Road, where water at the rate of 50 second- 
feet is diverted into the recently constructed Coyote- 
Alamitos Canal. The remaining 15 second-feet is 
pumped into the Evergreen Canal. The Coyote- Alami- 
tos Canal has a capacity of 50 second-feet and con- 
veys water a distance of about 9 miles to the Alamitos 
percolation pond. The Evergreen Canal has a capacity 
of 15 second-feet, and comprises about 2,500 feet of 
pipe line and about 7 miles of canal. Water in the 
canal is conveyed to Dry Creek. 

Waters conserved in Almaden Reservoir are con- 
veyed in the Almaden-Calero Canal, having a capac- 
ity of 100 second-feet, a distance of about 4.5 miles to 
Calero Reservoir. The conserved w^aters of Almaden 
and Calero Reservoirs are percolated in the Alamitos 
Creek stream bed and the Alamitos percolation pond. 
Waters conserved in Guadalupe Reservoir are released 
for percolation in the Guadalupe Canal stream bed 
and the Alamitos percolation pond. 

Lexington Reservoir conserves the wdnter flows of 
Los Gatos Creek, which are released for percolation 
during periods of low runoff. AYaters released from 
Lexington Reservoir are diverted from Los Gatos 
Creek through the Upper Page Canal and the Yasona 
Canal to percolation ponds on San Tomas Aquinas 
Creek and Saratoga Creek. AYaters conserved in 
Stevens Creek Reservoir are released for percolation 
in the stream bed of Stevens Creek. 

Conservation works of the San Jose AYater AYorks 
include Lake Elsman, formerly known as Austrian 
Reservoir, and AA^illiams Dam and Reservoir, both on 
Los Gatos Creek ; Lake Ranch Dam and Reservoir on 
Beardsley Creek ; and Upper Howell Dam and Reser- 
voir and Lower Howell Dam and Reservoir, both on 
Rundell Creek. Petinent data pertaining to these 
works are presented in the following tabulation : 

Reservoir 


storage 

Stream bed capacity^ 
elevation, in 

Dam Location hi feet acre- feet 

Lake Elsman ^Los Gatos Creek 940 6,140 

Williams Los Gatos Creek 1,152 160 

Lake Ranch Beardsley Creek 1,771 323 

Upper Howell Rnndell Creek 1,376 243 

Lower Howell Rundell Creek 1,349 153 


The South Santa Clara Yalley Water Conservation 
District in South Santa Clara Yalley has initiated 
the construction of a dam and reservoir on Llagas 
Creek and is giving consideration to the construction 
of a dam and reservoir on Uvas Creek. 

Chesbro Dam on Llagas Creek, presently under con- 
struction by the South Santa Clara Yalley AA^ater 
Conservation District, is an earthfill structure with 
chute spillway, and is located in Section 30, Township 
9 South, Range 3 East, M. D. B. & M., some 3 miles 
west of Morgan Hill. The elevation of the stream 
bed at the dam is 441 feet, and the storage capacity 
of the reservoir when completed will be 7,500 acre- 
feet. The dam when completed will be 87 feet in 
height from stream bed to spillway lip, and wdll have 
a crest elei-ation of 543 feet. The dam will have a 
crest length of about 700 feet, a crest wddth of 30 feet, 
and 3 : 1 upstream and downstream slopes. 

Appropriation of Water. Since the effective date 
of the AA^ater Commission Act on December 19, 1914, 
applications to appropriate water of streams in the 
Santa Clara Yalley have been filed with the Division 
of AYater Resources or its predecessors. As of Decem- 
ber 31, 1954, 81 applications to appropriate water of 
streams of the Santa Clara Yalley were on file wdth 
the Division of AA^ater Resources. These applications 
are listed in Appendix H, together with pertinent 
information on the proposed diversions and uses of 
water, and the present status of the applications. 

The applications listed in Appendix H should not 
be construed as comprising a complete or even partial 
statement of water rights in the Santa Clara Yalley. 
They do not include appropriative rights initiated 
prior to December 19, 1914, riparian rights, correla- 
tive rights of overlying owners in ground water 
basins, nor prescriptive rights which ma^^ have been 
established on either surface streams or ground 
water basins, none of which are of record with the 
Division of AA^ater Resources. In general, water rights 
may be firmly established only by court decree. 

Dams Under State Supervision. The Department 
of Public AYorks, acting through the agency of the 
State Engineer, supervises the construction, enlarge- 
ment, alteration, repair, maintenance, operation, and 
removal of dams, for the protection of life and prop- 
erty within California. All dams in the State except- 
ing those under federal jurisdiction, are under the 
jurisdiction of the Department. ‘‘Dam” means any 
artificial barrier, together with appurtenant works, if 
any, across a stream, w^atercourse, or natural drain- 
age area, which does or may impound or divert water, 
and which either (a) is or will be 25 feet or more in 
height from natural stream bed to crest of spillway, 
or (b) has or will have an impounding capacity of 50 
acre-feet or more. Any such barrier, which is or will 
be not in excess of six feet in height, regardless of 
storage capacity, or which has or will have a storage 



Orchards in Bloom, 
Santa Clara Valley 


Courtesy San Jose 
Chamber of Commerce 




WATER UTILIZATION AND SUPPLEMENTAL REQUIREMENTS 


53 


-capacity not in excess of 15 acre-feet regardless of 
lieight, is not considered a dam. Approximately 26 
dams in and adjacent to the Santa Clara Valley are 
presently under State supervision. Pertinent data re- 
lating to these dams are included in Appendix I. 

Land Use 

As a first step in estimating the water requirements 
in the Santa Clara Valley, determinations were made 
of the nature and extent of land use during the base 
periods and during the investigational seasons. Simi- 
larly, the probable nature and extent of ultimate 
land use as related to water requirement was esti- 
mated. 

Past and Present Patterns of Land Use. The 

United States Bureau of the Census has reported that 
the irrigated area in Santa Clara County increased 
from 70,132 acres in 1919 to 96,130 acres in 1929, de- 
creased to 95,959 acres in 1939, and increased to 101,- 
172 acres in 1949, 

A detailed land use survey of agricultural lands, 
and a general delimitation of urban areas in the Santa 
Clara Valley, were made during 1947-48, 1948-49, and 
1954-55 in connection with the current investigation. 
Agricultural developments were mapped, showing the 
location and distribution of cropped lands. 

In 1948-49, urban areas of North Santa Clara Val- 
ley were mapped in connection with the current 
State-wide Water Resources Investigation, supple- 
menting the aforementioned survey. Developments 
wure grouped into single-family, residential, multiple 
dwelling, commercial, industrial, irrigated park, in- 
stitutional, and other miscellaneous classifications. 
For purposes of this bulletin, the land use pattern 
existing during the 1948-49 season was considered to 
represent present” conditions of development in 
the area, and is so referred to in subsequent discus- 
sion. 

Plate 16, entitled ^Mjand Use, 1955,” depicts areas 
of irrigated land, urban developments, and nonirri- 
gated land, determined from the foregoing surveys. 
A tabulation, listing class and type of land use in 
North and South Santa Clara Valleys during 1948-49, 
is presented in Table 25, 

Estimates of average land use patterns prevailing 
in North and South Santa Clara Valleys during the 
respective base periods were based on the land use 
surve^^s of 1947-48 and 1948-49, records of electrical 
energy consumption, and records of water deliveries. 
Average areas of irrigated lands during these pe- 
riods were estimated from the 1947-48 land use 
data, by application of ratios based on records 
of agricultural electric energy consumption, adjusted 
for ground water level fluctuations and variations in 
available precipitation. The average base period urban 
areas in North Santa Clara Valley were estimated 
from the 1949 data, using records of water deliveries 


TABLE 25 

PATTERN OF LAND USE IN NORTH AND SOUTH 
SANTA CLARA VALLEYS, 1948-49 


(!n acres) 



North Santa Clara Valley 

South Santa Clara Valley 

Class and type 
of land use 

Fore- 

bay 

Zone 

Pres- 

sure 

Zone 

Total 

Fore- 

bay 

Zone 

Pres- 

sure 

Zone 

Total 

Irrigated Lands 
Alfalfa 

500 

2,000 

2,500 

100 

1,000 

1,100 

Permanent pas- 
ture 

1,100 

1,700 

2,800 

900 

700 

1,600 

Deciduous or- 
chard 

48,700 

23,200 

71,900 

11,200 

6,300 

17,500 

Beans 

200 

1,000 

1,200 

200 

500 

700 

Tomatoes 

300 

300 

600 

200 

900 

1,100 

Truck ^ ^ . 

3,600 

12,700 

16,300 

600 

3,100 

3,700 

Sugar beets 

2,000 

1,000 

3,000 

200 

1,500 

1,700 

Vineyards 

2,100 

0 

2,100 

2,000 

300 

2,300 

Subtotals 

58,500 

41,900 

100,400 

15,400 

14,300 

29,700 

Nonirrigated Lands 

Dry-farmed and 
native grasses- 

11,900 

11,400 

23,300 

6,300 

2,800 

9,100 

Dry-farmed or- 
chard 

1,000 


1,000 

400 


400 

Fallow lands 

200 

400 

600 

400 

400 

800 

Brush and trees _ 

2,700 

1,500 

4,200 

600 

500 

1,100 

Interior hills 

---- 

--- 

---- 

5,200 

---- 

5,200 

Subtotals 

15,800 

13,300 

29,100 

12,900 

3,700 

16,600 

Urban Areas 
Residential 

3,200 

6,400 

9,600 




Multi-residen- 

tial 

100 

200 

300 




Commercial 

100 

600 

700 







Industrial- 

100 

1,200 

1,300 







Irrigated parks „ „ 

300 

300 

600 






Airfields 

100 

100 

200 






Institutions 

300 

300 

600 





Military 



1,200 

1,200 







Streets and 
sidewalks 

1,700 

4,700 

6,400 




Vacant lots 

500 

2,500 

3,000 

---- 

---- 

---- 

Subtotals 

6,400 

17,500 

23,900 

*800 

*300 

*1,100 

Farmsteads and 
Miscellaneous 

Farmsteads 

700 

1,200 

1,900 

300 

300 

600 

Roads and rail- 
roads 

4,700 

3,300 

8,000 

2,400 

1,800 

4,200 

Water surface 

400 

1,400 

1,800 


--- 

---- 

Subtotals 

5,800 

5,900 

11,700 

2,700 

2,100 

4,800 

TOTALS„^. 

86,500 

78,600 

165,100 

31,800 

20,400 

52,200 


* Breakdown of subtotals not available. 


by the San Jose Water Works and other entities as 
indices. It was assumed that the area of farmsteads 
varied in proportion to irrigated agricultural develop- 
ment, while the areas of miscellaneous land classifi- 
cations remained equal to the 1948 values. 

A summary of the estimated average patterns of 
land use prevailing during the 13 -year and 16-year 
base periods for North and South Santa Clara Val- 
leys, respectively, is given in Table 26. 

Probable Ultimate Land Use. Several assumptions 
were made as to the probable distribution of ulti- 
mate urban and agricultural developments in North 
Santa Clara Valley, and in portions of the contiguous 



54 


SANTA CLARA VALLEY INVESTIGATION 


hills and marshlands considered habitable. Based 
oil. present tendencies, it was assumed that all land 
susceptible of development in the forebay zone of 
the northern valley, and on adjacent habitable hills, 
will ultimately be used for urban purposes. However, 
it seems likely that a small portion of the pressure 
zone in North Santa Clara Valley will remain in 
agricultural use, and a figure of 10 per cent was 
arbitrarily taken as the proportion of that area which 
will ultimately be occupierl by that el ass. 

To compute the net valley floor acreages used in 
evaluating the amounts of urban and agricultural 
development, present wastelands and the estimated 
ultimate rural road areas were deducted from the 
gross investigational area. Outside the northern valley 
are about 53,700 acres of foothill and salt marsh- 
lands considered susceptible of urban development. 
Of this acreage, about 9,300 acres of salt marshes 
adjacent to San Francisco Bay are now used for 
evaporating sea water for salt production, or are 
owned by the salt companies for this purpose for 
future development. Thus, the assumed net habitable 
portion of the hills and marshlands adjacent to the 
investigational area is about 44,400 acres, of which 
about 4,000 acres are marshlands, and about 40,400 
acres are hills. It was further assumed that under 
ultimate conditions of development the hill lands will 
have about one-half the density of valley floor develop- 
ment, but will be of similar pattern. 

The present land use pattern in urban areas of 
the San Francisco Bay Area, estimated in connection 
ydth studies being made by the Division of Water 
Resources, for the State-wide Water Resources In- 
vestigation, was used as a guide in estimating the 
pattern and proportions of the probable ultimate 
urban area in North Santa Clara Valley. It was as- 
sumed that the probable ultimate industrial area 
will be largely located in the pressure zone. 

The estimated pattern and proportions of land use 
v/ithin the probable ultimate urban area of North 
Santa Clara Valley is presented in Table 27. 

TABLE 26 

SUMMARY OF AVERAGE PATTERN OF LAND USE 
DURING BASE PERIODS IN NORTH AND 
SOUTH SANTA CLARA VALLEYS 

(in acres) 


Class of land use 

North Santa Clara Valley 

South Santa Clara Valley 

Forebay 

Zone 

Pressure 

Zone 

Total 

Forebay 

Zone 

Pressure 

Zone 

Total 

Irrigated lands 

53,300 

39,000 

92,300 

13,800 

12,900 

26,700 

Nonirrigated lands. 

23,300 

23,500 

46,800 

14,700 

5,200 

19,900 

Urban areas 

4,200 

10,400 

14,600 

600 

200 

800 

Farmsteads 

600 

1,100 

1,700 

300 

300 

600 

Miscellaneous 

5,100 

4,600 

9,700 

2,400 

1,800 

4,200 

TOTALS 

86,500 

78,600 

165,100 

31,800 : 

20,400 

52,200 


TABLE 27 

PATTERN OF URBAN LAND USE IN NORTH SANTA CLARA 
VALLEY UNDER PROBABLE ULTIMATE DEVELOPMENT 


(In percent) 


Type of land use 

Total 

Forebay 

Zone 

Pressure 

Zone 

Single-famdy residential ._i 

41.8 

44.8 

38.1 

Multiple-family residential 

3.3 

3.6 

3.0 

Commercial __ 

4.1 

, 4.4 

3.7 

Industrial. ___ 

8.1 

3.7 

13.5 

Irrigated parks ..... 

7.0 

' 7.6 

6.3 

Institutions 

3.2 

3.4 

2.8 

Airfields .. . 

2.5 

2.7 

2.2 

Streets and sidewalks. . _ 

30.0 

29.8 

30.4 

Vacant 

0.0 

0.0 

0.0 

'T'OTAT.S 

100.0 

100 0 

100.0 


The percentages indicated for industrial develop- 
ment in Table 27 are greater than the present ratio 
of industrial to total urban land use, which pres- 
ently amounts to about one per cent. The assumed 
increase was based on the consideration that when 
agriculture ceases to be of major importance, indus- 
try will assume the dominant role in the economy of 
North Santa Clara Valiev. 


Lands in South Santa Clara Valley regarded as 
irrigable are indicated on Plate 16. It was assumed 
that 95 per cent of the gross irrigable area will be 
irrigated in any one year. It was further assumed 
that the present proportionate distiubiition of land 
use will prevail for new lands brought under irriga- 
tion in South Santa Clara Valley. For urban areas, 
ultimate land use was considered to be about 35 per 
cent greater than that under present conditions. 

The patterns of land use estimated for probable 
ultimate development in North and South Santa 
Clara Valle^^s are indicated in Table 28. 


TABLE 28 


ESTIMATED PROBABLE ULTIMATE PATTERN OF LAND USE 
IN NORTH AND SOUTH SANTA CLARA VALLEYS 

(In acres) 


Class and type of 
land use 

North Santa Clara Valley 

South Santa Clara Valley 

Forebay 

Zone 

Pressure 

Zone 

Total 

Forebay 

Zone 

Pressure 

Zone 

Total 

Irrigated lands 

Nonirrigated lands. 

Urban areas 

Farmsteads 

Miscellaneous 

Subtotals ^ 

Hills 

0 

0 

83,400 

0 

3,100 

7,300 

0 

67,600 

200 

3,500 

7,300 

0 

151,000 

200 

6,600 

22,000 

0 

1,200 

400 

8,200 

17,300 

0 

300 

400 

2,400 

39,300 

0 

1,500 

800 

10,600 

86,500 

40,400 

0 

78,600 

0 

4,000 

165,100 

40,400 

4,000 

31,800 

20,400 

52,200 

Marshlands 




Subtotals 




40,400 

4,000 

44,400 




TOTALS : 




126,900 

1 82,600 

209,500 

31,800 

20,400 

52,200 



AVATER UTILIZATION AND SUPPLEMENTAL REQUIREMENTS 


55 


Unit Use of Water 

The second step in evaluation of water require- 
ments of the Santa Clara Valley involved the deter- 
mination of unit values of consumptive use of water 
for the forebay zones, and unit values of applied 
water for the pressure zones, for each of the several 
types of water-consuming land use. 

Estimates of unit values of consumptive use of 
water were largely based on the results of prior in- 
vestigations and studies in other areas. A procedure 
suggested by Harry P. Blaney and Wayne D. Griddle 
of the Soil Conservation Service, United States De- 
partment of Agriculture, in their reports entitled ‘‘A 
Method of Estimating Water Requirements in Irri- 
gated Areas From Climatological Data, dated De- 
cember, 1947, and ‘‘Determining AA^ater Requirements 
in Irrigated Areas Prom Climatological and Irrigation 
Data, dated August, 1950, was generally utilized 
for adjustment of available data on unit consumptive 
use by irrigated crops in other localities to correspond 
with conditions existing in the Santa Clara A^alley. 
This method involves correlation of the data on the 
basis of variations in average monthly temperatures, 
monthly percentages of annual daytime hours, precip- 
itation, and lengths of growing season. It disregards 
certain generally unmeasured factors, such as wind 
movement, humidity, etc. Average monthly temper- 
atures at San Jose and Hollister were used for North 
and South Santa Clara A^alleys, respectively, since 
these were considered representative of the two areas. 
Monthly percentages of annual daytime hours were 
determined for latitude 37 15' N., which passes ap- 

proximatel}^ through the center of the area of in- 
vestigation. 

The following is an outline of the procedure utilized 
for estimating unit values of consumptive use of 
water : 

1. The unit value for each irrigated crop during 
its growing season was taken as the product of avail- 
able heat and an appropriate coefficient of consump- 
tion, where: (a) the aAmilable heat was the sum of 
the products of aA^erage monthly temperature and 
monthU per cent of daytime hours, and (b) the co- 
efficient of consumption Avas one AAJiich has been se- 
lected as appropriate for California by Harry P. 
Blaney. Certain exceptions inAuUed the use of modi- 
fied coefficients, and coefficients estimated from con- 
sumpth^e use data aA^ailable from other sources. 

2. The unit Amlue for each irrigated crop during 
its nongroAving season Avas taken as the amount of 
precipitation available, but not exceeding one to tAvo 
inches of depth per month, depending on the type of 
crop. 

3. The seasonal unit A^alue for each irrigated crop 
Avas taken as the summation of A^alues determined 
under items 1 and 2 for that crop. 


4. Unit seasonal A^alues for native annual grasses 
Avere taken as the summation of available precipita- 
tion up to but not exceeding tAVO inches in depth per 
month. 

5. Unit seasonal values for free water surfaces Avere 
estimated from short-period evaporation records at 
Alviso and along Coyote Creek. Unit seasonal con- 
sumptwe use of water by roads and railroads Avas 
estimated from evaporation data and from amount of 
precipitation estimated to be retained on such type 
of land use. 

6. Unit seasonal A^lues for native vegetation other 
than annual grasses were estimated on the basis of 
aAmilable data for corresponding consumpth^e use of 
Avater in similar localities, due consideration being 
given to density and type of A^egetation and depth to 
ground Avater. 

7. The aA^erage unit seasonal Amlue for farmsteads 
Avas estimated at 2.0 feet of depth, the estimate 
being based on data obtained in other similar locali- 
ties. 

8. Unit seasonal consumpth^e use of Avater values 
for urban area classifications AA^ere estimated from 
data obtained from the land use suiweys made in 
connection with the current State-AAude AA^ater Re- 
sources Iiwestigation. 

Estimated mean unit seasonal a^ allies of consump- 
tiA^e use of Avater in the forebay zones of North and 
South Santa Clara A^alleys, including A^aliies for con- 
sumption of both apjilied Avater and precipitation, 
are presented in Table 29. AYeighted unit A^alues of 
seasonal consumptiA^e use of Avater for the different 
classes of land use, Adhere pertinent, are also presented 
in Table 29. The Aveighted unit a^ allies Avere deter- 
mined by diAuding the summation of unit Amlues of 
consiimptwe use of each type of land use, multiplied 
by their respectwe acreages, by the summation of 
acreage. 

Although consiimptNe use of Avater is an appropri- 
ate measure of Avater requirement in the forebay 
zones of the Santa Clara A^alley, it is not a correct 
measure of Avater requirement in the pressure zones. 
Since the iinconsiimed portion of applied Avater 
in the pressure zones is preA^ented from returning 
to the underhang aquifers for re-use, because of the 
relatiA^ely impermeable clay strata overlAung the aqui- 
fers, determinations of water requirement in these 
zonea Avere based on recorded and estimated applied 
water. 

The term ‘ ‘ applied water, ^ ^ as used in this bulletin, 
refers to that water other than precipitation which 
is delivered to a farmer ^s headgate in the case of irri- 
gation use, or to an indhdduaUs meter in the case of 
urban use, or its equivalent. During two seasons of 
the investigation measurements were made of the 
amount of irrigation water applied to selected plots 
of principal crops groAvn in the Santa Clara A^alley. 



56 


SANTA CLARA VALLEY INVESTIGATION 


TABLE 29 

ESTIMATED UNIT VALUES OF MEAN SEASONAL CON^ 
SUMPTIVE USE OF WATER IN FOREBAY ZONES OF 
NORTH AND SOUTH SANTA CLARA VALLEYS 


(In feet of depth) 


Class and type of 
land use 

North Santa Clara Valley 

South Santa Clara Valley 

Applied 

water 

Precip- 

itation 

Total 

Applied 

water 

Precip- 

itation 

Total 

Irrigated lands 







Alfalfa^ — 

2.1 

1.5 

3,6 

2.1 

1.5 

3.6 

Permanent pas- 







ture 

2.2 

1.2 

3.4 

2.2 

1.2 

3.4 

Deciduous 







orchards- 

1.2 

1,3 

2.5 

1.2 

1.3 

2.5 

Beans ^ - 

0.7 

1.1 

1.8 

0.8 

1.0 

1.8 

Tomatoes 

0.9 

1.2 

2.1 

0.9 

1.2 

2.1 

Truck 

1.2 

1.1 

2.3 

1.3 

1.0 

2.3 

Sugar beets 

1,2 

1.1 

2.3 

1.3 

1.0 

2.3 

Vineyards 

0.9 

1.2 

2.1 

1.0 

1.1 

2.1 

Weighted 







average 

1.2 

1.3 

2.5 

1.2 

1.3 

2.5 

Nonirrigated lands 







Dr 5 ''-farmed and 







native grasses 



1.4 



1.4 

Dry-farmed 







orchard - _ 



1.2 



1,1 

Brush and trees _ 



3,0 



3.0 

Fallow lands 



0.8 



0.8 

Interior hills 






1.3 

Weighted 







average--- 



1.6 



1.4 

Urban areas 







Residential 

2.0 


2.0 




M ulti-residential 

6.0 


6.0 




Commercial 

4.0 


4.0 




Industrial- 

8.0 


8.0 




Irrigated parks-- 

1.0 

1.4 

2.4 




Air fields 

0.4 

0.6 

1.0 




Institutions 

2.0 


2.0 




Streets and side- 







walks _ - - 


0.5 

0.5 




Vacant lots - _ 

--- 

1.2 

1.2 




Weighted 







average 

1.4 

6.3 

1.7 

1.4 

0.3 

1.7 

Farmstead and mis- 







celianeous 







Farmstead 

1.0 

1.0 

2.0 

1.0 

1.0 

2.0 

Roads and rail- 







roads 



0.7 



0.7 

Water surface 



4.0 



4.0 


Records of such application of water pumped from 
wells were obtained for 106 plots during 1947-48, 
and for 40 plots during 1948-49. For each well, the 
pump discharge, acreage of each tj^pe of crop irri- 
gated, number of Irrigations, period of irrigation, 
and arnoiints of water applied in each irrigation 
were recorded. From these data, monthly and total 
seasonal applications of water to each crop were de- 
termined. Detailed results of these studies are given 
in Appendix J, and location of the plots is indicated 
on Plate 16. Estimates of weighted seasonal applica- 
tion of ground water on representative plots of prin- 
cipal crops, based on the foregoing detailed studies 
and on other studies conducted in comparable areas 
having similar crops, are presented in Table 30 for 


the forebay and pressure zones of the Santa Clara 
Valley. These estimates were utilized in the deter- 
mination of total applied water to irrigated crops. 

TABLE 30 

ESTIMATED WEIGHTED MEAN SEASONAL AP- 
PLICATION OF GROUND WATER TO PRINCIPAL 
CROPS IN SANTA CLARA VALLEY 

(In feet of depth) 


Crop 

Applied water 

1 Forebay zones 

1 Pressure zones 

Alfalfa 

2.7 

2.8 

Beans - 

1. 1 

1.1 

Deciduous orchard 

2.1 

1.4 

Permanent pasture - 

2.6 

2.6 

Sugar beets-- - - 

l.S 

1.3 

Tomatoes _ - - 

1.5 

1.5 

Truck-- -- -- - „ 

2.4 

2.7 

Vineyard - 

1.2 

i 

1.0 


Urban draft on ground water in North Santa Clara 
Valley was estimated from data obtained by the Di- 
vision of Water Resources in connection with the 
State-wide Water Resources Investigation. Unit values 
of urban Tvater requirement were determined from 
surveys of water use in typical areas for each of the 
types of urban land use. Water meter readings for 
a 12-month period in 1948-49 -were obtained from 
■water supply agencies serving the areas, and unit 
values of water use were computed. 

LTnit values of water requirement, estimated by the 
foregoing method, were applied to the urban areas of 
San Jose, Sunnyvale, Mountain View, Los Altos, 
Cupertino, and Monte Vista, and the resulting totals 
were compared with measured deliveries of Tvater. 
Some adjustments in the unit values -were required 
so that derived values agreed with measured deliv- 
eries. These adjusted derived values were considered 
also applicable to urban areas in South Santa Clara 
Valley. 

A siimmaiw of the derived iinit values of urban 
draft on ground water, resulting from the foregoing 
studies, is shown in Table 31. This table presents 
estimated metered deliveries of water on net devel- 
oped areas, and required draft on ground water for 
net developed areas. The unit values of draft on 
ground water are based on an assumed 10 per cent 
conveyance loss in distribution systems. This rate of 
loss was generally substantiated by records of the 
San Francisco Water Department and the East Bay 
Municipal Utility District. 

Based on the data presented in Tables 30 and 31, 
it was estimated that the total application of ground 
water during the 1947-48 season in North and South 
Santa Clara Valleys was about 225,000 acre-feet. As 
a check on this figure, the Pacific Gas and Electric 
Company and the Coast Counties Gas and Electric 



WATER UTILIZATION AND SUPPLEMENTAL REQUIREMENTS 


57 


TABLE 31 


ESTIMATED PRESENT UNIT VALUES OF URBAN DRAFT 
ON GROUND WATER IN SANTA CLARA VALLEY 

(In feet of depth) 



Gross 

draft 

De- 

Requirement 

Type of urban use 

livered i 
to meter 

Forebay 

zones 

Pressure 

zones 

Residential (one- and two-family 
dwellings) ^ 

2.2 

2.0 

2.0 

2.2 

Multiple-family residential (three or 
more families) 

6.6 

6.0 

6.0 

6.6 

Commercial - ^ 

4.4 

4.0 

4.0 

4.4 

Industrial. . .. 

8.8 

8.0 

8.0 

8.8 

Irrigated parks ..... 

1.1 

1.0 

1.0 

1.1 

Institutions . 

2.2 

2.0 

2,0 

2.2 

Airfields 

0.4 

0.4 

0.4 

0.4 


Company, now owned hy the Pacific Gas and Electric 
Company, furnished records of electrical power con- 
sumption for pumping, from which it was estimated 
that ground water pumping was 233,000 acre-feet in 
North and South Santa Clara Valleys. The estimate 
based on data furnished by the companies gave con- 
sideration to the relationship between pumping plant 
horsepower, drawdown, and power consumption per 
unit of water pumped at various lifts, as determined 
by pump performance tests conducted in the valley 
by the companies. In view of the nature of the basic 
data, the check indicated was believed to have been 
Yevy close. 

Post and Present Wafer Requirements 

In both North and South Santa Clara Valleys the 
basic ground water basins are the free ground water 
or forebay zones. Ground water in these zones not 
only constitutes the source of water pumped for use 
on overlying lands, but the free ground water basins 
also serve as reservoirs from which flow enters the 
confined aquifers of the pressure zones to supply most 
of the extractions therefrom. The physical character- 
istics of the forebay zones permit unused portions of 
precipitation, stream flow, and irrigation water to 
percolate to the water table, where the waters are 
available for future use or re-use. However, this is not 
true of the pressure zones, since relatively impermea- 
ble clay strata prevent surface waters from reaching 
the principal water-yielding aquifers. 

The total present water requirement, as determined 
for the Santa Clara Valley, includes consumptive use 
of water in the forebay zones plus the draft on 
ground water in the pressure zones, during the base 
periods, and under mean conditions of water supply 
with 1948 development. These quantities were esti- 
mated by multiplying the acreage of each type of 
land use by its respective unit value of consumptive 
use of water in the forebay zones, and unit draft on 
ground water in the pressure zones. The total con- 
sumptive use of precipitation and applied water in 


the forebay zones, added to draft on ground water in 
the pressure zones, gave the amount of the seasonal 
water requirement met by the forebay zones. 

It was estimated that the water requirement met 
from the forebay zone of North Santa Clara Valley 
averaged about 274,100 acre-feet per season during 
the 13-year base period. With 1948 conditions of de- 
velopment, it was estimated that the total mean sea- 
sonal water requirement met from the forebay zone 
would have been about 297,200 acre-feet, an increase 
of about eight per cent above the actual base peidod 
average. The increase can be attributed to expansion 
of the areas of land under irrigation or urban devel- 
opment, and corresponding decrease in the area of 
nonirrigated lands. This estimate is presented in 
Table 32. 

TABLE 32 


ESTIMATED PAST AND PRESENT SEASONAL WATER 
REQUIREMENTS MET FROM FOREBAY ZONE 
OF NORTH SANTA CLARA VALLEY 



Weight- 

ed 

mean 

seasonal 

Average for 13- 
year base period, 
1935-36 through 
1947-48 

Mean with 

1948 land use 

Class of land use 

unit 
water 
require- 
ment, 
in feet 
of depth 

Area, 

in 

acres 

Total 

w'ater 

require- 

ment, 

in 

acre-feet 

Area, 

in 

acres 

Total 

water 

require- 

ment, 

in 

acre-feet 

Forebay Zone 

Irrigated lands 

2.5 

53,300 

133,200 

58,500 

146,200 

Nonirrigated lands 

1,6 

23,300 

37,300 

15,800 

25,300 

Urban areas _ 

1.7 

4,200 

7,100 

6,400 

10,900 

Farmsteads 

2.0 

600 

1,200 

700 

1,400 

Miscellaneous _ 

1.0 

5,100 

5,100 

5,100 

5,100 

Subtotals 


86,500 

183,900 

86,500 

188,900 

Pressure Zone 






Irrigated lands _ 

1.8 

39,000 

70,200 

41,900 

75,400 

Nonirrigated lands 

0 

23,500 

0 

13,300 

0 

Urban areas 

1.8 

10,400 

18,700 

17,500 

31,500 

Farmsteads 

1,2 

1,100 

1,300 

1,200 

1,400 

Miscellaneous 

0 

4,600 

0 

4,700 

0 

Subtotals 


78,600 

90,200 

78,600 

108,300 

TOTALS 


165,100 

274,100 

165,100 

297,200 


It was estimated that in South Santa Clara Valley 
the seasonal water requirement met from the forebay 
zone averaged about 82,300 acre-feet during the 16- 
3 ^ear base period, with a mean value of about 86,900 
acre-feet per season under 1948 conditions of devel- 
opment. The increase in water requirement may be 
attributed to an expansion of area under agricultural 
and urban water service. A summary of this estimate 
is pi*esented in Table 33. 

As has been stated, the net seasonal draft on 
ground water in North and South Santa Clara Val- 
leys was estimated by adding the consumptive use of 
applied water in the forebay zones to the total draft 
of ground water in the pressure zones. In North 



58 


SANTA CLARA VALLEY INVESTIGATION 


TABLE 33 


ESTIMATED PAST AND PRESENT SEASONAL WATER 
REQUIREMENTS MET FROM FOREBAY ZONE 
OF SOUTH SANTA CLARA VALLEY 


Class of land use 

Weight- 

ed 

mean 

seasonal 
unit 
water 
require- 
ment, 
in feet 
of depth 

Average for 16- 
year base period, 
1932-33 through 
1947-48 

Mean with 

1948 land use 

Area, 

in 

acres 

Total 

water 

require- 

ment, 

in 

acre-feet 

Area, 

in 

acres 

Total 

water 

require- 

ment, 

in 

acre-feet 

Forebay Zone 






Irrigated lands __ 

2.5 

13,800 

34,500 

15,400 

38,500 

Nonirrigated lands 

1.4 

14,700 

20,600 

12,900 

18,100 

Urban areas- 

1.7 

600 

1.000 

800 

1,400 

Farmsteads,, 

2.0 

300 

600 

300 

600 

Miscellaneous 

0.7 

2,400 

1,700 

2,400 

1,700 

Subtotals 


31,800 

58,400 

31,800 

60,300 

Pressure Zone 






Irrigated lands 

1.8 

12,900 

23,200 

14,300 

: 25,700 

Nonirrigated lands 

0 

5,200 

0 

3,700 

0 

Urban areas - 

1.7 

200 

300 

300 

500 

Farmsteads _ 

1.2 

300 

400 

300 

400 

Miscellaneous 

0 

1,800 

0 

1,800 

0 

Subtotals 


20,400 

23,900 

20,400 

26,600 

TOTALS 


52,200 

82,300 

52,200 

86,900 


TABLE 34 


ESTIMATED AVERAGE AND MEAN SEASONAL DRAFT ON 
GROUND WATER IN NORTH SANTA CLARA VALLEY 


Class of land use 

Unit 

seasonal 

draft, 

in 

feet 

of depth 

Average for 13- 
year base period, 
1935-36 through 
1947-48 

Mean with 

1948 land use 

Area , 
in 

acres 

Total 

draft, 

in 

acre-feet 

Area, 

in 

acres 

Total 

draft. 

in 

acre-feet 

Forebay Zone 






Irrigated lands 

1.2 

53,300 

64,000 

58,500 

70,200 

Nonirrigated lands „ . 

0 

23,300 

0 

15,800 

0 

Urban areas 

1.4 

4,200 

5,900 

6,400 

9,000 

Farmsteads . _ 

CO 

600 

600 

700 

700 

iVlisceilaneous 

0 

5,100 

0 

5,100 

0 

Subtotals 


86,500 

70,500 

86,500 

79,900 

Pressure Zone 






Irrigated lands 

1.8 

39,000 

70,200 

41,900 

75,400 

Nonirrigated lands. 

0 

23,500 

0 

13,300 

0 

Urban areas 

1.8 

10,400 

18,700 

17,500 

31,500 

Farmsteads 

1.2 

1,100 

1,300 

1,200 

1,400 

Miscellaneous 

0 

4,600 

0 

4,700 

0 

Subtotals 


78,600 

90,200 

78,600 

108,300 

TOTALS 


165,100 

160,700 a 

165,100 

188,200 


® Includes 2,000 acre-feet of imported water^ and 3,900 acre-feet diverted from Sara- 
toga and Los Gatos Creeks. 

^Includes 4,000 acre-feet of imported water, and 5,000 acre-feet diverted from Sara- 
toga and Los Gatos Creeks. 


Santa Clara Vallejo the estimated net draft on ground 
water averaged about 154,800 acre-feet per season 
during the 13-year base period, and 179,200 acre-feet 
under mean conditions of water supply and 1948 land 
use. Table 34 presents a summar}^ of these estimates. 
It will be noted that the total seasonal draft on 
ground water for the base period, and the mean value 
with 1948 land use, exceed the foregoing estimates by 
5,900 and 9,000 acre-feet, respectively. The excess in 
each ease represents the sum of the average seasonal 
importation of water and the water diverted from 
Saratoga and Los Gatos Creeks. 

The total seasonal draft on ground water in South 
Santa Clara Vallejo was estimated to have been about 
41,600 acre-feet during the 16-year base period, and 
approximately 46,400 acre-feet under mean condi- 
tions of water supply and with 1948 development. 
Table 35 presents a summary of these estimates of 
total seasonal draft on ground water in South Santa 
Clara Valley. 

TABLE 35 


ESTIMATED AVERAGE AND MEAN SEASONAL DRAFT ON 
GROUND WATER IN SOUTH SANTA CLARA VALLEY 


Class of land use 

Unit 

draft, 

in 

Average for 16- 
year period, 

1 1932-33 through 
1948-49 

Mean with 

1948 land use 

feet 

of 

depth 

Area, 

in 

acres 

Total 
draft, in 
acre- 

feet 

Area, 

in 

acres 

Total 
draft, in 
acre- 
feet 

Forebay Zone 

Irrigated lands. 

1.2 

13,900 

16,700 

15,400 

18,500 

Nonirrigated lands. - . 

0 

14,600 

0 

12,900 

0 

Urban areas 

1.2 

600 

700 

800 

1,000 

Farmsteads 

1.0 

300 

300 

300 

300 

Miscellaneous 

0 

2,400 

0 

2,400 

0 

Subtotals 


31,800 

17,700 

31,800 

19,800 

Pressure Zone 






Irrigated lands 

1.8 

12,900 

23,200 

14,300 

25,700 

Nonirrigated lands.. . . 

0 

5,200 

0 

3,700 

0 

Urban areas 

1.7 

200 

300 

300 

500 

I armsteads _ . 

1.2 

300 ; 

400 

300 

400 

Miscellaneous 

0 

1,800 i 

0 

1,800 

0 

Subtotals 


20,400 

23,900 

20,400 

26,600 

TOTALS 


52,200 

41,600 

52,200 

46,400 


Probable U If i mate Water Requirement 

The population of Santa Clara County increased 
from about 60,000 in 1900 to about 291,000 in 1950. 
As has been stated, this growth was accompanied by 
substantial agricultural development. However, in re- 
cent years the desirability of North Santa Clara Val- 
ley for residential and industrial development has be- 
come a more important factor. Many orchards and 
other irrigated lands have been replaced by subdivi- 
sions within the last decade. Some of the urban ex- 
pansion has been spurred by enhancement of job op- 



WATER UTILIZATION AND SUPPLEMENTAL REQUIREMENTS 


59 


portiinities elsewhere within the San Francisco Bay 
area. However, a large part of the change in economy 
has been caused by progressive development of estab- 
lished industries in Santa Clara County, and to the 
introduction of new industries in the area. In view of 
these circumstances, and since continued expansion 
seems inevitable, it was assumed that under probable 
ultimate conditions of development North Santa 
Clara Valley will be largely urban. 

The economic stimulus provided hy growth of 
North Santa Clara Valley and other areas in the San 
Francisco Bay area should contribute to further de- 
velopment of South Santa Clara Valley. However, 
this valley is not as favorably located with respect to 
present major urban areas as is the northern valley. 
It was assumed, therefore, that while most of the 
southern valley floor lands wull ultimateU require 
water service, the ultimate proportions of urban and 
irrigated agricultural developments, as well as crop 
patterns within the latter group, will equal the pres- 
ent proportions. 

The total probable ultimate water requirement in 
the Santa Clara Valley has been defined heretofore as 
the sum of consumptive use of applied water in the 
forebay zones, plus the draft on ground water in the 
pressure zones, under ultimate conditions of develop- 
ment. By applying appropriate unit values of water 
requirement to the estimated ultimate land use pat- 
tern, it was estimated that this would be about 466,- 
100 acre-feet per season. Of this total quantity about 
405,500 acre-feet wmuld be utilized each season in 
North Santa Clara Valley, while about 60,600 acre- 
feet would be used in South Santa Clara Valley. 

TABLE 36 


PROBABLE ULTIMATE MEAN SEASONAL WATER REQUIRE- 
MENT IN NORTH SANTA CLARA VALLEY 


CJass of land use 

Unit water 
requirement, 
in feet 
of depth 

Area, 

in 

acres 

Total water 
requirement, 
in 

acre-feet 

Forebay Zone 




Irrigated lands _ „ _ „ „ . 

0 

0 

0 

Urban areas _ - 

1.9 

83,400 

158,500 

Farmsteads . 

0 

0 

0 

Miscellaneous _ 

0 

3,100 

0 

Subtotals — _ _ 


86,500 

158,500 

Pressure Zone 




Irrigated lands. _ 

1.8 

7,300 

13,100 

Urban areas . 

2.7 

67,600 

182,500 

Farmsteads 

1.2 

200 

200 

Miscellaneous 

0 

3,500 

0 

Subtotals 


78,600 

195,800 

Habitable bills and marshlands 




Hills 

1 . 0 ^ 

40,400 

40,400 

Marshlands 

2.7 

4,000 

10,800 

Subtotals 


44,400 

51,200 

TOTALS 


209,500 

405,500 


a Reduced by one-balf to allow for low density. 


Tables 36 and 37, respectively, summarize the esti- 
mates of probable ultimate water requirement in 
North and South Santa Clara Valleys. 

TABLE 37 


PROBABLE ULTIMATE MEAN SEASONAL WATER REQUIRE- 
MENT IN SOUTH SANTA CLARA VALLEY 


Class of land use 

Unit water 
requirement, 
in feet 
of depth 

Area, 

in 

acres 

Total water 
requirement, 
in 

acre-feet 

Forebay Zone 




Irrigated lands 

1.2 

22,000 

26,400 

Urban areas. .. 

1.4 

1,200 

1,700 

Farmsteads 

1 .0 

400 

400 

Miscellaneous . _ _ 

0 

8,200 

0 

Subtotals 


31,800 

28,500 

Pressure Zone 




Irrigated lands 

1.8 

17.300 

31,100 

Urban areas 

1.7 

300 

500 

Farmsteads 

1.2 

400 

500 

Miscellaneous 

0 

2,400 

0 

Subtotals _ _ _ 


20,400 

32,100 

TOTALS 


52,200 

60,600 


Nonconsumpfive Wafer Requirements 

Certain noneonsumptive requirements for water, 
such as those for flood control, recreation, and con- 
servation of fish and wildlife, will be of significance in 
the design of works to meet requirements for w^ater in 
Santa Clara Valley. In most instances the magnitudes 
of the noneonsumptive requirements are relatively 
indeterminate, and are dependent upon allocations to 
be made during design of the w^orks and after consid- 
eration of economic factors. Water requirements for 
flood control, recreation, and conservation of fish and 
wildlife are discussed in general terms in this sec- 
tion, but not specifically evaluated. 

Flood Control. Destruction and havoc caused by 
floods in California have frequently been accompanied 
by the economic anomaly of wastage of large amounts 
of water from areas of deficient w^ater supply. Stor- 
age of such flood waters in upstream reservoirs would 
have accomplished the dual purpose of conservation 
of needed water and reduction of flood damages. Re- 
sults of the State-wide Water Resources Investigation 
to date indicate that if California is to attain growth 
and development commensurate wdth her manifold re- 
sources, nearly all of the potential reservoir storage 
capacity of the State must be constructed and dedi- 
cated to operation for water conservation purposes. 
This in itself will result in a substantial increase in 
downstream flood protection. How^ever, any portion of 
the available reservoir storage capacity that is oper- 
ated wholly or partially for flood control purposes 
will correspondingly reduce the capacity available for 
conservation. 




Anderson Reservoir 
on Coyote Creek 



Anderson Dam 
on Coyote Creek 


WATER UTILIZATION AND SUPPLEMENTAL REQUIREMENTS 


61 


No space in reservoirs const meted by the Santa 
Clara Valley Water Conservation District in North 
Santa Clara Valley is specifically dedicated to flood 
control, and only incidental flood protection is real- 
lized from their operation. Although such operation 
may reduce the frequency of flood occurrence, it may 
also create a false sense of security conducive to en- 
croachment on flood plains, with resultant greater 
damage during the less frequent occasions of flooding 
by reservoir spill. 

A major problem confronting North Santa Clara 
Valley is the problem of disposal of storm drainage 
from urban and industrial developments. These de- 
velopments have, in some instances, been located on 
poorly drained areas and have encroached on stream 
channels and tidal flats, which formerly provided a 
means for the disposal of flood waters. Increased 
urbanization has also augmented storm runoff. Plans 
for development of lands in North Santa Clara Valley 
should provide for the control and disposal of all flood 
waters along and adjacent to main stream channels, 
and should also provide for the collection of storm 
drainage, particularly within areas devoted to urban 
development, and its delivery to flood channels. 

The area extending south and east from Gilroy to 
the Pajaro River in South Santa Clara Valley has 
been subject to destructive floods five times since 1937. 
The lands flooded were subjected to inundation for a 
long period, which greatly restricts their adaptability 
to cropping. Along Llagas Creek, east of Gilroy and 
San Martin in South Santa Clara Valley, old drainage 
channels have been obstructed, which, during periods 
of flood flow results in the waterlogging of adjacent 
orchard lands. Solution to the flood control problems 
in South Santa Clara Valley includes channel clear- 
ing, bank protection, levees, and drain ditches for re- 
moval of water from submerged and waterlogged 
areas. 

Recreation and Fish and Wildlife. With antici- 
pated continued growth in population of California, 
it is expected that the public demand for preservation 
and enhancement of recreational facilities will be 
sufficient to assure provision of water supplies neces- 
sary for such purposes. In the aggregate the amount 
of water used for domestic and service facilities in 
recreational areas in watersheds tributary to the 
Santa Clara Valley is relatively small. As for waters 
employed for boating, swimming, and other water 
sports, most are available naturally or as a result of 
woi'ks constructed and operated for other purposes, 
and the nonconsumptive recreational use of the water 
is incidental to the other uses. Of considerable im- 
portance among the employments of water for recrea- 
tional purposes are those associated with the preserAU- 
tion and propagation of fish and wildlife. 

So far as is knOAvn, no artificial lakes in watersheds 
tributary to the Santa Clara Valley are utilized exclu- 
swely for fish life, such use being incidental to the 


primary purposes for Avhich the reservoirs Avere con- 
structed. 

Water released doAvn a stream to maintain the mini- 
mum floAV required for fish life does not constitute a 
consumptive use of the Avater. The demands of fish 
life, hoAVCA^er, are frequently incompatible with dh^er- 
sion and use of the water for other beneficial purposes. 
HoAveA^er, reservoirs constructed to regulate stream 
floAvs for other purposes Avill provide a greatly in- 
creased lake fishery. 

Factors of Wafer Demand 

Factors of water demand, as used in this bulletin, 
refer to rates, times, and places of delivery of water, 
losses of Avater, quality of water, etc., imposed by the 
control, development, and use of the AA^ater for bene- 
ficial purposes. Irrigation practices in the Santa Clara 
Valley, as determined by irrigation efficiency, monthly 
demands, and permissible deficiencies in application 
of water, must be gwen consideration in preliminary 
design of works to meet supplemental water require- 
ments. Similar consideration must be given to monthly 
demands in urban water supply development. These 
demand factors, Avhieh were not measured or consid- 
ered in the foregoing estimates of water requirements, 
are discussed in the folloAving sections. 

Irrigation Efficiency. Studies Avere made to deter- 
mine the approximate average irrigation efficiency 
realized from application of ground water in the 
Santa Clara Valley. Irrigation efficiency is defined as 
the ratio of consumptive use of applied water to the 
total amount of applied Avater, and is commonly ex- 
pressed as a percentage. 

The season of 1947-48 Avas selected for these studies, 
since in that season the coA^erage of plot studies of 
application of water was the most comprehensive. In 
order to estimate the total amount of ground water 
applied for irrigation, appropriate crop acreages, as 
mapped during the 1948 land use survey, were mul- 
tiplied by average seasonal values of depth of applied 
AA^ater for the several crops, as presented in Table 30. 
The computation of applied ground water in the 
Porebay Zone of North Santa Clara Valley resulted 
in an estimate of about 121,900 acre-feet, Avhereas in 
the Forebay Zone of South Santa Clara Valley it was 
about 31,200 acre-feet. 

By dividing the estimated A^alues of 70,200 acre- 
feet and 18,500 acre-feet, for consumptwe use of 
ground water in the forebay zones of North and South 
Santa Clara Valleys, respectively, by the foregoing 
estimated values for applied ground water, it AA^as 
estimated that irrigation efficiencies realized from the 
application of ground water in the respective forebay 
zones in 1947-48 AA^as approximate^ 58 per cent and 
61 per cent. 

Monthly Demands for Water. Irrigation demands 
for AA^ater in the Santa Clara Valley are seasonal in 



62 


SANtA CLAkA Y alley INVi^STlGATlON 


nature, being confined chiefly to the period from May 
through October. The maximum rate of demand oc- 
curs during the months of June and July when nearly 
37 per cent of the total seasonal demand occurs. On 
the other hand, the demand pattern for urban water 
is continuous throughout the season, with a relatively 
smaller variation between the maximum and mini- 
mum monthly rates. 

Estimated monthlj^ irrigation and urban demands 
for water in the Santa Clara Vallejo, in percentages 
of the seasonal totals, are presented in Table 38. The 
values for irrigation were based on average monthly 
agricultural power sales of the San Jose Division of 
the Pacific Gas and Electric Company for the period 
from 1947 through 1951. Urban values were based on 
the averages of records of monthlj^ deliveries of water 
for iirbaii purposes to San Jose, Mouiitaiii View, 
Campbell, Santa Clara, and Sunnyvale, for the period 
from 1948 through 1953. 

TABLE 38 

ESTIMATED AVERAGE MONTHLY DISTRIBUTION 
OF SEASONAL DEMANDS FOR WATER 
IN SANTA CLARA VALLEY 

(In percent of seasono! total) 


Month 

Irrigation 

Urban 

October ^ _ 

12 

8 

November 

5 

6 

December 

1 

5 

January 

0 

5 

February 

1 

5 

March 

2 

6 

April 

3 

7 

May 

10 

10 

June „ „ 

19 

11 

July 

18 

13 

Aujjust„ 

13 

13 

September^ „ _ „ _ 

IG 

11 

TOTALS 

100 

100 


Permissible Deficiencies in Application of Water, 

Studies to determine deficiencies in the suppl}^ of irri- 
gation water that may be endured without permanent 
injury to perennial crops were not made in connec- 
tion with the Santa Clara Valley Investigation. How- 
ever, the results of past investigation and study of 
endurable deficiencies in the Sacramento Eiver Basin 
may be of interest, insofar as they may relate to 
the Santa Clara Valley. In this respect the following 
is quoted from Division of Water Resources Bulletin 
No. 26, ‘‘Sacramento River Basin,'’ 1931. 

“. . . A full irrigation supply furnishes water 
not only for the consumptive use of the plant but 
also for evaporation from the surface during ap- 
plication and from the moist ground surface, and 
for water which is lost through percolation to 
depths beyond the reach of the plant roots. Less 
water can be used in years of deficiency in supply 
by careful application and by more thorough 
cultivation to conserve the ground moisture. In 


these ways the plant can be furnished its full con- 
sumptive use with much smaller amounts of 
water than those ordinarily applied and the yield 
will not be decreased. If the supply is too defi- 
cient to provide the full consumptive use, the 
plant can sustain life on smaller amounts but 
the crop yield will probably be less than normal. 

“ It is believed from a study of such data as are 
available that a maximum deficiency of 35 per 
cent of the full seasonal requirement can be en- 
dured, if the deficiency occurs only at relatively 
long intervals. It is also believed that small de- 
ficiencies occurring at relatively frequent inter- 
vals can be endured . . . ” 

In the design of works to meet urban water de- 
mands, it is common practice to provide for a full 
water supply without deficiency at any time. How- 
ever, it has been the experience of many eoiiiiiiuiiities 
in California that substantial deficiencies may be en- 
d^ured for extended periods of time by rationing the 
limited water supplies at hand. No information is 
available regarding the economic effects of such 
rationing of urban water. In the Santa Clara Valley, 
deficiencies in surface water supplies can be met by 
pumping from the ground water basin. 

SUPPLEMENTAL WATER REQUIREMENTS 

The previoushv presented data, estimates, and dis- 
cussion regarding water supply and requirement in 
the Santa Clara V^alley indicate that the present and 
probable future water problems of the area are 
largely limited to those connected with ground 
water, and that their effects in North Santa Clara 
Valley are largely related to urban development, and 
in South Santa Clara Valley to irrigated agriculture. 
It is further indicated that ground water problems, 
created in various portions of the area by progressive 
lowering of water levels, may be limited or prevented 
if adequate supplemental water supplies are devel- 
oped and utilized in the area. The present and prob- 
able ultimate requirements for supplemental water in 
the Santa Clara Valley are discussed and evaluated 
in the following sections. As previously defined, re- 
quirements for supplemental water refer to the 
amount of water, over and above the sum of safe 
ground water yield and safe surface water yield, 
which must be developed to satisfy water x^equire- 
ments. Water requirements in turn refer to the 
amount of water needed to provide for all beneficial 
consumptive use of water and for irrecoverable losses 
of water incidental to such beneficial use. 

Present Supplemental Water Requirement 

The present requirement for supplemental water 
in the Santa Clara Valley was evaluated as the differ- 
ence between safe yield of ground water and present 
draft on ground water. 



WATER UTILIZATION AND SUPPLEMENTAL REQUIREMENTS 


63 


It was estimated in Chapter II that the safe sea- 
sonal ground water yield from the Porebay Zone of 
North Santa Clara Valley" amounts to about 134,400 
acre -feet, and from the Porebay Zone of South Santa 
Clara Valley to about 39,300 acre-feet. These values 
were determined as the seasonal draft of water from 
the ground Avater basins which might be maintained, 
under mean conditions of AA^ater supply- and climate, 
AAdthout further progressUe loAvering of water levels 
beloAA^ aArrage leirls prevailing during the respective 
base periods in North and South Santa Clara Valleys. 
It was further estimated that the safe seasonal ground 
AA^ater yields in the respective pressure zones of North 
and South Santa Clara Valleys amount to 84,300 
acre-feet and 26,600 acre-feet, respectWely. 

Seasonal draft on ground Avater in North Santa 
Clara Valley, AAuth the present pattern of land use 
and under mean conditions of Avater supply and cli- 
mate, Avas estimated to be 179,200 acre-feet, of which 
170,000 acre-feet is supplied from the Porebay Zone 
and the remaining 9,200 acre -feet from aquifers be- 
neath San Prancisco Bay. The estimated total present 
requirement for supplemental water, therefore, is 
some 44,800 acre-feet per season. However, the safe 
yield of the Pressure Zone, as defined in Chapter II, 
is limited by the maximum rate of pumping draft 
which can be sustained, during the height of the 
pumping season, without inducing intrusion of water 
from beneath San Prancisco Bay into the confined 
aquifers of the zone. On this basis, the seasonal safe 
yield of the pressure zone aquifers AA^as estimated to 
be about 84,300 acre-feet AAuth the monthly pumping 
demand pattern that existed during the 1948 pump- 
ing season. The present mean seasonal pumpage from 
the confined aquifers of the Pressure Zone was esti- 
mated to be 104,300 acre-feet. Therefore, the present 
requirement for supplemental water in the Pressure 
Zone, the difference betw^een safe yield and pumpage 
of ground Avater, amounts to an estimated 20,000 acre- 
feet per season. The estimated present seasonal re- 
quirement for supplemental Avater in the Porebay 
Zone of North Santa Clara Vallejo is 24,800 acre-feet, 
the difference betAA^een the total supplemental re- 
quirement and that of the Pressure Zone. 

Seasonal draft on ground AA^ater in South Santa 
Clara Valley, AAlth the present pattern of land use 
and under mean conditions of Avater supply and cli- 
mate, AA^as estimated to be 46,400 acre-feet, as shoAAm 
in Table 35. The estimated total present requirement 
for supplemental AA^ater in South Santa Clara Valley, 
therefore, is about 7,100 acre-feet per season. The 
safe yield of the Pressure Zone, as in the case of the 
Pressure Zone of the northern valley, is limited by 
the maximum rate of pumping draft Avhich can be 
sustained during the height of the pumping season 
Avithoiit resulting in the formation of a ground water 


trough. On this basis the safe seasonal yield AAms esti- 
mated to be about 26,600 acre-feet, Avith the monthly 
pumping demand pattern that existed during the 
1948 pumping season. The present mean seasonal 
pumpage from the confined aquifers of the Pressure 
Zone AA^as estimated also to be 26,600 acre-feet. There- 
fore, it is indicated that there is no present require- 
ment for supplemental AA'ater in the Pressure Zone of 
South Santa Clara Valley. 

Probable Ultimate Supplemental 
Water Requirement 

As has been stated, the probable ultimate require- 
ment for supplemental AAnter in the Santa Clara Val- 
ley was cA^aluated as the difference betAveen present 
and probable ultimate draft on ground AA^ater, plus 
the present requirement for supplemental Avater. De- 
velopment and utilization of a supplemental Avater 
supply in the amount of this forecast Avould assure 
an adequate supply of water for lands presently re- 
cemng water service, as well as for those additional 
lands which will receive Avater in the future. Further- 
more, present problems resulting from progressive 
loAvering of ground water levels and threat of sea- 
water intrusion from beneath San Prancisco Bay 
AAnuld be eliminated. 

Estimates of present and probable ultimate draft 
on ground water in North and South Santa Clara 
Valleys, under mean conditions of water supply and 
climate, haA^e been presented in Tables 34, 35, 36, and 
37, and a corresponding estimate of the present re- 
quirement for supplemental water was developed in 
the preceding section. Utilizing these estimates, the 
forecasts of probable ultimate seasonal requirement 
for supplemental water in North and South Santa 
Clara Valleys, under mean condition of AA^ater suppty 
and climate, are presented in Table 39. 

TABLE 39 


PROBABLE ULTIMATE MEAN SEASONAL SUPPLEMENTAL 
WATER REQUIREMENTS IN SANTA CLARA VALLEY 

(In acre-feet) 


Division 

1 

2 

3 

4 

5 

Present 

draft 

on 

ground 

water 

Prob- 

able 

ultimate 

water 

require- 

ment 

Prob- 

able 

increase 

in 

water 
require- 
ment 
(2 —1) 

Present 

supple- 

mental 

require- 

ment 

Prob- 

able 

ultimate 
supple- 
mental 
water 
require- 
ment 
(3 -b 4) 

North Santa Clara Valley : 

188,200* 

405,500 

217,300 

44,800 

262,100 

South Santa Clara Valley ; 

46,400 

60,600 

14,200 

7,100 

21,300 

TOTALS 

234,600 

466,100 

231,500 1 

51,900 

283,400 


* Includes 4,000 acre-feet of imported water, and 5,000 acre-feet diverted from 
Saratoga and Los Gatos Creeks. 



SANTA CLARA VALLEY INVESTIGATION 


64 


The foregoing* estimate of probable ultimate sup- 
plemental water requirement does not take into ac- 
count the yield of certain local projects which have 
been constructed and put into operation since the 
base period. Studies described in sections of the bul- 
letin which follow indicate that the seasonal yield of 
these projects is about 45^000 acre-feet. In addition, 
certain projects are described, which if constructed 


would provide additional water. Of these projects, the 
Northern Valley Project and the Uvas and Llagas 
Creeks Project appear most likely to be eonstrueted. 
Assuming construction of these two projects, which 
would provide a seasonal yield of 25,000 acre-feet of 
water, it is indicated that a seasonal import of about 
213,000 acre-feet of v/ater ^yill be required to satisfy 
ultimate water requirements in the Santa Clara 
Valley. 



CHAPTER IV 


PLANS FOR WATER DEVELOPMENT 


It has been shown heretofore that the present basic 
water problems in the Santa Clara ValleA^ are pro- 
gressive and permanent lowering of ground water 
levels, and the threat of sea-water intrusion from be- 
neath San Francisco Bay to aquifers of the pressure 
zone of North Santa Clara Valley. Elimination of 
these problems, prevention of their recurrence in the 
future, and the provision of water for lands not pres- 
ently served will require the further conservation of 
local water supplies, and the importation of water 
from an outside source or sources. In the preceding 
chapter, estimates were presented as to the amount 
of supplemental water required for these purposes, 
both at the present time and under probable ultimate 
conditions of development. 

It has been shown that surplus flows of water are 
presently available to the Santa Clara Valley from 
certain local streams. This surface water is available 
during the winter and spring months of nearly every 
season. Studies which are described in this chapter 
indicate that the surplus flows, if properly controlled 
and regulated, would meet the present requirement 
for supplemental water in North Santa Clara Valley, 
and would meet the probable ultimate requirement 
for supplemental water in South Santa Clara Valley. 

As was stated in Chapter I, the Division of Water 
Resources is presently conducting surveys and studies 
for the State-wide Water Resources Investigation, 
under the direction of the State Water Resources 
Board. This investigation has as its objective the 
formulation of The California Water Plan, for full 
conservation, control, protection, and utilization of 
the Statens water resources, to meet present and fu- 
ture water needs for all beneficial purposes and uses 
in all parts of the State, insofar as practicable. Al- 
though this investigation is still in progress, it is 
sufficient Ij^ advanced to permit tentative description 
of certain proposed major featuies of The California 
Water Plan which could provide supplemental water 
to meet the probable ultimate requirements of the 
Santa Clara Valley. These projects would also pro- 
vide supplemental water supplies for many other 
water-deficient areas of California. In addition, bene- 
fits from the projects would include hydroelectric 
power, flood and salinity control, mining debris stor- 
age, and benefits in the interests of recreation and 
the preservation of fish and wildlife. 

In general, the cited major features of The Cali- 
fornia Water Plan would be large multipurpose proj- 
ects requiring relatively large capital expenditures. 


Their scope, with regard to both location of the works 
and benefits derived from their operation, would not 
be limited to any one local area, but would embrace 
considerable portions of California. In light of these 
facts, and in view of the remaining undeveloped 
local water supply, surveys and studies were made 
in order to estimate costs of supplemental Avater sup- 
plies for the Santa Clara Valley under more localized 
plans, that might be suitable for current financing, 
construction, and operation by appropriate local pub- 
lic agencies. These plans for initial dcA^elopment gen- 
erally are such that the Avorks could be integrated 
into future major projects. Their purposes are largely 
limited to conserA^ation of neAV Avater supplies suf- 
ficient to meet the present requirements for supple- 
mental Avater in North Santa Clara Valley, and suf- 
ficient to meet the probable ultimate requirements 
for supplemental Avater in South Santa Clara Valley. 

Major features of The California Water Plan 
which might be pertinent to solution of the ultimate 
Avater problems of the Santa Clara Valley are de- 
scribed in general terms in this chapter under the 
heading ^^The California Water Plan. The several 
plans considered for possible local development of 
supplemental Avater supplies are described under the 
heading Plans for Initial Local Development,^^ and 
locations of their principal features are shown on 
Plate 17, entitled Existing Water ConserA^ation 
Works and Works Considered for Future DeA^elop- 
ment. ’’ Those of the local plans that were found to 
be the most faA^orable for initial cleA^elopment are pre- 
sented in some detail in this chapter, together with 
estimates of their capital and annual costs, and unit 
costs of the developed supplemental Avater supplies. 
All of the plans considered Avould be subject to A^ested 
rights. 

THE CALIFORNIA WATER PLAN 

The Feather River Project, an adopted feature of 
The California Water Plan, could proAude supple- 
mental water to partially meet the probable ultimate 
requirement of the Santa Clara Valley. The Hetch 
Hetchy system of the City of San Francisco could 
provide supplemental Avater to meet the municipal 
requirements in North Santa Clara Valley. Consid- 
eration also has been gh^en to the possibility of ob- 
taining supplemental Avater for the Santa Clara 
Valley from the pool behind a possible salt-water bar- 
rier located in the north arm of San Francisco Bay. 
In addition, consideration has been giyen to the 


8— 19273 


( 65 ) 



66 


SANTA CLAEA VALLEY INVESTIGATION 


feasibility of reclaiming and conveying sewage from 
the City of San Francisco, peninsula cities and com- 
munities, and San Jose, for irrigation use in the 
Santa Clara Valley. 


Feather River Project 

The probable ultimate supplemental v^ater require- 
ment in the Santa Clara Valley could be partially 
met under a plan which would provide regulatory 
storage on the Feather River near Oroville in the 
Sacramento Valley, and conveyance of a portion of 
the regulated water suppty across the Sacramento- 
San Joaquin Delta, through Brushy Peak, thence 
through Livermore Valley to the Santa Clara Valley. 
Such storage and conveyance facilities would be made 
available hy construction of works which are de- 
scribed in detail in a publication of the State Water 
Resources Board, entitled Report on Feasibility of 
Feather River Project, and Sacramento-San Joaquin 


J_yiVCXi:SlUXl X XVXJCUl/ 


X X XXjXV/OXXL 


Features of 


The California Water Plan, dated May, 1951. These 
projects were authorized and adopted by the 1951 
Legislature, in an act v/hieh authorized their con- 
struction, operation, and maintenance by the Vv^ater 
Project Authority of the State of California. Subse- 
quently, more detailed studies have indicated some 
modification in certain of the storage and conveyance 
facilities described in the feasibility report. These 
are described in a publication of the Division of 
AVater Resources, entitled Program For Financing 
and Constructing The Feather River Project as The 
Initial Unit of The California AVater Plan,” Febru- 


ary, 1955. 

This recent publication indicates that water would 
be released from Oroville Reservoir down the Feather 
and Sacramento Rivers to the Sacramento-San Joa- 
quin Delta, where it would firm presently existing 
supplies. The water wnuld be conve^^ed across the 
Delta through the Delta Cross Channel, and diverted 
to the Santa Clara A^alley from Old River in the San 
Joaquin River Delta near the Alameda- Contra Costa 
county line. The Vvater would be lifted by pumping to 
a. main canal located at an elevation of about 230 
feet. This canal would parallel the Delta-Mendota 
Canal of the Central A^alley Project. Two miles south 
of the pump lift from Old River a portion of the 
water would be diverted into the Alameda-Santa 
Clara-San Benito Branch of the Feather River Proj- 
ect Aqueduct. This water would be lifted to an eleva- 
tion of about 705 feet, to a canal leading to the portal 
of a tunnel, 7,500 feet in length, through Brushy 
Peak. General features of this branch are shown on 
Plate 18, entitled ''The Alameda-Santa Clara-San 
Benito Branch of the Feather River Project Aque- 
duct, 1955.^’ 

From the western portal of the tunnel through 
Brushy Peak, a concrete-lined canal would carry the 
water around the east and south sides of Livermore 


Valle}^ to a tunnel, 3,400 feet in length, through 
Rocky Ridge. Rocky Ridge is located about 4 miles 
south of Livermore. A reinforced-eoncrete pipe would 
conve}" the water westerP/ from the end of the tunnel 
through Rocky Ridge to a 1,300-foot tunnel at Mis- 
sion Pass. Prom the end of the Mission Pass Tunnel 
the pipe conduit would continue southerly, above 
Mission San Jose and AA^arm Springs, to the proposed 
Airpoint regulating reservoir on the Arroyo De Los 
Coches. Airpoint Reservoir, with storage capacity of 
23,000 acre-feet, would be located in Santa Clara 
County about 2 miles east of 'Milpitas, and the maxi- 
mnm elevation of the water surface in the reservoir 
would be 615 feet. 

Prom Airpoint Reservoir a pipe conduit would 
extend, iii a southeaster^/ d.ireetioii, crossing Alum 
Rock Park, to a proposed regulating reservoir near 
Evergreen on Silver Creek, about 6 miles soiitlieast 
of San Jose. The maximum elevation of the Avater 
surface in this reserAuir Avould be about 540 feet, 
and the reservoir storage capacity AAUuld be about 
32,500 acre-feet. 

Prom EA^ergreen Reservoir a conduit, consisting 
mostly of canal, would extend southeasterly along 
the base of the hills on the eastern side of the Santa 
Clara Valley to a terminus on Pacheco Creek, just 
south of the Santa Clara-San Benito county line. 
The AAmter surface elcA^ation at the terminus Avould 
be about 380 feet. The distance from the intake on 
the main Feather RP/er Project Aqueduct to the 
terminus of the canal at Pacheco Creek is approxi- 
mately 108 miles. 

A pressure pipe lateral Avould start at a turnout 
on the main conduit about 1 mile iiorthAvest of 
Evergreen Dam, at an eleAmtion of 450 feet. It Avould 
traverse the Santa Clara A^alley, passing about 7 
miles south of San Jose, and continue Avesterly to 
the vicinity of Saratoga, and thence along the base 
of the foothills in a southwesterly direction, passing 
near Monte Arista and Los Altos to a terminus at Felt 
ReserAuir, at a maximum water surface eleA'ation 
of 380 feet. The total length of the lateral AAUuld be 
about 30 miles. 

As a basis for estimating costs for the Feather- 
River Project, it Avas considered that the Alameda- 
Santa Clara-San Benito Branch of the Feather Rhmr 
Project Aqueduct Avould be constructed in two stages. 
The first stage Avould provide 120,000 acre-feet of 
Avater per season to San Benito County, the Santa 
Clara A^alley, the bayside area of Alameda County, 
and LNermore Valley. The second stage Avould pro- 
vide an additional 120,000 acre-feet of Avater per 
season to these areas. In the financial analyses made 
for the Feather River Project, it AA^as indicated that 
a charge of from $17.50 per acre-foot to $22.50 per 
acre -foot would be required for delivery of water 
from the Alameda-Santa Clara-San Benito Branch, 



PLANS FOR WATER DEVELOPMENT 


67 


depending upon the assumptions as to interest rate^ 
period of repayment, and other relevant factors. 

Based upon historical records of flows of fresh 
water into San Francisco Bay, sufficient supplemental 
water could be supplied by the Feather River Project 
to meet in part the ultimate requirements of Alameda 
County, the Santa Clara Valley, and San Benito 
County, without impairment of existing demands 
upon and presently contemplated maximum exporta- 
tions of water from the Sacramento- San Joaquin 
Delta. Such demands include those for salinity con- 
trol as well as for irrigation. The plan for the diver- 
sion of a water supply from Old River in the Sacra- 
mento-San Joaquin Delta is feasible from an engineer- 
ing point of view. 

Analyses show that the chemical quality of water at 
different locations in the Sacramento-San Joaquin 
Delta is Class 1 for irrigation, and that it falls well 
within accepted standards for drinking water. How- 
ever, for domestic and municipal uses the water would 
require bacteriological treatment and filtration^ as do 
practically all raw waters. 

Other Plans Under Consideration 

A possible source of water supply for North Santa 
Clara Valley is the Hetch Hetchy system of the City 
of San Francisco, which diverts waters of the 
Tuolumne River in the Sierra Nevada, conserved in 
Hetch Hetchy and Eleanor Reservoirs, and conducts 
this water a distance of about 155 miles to a service 
area which includes most cities and communities of 
the San Francisco Peninsula south to and including 
Palo Alto. Construction of Cherry Valley Reservoir 
on Cherry Creek, a tributary of the Tuolumne River, 
is near completion, and will augment the water supply 
of the system. Present capacity of the Hetch Hetchy 
system is 136,000,000 gallons of water daily, or about 
150,000 acre-feet per season. 

Under provisions of the Raker Act, H.R. 7207, 
Public Law No. 41, 63rd Congress, Hetch Hetchy 
water may be used only for municipal purposes, and 
may be sold only to public agencies. There is excess 
capacity in the Hetch Hetchy system, over and above 
present water requirements of areas within its present 
service area. It is considered probable that the City of 
San Francisco would supply supplemental water to 
communities in the Santa Clara Valley having pub- 
licly owned water systems. Unit cost of water now 
delivered by the city to peninsular cities is about $70 
per acre-foot. 

In connection with the recent investigation of bar- 
riers in the San Francisco Bay system by the Division 
of Water Resources, consideration was given to the 
possibility of providing supplemental water to the 
Livermore and Santa Clara Valleys from the pool of a 
barrier constructed in the north bay. The fresh water 
would be pumped and conveyed to the areas of defi- 
ciency. The results of the investigation are contained 


in a report to the State Water Project Authority by 
the Division of Water Resources entitled, ‘‘Feasibility 
of Construction by the State of Barriers in the San 
Francisco Bay System,’’ prepared pursuant to the 
Abshire-Kelly Salinity Control Barrier Act of 1953, 
Chapter 1104, Statutes of 1953, 

Studies were made of alternative aqueduct routes 
from three different points of diversion in the barrier 
pools to supply water to the Livermore and Santa 
Clara Valleys. Diversion capacities were predicated 
upon supplying 94,000 acre-feet of water seasonally 
to Livermore Valley, and 63,000 acre-feet to the Santa 
Clara Valley. It was assumed that the water would be 
diverted and conveyed at a uniform rate to terminal 
reservoirs in each of the service areas, where the 
supply would be re-regulated and delivered to local 
agencies for distribution. 

One route would extend from Italian Slough in the 
San Joaquin Delta to Penitencia Creek east of San 
Jose, a total distance of about 65 miles. This route 
could be used with any of the barriers located in the 
north bay, and in many respects is similar to that 
proposed for the Feather River Project. The water 
would be diverted from the Feather River Project 
Aqueduct in the San Joaquin Valley and lifted by 
pumping to Livermore Valley, The diverted water 
would be conveyed around the northerly edge of Liv- 
ermore Valley to a regulating reservoir in Doolan 
Canyon, about 4 miles northwest of Livermore. Water 
for the Santa Clara Valley would be conveyed across 
Livermore Valley from Doolan Canyon Reservoir in 
a concrete-lined canal, concrete pressure pipe, and 
tunnel, to a regulating reservoir at the Airpoint site 
on Arroyo De Los Coches, 2 miles east of Milpitas. 
Water released from Airpoint Reservoir would be 
conveyed to a terminal point on Penitencia Creek, 
about 6 miles northeast of the central district of San 
Jose. 

The second route given consideration in the barrier 
studies provided for a diversion from the San Joa- 
quin River, about 1 mile west of Antioch. This route 
would extend for about 76 miles from the intake to 
a terminus on Penitencia Creek east of San Jose. 
This aqueduct could be utilized with the barrier lo- 
cated at or below Chipps Island. The diverted water 
would be lifted by pumping to a tunnel intake lo- 
cated on the west side of Markley Canyon south of 
Pittsburg, From the tunnel the aqueduct would con- 
tinue to another tunnel under the hills north of 
Kirker Pass, thence across Clayton Valley to a tunnel 
under Lime Ridge, 2 miles south of Concord. From 
the outlet of this tunnel, the aqueduct would extend 
southerly along the easterly slope of San Ramon and 
Amador Valleys, and the northerly slope of Livermore 
Valley, to a dividing wye, 2 miles east of Parks Air 
Force Base. Water required in Livermore Valley 
would be diverted at the wye and delivered to Doolan 
Canyon Reservoir, discussed under the Italian Slough 



68 


SANTA CLARA VALLEY INVESTIGATION 


diversion. Water for the Santa Clara Valley would 
be conveyed from the wye south across Livermore 
Vallejo to a point 2 miles east of Pleasanton, from 
where the aqueduct location would be identical with 
that described for the Italian Slough diversion route. 

The third route considered provided for the di- 
version of water from Suisuii Bay, at a point about 
1.5 miles east of Avon, and its conveyance to the 
terminal on Penitencia Creek east of San Jose. The 
aqueduct would have a total length of about 70 miles. 
This aqueduct would be utilized with a barrier lo- 
cated at either Dillon Point or Point San Pablo. The 
water would be conveyed southerly by canal from 
the point of diversion to a point west of Concord, 
where it would be lifted by pumping to a canal lo- 
cated on the east side of Ygnacio Valley. This canal 
would extend southerly to a point about 3 miles east 
of Walnut Creek, where the water would be lifted to 
the route described for the Antioch diversion. The re- 
mainder of the aqueduct would be identical with that 
described for the Antioch diversion. 

The studies of routes in connection with the barrier 
investigation were only for the purpose of developing 
comparative estimates of costs for delivery of water 
to the Livermore and Santa Clara Valleys. A sum- 
mary of the estimated capital costs of the three aque- 
duct routes is presented in the following tabulation. 
The summary does not include the pro rata share of 
costs of the barrier which would make the diversion 


possible. 

Italian Slough diversion $24,888,000 

Antioch diversion 32,093,000 

Avon diversion 24,846,000 


In connection with the need for supplemental water 
in the Santa Clara Valley, consideration has also 
been given to the feasibility of reclaiming and con- 
veying sewage from the City of San Francisco, pen- 
insula cities and communities, and from San Jose, 
for irrigation use in the Santa Clara Valley. This 
study was made pursuant to House Resolution 198, 
adopted b^^ the A-Ssembly on June 1, 1949. It was con- 
cluded in this study that, in view of the limited 
amount of sewage from disposal plants or outfalls 
from the City of San Francisco which is acceptable 
as to mineral constituents for reclamation and utili- 
zation for irrigation use in the Santa Clara Valley, 
and in view of the relatively high unit cost that would 
be involved in the reclamation and utilization of 
such sewage in the Santa Clara Valley, no further 
consideration should be given at this time to this 
source as a possible supplemental water supply for 
the Santa Clara Valley. 

PLANS FOR INITIAL LOCAL DEVELOPMENT 

Possible plans for initial local developments of 
supplemental water supplies for the Santa Clara Val- 
ley, together with cost estimates, are described in 
this section. Design of features of the plans was neces- 


sarily of a preliminary nature and primarily for cost 
estimating purposes. More detailed investigation, 
which v/ould be required in order to prepare plans 
and specifications, might result in designs differing in 
detail from those presented in this bulletin. However, 
it is believed that such changes would not result in 
significant modifications in estimated costs. 

Capital costs of dams, reservoirs, diversion works, 
conduits, pumping plants, and appurtenances, in- 
cluded in the considei^ed conservation wmrks and eon- 
vejmnee and distribution systems, v/ere estimated 
from preliminarA^ designs based largely on data from 
surveys made during the current investigation. Ap- 
proximate construction quantities were estimated 
from these preliminary designs. Unit prices of con- 
strnctiou items were determined from recent bid data 
on projects similar to those in question, or from man- 
ufacturers’ cost lists, and are considered representa- 
tive of prices prevailing in the fall of 1954. The 
estimates of capital cost included costs of rights of 
way and construction, and interest during one-half 
of the estimated construction period at 3.5 per cent 
per annum, plus 10 per cent for engineering and 15 
per cent of construction costs for contingencies. Esti- 
mates of annual costs included interest on the capital 
investment at 3.5 per cent, amortization over a 50- 
year period on a 3.5 per cent sinking fund basis, re- 
placement, operation and maintenance costs, insur- 
ance, general expenses, and costs of electrical energy 
for pumping. 

In connection vfith the ensuing discussion safe 
yield is defined as the maximum sustained rate of 
draft from a reservoir that could have been main- 
tained through a criticallj^ deficient water supply 
Xieriod to meet a given demand for water for irri- 
gation or other purposes. However, in the ease of 
coordinated operation of surface and underground 
reservoirs safe jdeld is defined as the average com- 
bined seasonal yield from both surface and under- 
ground reservoirs which could be obtained over the 
base period 1934-35 through 1947-48 in North Santa 
Clara Valley, and 1932-33 through 1947-48 in South 
Santa Clara Valley. Nev/ water is defined as the yield 
of water resulting from a new water supply develop- 
ment and method of operation thereof, that would 
have been wasted without the proposed works. 

Because of geographical considerations, possible 
plans for initial local water development are pre- 
sented in this section separately for North Santa 
Clara Valley and South Santa Clara Valley. Loca- 
tions of the prox)osed works are shown on Plate 17. 

North Santa Clara Valley 

It was shown in Chapter III that the present re- 
quirement for supplemental water in North Santa 
Clara Valley is about 44,800 acre-feet per season, and 
that the ultimate seasonal supplemental requirement 
probably will be about 262,000 acre-feet. Expansion 



PLANS FOE WATER DEVELOPMENT 


69 


and intensification of urban and suburban develop- 
ment has occurred at a rapid rate during tlie past 
few years, and it is indicated that such rapid growth 
with attendant increasing requirement for water, 
will continue for some time in the future. 

Three possible plans were studied in connection 
with the current investigation to meet requirements 
for supplemental water in North Santa Clara Valley. 
The first plan includes construction of new works 
in North Santa Clara Valley, and their operation in 
conjunction with existing works. Studies indicated 
that construction of the new works and their proper 
operation would result in the full practicable conser- 
vation of the remaining water of local streams which 
presently wastes from the area. This plan is desig- 
nated the '^Northern Valley Project.” 

The second plan considered for initial construction 
would provide a dam and reservoir on San Prancis- 
quito Creek. This project would be operated inde- 
pendently of existing works of the Santa Clara Val- 
ley Water Conservation District, and Avould supply 
water for urban use in the vicinity of Palo Alto. 
The cost of water from this project would be rela- 
tively expensive. This plan is designated the ^‘Little 
Francis Project.” 

The third plan considered for initial construction 
would provide for a dam and reservoir in Santa Cruz 
County on Zayante Creek, at a site about 5 miles 
northeast of Felton, and conveyance of the conserved 
water westerly to Los Gatos Creek, where it would be 
available for use in North Santa Clara Valley. The 
cost of water from this project would be quite ex- 
pensive. This plan is designated the ‘‘Zayante 
Project.” 

Each of the three foregoing projects, location of the 
principal features of which are shown on Plate 17, is 
a project that could be constructed separately, or si- 
multaneously with one or more of the others. Of the 
three, only the Northern Valley Project would de- 
velop sufficient water to meet the present supple- 
mental requirement of North Santa Clara Valley. 
However, as was mentioned in Chapter III, the pres- 
ent supplemental requirement totalling 44,800 acre- 
feet per season, comprises 24,800 acre-feet in the 
Forebay Zone and 20,000 acre-feet in the Pressure 
Zone, and water developed to meet these requirements 
must be allocated accordingly. Such a pattern of dis- 
tribution would not be possible from works of the 
Northern Valley Project without construction of addi- 
tional works and excessive expense. Consequently, in 
studies for this bulletin it was assumed that the entire 
yield of water from the existing Lake Elsman, the 
proposed Little Francis Project, and the proposed 
Zayante Project, together with water developed by 
the proposed Coyote Well Field, a part of the North- 
ern Valley Project, would be diverted to the Pressure 
Zone. By such combined operation, with a prescribed 


pattern of distribution, the present supplemental 
water requirement of North Santa Clara Vallejo could 
be met. 

Northern Valley Project. In the design of proj- 
ects for initial local development in the Santa Clara 
Valley, it was considered desirable to provide works 
which would be operated in conjunction with existing 
facilities to give the fullest practicable development 
of local water supplies. Water conservation works 
that have been constructed in North Santa Clara 
Valley were described in Chapter III. Major surface 
reservoirs exist on Coyote, Almaden, Alamitos, Gua- 
dalupe, Arroyo Calero, Los Gatos, and Stevens 
Creeks. These reservoirs were built and are operated 
b 3 ^ the Santa Clara Valley Water Conservation Dis- 
trict, with the exception of Lake Elsman on Los Gatos 
Creek, which is owned and operated b^^ the San Jose 
Water Works. The aggregate storage capacity of the 
reservoirs is about 150,000 acre-feet. Percolating res- 
ervoirs, or spreading ponds, constructed and main- 
tained by the district, have a combined surface area 
of about 100 acres, and are located on Coyote, Los 
Alamitos, Los Gatos, San Tomas Aquinas, and Peni- 
tencia Creeks. These works, and the yields of water 
therefrom, were incorporated and utilized in the 
plans discussed herein. 

In essence, the Northern Valley Project would in- 
volve the draining of surface reservoirs at the fastest 
possible rate consistent with percolation capacities 
of stream channels and percolating ponds down- 
stream. In addition, all of the works would be oper- 
ated jointly, since maximum retention of surface 
water would necessitate the transportation of water 
from streams with high runoff to those with lesser 
runoff, to provide the required amount of stream 
percolation capacity for ground water recharge. 
Yield studies indicated that under this plan, a net 
total of about 48,300 acre-feet of water per season, 
of which 8,900 acre-feet is new water, now wasting 
from North Santa Clara Valley could be conserved. 
This amount would meet the present supplemental 
water requirement of 44,800 acre-feet, and in addi- 
tion would provide surplus water in the amount of 
about 3,500 acre-feet per season. In the operation of 
the project, about 14,500 acre-feet per season of the 
above conserved water would be furnished as a sur- 
face supply to lands in the Pressure Zone, thereby re- 
ducing draft on the confined aquifers. This amount 
would include an estimated 5,000 acre-feet per season 
from Lake Elsman, and 9,500 acre-feet pumped from 
Coyote Valley which would be furnished to San Jose. 

Under the Northern Valley Project, a portion of 
the water released from reservoirs on Coimte Creek 
would percolate in the natural channel of Coyote 
Creek from the Upper Gorge to The Narrows. The 
remainder of the flow would be diverted and con- 
veyed in the existing Coyote Canal to the existing 



70 


SANTA CLAKA VALLEY INVESTIGATION 


diversion works, where the water would be diverted 
to the east side of the valley for use in the Evergreen 
area, and to the west side of the valley for spreading 
in the Alamitos Creek percolating pond and in 
Guadalupe River below the pond, Los Alamitos 
Creek and Guadalupe River waters, now percolating 
in natural channels and in the percolating pond, 
would be transported westerly in a proposed conduit 
to Los Gatos Creek. Waters of the latter stream in 
excess of its channel percolation capacity would be 
conveyed northward in the existing Vasona Canal 
and the Vasona Extension Pipe Line. 

Operation of the project would result in increased 
percolation of water in Coj^'ote Valley, making it 
desirable to operate the ground water basin under- 
lying the valley to enable conservation of additional 
water. Pumps would be installed in a proposed well 
field near the northern end of Coj^ote Valley, and the 
conserved water would be deiivereci by pipe line for 
urban use in fean <Jose. 

Studies were also made of the merits of a project 
to convey water from Coyote Creek to Penitencia 
Creek for percolation in the channel of that stream. 
Such a project would include enlargement of the 
existing Co 3 mte Extension Canal, use of the recently 
completed Evergreen Pipe Line and Canal, and con- 
struction of a conduit consisting of unlined canal and 
reinforced-conerete pipe line from Dry Creek to Penh 
tencia Creek. It was indicated that no significant 
amount of new water would be developed by such a 
plan, above that which would result from the pres- 
ently proposed plans of the Santa Clara Valley 
Water Conservation District to serve surface water in 
the Evergreen area. 

Additional small reservoirs on Permanente, Stev- 
ens, Calabazas, Guadalupe, San Antonio, and Madera 
Creeks, not included in the Northern Valley Project, 


could also regulate portions of the runoff on these 
streams, both for percolation and for gravity service 
of water to urban areas. However, studies indicated 
that the small amount of new water developed there- 
from would be excessively costly. 

Estimates were made of the yield of existing and 
proposed works under the Northern Valley Project. 
Based on estimates of runoff during the base period, 
from 1935-36 through 1947-48, monthly yield studies 
were made of Anderson and Lexington Reservoirs to 
determine the yield of the project creditable to these 
existing reservoirs. After consideration of the results 
of yield studies, the works subsequently described 
were chosen for purposes of cost estimates to be pre- 
sented in this bulletin. A summary of yield studies 
of Anderson and Lexington Reservoirs, operated in 
accordance with the Northern Valley Project, is 
included in Appendix K. 

As a method of determining the yield of new water 
provided by operation of the project, a comparison 
was made of the estimated seasonal surface outflow 
from the Porebay Zone during the 13-year base period 
for base jjeriod, present, and proposed conditions. 
Results of this comparison are presented in Table 40. 

Table 40 indicates that under the Northern Valley 
Project the mean seasonal surface outflow from the 
Porebay Zone of North Santa Clara Valley would 
be reduced from about 99,000 acre-feet under base 
period operation to 42,200 acre-feet, resulting in a 
total seasonal conservation of about 56,800 acre-feet 
of water. However, of the total seasonal amount of 
water conserved 46,300 acre-feet was estimated, to be 
creditable to works under present operation. There- 
fore, the gross yield of new water from the Northern 
Valley Project would be 10,500 acre-feet. It was 
assumed that about 15 per cent of the gross yield of 
new water from the project would be lost through 


TABLE 40 

ESTIMATED NEW MEAN SEASONAL YIELD FROM NORTHERN VALLEY PROJECT 

(In acrs-feet) 


Stream 

Seasonal surface outflow during 13-year base period, 
1935-36 through 1947-48 

New yield from 
proposed works 

Base period 
operation* 

Present 

operation 

Proposed 

operation 

Gross 

Net 

Permanente Creek. _ „ 

* 2,300 

2,300 

2,300 

0 

0 

Stevens Creek 

3,700 

3,700 

3,700 

0 

0 

Calabazas Creek 

1,100 

1,100 

1,100 

0 

0 

Saratoga Creek 

4,000 

4,000 

4,000 

0 

0 

San Tomas Aquinas Creek ... . 

1,900 

1,900 

1,900 

0 

0 

Guadalupe River . _ __ ... . . _ _ 

32,600 

10,400 

8,700 

1,700 

1,400 

Coyote Creek 

41,400 

17,300 

8,500 

8,800 

7,500 

Silver and Dry Creeks. 

700 

700 

700 

0 

0 

Penitencia Creek ... 

2,500 

2,500 

2,500 

0 

0 

Unmeasured east-side streams 

i 4,100 

4,100 

4,100 

0 

0 

Unmeasured west-side streams _ 

4,700 

4,700 

4,700 

0 

0 

TOTALS 

99,000 

52,700 

42,200 

10,500 

8,900 


^ Prior to construction and operation of Anderson and Lexington Reservoirs, Lake Elsman, Coyote-Los Alamitos Conduit, Evergreen Conduit, and Vasona Canal Extension. 




PLANS FOR WATER DEVELOPMENT 


71 


incidental evaporation and transpiration. Therefore, 
the net yields, both present and new, would be about 
39,400 and 8,900 acre-feet, respectively. 

In order to obtain the foregoing yield of new water 
from the Northern Valley Project, present percola- 
tion capacities of natural channels and percolation 
reservoirs would have to be maintained. These capaci- 
ties \vere estimated from records furnished by the 
Santa Clara Valley Water Conservation District, and 
are presented in Table 41. 


TABLE 41 

ESTIMATED PERCOLATION RATES IN STREAMS OF 
NORTH SANTA CLARA VALLEY 


Stream 

Rate of 
percolation, 
in second-feet 

Penitencia Percolation Pond _ _ ^ . 

Coyote Creek 

15 

60 


20 

Between the pond and The Narrows _ „ _ _ 

15 

Alamitos Creek, Guadalupe Creek, and Alamitos Percolation 
Pond _ _ ^ _ 

50 

Los Gatos Creek* _ _ _ „ ^ _ 

85 

San Tomas Aquinas Creek „ ^ ^ 

' 25 

Saratoga (Campbell) Creek 

Calabazas Creek _ „ 

20 

5 

Stevens Creek, „ _ 

15 


* Includes percolation in all works on Los Gatos Creek, Vasona ' 
Page Ditch. 

Canal, and Upper 


Since, under the Northern Valley Project, releases 
of water from reservoirs would maintain stream flow 
for longer periods than at present, the percolation 
capacities of stream beds were estimated from records 
of stream flow after the channels had been wetted for 
long periods of time. During the portions of the year 
in which Coyote Creek water would be diverted to 
the Evergreen area for surface irrigation, and perco- 
lated in the Alamitos Percolation Pond and the Gua- 
dalupe River, water would be released to Coyote 
Creek from Anderson Reservoir at a rate of about 
160 second-feet. Of the release, about 65 second-feet 
would be diverted into the Coyote Canal for convey- 
ance to the east and west sides of the valley. The 
remaining 95 second-feet would be released to the 
natural channel. Under this method of operation, it 
was estimated that about 60 second-feet would perco- 
late in the reach from the Upper Gorge to the Lower 
Gorge, 20 second-feet in the Coyote Percolation Pond, 
and the remaining 15 second-feet in the stream bed 
between this pond and The Narrows. 

Sustained percolation in Coyote Valley, at the rate 
of 60 second-feet, Avould be essential to the effective- 
ness of the plan. However, increasing percolation to 
the extent proposed would soon fill the ground water 
reservoir underlying Coyote Valley, thus preventing 
further influent seepage. Therefore, it would be nec- 
essary to operate the ground water basin so as 
to maintain the required storage space. Under the 


Northern Valley Project, ground water levels in 
Coyote Valley would be lowered during seasons of 
subnormal water supply in amounts greater than 
occur under present conditions, so that in seasons of 
abundant runoff the basin would not completely fill. 
Thus, the water table would be prevented from rising 
above levels that produce effluent waters in Fisher 
Creek. This criterion would assure ample percolation 
capacity in the valley at all times, and, furthermore, 
would prevent high ground water levels from ad- 
versely^ affecting crops. It was estimated that under 
this method of operation about 9,500 acre-feet of 
water per season, or a constant flow of 13 second-feet, 
would have to be exported from Coyote Valley, after 
ground water levels are sufficiently lowered. In the 
transitional period, during which the water table 
would be lowered, water would be removed at a rate of 
about 15 second-feet. In estimating the required 
export it was assumed that subsurface outflow to 
South Santa Clara Valley would remain approxi- 
mately equal to its present value. 

To operate the Coyote Valley ground water basin, 
wells with pumps would be installed in the proposed 
Coyote Valley Well Field near the north end of the 
valley. The water pumped from the wells would be 
conveyed in the proposed Coyote Valley-San Jose 
Pipe Line for urban use in San Jose. Urban rather 
than agricultural use of this water would be desir- 
able, since the pumping plants operated more or less 
continuously for urban use could produce water more 
economically than if operated to meet a less constant 
irrigation demand. Furthermore, water pumped from 
the free ground water zone would relieve the pressure 
zone pumping draft by an equivalent amount. Dis- 
tribution problems would be minimized by intro- 
ducing the imported water into an existing system. 

Future irrigation of about 1,430 irrigable acres in 
Coyote Valley, not now supplied with water, would 
eventually reduce the amount of the export hy 
approximately 2,900 acre-feet per season. This item 
was neglected in the present studies, since the over-all 
conservation of waters would still be effected, so long 
as the percolation capacity in Coyote Valley was 
maintained. 

Under the foregoing plan of operation, the ampli- 
tude of ground water level fluctuations in Coyote 
Valley would be substantially more than at present. 
The present range in average water levels is about 60 
feet. If the ground water reservoir were operated as 
proposed, the range in water levels would be about 
120 feet, with a maximum average elevation of the 
water surface of 267 feet, compared to the present 
value of 284 feet. 

It was estimated that the combined percolation 
capacity of the Alamitos Percolation Pond, and the 
channel of the Guadalupe River below this pond, is 
about 50 second-feet. With a maximum diversion of 
water to them at the rate of 50 second-feet from Coy- 




PLANS FOR WATER DEVELOPMENT 


73 


ote Creek, flows from streams naturally tributary to 
the pond and the Guadalupe River would be diverted 
in the proposed Calero-Los Gatos Conduit for perco- 
lation in Los Gatos Creek. This conduit would extend 
from Arroyo Calero Creek in a northwesterly direc- 
tion, and would terminate at the existing Vasona Dam 
on Los Gatos Creek. 

Another feature of the Northern Valley Project 
would involve the operation of Lexington Reservoir 
on Los Gatos Creek. This reservoir regulates most of 
the runoff from Los Gatos Creek in excess of that 
conserved in Lake Elsman and diverted fx’om Los 
Gatos Creek by the San Jose Water Works. Under the 
project, water would be released from Lexington 
Reservoir for percolation in Los Gatos Creek, and in 
major streams north of this creek. The reservoir 
would be drained as rapidlj^ as possible consistent 
with maximum, continuous percolation capacities. 

The maximum rate of release of water into Los 
Gatos Creek from Lexington Reservoir would be about 
130 second-feet. This would occur when conditions in 
Los Gatos Creek and in creeks to the north were such 
as to permit spreading of water at full capacity, with 
no water available for import through the Calero-Los 
Gatos Conduit. Approximately 85 second-feet of this 
quantity would remain in Los Gatos Creek for perco- 
lation, or would percolate in the Vasona Canal or the 
Upper Page Ditch. The remaining 45 second-feet 
would be diverted from Los Gatos Creek and conveyed 
northward in the existing Vasona Canal to San Tomas 
Aquinas Creek, where 25 second-feet would be re- 
leased for percolation. The remaining 20 second-feet 
would be conveyed to Saratoga Creek in the Vasona 
Canal Extension. When available in the Alamitos 
Creek group, water at rates up to 50 second-feet 
would be exported to Los Gatos Creek, and the re- 
leases of water from Lexington Reservoir would be 
reduced by an equivalent amount. 

General features of proposed dams, reservoirs, con- 
duits and other works of the Northern Valley Project 
are described in the following subsections. 

(1) Coyote Valley Well Field and Coyote Valley- 
San Jose Pipe Line. The Coyote Valley Well Field 
would be located in Sections 22, 26, 27, and 35, 
Township 8 South, Range 2 East, M. D. B. & M., in 
the northern end of Coyote Valley. It would consist 
of seven wells and pumps, spaced about one-quarter 
mile apart. The wells would be in a line adjacent and 
parallel to Coyote Creek, and would be about 250 feet 
deep. A deep-well multistage turbine-type pump, 
with a capacity of 1,000 gallons per minute would be 
installed at each well. From the wells the water would 
be conveyed through the Coyote Valley-San Jose Pipe 
Line a distance of about 12.8 miles to the 12th and 
Martha Streets pumping plant of the San Jose Water 
Works. The pipe line would be of reinforced-concrete, 
with a diameter of 2.5 feet and a capacity of about 15 
second-feet. A plan and profile of the proposed con- 


duit are shown on Plate 19, entitled ^^Cojmte Valley 
Well Field and Coyote Valley-San Jose Pipe Line, 
1955 .^^ 

Pertinent data with respect to the various features 
of the well field and the pipe line, as designed for cost 
estimating purposes, are presented in Table 42. 

TABLE 42 

GENERAL FEATURES OF COYOTE VALLEY WELL FIELD 
AND COYOTE VALLEY-SAN JOSE PIPE LINE 


Coyote Valley Well Field 

Number of wells—7 

Type of pumps — Deep-well, multistage turbine 
Discharging capacity — -1,000 gallons per minute per well 
Depth of wells — ^250 feet 
Drawdown — 25 feet 

Minimum static water level elevation — 152 feet 

Coyote Valley-San Jose Pipe Line 

Discharging capacity — 15 second feet 
Type — Reinforced-concrete pipe 
Length — 12 . 8 miles 
Diameter — 2 . 5 feet 

Average elevation of well field — ^270 feet 
Elevation of pipe outlet — 100 feet 


(2) Calero-Los Gatos Conduit. Water conserved 
in Calero Reservoir would be diverted from Arroyo 
Calero in Section 31, Township 8 South, Range 2 
East, M. D. B. & M., at a stream bed elevation of 
about 381 feet. The waters would be conveyed north- 
westerly in a canal for a distance of about 9 miles to 
Guadalupe Creek, and then in a pipe line for a 
distance of about 6 miles. The waters would be dis- 
charged to Los Gatos Creek immediately above 
Vasona Dam. En route, the canal would intercept all 
or portions of the flows of Alamitos and Guadalupe 
Creeks. 

The canal portion of the conduit, with a capacity 
of 50 second-feet, would be of trapezoidal section and 
unlined, with 1 : 1 side slopes, a bottom width of 4.0 
feet, depth of 3.1 feet, and freeboard of 1.4 feet. Its 
slope would he approximately 3.8 feet per mile, and 
its velocity about 2.3 feet per second. Main roads 
and streams along the length of the canal would he 
crossed with reinforced-concrete pipe culverts. The 
pipe line portion of the conduit would be of rein- 
forced-concrete pipe with a diameter of 48 inches. 
The inlet elevation of the pipe line would be about 
341 feet, and the outlet elevation about 305 feet. 

The diversion structure on Arroyo Calero would 
be a reinforced-concrete open weir, some 120 feet in 
length and 3 feet in height above stream bed. It would 
be divided by 1-foot wide concrete piers into 7-foot 
flashboard bays. The stream bed elevation at the site 
of the diversion is about 381 feet. An opening at the 
left end of the weir would provide entrance to a side 
channel, leading downstream about 60 feet to the 
headworks of the canal. The side channel would have 
a concrete gravity parapet wall of the overponr type, 
and a 4-foot by 5-foot sluice gate would be provided 
for sand clearance. The headworks would consist of a 
concrete headwall across the end of the side channel, 



74 


SANTA CLARA VALLEY INVESTIGATION 


with a 48-inch diameter slide gate and a trashrack. 
Similar types of structures would be constructed on 
Alamitos and Guadalupe Creeks. 

The diversion structure on Guadalupe Creek would 
be located about 1.2 miles upstream from the point of 
crossing of the conduit. The flow thus diverted would 
be conveyed in a northerly direction in the Gua- 
dalupe Creek Intercepting Canal along the right 
bank of Guadalupe Creek, to join the main conduit 
from Arroyo Calero at the point of beginning of the 
pipe line portion of the conduit. The Guadalupe 
Creek Intercepting Canal, with a capacity of 25 
second-feet, would be of trapezoidal section and 
unlined, with 1:1 side slopes, a bottom width of 2.5 
feet, depth of 2,5 feet, and freeboard of 1.0 foot. 
Its slope would be approximately 4.2 feet per mile, 
and its velocity about 2.0 feet per second. 

Principal features and a plan and profile of the 
proposed conduit are shown on Plate 20, entitled 




data with respect to the various features of the con- 
duit, as designed for cost estimating purposes, are 
presented in Table 43. 


TABLE 43 


GENERAL FEATURES OF CALERO-LOS GATOS CONDUIT 


Canal, Arroyo Calero to Guadalupe Creek 
Capacity — 50 second-feet 
Type— Trapezoidal, unlined 
Length — -9 . 1 miles 
Side slopes— 1:1 
Bottom width — 4 , 0 feet 
Depth — 3 . 1 feet 
Freeboard — 1 . 4 feet 
Slope—3 . 8 feet per mile 
Velocity — ^2.3 feet per second 

Pipe line, Guadalupe Creek to Los Gatos Creek 

Capacity— 50 second-feet 
Type— Reinforced-concrete 
Length — - 4 . S miles 
Diameter — 4 feet 

Guadalupe Creek Intercepting Canal 
Capacity— 25 second-feet 
Type— Trapezoidal, unlined 
Length— 1.2 miles 
Side slopes— 1:1 
Bottom width— -2 . 5 feet 
Depth — 2 . 5 feet 
Freeboard — 1 . 0 foot 
Slope — 4.2 feet per mile 
Velocity — ^2.0 feet per second 

Diversion Works 

Arroyo Calero — ^reinforced-concrete open weir with fiashboards, 3 feet high 
and 120 feet long. 

Alamitos Creek — reinforced-concrete open weir with fiashboards, 5 feet high 
and 25 feet long, 

Guadalupe Creek — reinforced-concrete open weir with fiashboards, 12 feet 
high and 45 feet long. 


The capital eosts of the Northern Valley Project, 
on a 3.5 per cent interest basis, and based on prices 
prevailing in the fall of 1954, were estimated to be 
$2,230,000. The corresponding afinual costs were esti- 
mated to be about $152,000. The resultant estimated 
average unit cost of the 8,900 acre-feet of new water 
is about $17,00 per acre-foot, excluding eosts of 
pumping the water from the ground water basin. The 


estimates of capital and annual costs of the Northern 
Valley Project are summarized in the following 
tabulation. Detailed cost estimates are presented in 
Appendix L. 

Estimated Costs 
Capital Annual 

Coyote Well Field and Coyote 

Valley- San Jose Pipe Line— $1,204,000 $90,800 

Calero -Los Gatos Conduit 1,018,(K)0 60,800 


Totals 


$2,232,000 $151,600 


Little Francis Project. In Chapter II it was 
pointed out that the transmission capacity of the 
aquifers furnishing water to the pressure zone of 
North Santa Clara Valley is limited, and that the 
present pumping draft in the pressure zone exceeds 
the safe yield of these aquifers. This results in 
decreasing piezometrie levels in the pressure zone 
and the threat of sea- water intrusion. These problems 
could be eliminated by reduction of the net pumping 
draft in the pressure zone to an average season a,l 


amount of about 84,000 acre-feet. To accomplish this, 
all water demands in the pressure zone, in excess of 
about 84,000 acre-feet ner season would have to he 


met by a surface w^ater supply 


llilpUA tCU. UiXC 


forebay zone or from some other outside source or 
sources. Under the Little Francis Project, about 3,000 
acre-feet of water per season, presently wasting from 
San Prancisquito Creek into San Francisco Bay, 
would be conserved and furnished to the City of 
Palo Alto, to enable reduction of the ground water 
pumping draft on the pressure zone in that area. 
Such use of water conserved by the project would he 
a small step toward elimination of the present serious 
water problems of the pressure zone. 


The Little Francis Project would include construc- 
tion of a dam and reservoir on San Francisquito Greek 
at a site about 5.4 miles upstream from U. S. Highway 
101 in San Mateo County. The conserved waters 
would be released from the reservoir, and conveyed 
for a distance of about 1.7 miles in a general easterly 
direction in a concrete-lined canal, to a water treat- 
ment plant to be located northwest of the junction of 
San Francisquito Creek and Los Trances Creek. 
From the treatment plant the water would be pumped 
easterly in a pipe line for a distance of about 0.7 
mile, to a distribution reservoir to be located on a 
knoll adjacent to the existing right of way of the 
Hetch Hetchy Aqueduct. From the reservoir the 
treated water would flow in a pipe line, following a 
route parallel to the aqueduct right of way for a 
distance of approximately 1.6 miles, to the intersec- 
tion of Junipero Serra Boulevard and Page Mill 
Road, where a proposed connection with the munici- 
pal water works of the City of Palo Alto would he 
located. Principal features of the project are shown 
on Plate 21, entitled “Little Francis Project, 1955.’^ 
Little Francis Dam would be located on San Fran- 
cisquito Creek about 1.9 miles downstream from the 



PLANS FOR AYATER DEVELOPMENT 


75 


existing Searsville Lake, in projected Section 17, 
Township 6 South, Range 3 West, M. D. B. & M., 
where the stream bed elevation is about 209 feet. The 
construction of the dam to an elevation of 300 feet, 
with spillway crest elevation of 290 feet, would create 
a reserA^oir having a storage capacity of about 7,300 
acre-feet. The estimated mean seasonal runoff from 
the drainage area of 28.1 square miles above the dam 
site is about 12,300 acre-feet. The estimated safe sea- 
sonal yield of the reservoir would be about 3,000 acre- 
feet. A summary of the yield study is included in Ap- 
pendix K. 

Topography of Little Francis dam and reservoir 
sites was obtained from the Palo Alto Quadrangle of 
the United States Geological Survey, at a scale of 
1:24,000 with contour interval of 20 feet. Storage 
capacities of the reservoir at various stages of water 
surface elevation are given in Table 44. 

TABLE 44 


AREAS AND CAPACITIES OF LITTLE FRANCIS 
RESERVOIR 


Depth of 
water at 
dam, in feet 

Water surface 
elevation, 
USGS datum, 
in feet 

Water surface 
area, 
in acres 

Storage 
capacity, 
in acre-feet 

0 

209 

0 

0 

21 

230 

12 

100 

41 

250 

58 

750 

61 

270 

164 

3,000 

81 

290 

284 

7,350 

91 

300 

367 

11,850 


Based upon preliminary geological reconnaissance, 
the Little Francis dam site is considered suitable for 
an earthfill dam of any height up to about 100 feet. 
Foundation rock at the site consists of the Chico and 
possibly Purisima formations, which are made up of 
brown sandstone and conglomerate, yellow siltstone, 
and terrace sands and gravels. The colors of the rocks 
are broAvn and yellow, and they are massive Avith 
varying hardness. The grain size varies from line to 
cobbles. There are abundant deeply weathered joints, 
with probable faults normal to the dam axis. Several 
small shears were visible in the channel section. Some 
grouting would be required. 

Stripping under the impervious section of the dam 
would require the removal of about 5 feet of soil, and 
15 feet of weathered bedrock on the right abutment. 
Stripping on the left abutment would require the 
removal of about 2 feet of soil and 10 to 25 feet of 
Aveathered materials. Stripping from the channel sec- 
tion would require the removal of about 10 feet of 
silt, cobbles, and fractured bedrock. 

There are several available sources of material 
suitable for the impervious section of the dam. 
Weathered, clayey material of the Purisima formation 
is available at the dam site. Terrace silts and soils are 
available about 1 mile doAvnstream, and additional 


clays and silts are available about 2.5 miles upstream 
from Searsville Lake. Terrace sands and gravels suit- 
able for the pervious section of the dam are available 
within 1 mile upstream and downstream from the 
site, and material salvaged from excavation could also 
be used. Riprap could be quarried within about 3 
miles from the site. 

The reserA^oir area consists of a narrow, irregular 
valley. The area north of the San Francisquito Creek 
is covered with light brush, with a feAv trees. The area 
south of the creek is covered with a dense growth of 
brush and timber. ImproA^ements that would be in- 
undated by a reservoir of the chosen capacity at the 
Little Francis site consist of about 0.25 mile of Sand- 
hill Road and about 0,15 mile of Whiskey Hill Road, 
9 homes, 1 ranch, and about 1.9 miles of 12-inch 
diameter cast iron pipe line extending from Searsville 
Lake to Stanford University. The portions of the 
Sandhill and Whiskey Hill Roads which would be 
inundated are in the upper end of the reservoir area, 
and could be relocated by raising the grade of the 
existing roads. 

As designed for cost estimating purposes, the dam 
would be an earthfill structure, 81 feet in height from 
stream bed to spillway lip, and would have a crest 
elevation of 300 feet. It would have a crest length of 
about 1,365 feet, a crest width of 30 feet, and 2.5 : 1 
upstream and downstream slopes. The central imper- 
vious earthfill section would have a top width of 10 
feet, and 1 : 1 upstream and downstream slopes. The 
upstream face of the dam would be protected with a 
3-foot layer of riprap. The dam would have an esti- 
mated volume of 431,000 cubic yards. 

The concrete spillway Avould be of the chute type 
with an ogee weir, and Avould be located through a 
saddle on the left abutment. The maximum depth of 
water above the spillway lip would be 6 feet, and 
an additional 4 feet of freeboard would be provided. 
The spillway would have a discharging capacity of 
9,000 second-feet, based on an estimated flood runoff 
of 320 second-feet per square mile of watershed above 
the dam. The spillway would have a crest length of 
175 feet, and would discharge into a concrete-lined 
chute about 2,000 feet in length, with a stilling basin 
at the lower end. 

The outlet works would consist of a 36-inch diam- 
eter steel pipe, placed in a trench excavated beneath 
the dam and encased in concrete. Releases of water 
from the reservoir would be controlled at the up- 
stream end of the pipe by a 3 6 -inch diameter slide 
gate, hydraulically operated from the right abutment 
of the dam. The outlet would be controlled at the 
downstream end by a 30-ineh diameter hollow jet 
vah^e, and the water would be released into a stilling 
basin, from which it would either enter the convey- 
ance canal to the treatment plant, or spill through a 
Avasteway into the San Francisquito Creek channel. 
The stilling basin Avould be a reinforced-concrete 



76 


SANTA CLAEA VALLEY INVESTIGATION 


structure, 12 feet in width, 50 feet in length, and 10 
feet in height. The elevation of the floor of the stilling 
basin would be about 215 feet. Plow from the still- 
ing basin to the canal would be controlled by a 2-foot 
b}^ 2-foot slide headgate set in the head wall. Excess 
water in the stilling basin would spill to San Fran- 
cisquito Creek over a weir 20 feet in length, with a 
crest elevation of about 220 feet. 

The canal to the treatment plant would have a 
capacll V of 10 second-feet, and would extend from the 
stilling basin in an easterly direction for a distance 
of approximately 8,800 feet, to a point about 1.5 
miles southwest of Stanford University, and norths 
west of the intersection of Los Trances and San Pran- 
cisquito Creek, west of Alpine Eoad. The canal would 
be shotcrete-lined, and of trapezoidal section, wdth 
1:1 side slopes, bottom width of 2 feet, depth of 1.5 
feet, and freeboard of 0.5 foot. Its slope would be 
approximately 3.2 feet per mile, and the velocity 
of flow would be about 1.9 feet per second. The canal 
would follow the south bank of San Prancisquito 
Creek for about 0,25 mile, then would cross the creek 
at a point about 1,000 feet upstream from the spill- 
way stilling basin, and would continue in a north- 
easterly direction to terminate at the treatment plant 
at an elevation of about 212 feet. Two 20-inch diam- 
eter welded steel siphons would be required to convey 
the flow across the creek and beneath the spillway 
channel. 

Water entering the treatment plant would pass 
through flash mixing tanks, where lime and soda ash 
would be added. Alum would be added as required 
to promote flocculation of suspended matter. After 
thorough mixing, the water would be conveyed 
through settling basins, where the sludge would be 
settled and mechanically removed. After leaAdng the 
settling basins the water would pass through rapid 
sand filters, and would be chlorinated before being 
pumped to the distribution reservoir. The treatment 
plant would include 2 flash mixing tanks with a 45- 
minute mixing period ; 4 settling basins with a 4-hour 
detention period; 4 filter units of 2 filters each, with 
a total area of 160 square feet; pipe gallery; oper- 
ating gallery ; raw and waste water channels ; admin- 
istrative ofliees and laboratory ; chemical building 
to house chlorine cylinders, scales, a chlorinating 
machine, chemical feeder, and garage; wash water 
tank; and other necessary appurtenances. 

A pumping plant would be located adjacent to the 
treatment plant, and would consist of an enclosed 
reinforced-concrete structure, housing 3 electrically 
driven and 1 standbj^ gasoline driven multistage cen- 
trifugal pumping units. Bach of the electrically driven 
units would have a discharging capacity of 2.7 
second-feet, and would be driven by a 60-horsepower 
motor. The standby unit would have a capacity of 7.8 
second-feet, and would be driven by a 150-horsepower 


gasoline engine. The pumps would operate at a maxi- 
mum pressure head of 138 feet, pumping from a 
water surface elevation at the intake of 203 feet to 
a maximum water surface elevation at the distribu- 
tion reservoir of 333 feet. 

The pump discharge line would he about 3,600 feet 
in length, and would extend from the pumping plant 
in an easterly direction to a summit adjacent to the 
right of way of the Hetch Hetchy Aqueduct, where a 
distribution reservoir would be located. The pipe line 
would consist of a buried, 20-irich diameter^ welded 
steel pipe, and would have a discharging capacity of 
7.8 second-feet. 

The distribution reservmlr v/ould be of the paved 
cavity type, with a reinforced-concrete roof. The 
reservoir, with floor elevation of 321 feet, would have 
a floor diameter of 150 feet and 1.5:1 side slopes. It 
would have a storage capacity of 2,000,000 gallons, 
with a maximum water depth of 12 feet. At least 1.5 
feet of earth cover would be maintained on the roof 
to keep the treated water cool. 

The conduit to the connection with the v/ater dis- 
tribution system of the City of Palo Alto would con- 
sist of buried, 22-ineh diameter, welded steel pipe. It 
would follow a route adjacent and parallel to the 
existing right of way of the Hetch Hetchy Aqueduct. 
The pipe line would be about 8,500 feet in length, 
and would extend from the distribution reservoir to 
the intersection of Junipero Serra Boulevard and 
Page Mill Eoad. The maximum water surface eleva- 
tion at the inlet would be 333 feet, which would 
result in a pressure head elevation at the outlet of 
275 feet with the design rate of flow of 15 second-feet. 
The invert elevation of the pipe at the outlet would 
be about 160 feet. 

Pertinent data with respect to the general features 
of the Little Francis Project, as designed for cost 
estimating purposes, are presented in Table 45. 

The capital cost of the Little Francis Project, on a 
3.5 per cent interest basis, and based on prices pre- 
vailing in the fall of 1954, was estimated to be about 
$3,380,000. Corresponding annual costs were esti- 
mated to be about $220,000. The resultant estimated 
average unit cost of the 3,000 acre-feet per season of 
new water was about $75.00 per acre-foot, deliv- 
ered to the distribution system of the City of Palo 
Alto. The estimates of capital and annual costs are 
summarized in the following tabulation. Detailed cost 
estimates are presented in Appendix L. 

Estimated Costs 



Capital 

Annual 

Little Francis Dam and Reser- 


voir 

.$2g02g00 

$104,000 

Conduit to 

treatment plant 53,000 

3,000 

Treatment < 

77Q f\f\a 

04 000 

Pump line, 

distribution reser- 


voir, and 

pipe line to city 


system 

344,000 

21,000 

Totals 

$3,377,000 

$222,000 



PLANS FOE WATER DEVELOPMENT 


77 


TABLE 45 

GENERAL FEATURES OF LIHLE FRANCIS PROJECT 


Little Francis Dam 

Type— earthfill 
Crest elevation— 300 feet 
Crest length^ — 1,365 feet 
Crest width— 30 feet 

Height, spillway lip above stream bed— 81 feet 
Side slopes — 2.5:1, upstream and downstream 
Freeboard, above spillway lip— 10 feet 
Elevation of streambed — 209 feet 
Volume of fill^ — 412,900 cubic yards 

Little Francis Reservoir 

Surface area at spillway lip— 284 acres 

Storage capacity at spillway lip — 7,300 acre-feet 

Drainage area, San Francisquito Creek— 28.1 square miles 

Estimated mean seasonal runoff, San Francisquito Creek — 9,700 acre-feet 

Estimated safe seasonal yield — 3,000 acre-feet 

Type of spillway— Concrete-lined chute around left abutment 

Spillway discharge capacity— 9 ,000 second-feet 

Type of outlet — 36-inch diameter steel pipe beneath dam 


Conduits 



Little Francis 

Treatment 

Distribution 


Dam to 

plant to 

reservoir to 


treatment 

distribution 

City of Palo 


plant 

reservoir 

Alto system 

Type 

Concrete-lined 

20-inch diame- 

22-inch diame- 


canal 

ter welded 

ter welded 



steel pipe 

steel pipe 

Length, in miles 

1.7 

0.7 

1.6 

Capacity, in second-feet- _ 

10 

7.8 

15 

Inlet elevation, in feet 

218 

203 

321 

Outlet elevation in feet 

212 

333 

160 


Treatment plant 

Flash mixing tanks — 2 tanks, with a 45-minute mixing period 
Sedimentation basins — 4 basins, with a 4-hour detention period 
Rapid sand filters — 4 units of 2 filters each, with a surface area of 160 square 
feet per filter. 

Pumping plant 

Pumps — 3 centrifugal, with capacity of 1.7 million gallons daily each; one 
centrifugal, vuth capacity of 5 million gallons daily 
Maximum pumping pressure head — 138 feet 
Average water surface elevation at intake — 203 feet 
Installed pumping capacity — 10 million gallons daily 

Motors — 3 electric units, squirrel-cage, open type, 60 horsepower; one 
standby unit, gasoline, 150 horsepower 

Distribution reservoir 

Type — Concrete paved cavity, with reinforced-concrete roof with 1.5 feet 
of earth cover 

Storage capacity — 2 million gallons 

Dimensions — 150-foot diameter circular base, 1.5:1 side slopes, 12-foot 
maximum water depth 


Zayante Project. The Zayante Project would in- 
clude the construction of a dam and reservoir on Zay- 
ante Creek in Santa Cruz County. Water conserved 
in the reservoir would be pumped and conveyed by 
pipe line in a general northeasterly direction, through 
existing abandoned railroad tunnels through the 
Santa Cruz Range, and would discharge on the east- 
erly slopes of the range into Los Gatos Creek at 
AVrights, about 3 miles upstream from Lexington 
Reservoir. From Los Gatos Creek the water would be 
available for use in the Santa Clara A^alley, either 
by direct diversion into facilities of the San Jose 
AA^ater AA^orks Company, or by storage in Lexing- 
ton Reservoir for release to downstream percolation 


works. Principal features of the project are shown 
on Plate 22, entitled ''Zayante Project, 1955.'’ 

Zayante Dam would be located on Zayante Creek 
about 5 miles upstream from its confluence with the 
San Lorenzo River, in the southeast quarter of Sec- 
tion 36, Township 9 South, Range 2 AA'est, M. D. B. 
& M., where the stream bed elevation is about 476 feet. 
Construction of the dam to an elevation of 616 feet, 
with a spillway crest elevation of 603 feet, would cre- 
ate a reservoir having a storage capacity of about 
6,900 acre-feet. The estimated mean seasonal runoff 
from the drainage area of 9.5 square miles above the 
dam site is about 9,000 acre-feet. The estimated safe 
seasonal yield of the reservoir would be about 4,000 
acre-feet. 

A plane table topographic survey of the Zayante 
dam site was made by the Division of Water Re- 
sources in 1951, at a scale of 1 inch to 200 feet, 
with 10-foot contour interval. Reservoir topography 
was obtained in 1951 by photogrammetric methods, 
at a scale of 1 inch to 500 feet, with 20-foot contour 
interval. Areas and capacities of Zayante Reservoir 
at various stages of water surface elevation are given 
in Table 46. 

TABLE 46 


AREAS AND CAPACITIES OF ZAYANTE RESERVOIR 


Depth of 
water at 
dam, in feet 

Water surface 
elevation, 
uses datum, 
in feet 

Water surface 
area, 
in acres 

Storage 
capacity, 
in acre-feet 

0 

476 

0 

0 

24 

500 

8 

100 

44- 

520 

21 

390 

64 

540 

40 

990 

84 

560 

70 

2,090 

104 

580 

108 

3,880 

127- 

603 

153 

6,900 

144 _ _ _ 

620 

191 

9,800 

164- - _ 

640 

238 

14,100 

184- 

660 

292 

19,400 

204 

680 

350 

25,800 

224 

700 

413 

33,400 


The Zayante dam site lies in the Vaqueros forma- 
tion of Miocene age. The strata consist of fine-grained 
sandstone and siltstones, with intercalated layers of 
tan shales having a thickness of as much, as 8 
inches. Sandstone exposed on the channel edge is 
moist and shows a strong tendency to spall. There 
are many tight shears throughout the area. Joints are 
numerous near the surface, but probably tighter and 
more widely spaced with depth. Attitudes of the bed- 
ding are generally consistent, with the strike parallel 
to the stream course and the dip into the right abut- 
ment. 

Stripping for the foundation of an earthfill type of 
dam at this site should not exceed 6 feet of over- 
burden and 4 feet of fractured rock for the right 
abutment, and 5 feet of OA^erburden and 2 feet of rock 
for the left abutment. The stated depths are esti- 



78 


SANTA CLAEA VALLEY INVESTIGATION 


mated normal to the surface. Stripping in the channel 
section would consist of about 4 feet of mixed sand 
and gravel. It might be, however, that the possible 
presence of concealed landslide detritus would mate- 
rially increase the stripping estimates. Moderate 
grouting of joints and bedding planes would prob- 
ably be r6(][Uired. 

An estimated 1,500,000 cubic yards of earth suit- 
able for use in an impervious embankment is located 
near Olympia, about 2 miles downstream from the 
site. Material suitable for riprap would have to be 
hauled from a distance of at least 4 miles. 

Zayante Dam, as designed for cost estimating pur- 
poses, would consist of an earth and rockfill structure, 
with a crest length of 470 feet, a crest width of 28 
feet, and unstream and downstream slopes of 2.5 : 1. 
The central impervious core would have a top width 
of 10 feet, and 0.8:1 slopes. The upstream slope of 

^XClXXX VVV/LXXVA JJVy VvXUXX vy-L ^ 

The dam v/ould have an estimated volume of fill of 


433,800 cubic yards. 

The concrete-lined spillwa^^ would be of the ogee 
weir type, located across the right abutment of the 
dam, and discharging through a chute into Zayante 
Creek about 400 feet below the dam. It would have a 
discharging capacity of 8,900 second-feet, required for 
an estimated m.aximum flood flow of about 950 second- 
feet per square mile of drainage area. The maximum 
depth of water above the spillway lip would be 8 feet, 
and an additional 5 feet of freeboard wnuld be pro- 
vided. The outlet works would consist of a 3 6 -inch 
diameter steel pipe, placed in a trench excavated be- 
neath the dam and encased in concrete, Eeleases of 
water from the reservoir v/ould be controlled by 
means of gates in an inclined structure on the slope 
of the left abutment upstream from the dam. This 
structure would consist of a sloping 48-inch diameter 
steel pipe encased in concrete, and would be provided 
with four 18-inch diameter gate valves, hydraulically 
operated from a control house on the top of the 
structure. 

The reservoir area is generally rugged, and is cov- 
ered with small brush and some second-growth red- 
wood, and oak and madrone, which would have to be 
removed. The land has little agricultural value. Im- 
provements in the reservoir area consist of 5 cottages, 
with garages and water systems, that are occupied 
throughout the year, and 14 summer residences and 
w^^eekend cabins. Public utilities which would require 
relocation consist of about 3 miles of county roads, 
power lines, and telephone lines. 

The pumping plant w^ould be located on the left 
abutment near the downstream toe of the dam. The 
plant wwild consist of an enclosed reinforced-concrete 
structure, housing 3 electrically driven multistage, 
centrifugal pumping units. Each of the units would 
comprise a 10-inch diameter pump, with discharging 
capacity of 6.7 second-feet, driven by a 450-horse- 


power motor. The pumps would operate at a maxi- 
mum head of about 470 feet, pumping from an 
estimated minimum water surface elevation in the 
reservoir of 500 feet, to a discharge elevation of 895 
feet near Los Gatos Creek. The pump intakes would 
connect directly to the 3 6 -inch diameter reservoir 
outlet pipe, and would discharge into a 30-ineh diam- 
eter steel conduit in a manifold arrangement. A 10- 
inch diameter by-pass would be installed at the end of 
this system. Three 10-inch diameter check valves 
would be placed on the discharge pipes of the pump- 
ing units, while three 10-inch diameter gate valves 
would be used on the intake side. The by-pass would 
be provided with a 10 -in eh diameter gate valve. 

The pipe line to Los Gatos Creek would consist of a 
30-inch diameter steel pipe, about 6.4 miles in length, 
and would utilize a portion of the former road bed of 
the Southern Pacific Eailroad between Santa Cruz 
and Los Gatos, vhieh was abandoned in March of 
1941. Prom the pumping plant, the pipe line would 
extend up the left abutment of the dam for a distance 
of 500 feet to the railroad bed, located at an elevation 
of 636 feet. The pipe line would then follow the 

! 1 O^TTn"! on Qnrl nPT’Cirlo n-F +ho Vko/I m o 

V/J- PLf V. AJA CL XXV/X LFXXV./Ct*C3 

erly direction, terminating about 0.1 mile southwest 
of the station of Wright on Los Gatos Creek, at an 
elevation of about 895 feet. Three railroad tunnels 
would be utilized en route. It was estimated that 
2,400 linear feet of excavation would be necessary to 
clear the tunnel portals. 

Pertinent data with respect to general features of 
the Zayante Project, as designed for cost estimating 
purposes, are presented in Table 47. 

TABLE 47 

GENERAL FEATURES OF ZAYANTE PROJECT 


Earthfili Dam 

Crest elevation— 616 feet 
Crest length— 470 feet 
Crest width — 28 feet 

Ueight, spillway lip above stream, bed— 127 feet 
Side slopes — 2 .5:1 upstream and dov/nstream 
Freeboard, above spillway lip — 13 feet 
Elevation of stream bed — 476 feet 
Volume of fill — 433,800 cubic yards 

Reservoir 

Surface area at spillway lip — 153 acres 

Storage capacity at spill w'ay lip— 6,900 acre-feet 

Drainage area — 9 . 5 square miles 

Estimated mean seasonal runoff — 9,000 acre-feet 

Estimated safe seasonal yield — 4,000 acre-feet 

Type of spillway — Ogee weir, concrete-lined chute 

Spillway discharging capacity— 8,900 second-feet 

Type of outlet — 36-inch diameter steel pipe beneath dam 

Pumping Plant 

Pumps — 3 each, multistage, centrifugal, 6.7 second-foot capacity 

Minimum water surface elevation in reservoir — 500 feet 

Discharge elevation — 895 feet 

Maximum pumping head — 472 feet 

Installed pumping capacity — 20 second-feet 

Motors — 3 each, open type, 450 horsepower 

Conduit 

Type — welded steel pipe 

Length — 6.4 miles 

Di ameter — 3 0-inch 

Discharging capacity — 20 second-feet 



PLANS POE WATER DEVELOPMENT 


79 


The capital cost of the Zayante Project, on a 3.5 
per cent interest basis, and based on prices prevailing 
in the fall of 1954, was estimated to be about $2,660,- 
000, Corresponding annual costs were estimated to be 
about $180,000. The resultant estimated average unit 
cost of the 4,000 acre-feet of water per season by the 
Zayante Project is, therefore, about $45.00 per acre- 
foot. The estimates of capital and annual costs are 
summarized in the following tabulation. Detailed cost 
estimates are presented in Appendix L. 

Estimated Costs 



Capital 

Annual 

Dam and reservoir 

$1,299,400 

$63,000 

Pumping plant 

120,200 

47,300 

Pipe line 

1,237,600 

69,100 

Totals 

$2,657,200 

$179,400 


Discussion of Plans for Initial Local 
Development for North Santo Clara Volley 

In the foregoing sections, three plans were pre- 
sented which would provide new water for use in 
North Santa Clara Valley. The Northern Valley 
Project would involve construction of works, which, 
when operated in conjunction with existing works, 
would provide a safe yield of about 8,900 acre-feet of 
new water per season, at a cost of about $17.00 per 
acre-foot, excluding costs of pumping the water from 
the ground water basin. The second plan, the Little 
Francis Project, would involve construction of a dam 
and reservoir on San Prancisquito Creek, and treat- 
ment and conveyance of the conserved water for use 
in the City of Palo Alto. The project would provide a 
safe yield of about 3,000 acre -feet of water each 
season, at a cost of about $75.00 per acre-foot. The 
third plan, the Zayante Project, would involve con- 
struction of a dam and reservoir on Zayante Creek in 
Santa Cruz County, and conveyance of the conserved 
water in pipe line and existing tunnels to the Santa 
Clara Valley. The project would provide a safe sea- 
sonal yield of about 4,000 acre-feet, at a cost of about 
$45.00 per acre-foot, excluding costs of distribution 
or cost of pumping from the ground water basin if 
the water were diverted into existing percolation 
Avorks. 

The three projects would provide a total of about 
15,900 acre-feet of neAv Avater per season, at a 
AA^eighted average unit cost of $35.00 per acre-foot. 
This cost is considerably aboA^e the range of recently 
estimated costs of AA^ater from the Feather River 
Project, and suggests that the continued additional 
development of local Avater supplies in the Santa 
Clara Valley is uneconomic, and that consideration 
should be gh^en to means of obtaining future supple- 
mental AA^ater supplies from an outside source or 
sources. 


South Santo Clara Volley 

It AA^as shoAvn in Chapter III that the estimated 
present requirement for supplemental water in South 
Santa Clara Valley is about 7,000 acre-feet per 
season, and that the ultimate seasonal supplemental 
requirement probably Avill be about 21,000 acre-feet. 

The results of surveys and studies shoAA^ that 
the probable ultimate requirement for supplemental 
AA^ater in South Santa Clara Vallejo could be met by 
the construction and operation of a reservoir of 34,000 
acre-foot storage capacity on llA^as Creek, a diA^er- 
sion conduit of 50 second-foot capacity from Uvas 
Creek to Llagas Creek, and percolation ponds on 
Llagas Creek from U. S. HighAvay 101 about 4.2 miles 
doAvnstream, and the utilization of AA^ater yielded 
from Chesbro Reservoir, noAV under construction on 
Llagas Creek by the South Santa Clara Valley Water 
Conservation District. The estimated safe yield of 
new water from this system of works AAnuld be about 
22,000 acre-feet. Of this ncAv yield, an aA^erage of 
about 16,300 acre-feet of Avater per season would 
be made aA^ailable from the proposed reservoir on 
Uvas Creek, and 5,700 acre-feet per season from 
Chesbro Reservoir on Llagas Creek. These plans are 
described in some detail in the folloAving section. 

The South Santa Clara Valley Water Conservation 
District is planning construction of a dam and reser- 
voir on Uvas Creek with a storage capacity of 10,000 
acre-feet. This reserAmir, if operated in conjunction 
Avith Chesbro Reservoir, and with a percolation 
capacity of 50 second-feet in Llagas Creek, Avould 
provide new water in the amount of about 9,900 acre- 
feet per season. The combined ncAA^ seasonal yield of 
Chesbro Reservoir and this reservoir on Uvas Creek 
would be about 15,600 acre-feet. 

Uvas and Llagas Creeks Project. This project 
Avould include the construction of a dam and reser- 
voir on Uvas Creek, a conduit to convey a portion of 
the conserA^ed water to Llagas Creek, and a number 
of small check dams on Llagas Creek to increase per- 
colation. The project would be operated in' conjunc- 
tion Avith Chesbro ReserAnir on Llagas Creek. W^ater 
eonseiwed by the project would preA^ent progress! A^e 
and permanent lowering of ground Avater levels in 
South Santa Clara Valley, and Avould provide for the 
ultimate supplemental Avater requirement. Principal 
features of the project are shoAAn on Plate 23, entitled 
^^UA^as and Llagas Creeks Project, 1955.’^ 

Uvas Dam Avould be a rock and earthfill structure 
AAdth chute spilhvay, located on Ua^s Creek in Section 
18, ToAAUiship 10 South, Range 3 East, M. D. B. & M., 
at the site of the Gilroy Water Works Diversion 
Dam, some 7 miles nortliAvest of the City of Gilroy. 
The stream bed elevation at the site is 392 feet. Flood 
AA-aters of Uvas Creek conserved by Uvas ReserAmir 
Avould be released at an eleAmtion of approximate^" 



Chesbro Dom on Llagas 
Creeks N\ay 26, 1955 



Gilroy Wafer Works Dam 
at Uvas Dam Site 
on Uvas Creek 



PLANS POE WATER DEVELOPMENT 


81 


425 feet, and transported to Llagas Creek in a con- 
duit, consisting of 1.8 miles of reinforced-concrete 
pipe and 1.5 miles of unlined canal, which would 
terminate at an elevation of about 350 feet on Llagas 
Creek. The diversion of Uvas Creek water would be 
necessary, since sufficient capacity for its percolation 
is not available in the Carnadero and Uvas Creek 
channels. The diverted water would flow to percola- 
tion ponds to be located on Llagas Creek between 
U. S. Highway' 101 and Rucker Avenue. 

A topographic survey of the Uvas dam site was 
made by Blackie and Wood, Civil Engineers, in Sep- 
tember, 1952, at a scale of 1 inch to 50 feet, with 10- 
foot contour intervals. A map of the reservoir area 
was presented in the Blackie and Wood Report to 
the Honorable Board of Directors South Santa Clara 
Valley Water Conservation District on Llagas Creek 
and Uvas Creek Well Replenishment Project, Proj- 
ect Report No. 14, and has a scale of 1 inch to 100 
feet, with 20-foot contour intervals. Storage capaci- 
ties of Uvas Reservoir at various stages of water sur- 
face elevation, derived from this map, are given in 
Table 48. 

TABLE 48 


AREAS AND CAPACITIES OF UVAS RESERVOIR 


Depth of 
water at 
dam, in feet 

Water surface 
elevation, 
USGS datum, 
in feet 

Water surface 
area, 
in acres 

Storage 
capacity, 
in acre-feet 

0 

392 

0 

0 

28 

420 

50 

100 

48 

440 

105 

2,000 

68 

460 

180 

5,400 

88 

480 

270 

10,000 

108 

500 

390 1 

17,500 

128 

520 

530 

26,500 

142 

534 

630 

34,400 

148 j 

540 j 

680 1 

38,200 

168 

560 

850 

54,000 


Based upon preliminary geological reconnaissance, 
the Uvas dam site is considered suitable for a rock or 
earthfill dam with a maximum height of about 
200 feet. Bedrock at the site consists of a gray to 
greenish, very fine-grained to aphanitic, slightly 
metamorphosed sandstone, with occasional associated 
shales, and containing localU^ a few small lenses of 
chert. It is generally tight, although finely jointed 
where weathering extends to a depth of several inches 
below the surface. Some blocky-type jointing occurs, 
with up to 2 inches of separation on the surface 
being noted in some places. However, these joints 
should tighten a short distance below the surface. No 
shears or faults of significance were observed. On the 
right abutment, in addition to the above tj/pe of rock, 
some medium-grained, relatively unmetamorphosed, 
red to tan sandstone was noted in talus slopes, but 
was not found outcropping. A small pocket of purple, 
strongly weathered, and metamorphosed (schistose) 


volcanic rock was noted near the axis at the base of 
the right abutment. 

No serpentine was found, even in drill holes re- 
cently drilled for the South Santa Clara Valley Water 
Conservation District, except as stream float. The 
rock is apparently a part of the Franciscan series of 
Jurassic Age. Some small-scale landsliding and mantle 
creep occur on the right abutment. This slope has 
apparently been subjected in the past to slow down- 
ward movement of overburden. 

Stripping under the impervious section of the dam 
would require the removal of about 9 feet of soil and 
3 feet of weathered rock on the right abutment. 
Stripping on the left abutment would require the 
removal of about 3 feet of rock. Stripping from the 
channel section would require the removal of about 
37 feet of earth and gravel. 

A suitable location for a chute spillway exists in 
the left abutment ridge, at an elevation about 200 feet 
above stream level. The height of dam selected, how- 
ever, would necessitate a spillway cut of about 60 
feet, but the ridge is thin at this point. The excavation 
would be almost entirely in sandstone, and this mate- 
rial could be salvaged in its entirety for use in 
construction of the dam. 

There is apparently sufficient soil material for im- 
pervious fill within one-half mile of the dam site. A 
considerable amount was located downstream. Some 
earth would also be obtained as salvage from stripping 
of the broad terrace on the right side of the channel. 
Another good source of impervious material appears 
to be on the upstream base of the right abutment. 

Aggregates, consisting of typical Franciscan gravels 
mixed with sand, and including meta-sediments, vol- 
canies, cherts, and some serpentine fragments, could 
be recovered from the stream channel locally. Gravels 
at the axis are thin, and confined to a narrow zone of 
active channel, but much more extensive deposits 
were noted upstream within a distance of 1 mile. 
The sandstone bedrock would supply adequate quan- 
tities of rockfill, and possibly riprap. Much of this 
material could be salvaged from stripping of the 
abutments, and from excavation in the spillway cut. 

The reservoir would inundate approximately 700 
acres of land, which would require clearing of a 
sparse growth of trees and brush. About 4.5 miles of 
county road would require relocation. Twelve resi- 
dences and a number of barns and buildings would 
also be inundated. 

As a result of yield studies, geologic reconnaissance, 
and preliminary economic analysis, an earthfill dam, 
142 feet in height from stream bed to spillway lip, 
and with a crest elevation of 549 feet, was selected to 
illustrate estimates of costs of the Uvas Dam and 
Reservoir. The dam would have a crest length of about 
1,255 feet and a crest width of 30 feel, and 2.5:1 
upstream and downstream slopes. The central imper- 


4—19273 



82 


SANTA CLARA VALLEY INVESTIGATION 


vious core would have a top width of 10 feet, and 
0.75:1 slopes. The outer pervious zones would consist 
of stream bed gravels and material salvaged from 
stripping and excavation. The volume of fill would be 
an estimated 2,165,000 cubic yards. 

The spillway would be of the chute type, located on 
the left abutment. The maximum depth of water above 
the spillway lip would be 10 feet, and an additional 
5 feet of freeboard would be provided. The spillway 
would have a discharging capaeity of 20,000 second- 
feet, required for an assumed maximum flood flow of 
660 second-feet per square mile of drainage area. The 
spillway would discharge into a draw which joins 
Uvas Creek downstream from the toe of the dam. 

The outlet works would consist of a 3 6 -inch diam- 
eter steel pipe, placed in a trench excavated in rock 
beneath the left abutment of the dam and encased in 
concrete. Releases of water from the reservoir would 
be controlled at the upstream end of the pipe by a 
36-inch diameter hydraulically controlled gate. The 
outlet would be controlled at the downstream end of 
the pipe by a 30-ineh diameter hollow jet valve. The 
water would be released into a stilling basin, from 
which it would either enter the LTvas-Llagas Conduit, 
to be conveyed to Llagas Creek for percolation, or 
would spill through a wasteway into the Uvas Creek 
channel. The stilling basin would be a reinforcecL 
concrete structure, 12 feet in width, 60 feet in length, 
and 12 feet in height. The elevation of the bottom of 
the stilling basin would be about 419 feet. Flow 
from the stilling basin to the conduit would be con- 
trolled by a 5-foot by 4-foot slide gate set in the head- 
wall. Excess water in the stilling basin, as well as 
w^ater released at the rate of 10 second-feet for perco- 
lation in Uvas Creek, would discharge over a weir to 
return to the channel downstream from the dam. The 
length of the weir would be 20 feet, and its crest ele- 
vation 425 feet. 

The Uvas-Llagas Conduit, with a capacity of 50 
second-feet, would consist of about 1.8 miles of 48- 
inch diameter reinforeed-eonerete pipe and 1.5 miles 
of unlined canal. The pipe line, beginning at the dam 
outlet stilling basin, would follow the left bank of 
Uvas Creek for a distance of about 1,2 miles. It would 
then swing northerly a distance of about 0.5 mile, to 
discharge into the unlined canal at Sycamore Road, 
on the saddle between Uvas and Llagas Creeks. The 
water would be conveyed northerly in the canal to a 
concrete-lined chute to Llagas Creek, located about 
0.5 miles downstream from the Machado School. Here 
the water would drop 50 feet to the stream bed, 
where the elevation is about 350 feet. The unlined 
canal would be of trapezoidal section, with I-.l side 
slopes, bottom width of 5 feet, depth of 2.5 feet, and 
freeboard of 1 foot. The slope of the canal would be 
about 5.9 feet per mile, and the maximum velocity 
of water in the canal would be 2.7 feet per second. 


The chute would be about 200 feet in length, includ- 
ing a stilling basin 50 feet in length. The diverted 
water would flow in the natural channel of Llagas 
Creek to percolation ponds extending from U. S. 
Highway 101 about 4.2 miles downstream. 

The present capacity for percolation of water in 
Llagas Creek was estimated from measurements made 
during the current investigation and from prior 
studies. The estimated percolation rate amounts to 
about 30 second-feet over the Porebay Zone from 
Llagas Avenue to Rucker Avenue. Other data indi- 
cate that the present rate of percolation from Llagas 
Creek is susceptible of increase to about 50 second- 
feet, by the construction of low dams in the channel 
to increase the area of wetted stream bed. About 50 
acres of stream bed would be required to obtain this 
percolation capacity. 

TTnder the project, 23 low sausage-type dams would 
be constructed at strategic locations on Llagas Creek, 

TABLE 49 

GENERAL FEATURES OF UVAS AND LLAGAS 
CREEKS PROJECT 


Uvas Bam — earthfill 

Crest elevation— 549 feet 
Spillway elevation— 534 feet 
Crest length — 1 ,255 feet 
Crest width — 30 feet 

Height, spillway lip above stream bed — 142 feet 
Side slopes — 2.5:1 upstream and downstream 
Freeboard, above spillway lip — -15 feet 
Elevation of stream bed — 392 feet 
Volume of fill — 2,250,000 cubic yards 

Uvas Reservoir 

Surface area at spillway lip— 830 acres 

Storage capacity at spillway hp — 34,000 acre-feet 

Drainage area — -30.3 square miles 

Estimated mean seasonal runoff — 26,500 acre-feet 

Estimated seasonal new yield — 16,300 acre-feet 

Type of spillway — lined chute with ogee weir control 

Spillway discharging capacity— 20,000 second-feet 

Type of outlet— 36-ineh diameter steel pipe beneath dam 


Uvas-Llagas Conduit 


iJvas Dam to Sycamore Road 

Sycamore Road to Llagas Creek 

Type — reinforced-concrete pipe line 

T'ype^ — ^uniined canal 

Length — 1 . 8 miles 

Length — 1 . 5 miles 

Diameter — 48 inches 

Side slope — 1:1 in cut 

Velocity — 4.0 feet per second 

1.5:1 infill 

Capacity — 50 second-feet 

Bottom width — 5 . 0 feet 

Depth — 2 . 5 feet 

Freeboard — 1 . 0 foot 

Slope — 5,9 feet per mile 

Velocity — 2 . 7 feet per second 
Capacity — 50 second-feet 


Llagas Creek Percolation Ponds 

Total area — 50 acres 

Maximum percolation capacity — 50 second -feet 
Sausage dams 

Type — rock filled and covered with chain link mesh 
Number — 23 

Average crest length — 100 feet 
Height above stream bed — 3 . 0 feet 
Total volume of fill — 2,800 cubic yards 



PLANS FOR WATER DEVELOPMENT 


83 


between Llagas and Rucker Avenues. The dams would 
be constructed to a height of 3 feet, and their average 
crest length would be about 100 feet. The dams would 
be of rock fill and covered with chain link mesh. They 
would be provided with rockfilled aprons, 10 feet or 
more in length, with a rolled rockfilled sausage^’ 
section at the downstream end of the aprons. The 
aprons would be located immediately below the dams. 

Under the method of operation proposed for the 
Uvas and Llagas Creeks Project, releases of water 
would be made from Uvas Creek Reservoir to permit 
maximum percolation in Uvas Creek at a rate of 
10 second-feet. Additional releases of water would be 
made up to a rate of 50 second-feet, providing such 
releases could be diverted to and percolated in the 
Llagas Creek percolation ponds. The availability of 
percolation capacity in Llagas Creek would depend 
upon the rate of release of stored water from Chesbro 
Reservoir. 


Pertinent data with respect to general features of 
the Uvas and Llagas Creeks Project, as designed for 
cost estimating purposes, are presented in Table 49. 

The capital cost of the Uvas and Llagas Creeks 
Project, on a 3.5 percent interest basis and with 
prices prevailing in the fall of 1954, was estimated 
to be about $3,920,000. Corresponding annual costs 
were estimated to be about $194,000. The resultant 
estimated average unit cost of the 16,300 acre-feet 
per season of new water from the Uvas and Llagas 
Creeks Project was about $11.90 per acre-foot. The 
estimates of capital and annual costs are summarized 
in the following tabulation. Detailed cost estimates 
ai^e presented in Appendix L. 

Estimated Cost 
C apital Annual 

Uvas Dam and Reservoir $3,604,000 $173,500 

Uvas-Llagas Conduit 273,900 16,600 

Llagas Creek Percolation Ponds 40,000 4,000 


Totals 


$3,917,900 $194,100 



CHAPTER V 


SUMMARY OF CONCLUSIONS, AND RECOMMENDATIONS 


As a result of field investigation and study and 
analysis of available data on the water resources 
and water problems of the Santa Clara Yalley, 
the following conclusions and recommendations are 
made : 

SUAAMARY OF CONCLUSIONS 

1. There are two present basic water problems in 
the Santa Clara Valley. One of these is the threat 
of sea-water intrusion into the confined aquifers 
underlying North Santa Clara Valley, which results 
from a rate of ground water draft in excess of safe 
yield of the aquifers. The other problem is the pro- 
gressive perennial lowering of ground water levels in 
forebay zones of the valley. 

2. The present principal sources of water supply 
of the Santa Clara Valley are direct precipitation, 
runoff from the tributary drainage areas of the 
Diablo Range and Santa Cruz Mountains, and sub- 
surface inflow from beneath San Francisco Bay. 
There are no significant exports of water from the 
valley. However, a relativel^^ small amount of water 
is imported to North Santa Clara Valley through the 
Hetch Hetehy system owned by the City of San Fran- 
cisco. 

3. The present mean seasonal requirement for sup- 
plemental water in the Santa Clara Valley is about 

52.000 acre-feet, distributed as follows: North Santa 
Clara Valley, 45,000 acre-feet, and South Santa Clara 
Valley, 7,000lCTi3iet. 

4. Under conditions of ultimate development, the 
probable seasonal requirements for supplemental 
water in North and South Santa Clara Valleys should 
approximat e 262.0 00 an(L™24,000 acre-feet, respec- 
tively. 

5. The surface and ground water supplies of the 
Santa Clara Valley generally are of good mineral 
quality, and suitable for irrigation and other pur- 
poses. 

6. The estimated safe seasonal yield of the ground / 
water basins of North and South Santa Clara Valleys f 
is about 134,000 ancj 39,000 acre-feet, respectively. 

7. The present seasonal extraction of ground water 
from North Santa Clara Valley in the amount of 
about 179,000 acre-feet exceeds the safe yield hj about 

45.000 acre-feet. Corresponding ground water extrac- 
tion of South Santa Clara Valley in the amount of 
about 46,000 acre-feet per season exceeds the safe 
yield by about 7,000 acre-feet. 

8. An immediate source of supplemental water is 
available locally to the Santa Clara Valley in waters 


of the surface streams that presently waste to San 
Francisco Bay and the Pajaro River. Salvage of this 
water would involve the development of both surface 
and ground water storage capacity. It is indicated 
that the present mean seasonal waste of water from 
North Santa Clara Valley to San Francisco Bay, with 
recently completed works in operation, is about 53,000 
acre-feet, excluding the estimated 12,300 acre-feet 
presently wasting from San Francisquito Creek. The 
indicated mean seasonal waste of water from South 
Santa Clara Valley to the Pajaro River is about 49,000 
acre-feet. It would be feasible to salvage a portion of 
these presently wasted waters. However, complete 
salvage of such waters would be insufficient to meet 
the probable ultimate supplemental water require- 
ments. 

9. Satisfaction of the ultimate water requirements 

in the Santa Clara Valley will require an import of 
so me a cre-feet of water per season from a 

source or sources outside the valley, 

10. Completion of the works under construction by 
the Santa Clara Valley Water Conservation District 
and the proposed Calero-Los Gatos Conduit, and their 
operation as proposed in this bulletin, would eliminate 
the present overdraft and provide a small amount of 
additional supplemental water in the Forebay Zone of 
North Santa Clara Valley. Construction and opera- 
tion of the Coyote Valley Well Field, the Coyote 
Valley- San Jose Pipe Line, and the Little Francis 
Project would reduce the overdraft in the Pressure 
Zone of North Santa Clara Valley by about 12,500 
acre-feet per season. Taking into consideration the 
yield of about 5,000 acre-feet per season from Lake 
Blsman, the remaining overdraft in the Pressure Zone 
would be about 1,500 acre-feet per season. 

11. Completion and operation of Chesbro Dam and 
Reservoir on Llagas Creek by the South Santa Clara 
Valley Water Conservation District should reduce the 
present overdraft in South Santa Clara Valley by 
about 5,700 acre-feet per season. Construction and 
operation of Uvas Dam and Reservoir on Uvas Creek, 
with a storage capacity of 34,000 acre-feet as proposed 
herein, and construction and operation of the pro- 
posed Llagas Creek Percolation Ponds, would elimi- 
nate the present overdraft in South Santa Clara 
Valle}^, and provide for the probable ultimate supple- 
mental water requirement. 

12. Additional water could be developed for use in 
North Santa Clara Valley by construction of the 
Zayante Project. The estimated safe seasonal yield of 
this project is about 4,000 acre-feet. 


( 85 ) 



86 


SANTA CLAKA VALLEY INVESTIGATION 


13. The ultimate supplemental water requirement of 
North Santa Clara Valley would be largelj^ provided 
for by importation of water from the Sacramento- 
San Joaquin Delta under the authorized Feather 
River Project. In the report of the Division of Water 
Resources on ‘ ‘ Program for Financing and Construct- 
ing the Feather River Project as the Initial Unit of 
The California Vv^ater Plan’', February, 1955, charges 
for Feather River Project water delivered to the 
Santa Clara Valley were assumed at from $17.50 to 
$22.50 per acre-foot, based on an initial project to 
provide 120,000 acre-feet of water per season to San 
Benito County, Santa Clara Valley, and Alameda 
County. 

14. Based on 1954 prices, the unit cost of the 8,900 
acre-feet of yield of new water provided b}^ the North- 
ern Valley Project for North Santa Clara Valley 
would- be about $17.00 per acre-foot, excluding costs 
of pumping the water from the ground water basin. 
Unit costs of the 3,000 acre-feet of water per season 
conserved by the Little Francis Project would be 
about $74.00 per acre-foot, and for the 4,000 acre-feet 
of safe seasoiiai jueici irom the ^ayante Project the 
unit costs would be about $45.00 per acre-foot. 

lo. The unit cost ot the 16,300 acre-feet per season 
of yield of new water for South Santa Clara Valley 


from the Uvas and Llagas Creeks Project would be 
about $12.00 per acre-foot. 

RECOMMENDATIONS 

It is recommended that the County of Santa Clara, 
and the agencies therein responsible for furnishing 
water supplies in the Santa Clara Valley: 

1. Initiate studies to determine the effects of re- 
cently completed water development projects on the 
safe yield of ground water basins in the Santa Clara 
Valley. 

2. Initiate studies to determine the most feasible 
way to supply supplemental water to the Pressure 
Zone of North Santa Clara Valley, 

3. Proceed with their planned local projects for 
water resource development as far as is practicable. 

4. Proceed with development of the Northern Val- 
ley Project and the Uvas and Llagas Creeks Project, 
as set forth in this bulletin. 

5. Give early consideration to the implementation 
of plans for securing a water supply from the Feather 
River Project to supplement local supplies. 

6. Initiate a program for the acquisition of lands, 
easements, and rights of way necessary for the con- 
struction of required water conservation works. 



PLATE I 



PLATE 2 





^reeh 


’«mpUn 




FRAtmSCO^ 

\'~BAy 












LEGEND 


PRECIPITATION STATIONS 


CLARA VALLEY INVESTIGATION 


SANTA 


GAGING STATIONS 


LINES OF EQUAL MEAN 
SEASONAL PRECIPITATION 

1898-1947 


PRECIPITATION IN INCHES 


BOUNDARY OF DRAINAGE BASIN 


BOUNDARY OF INVESTIGATED AREA 




mat , 


ACCUMULATED DEPARTURE FROM MEAN SEASONAL PRECIPITATION AT SAN JOSE AND GILROY 


2 

< 

6 

z 

0 

*n 

1 

PI 

X 

X 

m 

(p 

O 

c 


PI 

(fl 


ACCUMULATED DEPARTURE FROM 50 YEAR MEAN 
SEASONAL PRECIPITATION IN PER CENT 



ACCUMULATED DEPARTURE FROM 50 YEAR MEAN 
SEASONAL PRECIPITATION IN PER CENT 



"O 

n 

> 

H 

m 

•A 


7J 

n 

o 

O 

a 

m 

a 

(/) 

m 

> 

(/) 

o 

z 

> 

r 

"D 

m 

o 

H 

> 

H 

O 

z 

> 

H 

(/) 

> 

Z 

c. 

O 

(/) 

m 


O 

r 

o 

-< 


TOTAL SEASONAL PRECIPITATION IN INCHES 


1884-65 


1869-90 


1894-95 


1904-05 


1914-15 


1924-25 


1929-30 


1939-40 


1949-50 


1874-75 


1879-80 


1884-85 


1894-95 


1699-1900 


1904-05 


1909-10 


1924-25 


1929-30 


1939-40 


1944-45 


U) A 

» O 




* M 


CO 

> 

z 


o 

CO 

m 


TOTAL SEASONAL PRECIPITATION IN INCHES 


1949-50 I 



o 

r 

zi 

o 

-< 


PLATE 3 




PLATE 5 


b. 

Ul 

O 

z 

D 

oc 


COYOTE CREEK NEAR MADRONE 


UVAS CREEK NEAR MORGAN HILL 


200 

160 

160 

140 

120 

100 

80 

60 

40 

20 

0 



RECORDED AND ESTIMATED SEASONAL NATURAL RUNOFF 



DIVISION OF WATER RESOURCES 





PLATE 7 



.S’rV^rr. 


^ancisc^ 

\ BAY 






C^artct 


^anja 


SANTA CLARA VALLEY INVESTIGATION 


LEGEND 


LINES OF EQUAL DEPTH 


so LINES OF EQUAL DEPTH TO GROUND WATER IN FEET 


BOUNDARY OF DRAINAGE BASIN 


GROUND WATER 

FALL OF 1953 


BOUNDARY OF INVESTIGATED AREA 


■ .SAJ^ 


mat- 



PLATE 8 




DIAGRAMMATIC PROFILES OF PRESSURE AND FOREBAY ZONES 
IN NORTH AND SOUTH SANTA CLARA VALLEYS 


DIVISION OF WATER RESOURCES 



PLATE 9 









fRANCISC^ 

\^AV 


Sfl'*:' c 










NTA 


^ANI fi. 


SANTA CLARA VALLEY INVESTIGATION 


LEGEND 


LINES 


OF EQUAL ELEVATION 


20 LINES OF EQUAL ELEVATION OF GROUND WATER IN FEET 


GROUND WATER 
FALL OF 1953 


BOUNDARY OF DRAINAGE BASIN 


BOUNDARY OF INVESTIGATED AREA 


S an^ 
,/Ianta 


MAr, 



PLATE 10 



NORTH SANTA CLARA VALLEY - FOREBAY ZONE - WELL 7S/IW- 35CI 


h 

y 

y 

L 


y 

U 

(r 

D 

if) 

0 

z 

D 

0 

QC 

0 

5 

0 

tt 

L 

I 

h 

(L 

y 

0 




























rr: 


— *20 — 














ito 


























Ground Surfoi 


rr 


"A 

A 









































\ 

\ t 










0 































V 

\ 




























N 

- V- - 














V 

V 

/ 










20 


































T/ 
































A 


n 

A 












J 

































n 

I 











7 









* 


















V 





/ 

\ / 


1 











/ 






/! 


A 

z 


60 























_4 

4-t 


1 

















7^ 



i 




























\J 

















/ 




1 

i 




00 







































"T" 


1 


i 

W 








































/ 


T 


f 


1 











































T 


J 

ZSL 

_\l 



120 


NORTH SANTA CLARA VALLEY - PRESSURE ZONE -WELL 6S/IE-30MI 




SOUTH SANTA CLARA VALLE Y- PRESSURE ZONE -WELL I0S/3E-I3RI 

MEASURED DEPTH TO WATER LEVEL AT SELECTED WELLS IN SANTA CLARA VALLEY 


DIVISION OF WATER RESOURCES 


PLATE M 




PLATE 12 





^reek 


ompheU 


fRANCISC^ 

y^AY 




PACfFU 


0^m 




Capjfa^^' 


" .SAl^ 

t/" SANT A 






^ v/ ^AnTA <v-^ 


r An. V.*) 

V.\ '<^ -./ 

X 


LEGEND 


“'TT — 






, _ , ^ — .-2 LINES OF EQUAL CHANGE IN GROUND WATER IN FEET 
-INDICATES LOWERING + INDICATES RISE 

• ••••• BOUNDARY OF DRAINAGE BASIN 

BOUNDARY OF INVESTIGATED AREA 


STATE OF CALIFORNIA 
DEFARTMENT OF FUSLIC WORKS 

DIVISION OF WATER RESOURCES 

SANTA CLARA VALLEY INVESTIGATION 


LINES OF EQUAL CHANGE 


GROUND WATER ELEVATIONS 

FALL OF 1948 TO FALL OF 1953 

SCALE OF MILES 



PLATE »3 




Treeh 




fRANCISC^ 

\~BAY 


^ Jfe w y 


CsB^SS'- 


Cu2^ 


'■k stitmfm 


I-' 

■Savta J— 


DIVISION OF WATER RESOURCES 

SANTA CLARA VALLEY INVESTIGATION 

EQUAL CHANGE IN GROUND WATER ELEVATIONS 

IN 

north SANTA CLARA VALLEY 

FALL OF 1935 TO FALL OF 1948 


LEGEND 


LINES- OF EQUAL CHANGE IN GROUND WATER IN FEET 
-INDICATES lowering INDICATES RISE 

BOUNDARY OF DRAINAGE BASIN 
BOUNDARY OF INVESTIGATED AREA 


LINES OF 








3 



PLATE 14 



LEGEND 

— —1.0 LINES OF EQUAL SUBSIDENCE IN FEET 

• ••••• BOUNDARY OF DRAINAGE BASIN 
— ■ BOUNDARY OF INVESTIGATED AREA 


Ooto from U.S.C.B G. Survey 


•TATS or CAUrOSNIA 
OSFAItTMBNT OF FUSUC WORK* 

DIVISION OF WATER RESOURCES 

SANTA CLARA VALLEY INVESTIGATION 


LINES OF EQUAL SUBSIDENCE OF GROUND SURFACE 

IN 

NORTH SANTA CLARA VALLEY 

FOB THE PERIODS 

1934-1948 AND 1948-1954 

SCALE OF MILES 

I 0 ! 2 S 


LINES OF EQUAL SUBSIDENCE 
1948 TO 1954 



PLATE 15 





^Creeh 


■omp6*ti 






% U'*‘\ 


Cqpi^^V 


,K«4nta 

-54 ^7 A }S- 


SANTA CLARA VALLEY INVESTIGATION 


LEGEND 


LINES OF EQUAL ELEVATION OF GROUND WATER 


as LINES OF EQUAL ELEVATION OF GROUND WATER IN FEET 


BOUNDARY OF DRAINAGE BASIN 


NORTH SANTA CLARA VALLEY 
SEPTEMBER-OCTOBER. 1953 


BOUNDARY OF INVESTIGATED AREA 


san]-J 


SCALE OF MILES 


mat, 





FRA^ISC^ 

\ BAY 


LEGEND 


■ S AN'y 




^ ^'y' A x’ ^ X X ' -X_ * 

‘ , ’' VT" .•■ ' . c<f y \. V ■■•' • ^ ■ ■■ v<^ 

;/ /< ^ x/ ^ X ^ x)^ ..X., " .;"^... " /\ ^ /X ^ 






\/ 






• 


Jg 


-ttPS* 


Creek 




Cefico 


r 












\ ^Si y/ 

54NTA rSy 

^fiUZ ^ ^?> 


to 


^ ' \X " " ,X '’ ,/ 

V '>r '» • X" »‘ >\ 

vXXXx" V 


iRRIGATCD LANDS. 1949 
IRRIGABLE LANDS 
URBAN DEVELOPMENT. 1949 
URBAN DEVELOPMENT SINCE 1949 


DIVISION OF WATER RESOURCES 

SANTA CLARA VALLEY INVESTIGATION 


@ LOCATION OF USE OF WATER STUDIES 
• ••••• BOUNDARY OF DRAINAGE BASIN 
— BOUNDARY OF INVESTIGATED AREA 


LAND USE 

1955 


SA-S 







PLATE 17 



Creek 


SJlj^ 


FRANCISCO^ 

'\~BAy 


w C 


A 


^f^UZ 


LAKE ELSMArf 


SANTA CLARA VALLEY INVESTIGATION 


LEGEND 


EXISTING WATER CONSERVATION WORKS 

AND 

WORKS CONSIDERED FOR FUTURE DEVELOPMENT 

1955 


PROPOSED WORKS 


^ tMC TUNMtL • 'iC 1 

lo.t ^ I 

^ i 

ZAYAHTE -LOS , GATOS PfPE UN£\ 


EXISTING WORKS 


ZAYANTERES. 


• • • BOUNDARY OF DRAINAGE BASIN 


PUMPING PLANT ^ 


BOUNDARY OF INVESTIGATED AREA 


■ SANJA 


M A > 


TUNNCL MO 3- 


ZAYANTE RES. PROJECT 


SEE INSERT - ZAYANTE RES. PROJECT 


PLATE 16 




PLATE 19 




PLATE 20 



fNUNEb CA^ 




wadalupe\ ^ 

CREEK ^ V. 

E^^TfNG CANAL 


GENERAL PLAN 


SCALE OF FEET 
2000 


4000 


/) 0007/3 


-I 250 SANTA CLARA VALLEY INVESTIGATION 

76 78 ^ 

CALERO-LOS GATOS CREEK CONDUIT 
1955 


250 


SCALE OF FEET 


SECTION OF INTERCEPTING CANAL 


350 


u. 2 

3 

o 

Z 

o 

“ o 


275 


36 38 40 42 

LENGTH IN THOUSANDS OF FEET 

PROFILE OF CONDUIT 


SECTION OF CANAL 


275 

STATS OF CAUFORNIA 
DEPARTMENT OF PUBUIC WORKS 

DIVISION OF WATER RESOURCES 


325 


300 


O Fi 

i5 

Ui 

-J 

Ui 




« •» 


BOTTOM OF CANAL 


^Ncjurs! 




^ •» 


GUADALUPE CREEK 
INTERCEPTING CANAL 

_ S • 0.000792 

LENGTH^6300' 


BOTTOM OF CANAL 


4' DIAMETER PIPE 

BURIED 6' BELOW GROUND SURFACE 




PROFILE or DAM 

LOOKING UPSTREAM 


ELEVATION IN FEET 

uses DATUM 


PLATE 21 



9 10 \ I 12 

LENGTH IN THOUSANDS OF FEET 

PROFILE OF CONVEYANCE SYSTEM 



WASH WATER 
TANK 


OFFICES ANO 
LABORATORY 


FLASH 

MIXING 


lii 


SOFTENING- SEDIMENTATION BASINS 



CHLORINATION 


STATE OF CAUFOftNIA 
DEPARTMENT OF PUBUC WORKS 

DIVISION OF WATER RESOURCES 

SANTA CLARA VALLEY INVESTIGATION 


LITTLE FRANCIS PROJECT 


DIAGRAMMATIC PROFILE OF TREATMENT PLANT 


1955 



PLATE 22 




LENGTH IN FEET 

PROFILE OF DAM 

LOOKING UPSTREAM 



U-Zb' 

CREST ELEV 


6I6‘ 


SECTION OF DAM 


SCALE or FEET 
0 100 200 



2.0 

LENGTH IN MILES 


3.5 A.O 

PROFILE OF CONDUIT 


STATK OF CALIFORNIA 
OCFARTMCNT OF FURUC WORKS 

DIVISION OF WATER RESOURCES 

SANTA CLARA VALLEY INVESTIGATION 


ZAYANTE PROJECT 

1955 


PLATE 23 


STATION ITa-t-SO 

END OF CONDUIT 



700 800 

LENGTH IN FEET 

PROFILE OF DAM 

LOOKING UPSTREAM 



7 8 9 10 II 

LENGTH IN THOUSANDS OF FEET 

PROFILE OF CONDUIT 


SECTION OF DAM 

SCALE IN FEET 
0 100 200 



SECTION OF CONDUIT 

SCALE OF FEET 
^ ^ ^ ^ ^ 


STATE OF CALIFORNIA 
DEPARTMENT OF PUBLIC WORKS 

DIVISION OF WATER RESOURCES 

SANTA CLARA VALLEY INVESTIGATION 

UVAS AND LLAGAS CREEKS PROJECT 

1955 



APPENDIX A 

AGREEMENTS AUTHORIZING INVESTIGATION 

AND REPORT 


-19273 


( 87 ) 



TABLE OF CONTENTS 

AGREEMENTS AUTHORIZING INVESTIGATION AND REPORT 

Page 


AgTeement Between the State Water Eesources Board, the County of Santa 
Clara, the City of San Jose, and the Department of Public Works, dated 
April 1, 1948 89 

Supplemental Agreement Between the State Water Eesources Board, the 
County of Santa Clara, the City of San Jose, and the Department of 
Public Works, dated February 18, 1949 91 


( 88) 



APPENDIX A 


89 


AGREEMENT BETWEEN THE STATE WATER RESOURCES BOARD, THE COUNTY OF 
SANTA CLARA, THE CITY OF SAN JOSE, AND THE 
DEPARTMENT OF PUBLIC WORKS 


This Agreement, executed in quintuplicate, en- 
lered into by the State Water Resources Board, 
iiereinafter referred to as the ^^Board’’; the County 
of Santa Clara, hereinafter referred to as the 
‘‘County^^; the City of San Jose, hereinafter referred 
to as the ^^City^’; and the Department of Public 
Works, acting through the agency of the State Engi- 
neer, hereinafter referred to as the ‘‘State Engineer'’: 

WITNESSETH: 

Whereas, by the State Water Resources Act of 
1945, as amended, the Board is authorized to make 
investigations, studies, surveys, hold hearings, prepare 
plans and estimates, and make recommendations to 
the Legislature in regard to water development proj- 
ects, including flood control plans and projects; and 

Whereas, by said act, the State Engineer is author- 
ized to cooperate with any county, city. State agency 
or public district on flood control and other water 
problems and when requested b}" au}^ thereof may 
enter into a cooperative agreement to expend money 
in behalf of any thereof to accomplish the purposes 
of said act; and 

Whereas, the County and the City desire and 
hereby request the Board to enter into a cooperative 
agreement for the making of an investigation and 
report on the underground water supply in the 
County of Santa Clara, including quality, replenish- 
ment and utilization thereof, and, if possible, a 
method or methods of solving the water problems in- 
volved; and 

Whereas, the Board hereby requests the State 
Engineer to cooperate in making an investigation and 
report on the underground water supply in the 
County of Santa Clara, including quality, replenish- 
ment and utilization thereof, and, if possible, a method 
or methods of solving the water problems involved ; 

Now Therefore, in consideration of the premises 
and of the several promises to be faithfully performed 
by each as hereinafter set forth, the Board, the 
Countjq the City, and the State Engineer do hereby 
mutually agree as follows : 

ARTICLE I— WORK TO BE PERFORMED: 

The work to be performed under this agreement 
shall consist of investigation and report on the under- 
ground water supply in the County of Santa Clara, 
including quality, replenishment and utilization 
thereof, and, if possible, a method or methods of solv- 
ing the water problems involved. 


The Board by this agreement authorizes and directs 
the State Engineer to cooperate by making said in- 
vestigation and report and by otherwise advising and 
assisting in making an evaluation of present and ulti- 
mate underground water problems in the County of 
Santa Clara, and in formulating a solution or solu- 
tions of the water problems thereof. 

During the progress of said investigation and 
report all maps, plans, information, data and records 
pertaining thereto which are in the possession of 
any party hereto shall be made fully available to any 
other party for the due and proper accomplishment 
of the purposes and objects hereof. 

The work under this agreement shall be diligently 
prosecuted with the objective of completion of the 
investigation and report on or before December 31, 
1949, or as nearly thereafter as possible. 

ARTICLE II— FUNDS: 

The County and the City, upon execution by them 
of this agreement, shall each transmit to the State 
Engineer the sum of Five Thousand Five Hundred 
Dollars ($5,500) for deposit, subject to the approval 
of the Director of Finance, into the Water Resources 
Revolving Fund in the State Treasury, for expendi- 
ture by the State Engineer in performance of the 
work provided for in this agreement. Also, upon exe- 
cution of this agreement by the Board, the Director 
of Finance will be requested to approve the trans- 
fer of the sum of Eleven Thousand Dollars ($11,000) 
from funds appropriated for the support of the 
Board by the Budget Act of 1947, for expenditure 
by the State Engineer in performance of the work 
provided for in this agreement and the State Con- 
troller will be requested to make such transfer. 

If the Director of Finance, within thirty (30) days 
after receipt by the State Engineer of said Eleven 
Thousand Dollars ($11,000) from the County and 
the City, shall not have approved the deposit thereof 
into said Water Resources Revolving Fund, together 
with the transfer of the sum of Eleven Thousand 
Dollars ($11,000) from funds appropriated for the 
support of the Board by the Budget Act of 1947, 
for expenditure by the State Engineer in perform- 
ance of the work provided for in this agreement, said 
sums contributed by the County and the City shall be 
returned to them by the State Engineer. 

It is understood by and between the parties hereto 
that the sum of Twenty-two Thousand Dollars 
($22,000) to be made available as hereinbefore pro- 



90 


SANTA CLARA VALLEY INVESTIGATION 


vided is adequate to perform approximately half of 
the above specified work and it is the intention of the 
County and of the City to each make a further sum 
of Five Thousand Five Hundred Dollars ($5,500) 
available at the commencement of the second year of 
said investigation which will be subject to a matching 
or contribution in a sum of Eleven Thousand Dollars 
($11,000) by the Board for the completion of said- 
investigation and report. 

The Board and the State Engineer shall under 
no circumstances be obligated to expena for or on 
account of the work provided for under this agree- 
ment any amount in excess of the sum of Twenty- two 
Thousand Dollars ($22,000) as made available here- 
under and when said sum is exhausted, the Board 
and the State Engineer may discontinue the work 
provided for in this agreement and shall not be liable 
or responsible for the resumption and completion 
thereof until further sums as specified in the pre- 
ceding paragraph are made available. 

Upon completion of and final payment for the work 
provided for in this agreement, the State Engineer 

Approval Recommended : 

/s/ Spencer Burroughs 
Principal Attorney 
Division of V^ater Resources 

Approved as to Form : 

/s/ Howard W. Campen 
County Counsel 
County of Santa Clara 

/s/ Robert E. Cassin 
City Attorney 
Cit 3 ^ of San Jose 

Approved : 

/s/ (JAMES S. Dean 

Director of Finance 


shall furnish to the Board, and to the County, and to 
the Cit}^, a statement of all expenditures made under 
this agreement. One-half of the total amount of all 
said expenditures shall be deducted from the sum 
advanced from funds appropriated to said Board, 
and one-fourth of the total amount of all said ex- 
penditures shall be deducted from each sum advanced 
by the County and by the City and any balance 
which may remain shall be returned to the Board, to 
the County, and to the City, on the basis of one-half 
to the Board, one-fourth to the County and one- 
fourth to the Cit}^. 

ARTICLE III^EFFECTIVE DATE 

This agreement shall become effective immediate^ 
upon its execution b}^ all the parties hereto. 

In Witness Whereof, the parties hereunto have 
affixed their signatures, the County of Santa Clara 
on the 26 day of Januar^^, 1948, the City of San 
Jose on the 26 da.y of January, 1948, the Board on 
the 1st daj^ of April, 1948 and the State Engineer 
on the 31 day of March, 1948. 

COUNTY OF SANTA CLARA 

By/s/ E. 0. Wood 

Chairman, Board of Supervisors 

Attest : Aubert J. Newlin, Clerk 

By /s/ Richard Olson 

Deputy Clerk, Board of Supervisors 

[seal] 

CITY OF SAN JOSE 

By /s/ Albert J. Ruppo 
Mayor 

Attest : 

/s/ Dorothy Covill 

City Clerk [seal| 

STATE WATER RESOURCES BOARD 

By /s/ Royal Miller 
Chairman 


Approved as to Legality : 

/s/ C. C. Carleton 
Chief Attorne.y 
Department of Public Yv^orks 


DEPARTMENT OP PUBLIC WORKS 
STATE OP CALIFORNIA 

C. H. Purcell 
Director of Public Works 

By /s/ A. H. Henderson 
Deputy Director 

Edward Hyatt, State Engineer 

By /s/ A. D. Edmonston 

Assistant State Engineer 



APPENDIX A 


91 


SUPPLEMENTAL AGREEMENT BETWEEN THE STATE WATER RESOURCES BOARD, THE 
COUNTY OF SANTA CLARA, THE CITY OF SAN JOSE, AND 
THE DEPARTMENT OF PUBLIC WORKS 


This Agreement, executed in quintiiplicate, en- 
tered into by the State Water Resources Board, here- 
inafter referred to as the ^ ^ Board ’ ^ ; the County of 
Santa Clara, hereinafter referred to as the ‘ ^ County ^ ’ ; 
the City of San Jose, hereinafter referred to as the 
“City”; and the Department of Public Works of the 
State of California, acting* through the agency of the 
State Engineer, hereinafter referred to as the “State 
Engineer ^ ^ : 

WITNESSETH: 

Whereas, by agreement heretofore entered into by 
and between the ji^iTies hereto, executed by the 
County on the 26th day of January, 1948, by the City 
on the 26th daj^ of January, 1948, b^^ the Board on 
the 1st day of April, 1948, and by the State Engi- 
neer on the 31st day of March, 1948, the making by 
the State Engineer of an investigation and report on 
the underground water supply in the County of 
Santa Clara, including quality, replenishment and 
utilization thereof and, if possible, a method or 
methods of solving the problems involved, was pro- 
vided for; and 

Whereas, it was the expressed intention in said 
agreement that at the commencement of the second 
year of said investigation said County and City 
would each make available a further sum of Five 
Thousand Five Hundred Dollars ($5,500) subject to 
a matching or contribution in equal amount by the 
Board for the completion of said investigation and 
report; and 

Whereas, said additional funds are required to 
complete said investigation and report, and it is the 
desire of the parties hereto that an additional sum of 
Twenty- two Thousand Dollars ($22,000) shall be 
provided. Five Thousand Five Hundred Dollars 
($5,500) each by the County and City and Eleven 
Thousand Dollars ($11,000) by the Board; 

Now Therefore, in consideration of the premises 
and of the several promises to be faithfully per- 
formed by each as hereinafter set forth, the Board, 
the County, the City, and the State Engineer do 
hereby mutually agree as follows : 


1. The County and City each, upon execution by it 
of this agreement, shall transmit to the State Engi- 
neer the sum of Five Thousand Five Hundred Dol- 
lars ($5,500) for deposit, subject to the approval of 
the Director of Finance, into the Water Resources 
Revolving Fund in the State Treasury for expendi- 
ture by the State Engineer in continuing perform- 
ance of the work provided for in said prior agreement 
to which this agreement is supplemental. 

2. Upon execution of this agreement by the Board, 
the Director of Finance will be requested to approve 
the transfer of the sum of Eleven Thousand Dollars 
($11,000) from funds appropriated to the Board by 
Item 335 of the Budget Act of 1948 for expenditure 
by the State Engineer in continuing performance of 
the woi"k provided for in said prior agreement to 
which this agreement is supplemental, and the State 
Controller will be requested to make such transfer. 

3. The Board and the State Engineer shall under 
no circumstances be obligated to expend for or on 
account of the work provided for in said prior agree- 
ment to which this agreement is supplemental any 
amount in excess of the sum of Forty-four Thousand 
Dollars ($44,000) as made available under said prior 
agreement and this supplemental agreement and if 
funds are exhausted before completion of said work 
the Board and the State Engineer may discontinue 
said work and shall not be liable or responsible for 
the completion thereof. 

4. In so far as consistent herewith and to the extent 
adaptable hereto, all of the terms and provisions 
of said prior agreement to which this agreement is 
supplemental are hereby made applicable to this 
agreement and are hereby confirmed, ratified, and 
continued in effect. 

5. This agreement shall become effective immedi- 
ately upon its execution by all of the parties hereto, 
and its approval by the Director of Finance. 

In Witness Whereof, the parties hereunto have 
affixed their signatures, the County of Santa Clara 
on the 24th day of January, 1949, the City of San 
Jose on the 1st day of February, 1949, the Board on 
the 17th day of February, 1949, and the State Engi- 
neer on the 18th day of February, 1949. 


6—19273 



92 


SANTA CLAEA VALLEY INVESTIGATION 


Approved as to form: 


COUNTY OF SANTA CLAEA 


/s/ Harry C. Nail, Jr, 
Asst. County Counsel, 
County of Santa Clara 

/s/ Egbert E. Cassin 
City Attorney, 

City of San Jose 


By /s/ A. W. Brown 

Chairman, Board of Supervisors 


Albert J. Newliist, County Clerk 

By /s/ Eichard Olson, Deputy Clerk, 
Board of Supervisors 


[seal] 


Approval Eecommendcd : 


CITY OF SAN JOSE 


/s/ Henry Holsinger By /s/ Fred Watson 

Principal Attorney Mayor 

Division of Water Eesources > , ^ 

/s/ Dorothy Covill 

City Clerk 

[seal] 

Approval Recommended : STATE WATER RESOURCES BOARD 


/s/ C. C. Carleton 
C hief Attorney 
Department of Public Works 


By /s/ C. A. Griffith 
Chairman 


Approved : 


/s/ James S. Dean 

Director of Finance 


R.S. 

J.W.M. 



Form 

Budget 

y alue 

Descript. 


DEPARTMENT OP FINANCE 
APPROVED 
Feb. 24, 1949 
James S. Dean, Director 


DEPARTMENT OP PUBLIC WORKS 
STATE OP CALIFORNIA 

By C. H. Purcell 

Director of Public Works 

By /s/ Frank B, Durkee 
Deputy Director 


/s/ Edward Hyatt 
State Engineer 


[seal] 



APPENDIX B 


BIBLIOGRAPHY OF PRIOR REPORTS 

Reports on prior investigations, containing information pertinent to the 
evaluation of water problems in Santa Clara County, which have been re- 
viewed in connection with the current investigation, are listed in the following 
bibliography. 

Additional references of the geology of Santa Clara County are included 
in Appendix C. 


( 93 ) 



APPENDIX B 


95 


APPENDIX B 

BIBLIOGRAPHY OF PRIOR REPORTS 


Blaclde, E. E., and Wood, H. '‘Report to the Honorable Board 
of Directors of the South Santa Clara Valley Water Con- 
servation District on Water Supply and Well Replenishment 
Project.” Project Report No. 1. January, 1939. 

“Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District on 
Llagas Creek Storage.” Project Report No. 2. December, 1940: 

— — — “Report to the Honorable Board of Directors of the 
South Santa Clara Valley Water Conservation District on 
Llagas Creek Plow, 1941-42.” Project Report No. 3. Novem- 
ber, 1942. 

“Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District on 
Llagas Creek Plow, 1942-1943.” Project Report No. 4. Oc- 
tober, 1943. 

Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District on 
Llagas Creek Plow, 1943-1944.” Project Report No. 5. Jan- 
uary, 1945. 

— “Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District on 
Llagas Creek Flow, 1944-45.” Project Report No. 6. Novem- 
ber, 1945. 

— “Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District on 
Llagas Creek Flow, 1945-1946.” Project Report No. 7. No- 
vember, 1946. 

— — “Report to the Honorable Board of Directors of the 
South Santa Clara Valley Water Conservation District on 
Llagas Creek Well Replenishment Project.” Project Report 
No. 8. June, 1947. 

* “Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District 
on Llagas Creek Plow, 1946-47.” Project Report No. 9. 
November, 1947. 

— “Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District 
on Llagas Creek Plow, 1947-48.” Project Report No. 10. 
October, 1948. 

— “ — ■ “Report to the Honorable Board of Directors of the 
South Santa Clara Valley Water Conservation District 
on Llagas Creek Flow, 1948-49.” Project Report No. 11. 
March, 1950. 

• “Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District 

on Llagas Creek Plow, 1949-50.” Project Report No. 12. 
October, 1950. 

■ “Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District 

on Llagas Creek Flow, 1950-51.” Project Report No. 13. 
November, 1951. 

— “Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District 

on Llagas Creek and Uvas Creek Well Replenishment 
Project.” Project Report No. 14. January, 1952. 

“Report to the Honorable Board of Directors of the 

South Santa Clara Valley Water Conservation District 

on Uvas Creek Dam, Reservoir, Conduit and Well Replen- 
ishment Project Proposed to be Constructed Jointly with 
Santa Clara Valley Water Conservation District and on 
Proposed Llagas Creek Dam, Reservoir and Well Replen- 
ishment Project.” Project Report No. 15. March, 1953. 


Blaney, H. P., and Griddle, W. D. “A Method of Estimating 
Water Requirements in Irrigated Areas Prom Climato- 
logical Data.” United States Department of AgricuRure, Soil 
Conservation Service, Division of Irrigation. 1945. 

California State Department of Public Works, Division of 
Water Resources. “Santa Clara Investigation.” Bulletin 
No. 42. 1933. 

“South Coastal Basin Investigation, Geology and 

Ground Water Storage Capacity of Valley Pill.” Bulletin 
No. 45. 1934. 

— - “Report of Referee, City of Pasadena v. City of Alham- 
bra, et al.” Case No. Pasadena C-1323, Superior Court Los 
Angeles County. June, 1943. 

“Feasibility of the Reclamation and Conveyance of 

Sewage from San Francisco, Peninsula Cities and Com- 
munities, and San Jose, for Use in Santa Clara County.” 
April, 1951. 

. -‘Program for Financing and Constructing the Feather 

River Project as the Initial Unit of The California Water 
Plan.” February, 1955. 

California State Water Project Authority. “Feasibility of Con- 
struction by the State of Barriers in the San Francisco 
Bay System.” March, 1955. 

California State Water Resources Board. “Report on Feasi- 
bility of Feather River Project and Sacramento-San Joaquin 
Delta Diversion Projects Proposed as Features of The 
California Water Plan.” May, 1951. 

— “Water Resources of California.” Bulletin No. 1, 1951. 

Clark, W. O. “Ground Water for Irrigation in the Morgan 
Hill Area, California.” Contributions to the Hydrology of 
the United States, 1916. United States Department of the 
Interior, Geological Survey. Water-Supply Paper 400. 1917. 

— “Ground Water in the Santa Clara Valley, California.” 

United States Department of the Interior, Geological Sur- 
vey. Water-Supply Paper 519. 1924. 

Fortier, S. “Irrigation in Santa Clara Valley, California.” 
United States Department of Agriculture, Office of Experi- 
ment Stations, in cooperation with State of California. 
Bulletin 158, Separate No. 2, 1905. 

Holmes, L. C., and Nelson, J. W. “Reconnaissance Soil Sur- 
vey of the San Francisco Bay Region, California.” United 
States Department of Agriculture, Bureau of Soils, in co- 
operation with the University of California, Agricultural 
Experiment Station, 1917. 

Hunt, G. W. “Description and Results of Operation of the 
Santa Clara Valley Water Conservation District’s Project.” 
American Geophysical Union, Transactions of 1940, Part I. 
July, 1940. 

“Report to the Board of Directors of Santa Clara 

Valley Water Conservation District on Proposed Lexington 
Dam and Water Conservation Works.” August, 1947. 

“Report to the Honorable Board of Directors of the 

Santa Clara Valley Water Conservation District on Pro- 
posed Coyote Dam No. 2.” April, 1949. 

“Report to the Honorable Board of Directors of the 

Santa Clara Valley Water Conservation District on Pro- 
posed Cross-Valley Canals.” July, 1952. 

“Supplement to Report to the Honorable Board of 

Directors of the Santa Clara Valley Water Conservation 
District on Proposed Lexington Dam and Water Conserva- 
tion Works.” July, 1952. 



96 


SANTA CLAEA VALLEY INVESTIGATION 


Lawson, A. O. ^‘Geologic Atlas of the United States, San Fran- 
cisco, California.” United States Department of the Interior, 
Geological Survey, Folio No. 193. 1914. 

San Jose Chamber of Commerce. “7 Sources of Water Supply 
for Santa Clara County.” June, 1949. 

Santa Clara County Engineering Department. ^'Preliminary 
Heport on the Guadalupe Creek and Tributaries, Santa 
Clara County, California, for Flood Control and Runoff.” 
1944. 

Santa Clara County Planning Commission. “Flood Problems 
in Santa Clara County.” Monograph No. 3. 1952, 

Santa Clara Valley Water Coiiservatiun District, Board of 
Directors. “Ofhcial Statement on Lexington Dam.” Sep- 
tember, 1947, 

— - — “ “Official Statement on I Lexington Dam, II Cross- 
Yailey Canals,” September, 1952. 

Tibbetts, F. H., and Kieffer, S, E, “Report to Santa Clara 
Valley Water Conservation District Committee on Santa 
Clara Valley Water Conservation Project.” March, 1921. 


Tibbetts, F, H. “Report on Waste Water Salvage Project to 
Board of Directors, Santa Clara Valley Water Conservation 
District, San Jose, California.” October, 1931. 

“Supplemental Report on Completion of the 1934 Well 

Replenishment Project Including 1931 Waste Water Salvage 
Project.” Project Report No. 34. March, 1936. 

“Water-Conservation Project in Santa Clara County,” 

Transactions American Geophysical Union, Seventeenth 
Annual Meeting, part II. July, 1936, 

Tolman, 0. F., and Poland, J. F. “Ground-Water, Salt-Water 
Infiltration, and Ground-Surface Recession in Santa Clara 
Valley, Santa Clara County, California.” American Geo- 
physical Union, Transactions of 1940, Part I, July, 1940. 

United States Department of Agriculture, Office of Experiment 
Stations. “Irrigation Resources of California and Their 
Utilization.” Bulletin 254. 1913. 

W'eir, W. W., and Storie, R. E. “Soils of Santa Clara 
County, California.” University of California, Agricultural 
Experiment Station, Division of Soils. Februarj^ 1947. 



APPENDIX C 

GEOLOGY OF THE SANTA CLARA VALLEY 


( 97 ) 



APPENDIX C 


GEOLOGY OF THE SANTA CLARA VALLEY 

Page 

Introduction ____ _ 99 

Previous Work and Acknowledgments 99 

Scope of Investigation 99 

Geologic Poriiiations 99 

Nonwater=bearing Group i 99 

Jurassic System 99 

Cretaceous System 99 

Eocene Series 100 

Oligocene Series - - 100 

Miocene Series 100 

Pliocene Series 100 

Water-bearing Group 100 

Plio-Pleistoeene Series 100 

Upper Quaternaiy Series 102 

Geologic Structure 103 

Folds 103 

Faults - 104 

Geologic History and 

Origin of the Present Topography 104 

PLATES 

C-1. Areal Geology, 1955 following page 106 

C-2, Index Map 

C-3. Columnar Sections— Santa Clara County , “ 

C-n. Geologic Sections, r9oo 


( 08 ) 



APPENDIX C 


99 


GEOLOGY OF THE SANTA CLARA VALLEY 


INTRODUCTION 

The area discussed in this appendix lies entirely 
within Santa Clara County, but does not include the 
easternmost part of the county. The term Santa 
Clara Valley^’ as used herein refers only to the valley 
floor wdthin the county, North Santa Clara Valley 
refers to the valley floor north of the Lower Gorge of 
Coyote Creek, near the town of Coyote, The term 

South Santa Clara Valley refers to the valley floor 
south of the Lower Gorge. The southern valley, then, 
includes some of the area which is drained northward 
by Coyote Creek. 

Previous Work and Acknowledgments 

Geologic mapping of nearly?' all of the Santa Clara 
Valley and its environs was completed in the five 
years preceding 1950. The results of this mapping 
have been incorporated in Plate C-1, ‘‘Areal Geol- 
ogy,’^ the geologic map. The A^arious sources of the 
mapping and the areas covered by each source are 
shoAvn in Plate C-2, ‘ ‘ Index Map, ^ ^ A¥hich also shows 
the quadrangles covering the Santa Clara Valley and 
vicinity. Appreciation is expressed to all whose map- 
ping has been used. Particular appreciation is ex- 
pressed to Olaf P. Jenkins and the California Di- 
vision of Mines for their aid in the compilation of the 
geologic map for this appendix, and to Edgar H. 
Bailey of the United States Geological Survey and 
Bobert Ortalda for their helpful suggestions during 
the preparation of the appendix. 

Papers to which reference is made in the text of 
this appendix are as follows: 

Blackwelder, Elliot, “A Mastodon Skeleton Near San Fran- 
cisco Bay,” Washington Academy Science Journal 19, 1929. 

Branner, J. C., Newsom, J. F., and Arnold, Ralph, “Santa 
Cruz Folio, California,” Geol. Atlas of the United States, 
Folio 163, U. S. Geological Survey, 1909. 

Crittenden, Max, “Geology of the San Jose and Mount Ham- 
ilton Quadrangles, California,” California Division of 
Mines, Bulletin 157, 1951. 

Taliaferro, N. U., “Geologic History and Structure of the 
Central Coast Ranges of California,” California Division 
of Mines, Bulletin 118, 1943. 

Scope of Invesfigotion 

This appendix has been prepared to provide a geo- 
logic basis for certain studies made and reported in 
the accompanying bulletin. Descriptions of the water- 
bearing and nonwater-bearing sediments are included 
herein, wdth emphasis placed on the former and on the 
relationships between the two series. For purposes of 
ground water studies, the most important part of the 
geology is the description of the water-bearing sedi- 
ments. Other aspects of geology are briefly considered 


in order to complete the geologic descidption of the 
A^alley. 

The areal distribution of the geologic formations of 
the Santa Clara Valley region is showm on the geo- 
logic map (Plate C-1). The columnar sections (Plate 
C-3) describe in tabular form the formations through- 
out the region, and the cross sections (Plate C-4) show 
depth relations in various areas. 

GEOLOGIC FORMATIONS 

The rocks of the Santa Clara Valley region are 
mainly marine and fresh water sediments, ranging 
in age from upper Jurassic to Eecent. For ground 
water studies, the rocks of the region may be divided 
into two groups, the Avater-bearing and the nonA\^ater- 
bearing. 

Nonwafer-bearing Group 

The nonwater-bearing group consists of those rocks 
AAhich are relatively unimportant in the ground Avater 
study because they do not generally yield economi- 
cally important quantities of Avater, although they do 
form the basement underlying the Avater-bearing sedi- 
ments. The nonwater-bearing group is called bedrock 
in this bulletin. 

Jurassic System. Eocks of upper Jurassic age in- 
clude the Franciscan and Knoxville formations, 
AAdiich are mapped together on Plate C-1. 

The Franciscan formation consists of marine sedi- 
ments, slightly altered igneous rocks, serpentine, and 
small pods of metamorphosed sediments. The sedi- 
ments consist of arkosic sandstones, dark shales, lime- 
stones, cherts, and a few scattered lenses of conglom- 
erate. Interbedded with these sediments are basalts, 
basaltic tuffs, and basaltic agglomerates, all slightly 
altered to greenstones. All these sediments and igneous 
rocks have been intruded by andesite porphyry, dio- 
rite, and serpentine. 

The Knoxville formation consists of marine sand- 
stones, shales, and a fcAv conglomerates. Eocks proATn 
by fossil evidence to be Knoxville are of limited ex- 
tent and generally have not been differentiated from 
the Franciscan rocks in studies of this area. 

The only important conduits for water in the upper 
Jurassic rocks are faults and fracture systems. 
Springs are common along faults in these rocks, and 
some aatIIs produce up to 100 gallons per minute from 
faults. The production of most such fracture system 
Avells falls off or ceases in the dry season. 

Cretaceous System. Eocks of Cretaceous age in 
the Santa Clara Valley region are marine shales, sand- 
stones, and conglomerates. The formation names of 



100 


SANTA CLAEA VALLEY INVESTIGATION 


these rocks are shown on the columnar sections^ 
Plate C-3, 

Only minor quantities of water are produced from 
Cretaceous rocks in most areas, the water obtained 
generally coming from fractures as in the ease of the 
Jurassic rocks. There are tYvO known exceptions to 
this general rule, however. On the east edge of 
North Santa Clara Valley, east and northeast of 
Evergreen, the Cretaceous rocks are mostly conglom- 
eratic. The unw^cathcrcd conglomerates have a caleite 
matrix, which, upon weathering, becomes permeable, 
and the w'eathered conglomerate thereby furnishes 
some water to domestic w^ells. Some of the un weath- 
ered sandstone in the Santa Teresa Hills is also per- 
meable. Certain wells drilled in this sandstone yield 
15 to 40 gallons per minute. 

The sandstones and conglomerates in other areas 
are usually less permeable. The shales yield practi- 
cally no water. 

Eocene Series. Rocks of Eocene age outcrop in 
only three relatively small areas in the Santa Clara 
Valley region, as shown on Plate C-1. They are ma- 
rine shales and sandstones w^hose age has been proven 
by fossil identification and correlation. These rocks 
have little hydrologic importance. 

Oligocene Series. Rocks of Oligocene age outcrop 
only in the Santa Cruz Mountains near the western 
border of Santa Clara County. These rocks are marine 
sandstones and shales and have no hydrologic signifi- 
cance. 

Miocene Series. The Miocene series of this region 
consists of both sedimentary and igneous rocks. The 
sediments are fossiliferous marine sandstones, shales, 
claystones, siliceous shales, and gravels. The igneous 
rocks consist of basalts, often vesicular, basaltic ag- 

o’lom enlTG /\-P 

^ 

which are water-deposited. Fossils collected in the 
Palo Alto area in 1948, and identified with the aid of 
Dr. Myra Keen of Stanford University, shov/ that 
most of the rocks called Pliocene (Purisima. form.a- 
tion) by Bramier, New^som, and Arnold (1909), are 
actually Miocene. 

Water w^ells have been drilled into rocks of Mio- 
cene age ill several areas. The most successful wells 
derive their w^ater from fractures in basalt and from 
gravels associated wdth the basalt flows. Certain of 
these v/ells yield up to 60 gallons per minute for do- 
mestic purposes. Some of the springs which originate 
in sandstone yield np to 35 gallons per minute. 

Pliocene Series. Rocks of Pliocene age outcrop 
only in the San Juan Bautista and San Jose quad- 
rangles. The names of the Pliocene formations are 
showm on the columnar sections, Plate C-3. The Plio- 
cene series consists of marine conglomerates and sand- 
stones, wdth some lenses of marl and sandy marl, fresh 


water sandstones, sands, gravels, and conglomerates. 
Both marine and fresh water fossils are found in this 
series. 

Pliocene rocks, where exposed, appear to be fairly 
permeable, but since these sediments are limited in 
extent within the county, they are not believed to 
have much hydrologic importance. 

The Plio-Pleistocene sediments are difficult to dis- 
tinguish from older continental Pliocene sediments. 
In the San Juan Bautista and Hollister quadrangles, 
south of Santa Clara County, the contact between 
these sediments is gradational and obscure. Fossil 
evidence is lacking at the present time, and terminol- 
ogy is in a state of change. In this appendix, the term 
^^Plio-Pleistocene^’ will refer to sediments thought to 
be of late Pliocene and early Pleistocene age, and the 
term ^H^liocene” will refer to sediments of early and 
middle Pliocene age. 

Wofer-bearing Group 

Plio-Pleistoeene Series. The Plio-Pleistocene series 
is significant wdth respect to the ground water hydrol- 
ogy of the Santa Clara Valley. Deep w^ells, especially 
in the Los Altos, Cupertino, and Los Gatos areas, de- 
rive much of their water from this series, the over- 
lying upper Quaternaiw^ sediments being generally 
less than 400 feet thick. 

The formations of the Plio-Pleistoeene series out- 
cropping in the Santa Clara Vallejo include the Santa 
Clara, Pack wood, and San Benito formations. The 
probable age relations involving these formations are 
shown in the columnar sections, Plate C-3, and their 
areal extent is showui on the geologic map, Plate C-1. 

The Plio-Pleistocene series consists mostly of fresh- 
w^ater gravels, silts, and clays, all of w^hich are common 
in outcrops. Well-bedded gravels, sands, marls, and 
vitric tuii layers wdth interbedded olivine basalt flows 
are present near the base of the series in the klorg^'an 
Hill- Gilroy area. Approximately tw^o miles w^est of 
Stanford University, basal sand beds are about eight 
feet thick and contain a distinctive marine moliuscan 
fauna wdiich indicates that they are the equivalent of 
part of the Merced formation in San Mateo and San 
Francisco Counties (Myra A. Keen, oral communica- 
tion, 1947). About five miles w^est of Stanford LTni- 
versity, the basal beds consist of poorly bedded sands 
about 50 feet thick, w^hich contain small, interbedded, 
lenticular coal or lignite seams up to two inches thick. 
Here the sands grade iipw^ard into the thick gravels 
which make up most of the series. 

Depths of gravel and clay overlying the basal beds 
vary from 1,000 to 4,000 feet. Decrease in pebble size 
and proportionate increase in clay toward the central 
part of the northern valley, as well as the nature of 
the deposits, indicates that the bulk of the Plio- 
Pleistocene sediments w^ere deposited as great alluvial 
fans. 



APPENDIX C 


101 


Gravels of various sizes comprise about one-third of 
the Plio-Pleistocene series. In general, the coarsest 
gravels, and the largest proportion of gravel in the 
series, occur around the edges of the Santa Clara 
Yalley. However, this does not hold true in the south- 
ern valley, where the Plio-Pleistocene series outcrops 
only along the east side of the valley. The gravels in- 
clude sandstone and shale pebbles from older forma- 
tions; serpentine and metamorphic pebbles; igneous 
pebbles of balsaltic, andesitic, gabbroic, and granitic 
nature; and boulders and pebbles originally derived 
from well-cemented conglomerates. 

The individual beds of gravels are very irregular 
and lenticular. Groups of these can often be correlated 
from place to place, but correlation of individual beds 
is generally impossible. The clean gravels may grade 
into any combination of gravels, sands, and clays, 
which in turn may eventually pinch out or grade into 
either sands or clays alone. The term ^^graveP^ as used 
in this appendix does not imply any specified degree 
of rounding of the constituent fragments. The term 
^Gincemented fanglomerate ’ ^ would perhaps be more 
suitable in most areas, although other stream and lake 
deposits show many of the same characteristics as the 
alluvial fan deposits. 

The sands of the Plio-Pleistocene series, in general, 
are lenticular, medium-grained, and consist mostly of 
subangular grains of quartz and feldspar. Most of the 
sands in the outcrops are cross-bedded, but the indi- 
vidual layers showing cross-beding are usually small, 
one-half to six inches in thickness, and irregular. 

The term ‘^clay’^ as used in this appendix does not 
refer to the pure mineral clays which the word tech- 
nically denotes, but instead refers to all strata which 
are not permeable due to their high content of fine 
particles. Nearly all of the clays described by the 
drillers contain only a relatively small proportion of 
true clay, the remainder of the material being silt, 
sand, or gravel. 

Clays in the Plio-Pleistocene series fall into three 
broad genetic classifications. The two most common of 
these are stream- or flood-deposited clays, and clays 
which have been formed as the result of weathering. 
The other type of clay is marine- or tideflat-deposited 
clay. Clay of this latter type may be present at depths 
greater than 800 feet in the vicinity of San Jose in 
the Plio-Pleistocene sediments. 

The depositional clays may be blue, yellow, or 
brown, the last two colors being most common. Some 
of the 3 ^ellow clays may represent oxidized blue clays. 

The clays which are the result of weathering are 
brown, red, and yellow. They can be differentiated 
from the depositional clays by the pitted surface of 
the enclosed sand grains and pebbles. Most of the 
^‘cement gravels^’ and ‘Gight gravels’^ of the drillers 
are actually weathered gravels, sands, or gravelly silts. 
The most prominent layer of weathered materials oc- 
curs at a depth of about 800 feet in the middle of the 


northern part of the Santa Clara Yalley and out- 
crops in the Cupertino-Los Gatos area. This layer is 
from 100 to 400 feet thick. 

Calcium and magnesium carbonate deposits are 
found in a few localities near the base of the Plio- 
Pleistocene series. Most of these represent subsurface 
chemical deposits. They are generally very impure, 
discontinuous, and have no bedding. A few of the 
deposits are fairly pure, and these may represent 
marls and limestones chemically deposited in fresh- 
water lakes. In outcrops these carbonate deposits are 
thin (two feet or less) and grade laterally into sands 
and gravels within short distances. Some of the marls 
resemble tufa deposits. 

On the northeast side of the southern part of the 
Santa Clara Yalley there are olivine basalts and 
olivine basalt agglomerates interbedded with the Plio- 
Pleistocene sediments. Slight baking of the sediments 
underlying the basaltic flows can usually be observed, 
and the tops of the flows are highly vesicular. These 
basalts have been tightly folded along with the sedi- 
ments and are now thoroughly fractured. 

The Plio-Pleistocene series is folded and faulted 
where exposed. In the sections between the larger 
faults the sediments often dip from three to ten de- 
grees, this probably being approximately the original 
angle of deposition. Near the larger faults, which are 
generally more than five miles in length, dips vary 
upward from 30 degrees, and beds are even over- 
turned in a few localities. Therefore, it is apparent 
that the folding has been intensified by faulting. 

Little can be said about the structure of the Plio- 
Pleistocene rocks where concealed beneath upper 
Quaternary sediments. The series has undoubtedly 
been faulted, tilted, or folded in the areas where cov- 
ered, but definite location of structures cannot yet 
be made owing to the lack of deep well logs. 

It is probable that the base of the sediments here 
called Plio-Pleistocene is upper Pliocene in age in the 
southern part of the area, becoming progressively 
younger to the northwest. The top of the series has 
been removed by erosion in most areas of outcrop. 
Where present, it is probably middle Pleistocene in 
age, predating the extensive middle Pleistocene Coast 
Range disturbances. 

The Plio-Pleistocene series is not now an important 
source of water to the Santa Clara Yalley. Wells 
around the edges of the northern valley floor and in 
the foothills where these sediments outcrop derive 
much water from them, however. The best aquifers in 
the series are gravels. The weathered sediments men- 
tioned previously yield only small amounts of water 
to wells. Around the edges of the valley, many wells 
penetrate water-bearing gravels below this weathered 
layer. In the central portion of the northern valley, a 
few wells haA^e penetrated the Aveathered layer, but 
these have not produced as much additional water as 
might be expected. 



102 


SANTA CLARA VALLEY INVESTIGATION 


The CiipeiTino-Monte Vista area has many wells 
which yielded notable amounts of water when they 
were first drilled two to twenty years ago^ but which 
since hawe gradually fallen in production and have fin- 
ally been abandoned. This is probably due to the fact 
that the gravels of the Plio-Pleistocene series in this 
area pinch out toward San Francisco Bay. The rate of 
recharge of the gravels is apparentty much slower than 
the rate of pumping. Some of the gravel strata en- 
countered may be efiectively sealed off by clays from 
any recharge area. 

The fractured basalts interbedded with the Plio- 
Pleistocene series in South Santa Clara Vallejo are 
permeable, and springs are very abundant in and 
around the basalts. 


Upper Quaternary Series. The upper Quaternary 
senes is here defined as sediments or Recent and iate 
Pleistocene age which have been deposited after the 
main period of middle Pleistocene mountain building. 
The upper Quaternarj" series is the chief water-bear- 
ing formation in the Santa Clara Valley. Practically 
all of the main and side valley floors are covered with 
at least 50 feet of Recent and upper Pleistocene sedi- 
ments. In the main vallej^, the sediments probably 
reach a thickness of 1,000 feet or more. The lower 
limit is usualty very difficult to determine from well 
logs, because lithological differences with the iinder- 
lying Plio-Pleistocene series are not great. 


Areas of upper Quaternary deposits are shown on 
Plate C-1 by the symbol Q. Three genetic types of 
sediments are present. These are (1) alluvial fan de- 
posits (most common), (2) flood plain deposits, and 
(3) tideland and marine deposits. The alluvial fan 
deposits occur chiefly around the edges of the valley. 
The Coyote cone is an alluvial fan which extends 
across the valley to Morgan Hill. In the northern val- 
ley, the alluvial fans interfing’er with the tideland and 
flood plain deposits, which are the predominant sedi- 
ments in the central part of the valley. 


The upper Quaternary sediments consist of gravels, 
clays, sands, and various mixtures of these types. 
Numerous redwood logs are reported from v/ells at 
depths of between 35 feet and 400 feet. It is probable 
that the inaximuni thickness of the upper Quaternary 
fill is about 1,000 feet in the San Jose-Alviso area. 
The part of this thickness composed of sediments 
which are actually Recent in age is unknown. 

It should be remembered in the following discus- 
sion that strata of pure clay, sand, or gravel greater 
than one foot in thickness are rare. For example, what 
is usually termed a ten-foot gravel bed actually con- 
sists of perhaps two to twelve inches of clean gravel, 
the remainder being clay and gravel or sand and 
gravel. A thick clay bed usnally consists of only 
one-third to two-thirds silt and clay, the rest being a 
mixture of these with sand and gravel. 


Upper Quaternary gravels consist of rocks from all 
older formations. The constituent rock types include 
sandstones, shales, conglomerates, cherts, igneous 
rocks, and more rarely, metamorphic rocks. The de- 
gree of rounding generally becomes more perfect as 
the size increases. Most of the constituents over three 
inches in diameter are well rounded. Those from 
three inches to one-half inch in diameter are generally 
subrounded to subangular, and smaller fragments 
range from subronnded to angular, rlependuig on 
their source and composition. 

Upper Quaternary gravels occur most commonly as 
the predominant materials in the apex areas of allu- 
vial cones, and in stream beds below temporary base 
levels produced by resistant rock. The areas which 
are highest in gravel content are the edges of the 
northern valley, the areas upstream and dovuistream 
from the Lower Gorge of Coyote Creek, and the 
Guadalupe and Alamitos Creek areas near the tip of 
the Santa Teresa Hills. Some of the cleanest gravels 
in the valley occur upstream from the Lower Gorge 
of Coyote Creek. The gravels in the quarry pits of 
the southern valley show cross-bedding, lenticular 
bedding, and rapid changes in size and sorting, all of 
which are characteristic of stream deposits. 

Sands of the upper Quaternary sediments are gen- 
erally poorly sorted and consist principalty of quartz 
and chert grains. They also frequently contain high 
percentages of feldspar and serpentine, depending on 
the source rocks. 

The clays may be conveniently put into three ge- 
netic and two descriptive classes. The descriptive 
classes of the well drillers are usually yellow clays 
and blue clays. The yellow clays of the drillers 
include clays which are actually red, brown, and yel- 
low. The ‘'blue’’ cla^^s of the drillers generally in- 
clude blue, greenish blue, blue-gray, and gray clays. 
The genetic classes of clays include residual, alluvial, 
and marine or tideland tj^pes. Some of the surficial 
7 y"ellow cla 7 ys are made up almost entirely of wind- 
blown silts (loess). Most alluvial clays, which may be 
either yellow or blue, were laid down as flood or pond 
deposits and are therefore generally lenticular. The 
blue clays in the Stanford University area found in 
wells below 300 feet are probably stream deposits 
consisting mostly of serpentine and its decomposi- 
tion products. 

The more or less continuous blue claj^s in the 
central part of the northern valley are considered to 
be tideland deposits. Marine fossils have been re- 
ported in these clays to depths of 300 feet at Alviso 
and at the Port of Redwood City in San Mateo 
County. These clays are the most important in the 
valley, since they form the impermeable, nearly hori- 
zontal barriers which confine the aquifers within the 
pressure zones. The black tideland deposits around 
the southern end of San Francisco Bay are uncon- 
solidated equivalents of the deeper blue claj^s. The 



APPENDIX C 


103 


latter are thickest in the central part of the northern 
valley, indicating that an arm of San Francisco Bay 
has been present there during part of Recent and 
upper Pleistocene time. Assuming that conditions 
similar to those of today existed when the deeper 
blue clays were deposited, their extent probably de- 
limits the extent of former tidal lands. 

In the southern part of the valley near Gilroy and 
the Pajaro River, lenticular beds of tule and other 
plant remains up to three feet in thickness have been 
encountered in wells. Fresh-water mollusks were 
found in a blue clay near Gilroy at a depth of about 
350 feet during the period of this investigation. These 
were determined to be of the same species as those 
which occur in the present-day streams. These non- 
marine fossils indicate that the blue claj^s of this 
area are swamp or lake deposits. 

The upper Quaternary sediments of the Santa Clara 
Valley have been deposited over a period of about 
300,000 to 500,000 years. Common fossils found in 
^vells include redwood fragments, sw^amp plants, and 
shells of mollusks. The Recent shells belong to species 
that still live in San Francisco Bay or in streams 
today. 

Indian skeletons and artifacts have been found in 
many shell mounds, but these are seldom more than 
six feet beneath the surface. The only other fossil of 
interest was a mastodon skeleton uncovered near Red- 
wood City in San Mateo County. The skeleton was 
found in undisturbed light green clay 23 feet below 
the surface. The mastodon wus a type common in 
earh^ Recent and late Pleistocene times. (Black- 
welder, 1929.) 

In the Hollister quadrangle (San Benito County), 
and in the vicinity of the torvn of Niles (Alameda 
County), there is clear evidence that Recent sedi- 
ments have been faulted. These areas lie beyond the 
scope of this appendix, but suggest that similar dis- 
turbed sediments may also be present in the Santa 
Clara Valley. 

Pressure areas overlain by confining blue clay 
strata exist in the central portion of the northern 
valley and the southern portion of the southern val- 
ley. In these areas, shalloAv \vater overtying the blue 
clay is common, but is not generally used as a source 
of water. Elsewhere in the valley, free ground wuter 
conditions occur. 

Most of the aquifers from which pumping occurs in 
the upper Quaternary sediments are composed of 
gravels. Sand aquifers are also present, but w^ell cas- 
ings are seldom perforated in these zones, since sands 
would run into the wells rapidly, screens not com- 
monly being used by drillers in this area. Gravel en- 
velope w^ells often eliminate sanding and caving 
troubles, and such w^ells are usually among the high- 
est producers. 

The blue clays of the northern valley have yielded 
an estimated 4,000 acre-feet of w^ater per year to w^ells 


in recent years. When the w^ater table is low^, release 
of hydrostatic pressure on these clays allows the 
overlying sediments to compress them slightly, thus 
forcing some of the wuter out of the minute pore 
spaces. Subsidence of the land surface, as described 
in this bulletin, is believed to result from this com- 
pression of the clays. Pump repairmen report that in 
the pressure areas of the northern valley, w^rinkles 
frequently develop in deep w^ell casings at about 
200 feet. Another common phenomenon is the rise of 
casings relative to the ground surface. One driller 
reported that the top of an old cemented casing at 
the Palo Alto Yacht Harbor, which w^as originally at 
ground level, stood five feet above the surface in 1941. 

The source of the underground w^ater is percolation 
of stream runoff, of rainfall, of unconsumed irrigation 
wuter, and percolation pond infiltration in the free 
ground wuter areas of the valley. A small amount of 
wuter may also be contributed by lateral movement 
from the Plio-Pleistocene series around the edge of 
the valley. Once the water reaches the w^ater table, it 
moves generally tow^ard San Francisco Bay in the 
northern valley and towurd the Pajaro River in the 
southern valley. In the northern valley no proven 
outlet of the pressure wuter is knowm. The chemical 
composition of water in a w^ell of low^ mineral con- 
tent near Dumbarton Bridge is of such a nature as 
to indicate that gravels 200 feet deep at that point 
beneath San Francisco Bay have not been invaded by 
salt wuter. There are reports of fresh waters rising 
in the bay, but their validity has not been proven. 

The pressure w^ater of the southern valley joins 
wdth the pressure water from San Benito County 
and probably eventually discharges into the Pajaro 
River. 

GEOLOGIC STRUCTURE 

The Santa Clara Valley is, essentially, a doAvn- 
dropped valley, with uplifted mountains on both sides. 
The down dropping of the northern basin was ac- 
complished by complex faulting and folding around 
its margins. The faulting and folding w^ere caused by 
the same forces, probably acting at the same time. 
The direction of the forces exerted on the rocks of 
the California Coast Ranges before middle Pleistocene 
time is not definitely known. It seems clear, however, 
that a northward force on the Pacific Ocean side and 
a southw^ard force on the continential side would pro- 
duce most of the structures which have formed since 
that time. (Taliaferro, 1943.) 

Folds 

Most of the folding of the non water-bearing sedi- 
ments has little relation to the behavior of ground 
Avater in the Avater-bearing sediments. The Plio-Pleis- 
tocene water-bearing sediments are generally warped, 
and are highly folded in small areas near faults. 



104 


SANTA CLAEA VALLEY INVESTIGATION 


The most important structural feature in North 
Santa Clara Valley, as far as ground water is con- 
cerned, is the gentle dip of the upper Quaternary 
and Plio-Pleistocene series from the sides of the 
valley toward its center. This attitude has been pro- 
duced by two factors: (1) the original dip of the 
sediments toward the center of the valley, and (2) 
the presence of the thickest sediments at the center 
of the valley, resulting in more settling and compres- 
sion there than around the edges. In South Santa 
Clara Valley, the alluvium slopes toward the Pajaro 
Eiver. It is not known whether the upper Quaternary 
sediments have been warped additionally by actual 
sinking of the bedrock beneath the vallej^ relative to 
the surrounding mountains. 

The geologic cross sections (Plate C-4) show the 
nature of most of the larger folds in the Santa Clara 
Valley region. 

Faults 

The largest faults of the Santa Clara Valley region 
are the San Andreas fault on the west side near the 
county line, and the Haj^ward-Calaveras fault system 
on the east side of the valle 3 ^. Between these there 
exists a series of en echelon faults which are most 
prominent in the southwest part of the county. It 
seems likely that the latter faults were produced by 
differential movement along the San Andreas and 
Hayward-Calaveras faults. 

A displacement of approxiniatety one mile has oc- 
curred on the San Andreas fault since folding of the 
Orinda formation in Pliocene time, the southwest side 
moving’ relativeh^, in a northwesterly direction. 
(Crittenden, 1951.) The faults shown on Plate CA 
crossing the southern part of the Santa Clara Valley 
were projected from the outcrops on both sides of the 
vallej^. 

A small pressure area exists near the western edge 
of the valley south of Coyote near Bailey Avenue. The 
eoiiiiniiig beds of this pressure area appear to be 
blue clays of sw^amp origin. The swamps were prob- 
abty formed during the deposition of the upper 
Quaternary sediments when Coyote Creek was tem- 
porarily dammed by uplift on the north side of the 
fault which crosses the valley/ in the area described 
above. This same fault has probably produced the 
prominent scarplike feature along which Coyote 
Creek now- fiow^s after leaving the upper gorge. 

The fault shown on Plate C-1 ending at Evergreen 
may actually continue through Milpitas to the w^est 
side of the Coyote Hills in Alameda County. This 
fault ma}^ form, at least in part, the eastern boundary 
of the pressure area betw^een Evergreen and Milpitas. 

Faulting undoubtedly has some effect on the move- 
ment of ground w^ater in the w^ater-bearing series, but 
ground water levels are apparently too high for any 


of these faults to be detected b}^ means of ground 
water contours. 

GEOLOGIC HISTORY AND ORIGIN OF 
THE PRESENT TOPOGRAPHY 

The geologic history of the Santa Clara ValleA^ is 
generally identifiable with that of the California 
Coast Eanges. Most of this history has consisted of 
periodic inundations of the land by the sea, separated 
by periods of uplift, faulting, folding, and erosion. 
The complex history prior to the deposition of the 
Plio-Pleistocene series has little application to this 
report. Interested readers may obtain some under- 
standing’ of the salient events by studying’ the col- 
umnar and geologic sections, Plates C-3 and C-4. 

The geologic histoiw of the water-bearing series 
which follow^s is suggested as being the most reason- 
able interpretation of the available geologic evidence. 

In late Pliocene time, fresh-water streams and lakes 
were abundant in the San Juan Bautista and Hol- 
lister quadrangles and in the northeast part of the 
Morgan Hill quadrangle. A shoreline of either a ba}^ 
or the open ocean existed W'cst of Palo Alto. The 
primitive Diablo Eange had formed, as well as the 
Santa Cruz Eange. Both of these w^ere probabty lower 
and not as extensive in area as the\" are now^ In the 
late Pliocene, the mountains w^ere raised, the streams 
rejuvenated, and large alluvial fans were formed. At 
the time of maximum development of the fans, the 
valle}^ was nearly twice as wide as it is today. Most of 
the alluvial fans in the northern valle^^ apparently 
originated on the west side of the valle^^ It seems 
likety that some alluvial fans also originated on the 
east side of the northern vallej^, since they are knowm 
to have been formed on the east side of the southern 
vaile\^ in the Morgan Hill-Gilroy area. It has not been 
determined wdiether an arm of San Francisco Bay 
w^as present during Plio-Pleistocene time in Avhat is 
now^ North Santa Clara Valley. 

The topograph}^ in low^er Pleistocene time w’as simi= 
lar to that of today, except that the valle^^ was much 
wdder. The process of erosion and deposition contin- 
ued until middle Pleistocene time, cutting dowui the 
mountains wdiich had formed in the late Pliocene and 
depositing the sediments in the valley area. 

In middle Pleistocene time, the Santa Cruz Moun= 
tains and Diablo Eange were again uplifted, and the 
earlier Plio-Pleistocene sediments w-ere faulted, folded 
near the faults, and eroded around the edge of, but 
not in, the valle}^ The older sediments were also 
folded at this time, and erosion of these continued. 
This orogeny ended in middle Pleistocene time, but 
erosion of the deformed mountains continued until a 
mature erosion surface was formed. This mature sur- 
face probably stood at a maximum elevation of 1,000 



APPENDIX C 


105 


to 1,500 feet, and it became deeply weathered in most 
places. The Plio-Pleistocene sediments which were 
located in the northern valley and which apparently 
were not uplifted, also underwent weathering, and 
their clay content was considerabty increased by the 
process. These weathered sediments are now buried by 
upper Quaternary sediments. It is probable that depo- 
sition of upper Quaternary sediments commenced 
with the beginning of the middle Pleistocene orogeny, 
which helps to explain the difficulty of differentiating 
the two series. 

The aforementioned erosion surface was subse- 
quently deformed by faulting. During this deforma- 
tion, which may still be continuing, the erosion sur- 
face was broken into blocks. Those blocks which have 
subsequently^ risen the highest now form the tops of 
the ridges. As the blocks rose, accelerated erosion 
occurred. The sediments from this erosion process 


were deposited in the present valley, and constitute 
the Kecent and upper Pleistocene sediments referred 
to in this appendix. The cutting of deep Y-shaped 
canyons into the old erosion surface and the resultant 
deposition of sediments is continuing. 

The deposition of the upper Quaternary sediments 
has been in the form of alluvial fan, flood plain, and 
tideland deposits. The formation of the alluvial fans 
indicates that the streams wandered back and forth 
over broad expanses, as is shown today by abandoned 
gravel stringers which are not connected to active 
streams. An interesting result of the wandering of 
the streams on the alluvial fans is that Coyote Creek, 
after emerging from the upper gorge, has flowed 
both to the north, as it does today, and to the south. 
Many of the sediments deposited in the valley south 
of Morgan Hill have been deposited by Coyote Creek 
while it floAved to the south. 



PLATE C-l 



unconformity 


UNCONFORMITY 



UNCONFORMITY 


SEDIMENTARy ROCKS 

UPPER QUATERNARY SERIES 

ALLUVIAL FAN, FLOOD PLAIN. TIOELAND, MARINE GRAVEL, SAND. AND CLAY 

PLIO-PLEISTOCENE SERIES: 

SANTA CLARA, PACKWOOO, AND SAN BENITO 
FORMATIONS 

CONTINENTAL GRAVEL, SAND, CLAY, MARL, AND SOME LIMESTONE 
INTERBEDDED TUFF AND BaSaLT NEAR BASE 

PURISIMA FORMATION 

CONTINENTAL GRAVEL. SAND, CLAY AND MARL, GRADING DOWNWARD 
INTO marine CONGLOMERATE AND SANDSTONE 

ORINDA FORMATION 

conglomerate, sandstone, and SHALE. 


MONTEREY CROUP. SANTA MARGARITA 
TEMBLOR, VAQUEROS FORMATIONS, ETC, 

FOSSILIFEROUS MARINE SANDSTONE. SHALE, CONGLOMERATE. AND 
UNCONFORMITY ? A LITTLE LIMESTONE. SOME BASALT AND TUFF 

SAN LORENZO GROUP 

FOSSILIFEROUS MARINE SANDSTONE AND SHALE. 


^UNCONFORMITY ? 

UNCONFORMITY 


S < 


UNCONFORMITY 


HOOVER VALLEY FORMATION, UNNAMED FORMATIONS 
IN PALO ALTO AND LOS CATOS QUADRANGLES 

FOSSILIFEROUS SANDSTONE AND SHALE. A LITTLE CONGLOMERATE AND 
LIMESTONE. 

CHICO FORMATION. BERRYESSA FORMATION. 

OAKLAND (?) CONGLOMERATE 

FOSSILIFEROUS MARINE SHALE, SANDSTONE, AND CONGLOMERATE. 

FRANCISCAN AND KNOXVILLE FORMATIONS 

MARINE SANDSTONE, SHALE, A LITTLE CONGLOMERATE AND LIMESTONE, 
AND SLIGHTLY ALTERED IGNEOUS ROCKS 




IGNEOUS ROCKS 

OLIVINE basalt flows. BASALTIC AGGLOMERATE, AND VITRIC TUFFS IN 
PLIO-PLEISTOCENE SEDIMENTS 


INTRUSIONS AND FLOWS OF BASALT. BASALTIC AGGLOMERATE, AND 
RHYOLITIC AND VITRIC TUFF. 


SERPENTINE DIKES, SILLS, AND PLUGS IN THE FRANCISCAN SERIES 
AND ALONG FAULTS. 


n 


FAULTS 


ACCURATELY LOCATED 
APPROXIMATELY LOCATED OR 
FAULT ZONE 


COVERED 


CONTACT 


STATS OF CALIFORNIA 
OEPARTMCNT OF FURLIC WORKS 

DIVISION OF WATER RESOURCES 

SANTA CLARA VALLEY INVESTIGATION 


AREAL GEOLOGY 
1955 

SCALE OF MILES 

0 I 2 3 





MATEO 



r hamjltojn 


lEM LOJyJOND 


GJLROY HOT SPHS. 


S/\jN JUAN 
SAUTJSTA 


CO. 


HOLLISTEP 


PLATE C-2 


INDEX TO SOURCES OF GEOLOGIC MAP 


1 . Generalized from Geology of the San Jose and Mount Hamilton Quad- 

rangles, California, by Max Crittenden, California Divi- 
sion of Mines Bulletin 157, 1951. 

2. Generalized from Geology of the Northeast Part of the Morgan Hill Quad- 

rangle, California, by R. A. Ortalda, M. A. Thesis, Uni- 
versity of California, 1949. 

3. Generalized from Geology of the Hollister Quadrangle, California, by N. 

L. Taliaferro, California Division of Mines Bulletin 143, 
1950. 

4. Generalized from Geology of the San Juan Bautista Quadrangle, Cali- 

fornia, by J. E. Allen, California Division of Mines Bulle- 
tin 133, 1946. 

5. Modified from Geology of the Santa Cruz Quadrangle, California, by J. 

C. Branner, J. F. Newsom, and Ralph Arnold, U. S. Geo- 
logical Survey, Geol. Atlas of the United Staes, Folio 163, 
1909. 

6. Modified from original mapping by Edgar H. Bailey, U. S. Geological Sur- 

vey. This source also used for part of geologic map in Geo- 
logic Guidebook of the San Francisco Bay Counties, Cali- 
fornia Division of Mines Bulletin 154, 1951. 

7. Generalized from unpublished work by R. G. Thomas, 1948-1949. 

8. Mapped during current investigation. 


STATE OF CAUFOfINtA 
OEFAKTMENT OF PUBLIC WORKS 

DIVISION OF WATER RESOURCES 

SANTA CLARA VALLEY INVESTIGATION 

INDEX MAP 

1955 


3 


0 


SCALE OF MILES 
3 


6 




PLATE C-3 



DIVISION OF WATER RESOURCES 



PLATE C-4 


F F' 





T n r ~< tv 

••TQs- 

*o a r*. oo 


LEGEND 

SEDIMENTARY ROCKS 
ALLUVIAL AND TIDELAND DEPOSITS 

SANTA CLARA, PACKWOOD, AND SAN BENITO FORMATIONS 



PURISIMA AND ORINDA FORMATIONS 




MONTEREY GROUP. SANTA MARGARITA TEMBLOR. VAQUEROS 
FORMATIONS. ETC. 



SAN LORENZO GROUP 



HOOVER VALLEY FORMATION. UNNAMED FORMATIONS IN 
PALO ALTO AND LOS GATOS QUADRANGLES 



CHICO FORMATION. BERRYESSA FORMATION. OAKLAND (?) 
CONGLOMERATE 



FRANCISCAN AND KNOXVILLE FORMATIONS 


’i.vTQv,; 



F7\‘' »♦*! 


IGNEOUS ROCKS 

PLIO- PLEISTOCENE BASALT AND TUFF 

MIOCENE BASALT AND TUFF 

SERPENTINE 


note; lines of sections appear on plate c-i 


STATK OF CAUFONNIA 
DCFARTMEKT OF PUMJC WOMKS 

DIVISION OF WATER RESOURCES 

SANTA CLARA VALLEY INVESTIGATION 

GEOLOGIC SECTIONS 
1955 

HORIZONTAL SCALE OF MILES 
I 0 I 2 


APPEN3IX D 

RECORDS OF MONTHLY PRECIPITATION IN SANTA CLARA 
VALLEY NOT PREVIOUSLY PUBLISHED 

(On file with the Division of Water Resources) 


7—19273 


( 107 ) 



APPENDIX E 

RECORDS OF DAILY RUNOFF IN SANTA CLARA VALLEY 
NOT PREVIOUSLY PUBLISHED 

(On file with the Division of Water Resources) 


(109 ) 



APPENDIX F 

RECORDS OF DEPTHS TO GROUND WATER AT SELECTED 
WELLS IN SANTA CLARA VALLEY 

(On file with the Division of Water Resources) 


( 111 ) 



APPENDIX G 

RECORDS OF PARTIAL MINERAL ANALYSES OF GROUND 
WATERS IN SANTA CLARA VALLEY 


(113 ) 



APPENDIX G 


115 


PARTIAL MINERAL ANALYSES OF GROUND WATERS IN SANTA CLARA VALLEY 


Well number 

Depth, 

in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

Well number 

Depth, 

in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

Division 
of Water 
Resources 

Poland* 

Division 
of Water 
Resources 

Poland* 

5S/1W-36H1 

B14 

368 

Domestic » 

11/16/38 

0.79 


6S/1W-12R1 




5/1 1 /49 

1 13 

450 

5S/3W-35G1 


303 


5/18/49 

1.13 

425 





8/24/49 

0.85 

370 





7/18/49 

3.94 

540 

6S/1W-13F1 



Irrigation and 

5/11/49 

1.13 

460 





8/18/49 

3.10 

530 




domestic 

8/15/49 

0.85 

370 

5S/1E-31E1 


200 

Domestic 

5/12/49 

0.56 

380 

6S/1W-13J1 , 




5 / 1 1 /49 

0 56 

405 





8/25/49 

0.56 

340 





8/24/49 

0.85 

360 

5S/1E-3^P1 


250 

Irrigation 

5/10/49 

3.38 

900 

6S/1W-14C1 

B57 



1 1 /23 /38 

0.79 






8/17/49 

2.82 

670 





7/13/49 

1.13 

330 

6S/1W-1JD___. 



Irrigation^ 

5/10/49 

0.85 

460 





9/ 8/49 

0.56 

260 





8/16/49 

0.56 

290 

6S/1W-14E2 

B123 

469 


4/27/39 

1.18 


6S/1W-1L1 

B29 



11/18/38 

0.70 


6S/1W 14E3 




5/11/49 

0.56 

350 





5/11/49 

0.85 

405 




domestic 





9/19/49 

0.85 

350 

6S/1W-14L4 




5/11/49 

3.10 

960 

6S/1W-1M1 

B42 

300 

Irrigation 

11/21/38 

0.99 






8/16/49 

3.10 

600 

6S/1W-1P1 

B22 



11/18/38 

0.79 


6S/1W 14M1 

B119 

135 


4/27/39 

0.48 






5/11/49 

1.13 

445 


domestic 






9/19/49 

0.85 

350 

6S/1W-14R1 


516 


5/16/49 

0.85 

340 

6S/1W-1P2 

B24 


Irrigation _ 

11/18/38 

0.79 






9/ 8/49 

0.56 

250 





5/11/49 

1.13 

445 

6S/1W-15C2 

BOO 


Irrigation and 

11/23/38 

5.58 






8/14/49 

0.85 

330 




domestic 

5/11/49 

11.53 

1600 

6S/1W-1Q1 

B21 

250- 

Irrigation 

11/18/38 

0.99 






7/13/49 

11.25 

1750 



275 


5/10/49 

1.13 

445 





8/24/49 

12.68 

1400 





8/30/49 

0.85 

260 

6S/1W-15F1 

B92 



11/28/38 

0.51 


6S/lW-mi 



Irrigation 

8/16/49 

1.13 

460 





5/12/49 

0.85 

310 





9/19/49 

1.13 

400 





8/15/49 

0.56 

260 

6S/1W-2R1 

B45 

257 

Irrigation 

11/21/38 

0.93 


6S/1W-15F2 

B93 

100 


1 1 /0S/3S 

18 00 






5/16/49 

1.13 

370 



5/10/49 

11.27 






8/15/49 

0.56 

330 





8/15/49 

13.24 


6S/1W-3R1 

B47 



11/21/38 

1.41 


6S/1W-15L1 

B112 

323 


4/'?6/39 

0.39 






5/10/49 

0.56 

370 

6S/1W-16A1 


551 


5/12/49 

0.28 

290 





8/15/49 

1.13 

330 





8/24/49 

0.28 

240 

6S/iW-10El 

B74 



11/26/38 

0.99 


6S/1W-16F1 

BlOO 

435 


19/ 1 /.^S 

9 08 






5/12/49 

0.56 

310 



8/15/49 

0.56 

270 





8/24/49 

0.85 

280 

6S/1 W-16J1 


675 


5/16/49 

0.28 

310 

6S/1W-10E2 

B70 

385 

Irrigation 

11/26/38 

1.89 






8/24/49 

0.28 

270 

6S/1W-10K1 

B50 


Irrigation 

11/23/38 

0.70 


6S/1W'-17G1 


492 

Dnm<^stic 

5/12/49 

2.54 

860 





9/19/49 

0.85 

370 




1 8/15/49 

2.25 

700 

6S/1WM0N1 



Irrigation 

5/12/49 

1.13 

380 

6S/1W^-17K1 

B5 

583 


11/15/39 

1.80 






7/13/49 

1.13 

350 



5/19/49 

1.69 

870 





8/15/49 

1.41 

330 





7/12/49 

1.97 

710 

6S/1W-10P1 



Domestic 

5/12/49 

0.85 

340 





8/15/49 

1.69 

700 





8/15/49 

0.56 

290 

6S/1W-17M1 


600 

Irrigation 

5/17/49 

0.59 

300 

6S/1W-10P2 

B66 

368 

Irrigation and 

/38 

0.90 


6S/1W-18K1 

Cll 

230 

Irrigation and 

1 12/ 6/38 

0.46 





domestic 




domestic 


6S/1W-10P3 



Irrigation 

5/16/49 

3.10 

800 

6S/1W-18L1 

C8 

150 

Trri nation 

12/ 5/38 

2.59 






8/15/49 

3.66 

660 



5^6/49 

2.82 1 

1100 

6S/iW-llAl 

B30 


Irrigation 

11/18/38 

0.79 






7/22/49 

3.38 

1000 

6S/1W"-11B1 

B19 

360 

Irrigation 

11/16/38 

0.99 






8/ 3/49 

0.31 

930 

6S/1W-11C1 




5/11/49 

0.85 

440 

6S/1W-18N1 




5/18/49 

0.11 

340 

6S/1W-11J1 

B35 


Irrigation 

11/21/38 

0.90 






8/26/49 

0.84 

295 

6S/1W-11K1 

B37 

575 

Irrigation,,^ 

11/21/38 

1.18 


6S/1W-18P1 

C21 

305 

TrriP'a.t.inn 

12/ 7/38 

0.90 






5/16/49 

0.56 

360 

6S-1W/18Q1 


37 I 

Irrigation and 

5/16/49 

1.13 

470 





8/30/49 

0.56 

310 




domestic 

8/ 3/49 

1.13 

430 

6S/1W-11L1 

B41 


Irrigation 

11/21/38 

0.79 






9/6 /49 

1 . 13 

390 

6S/1W-11M1_..__ 



Irrigation 

5/11/49 

0.85 

340 

6S/1W-18R2 

C5 


Irrigation 

12/ 5/38 

0.59 





7/13/49 

0.56 

350 

6S/1W-19F1 


Irrigation 

5/17/49 

1.41 

630 

6S/1W-11N1 

B53 

608 

Irrigation 

11/23/38 

2.39 






8/ 3/49 

1 .41 

460 

6S/1W-11P1 

B54 


Irrigation and 

11/23/38 

0.99 


6S/1W-19M1 _ 


495 

Irrigation and 

: 5/16/49 

1.13 

520 




domestic 

5/12/49 

0.85 

350 




domestic 

i 7/13/49 

1.13 

390 





7/13/49 

0.85 

315 





8/16/49 

0.85 

370 





8/16/49 

0.85 

320 

6S/1W-20A1 


495 

Irrigation and 

5/12/49 

0.56 ^ 

290 

6S/1W-11R1 

B34 


Domestic 

11/21/38 

0.99 





domestic 

7/17/49 

0.56 

255 





5/11/49 

0.56 

390 





9/ 8/49 

0.28 

240 





8/15/49 

0.56 

330 

6S/1W-20D1______ 



Irri gation 

10/ 3/49 

0 . 56 

290 

6S/1W-12A1 



Irrigation 

5/10/49 

0.85 

490 

6S/1W-21H1__,_ 


469 

Irrigation 

9 /23/49 

0.56 

300 





8/16/49 

0.85 

330 

6S/1W-21R1 



Irrigation and 

5/12/49 

0.28 

300 

6S/1W-12C1 

B25 


Domestic 

11/18/38 

0.79 





domestic 








5/11/49 

0.85 

290 

6S/1W-22J1 


815 

Domestic 

5/12/49 

1.13 

350 

6S/1W-12D2 



Irrigation 

5/16/49 

1.13 

410 





8/16/49 

0.56 

270 





8/15/49 

0.56 

370 

6S/1W-23H1__,. 


515 

Irrigation 

5/11/49 

0.56 

370 

6S/1WG2E1____. 

B31 


Irrigation and 

11/18/38 

0.90 






8/16/49 

0.56 

310 




domestic 




6S/1W-24F1 




5/11/49 

2.25 

690 

6S/1W-12K1____. 

C5 


Irrigation 

12/ 5/38 

0.59 






8/24/49 

1.97 

660 

6S/1W-12M2 


323 


5/19/49 

0.85 

390 

6S/1W-25D1__,,_, 


360 

; Irrigation 

5/11/49 

1.69 

830 





9/19/49 

0.56 

340 





7/13/49 

1.69 

650 

6S/1W-12N1 


300 

Irrigation 

5/11/49 

0.85 

390 





9/27/49 

2.25 

620 





8/24/49 

0.56 

330 










116 SANTA CLARA VALLEY INVESTIGATION 


PARTIAL MINERAL ANALYSES OF GROUND WATERS IN SANTA CLARA VALLEY-Continued 


W eli number 

Depth, 

in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

j VVell number 

Depth, 

in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

Division 
of Water 
Resources 

Poland* 

Division 
of Water 
Resources 

Poland* 

6S/1W-25L2 


390 

Irrigation_. 

5/11/49 

0.56 

340 

6S/2W-10F1 ____ 


187 









7/13/49 

0.56 

350 





8/22/49 

0.56 

310 





9/ 7/49 

0.56 

250 

6S/2W-10N1 

C69 



12 / 2 Q /.38 

0 70 


6S/1W=26D1 


649 


5/16/49 

0.85 

290 

6S/2y/-10N2 

C 68 

300 









9/ 7/49 

0.56 

330 

6S/2W-12P1______ 

C32 

175 


12/ 8/38 

5? 20 


6S/1W-26F2 



Irrigation 

5/16/49 

0.56 

360 





5/19/49 

3.10 

870 





9/19/49 

0.56 

320 





8/22/49 

3.66 

780 

6S/1W-27F1__.__ 



Irrigation and 


0.56 

310 

6S/2W-13Ji 

C36 


nnti n 








7/13/49 

0.56 

265 




5/19/49 

1 41 

610 





9/ 8/49 

0.28 

270 





8/22/49 

1.41 

470 

6S/1W-27Q1 



Irrigation and 

5/12/49 

0.56 

270 

6S/2W-13M1 

C28 









domestic 

7/13/49 

0.56 

265 





5/19/49 

0.85 

425 





9/23/49 

0.28 

230 





8/22/49 

1.69 

580 

6 S/iW •‘27111 _ 


36U 

Irrigation 

5/12/49 

0.85 

370 

6S/2W-13N1__ _ _ 

C29 


Irrigation and 

12/ 8/38 

1.18 






7/13/49 

0.56 

350 




domestic 








8/16/49 

0.28 

310 

6S/2W-14M1 

C41 

1000 

Municipal 

12/23/38 

8.48 


OD/i\v-29^^1 _____ 


375 

Irrigation _____ 

5/ 12/49 

U.06 

315 





5/18/49 

1.69 

400 





8 /23 /49 

0 

900 





*7/10 /Ar, 

n oo 

Aai\ 

6S/iW-29Gl______ 


250 


5/12/49 

0.56 

340 





8/22/49 

o!28 

90 





8 / 3/49 

0.56 

315 

6S/2W-14M2 

C40 

800 


12/23/.38 

18 20 






8/23/49 

0.28 

270 





5/18/49 

6.20 

770 

6S/1W-29M2 _ _ 


540 


5/17/49 

1.13 

445 





7/18/49 

7.04 

750 





8 / 3/49 

1.13 

430 





8/22/49 

5.92 

700 





9/ 6/49 

0.85 

390 

6S/2W-14R1 


700 


5/19/49 

1.69 

370 

6S/lW-29rl 



Irrigation, 

5/17/49 

0.56 

315 





7/18/49 

1.41 

365 





9/16/49 

0.56 

260 





9/12/49 

1.41 

360 

6S/1W-30C4_ _ __ 



Irrigation and 

5/16/49 

1.13 

470 

6S/2W-1.5D1 


700 

Tt*T*i n 4 ' - T 1 







domestic 

8 / 3/49 

1.13 

430 




7/14/49 

0.85 

ooo 

280 





9/ 6/49 

1.13 

390 





8/22/49 

0.56 

340 

6S/1W-30P1 



Irrigation, , 

5/17/49 

1.41 

485 

6S/2W-‘15E1______ 

C52 


Iriigation 

12/28/38 

r\ 

V, # U 






8/23/49 

1.41 

430 





5/19/49 

1.13 

390 

6S/1W-31L3 _ _ 


381 

Irrigation 

9/ 6/49 
5/16/49 

1.14 

0.56 

370 

360 

6S/2W-I.5F1 

C49 


■ 

8/22/49 

0.85 

430 





8/23/49 

0.85 

330 

6S/2W-16H1_ 

600 

Irrigation 

5/19/49 

0.85 

315 

6S/1W-31P1 



Irrigation _ _ 

5/12/49 

0.85 

315 





7/14/49 

1.13 

460 

6S/1W-32Q1___ 


350 

Irrigation and 

5/17/49 

0.56 

315 





9/19/49 

0.56 

290 




domestic 

9/ 6/49 

0.56 

280 

6S/2W'-16Q1 



Trnga.tion 

5/19/49 

1.13 

470 

6S/1W-33C1 




5/11/49 

0.85 

390 





9/19/49 

o]85 

400 





8/15/49 

0.56 

330 

6S/2W-18B4 


350 

Irrigation 

5/18/49 

0.85 

325 

6S/1W-33L1 


: 391 

Irrigation and 

5/17/49 

0.56 

325 

6S/2W-18N2 


705 

Irrigation _ 

5/18/49 

1.13 

400 




domestic 

9/20/49 

0.56 

280 





8/18/49 

1.13 

390 

6S/1W-34L1_ __ 


1 420 

Irrigation, 

5/16/49 

0.56 

450 

6S/2W-20C1 


340 


p^/IQMG 

1 d'\ 

AAA 





9/ 7/49 

0.56 

300 


xrrigSi tioii — - ^ _ 

D/ 

9/19/49 

1.41 

40U 

430 

6S/1W-34L2 




7/13/49 

0.85 

350 

6S/9W-9nG2 


330 



O O C 


6S/1W-34P1 



Irrigation, _ _ 

5/17/49 

0.85 

370 



irrigBiXion £liiq 
domestic 

D/ iy/4y 

9/19/49 

1.13 

500 

340 





7/14/49 

0.56 

315 

6S/2W-22C1 



Irrigation 

5/19/49 

0.56 

370 





9/22/49 

0.85 

370 





9/19/49 

0.85 

350 

6S/1W-34R1 



Irrigation and 

5/12/49 

1.13 

i 560 

6S/2W-22H7 


150 

Irrigation and 

5/19/49 

0.85 

460 




domestic 

7/13/49 

0.85 

480 




domestic 

8/22/49 

1.41 

400 





: 9/ 8/49 

0.85 

470 

6S/2W-22K1 



TrrtgR+.ioTi 

5/19/49 

1.13 

390 

6S/1W-35N1_____ 


722 

Industrial 

5/16/49 

1.13 

390 





9/19/49 

0.56 

340 





9/19/49 

0.56 

330 

6S/2W-22Q1 



Irrigation 

5/20/49 

1.13 

355 

6S/1W~36E1 



Abandoned 

5/16/49 

0.85 

380 





8/22/49 

0.56 

340 





8/24/49 

2.55 

1060 

6S/2W-23D1 



Irrigation and 

5/19/49 

1.41 

340 

6S/1W-36F1 


350 


5/11/49 

0.56 

390 




stock 

7/18/49 

1.13 

460 

6S/1W-36G1 


350 

Irrigation __ 

9/ 7/49 
5/11/49 

0. 58 
0.85 

380 

480 

6S/2W-23M1 



T Fl*! rvTi 

S/22/49 

^ /l Q /do 

i . 13 

340 

Adfy 





7/13/49 

0.85 

390 

6S/2W-24A1 


677 

Irrigation 

o/ ±y/ 

5/16/49 

U . oO 

0.85 

300 

6S/lW-36Ji 


430 

Irrigation 

5/15/49 

0.56 

380 

6S/2W-24C1 




/l Q /J-Q 


Con 





10/ 4/49 

0.5 

310 





O/ 15#/ 

7/18/49 

1 / . oo 

0.56 

oyu 

365 

6S/2W-6D2 

D99 

352 

Abandoned _ _ 

4/20/39 

0.70 






8/22/49 

0.85 1 

360 

6S/2W-7D1 _ ___ 

D21 

225 

Municipal 

4/11/39 

0.99 


6S/2W-24C2 


800 

Trri ga.tinn 

5/16/49 

1.13 ^ 

520 

6S/2W-7J1 



Irrigation and 

5/19/49 

4.23 

1100 





7/18/49 

0.85 

330 




domestic 

7/18/49 

4.23 

870 





: 8/22/49 

0.56 

320 





8/18/49 

4.78 

900 

6S/2W-24D1 


665 

Irrigation 

5/19/49 

0.85 

335 

6S/2W-8J1 


125 


; 5/18/49 

1.13 

305 





7/18/49 

1.13 

365 





1 7/18/49 

0,85 

315 





9/12/49 

0.85 

340 





8/22/49 

0,56 

320 

6S/2W-24M2 


550 


5/16/49 

1.13 

340 

6S/2W-8N1 

D57 

505 

Irrigation and 

4/18/39 

1.16 






9/ 6/49 

0.85 

290 




domestic 




6S/2W-24P3._____ 



Irrigation and 

5/19/49 

0.85 

340 

6S/2W-8N4 



Irrigation 

5/18/49 

0.85 

365 




domestic 

9/20/49 

0.85 

33P 





S/22/49 

1.41 

580 

6S/2W-26H2 


400 

Irrigation and 

5/19/49 

0.85 

355 

6S/2W-8N5 

D 66 

400 

Dairv 

4/18/39 

0.90 






Q / Q /AQ 


OA K 

6S/2W-9H1 


200 ' 


5/19/49 

1.13 

365 

6S/2W-26N2 _ 


185 

Qoincs vie 

T rri ga.ti on 

y/ y/^y 
5/17 /49 

U • OO 
0 * 28 






8/22/49 

0.85 

290 




9/20/49 

0,56 

ooU 

310 

6S/2W-9L1 

D36 



4/12/39 

0.99 


6S/2W-27F1 


387 

Irrigation 

5/1Q/4Q 

0.85 

395 





: 5/19/49 

1.69 

1 870 





Kj/ iy / *±y 

8/22/49 

0.85 

390 





8/22/49 

1.97 

i 780 










APPENDIX G 


117 


PARTIAL MINERAL ANALYSES OF GROUND WATERS IN SANTA CLARA VALLEY-Continued 


Well number 

Depth, 

in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

Well number 

Depth, 

in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

Division 
of Water 
Resources 

Poland* 

Division 
of Water 
Resources 

Poland* 

6S/2W-27H2_.___ 



Irrigation 

5/19/49 

0.85 

370 

6S/1E-16R1 




10/ 3/49 

2.54 

700 





9/20/49 

0.56 

330 

6S/1E-17H1_ 


463 


5/11/49 

0.85 

415 

6S/2W-27Q1 


287 

Irrigation and 

5/19/49 

0.85 

460 

6S/1E-17R1 


300 


5/10/49 

1.41 

580 




domestic 







8/17/49 

1.41 

460 

6S/2W-27Q2._.___ 


375 

Irrigation 

5/20/49 

1.13 

325 

6S/1E-18D1 


354 



0.85 

460 





9/19/49 

0.56 

320 





8/15/49 

0.85 

300 

6S/2W-28M1 


600 

Municipal ^ 

5/20/49 

1.13 

380 

6S/1E-18L1 




.5/11/49 

1 .13 

490 





7/14/49 

0.85 

365 




domestic 

8/15/49 

0.85 

390 





8/22/49 

1.13 

380 

6S/1E-19F1 


120 

Irrigation and 

5/11/49 

2.28 

570 

6S/2W-29A1_. 


500 


5/20/49 

0.85 

390 





9/ 7/49 

0 85 

370 

6S/2W-29D2 


500 


8/31/49 

0.85 

370 

6S/1E-19M1_ 




8/16/49 

0.85 

370 

6S/2W-32C1 


500 


10/ 3/49 

0.85 

370 

6S/1E-19Q1 




.5/16/49 

0.85 

420 

6S/2W-33A1 



Irrigation. 

5/20/49 

0.85 

355 





9/ 7/4Q 

0 56 

370 





9>12'/49 

0.85 

380 

6S/1E-21G1 




5/10/49 

i!69 

485 

6S/2W-34M1 


660 


5/17/49 

0.56 

315 

6S/1E-21Q1 




.5/17/49 

1 .13 

470 





8/23/49 

0.56 

260 




domestic 

9/19/49 

0.85 

380 

6S/2W-35B3 


225 

Irrigation and 

5/19/49 

0.86 

425 

6S/1E-22B2 




5/16/49 

2.54 

800 




domestic 

10/ 3/49 

0.56 

370 





10/ 4/49 

2.54 

760 

6S/2W-35M1 


500 

Irrigation 

8/ 3/49 

0.56 

315 

6S/1E-22E2 




5/15/49 

1.69 

560 





8/23/49 

0.56 

300 





8/25/49 

1.13 

460 

6S/2W-36H2 


470 


5/16/49 

1.41 

470 

6S/1E-26G1 




5/17/49 

1.97 

690 





9/23/49 

1.41 

390 





8/25/49 

1.41 

490 

6S/2W-36L1 



Irrigation 

5/19/49 

0.85 

390 

6S/1E-27H1 


396 


.5/16/49 

1.97 

630 





9/ 7/49 

0.85 

340 




8/25/49 

1.69 

550 

6S/2W-36M1 


700 

Irrigation 

5/19/49 

0.85 

390 

6S/1E-27P2 




.5/16/49 

2.26 

630 





9/19/49 

0.85 

330 





10/ 4/49 

1.97 

550 

6S/3W-1B1 




5/18/49 

2,82 

460 

6S/1E-29B2_ 


460 


.5/1.5/49 

0.85 

450 





7/18/49 

1.97 

500 





9/ 6/49 

1.13 

420 





8/18/49 

1.97 

430 

6S/1E-30M1 



Irrigation _ 

5/16/49 

0.56 

350 

6S/3W-1D1 


750 

Municipal 

5/18/49 

1.54 

540 





8/16/49 

0.85 

340 





7/18/49 

1.41 

365 

6S/1E-30N1 


316 

Irrigation and 

5/16/49 

2.82 

900 





8/18/49 

1.97 

490 




domestic 

8/16/49 

2.82 

660 

6S/3W-1M1 


400 

Municipal 

5/18/49 

1.41 

570 

6S/1E-31L3 




5/1.5/49 

0 .56 

370 





7/18/49 

2.82 

500 




domestic 

8/25/49 

0^56 

330 





8/18/49 

1.13 

430 

6S/1E-33H1 



Irrigation 

5/15/49 

1.41 

520 

6S/3W-2D1 


367 


5/18/49 

1.41 

425 





8/25/49 

1.69 

460 





7/18/49 

1.13 

390 

6S/1E-33L1 


341 

Irrigation and 

8/25/49 

1.69 

550 





8/18/49 

1.41 

430 




domestic 




6S/3W-3L1 


746 

Municipal 

7/12/49 

1.97 

460 

6S/1E-34H2 



Irrigation 

5/17/49 

1.97 

580 





8/25/49 

1.97 

450 





8/25/49 

1.97 

490 

6S/3W-3P1 


320 

Municipal 

8/25/49 

1.69 

450 

6S/1E-34Q1 _ 


303 

Irrigation 

5/15/49 

22.60 

2,000 

6S/3W-12C1 


525 


5/18/49 

1.13 

390 





8/25/49 

18.30 

2,100 





7/18/49 

1.41 

365 

6S/1E-36J1 


430 


5/15/49 

0.56 

380 

6S/3W-12G1 


512 

Municipal 

5/18/49 

4.78 

670 





10/ 4/49 

0.56 

310 





7/18/49 

4.78 

600 

7S/1W-3G1 


550 


5/17/49 

0.85 

380 





8/18/49 

4.23 

640 





7/14/49 

0.56 

314 

6S/1E-1P2__ 

B24 



11/18/38 

0.79 






9/20/49 

0.56 

330 





5/11/49 

1.13 

445 

7S/1W-4B1___ 


360 

Irrigation __ ! 

5/17/49 

0.28 

295 





8/16/49 

0.85 

330 





8/26/49 

0.56 

240 

6S/1E-1Q1 

B21 

275 


11/18/49 

0.99 


7S/lW-4Dl-_ 


300 

Irrigation 

5/17/49 

0.56 

315 





5/11/49 

1.13 

445 





9/12/49 

0.56 

280 





8/16/49 

0.85 

260 

7S/1W-5E1 


229 

Irrigation and 

5/17/49 

1.41 

560 

6.S/1E-4L1__^ __ 


200 

Irrigation 

5/10/49 

1.97 

760 




doiTIGSt/lC 








8/30/49 

2.25 

620 

7S/1W-5F1._ 


440 

Irrigation 

5/17/49 

0.85 

340 

6S/1E-5G1 


278 

Irrigation . 

5/10/49 

2.82 

730 





8/31/49 

0.56 

290 





8/17/49 

2.54 

620 





9/12/49 

0.56 

290 

6S/1E-5Q1 



Domestic 

5/10/49 

1.41 

600 

7S/1W-5N2 



I rri ga.ti on 

5/17/49 

0.85 

410 





8/30/49 

1.14 

500 





9/20/49 

0.85 

320 

6S/1E-6A1 _ _ 



Irrigation and 

5/10/49 

0.85 

405 

7S/1W-5Q2 



Irrigation 

5/17/49 

0.56 

350 




domestic 

8/13/49 

0.57 

330 





7/14/49 

0.85 

315 

6S/1E-7E1 

B26 


Municipal 

11/18/38 

1.80 






Q/20/4Q 

0.56 

320 

6S/1E-8N1 


506 


5/10/49 

1.69 

630 

7S/1W-6C1-- 


465 

Irrigation 

K/ / / ^t7 

5/16/49 

1.13 

445 





8/25/49 

1.97 

550 





8/23/49 

1.67 

390 

6S/1E-8Q1 


614 

Irrigation 

5/10/49 

1.13 

405 

7S/1W-6P1 


606 

Irrigation 

5 /17 /49 

0.85 

405 





7/13/49 

0.85 

350 





9/ 7/49 

0.56 

250 





8/17/49 

0.85 

340 

7S/1W-6Q1 



Irrigation 

5/17/49 

0.56 

380 

6S/1E-9B1 


315 

Domestic. 

5/10/49 

2,54 

730 





9/20/49 

0.85 i 

330 





8/30/49 

2.25 

500 

7S/1W-7F1 


585 

Irrigation 

5/17/49 

0.85 

380 

6S/1E-15L1 


452 


5/10/49 

3.66 

950 





9/23/49 

1,13 

360 





8/17/49 

3.10 

780 

7S/1W-7H1 



Irrigation ^ 

5/17/49 

0.85 

370 

6S/1E-16F1 


493 

Irrigation. 

5/16/49 

1.69 

560 





9/12/49 

0.85 

300 





9/ 7/49 

1.41 

460 

7S/1W-8H1 


310 


5/17/49 

0.85 , 

315 

6S/1E-16G1 


500 

Irrigation 

5/10/49 

1.41 

580 





9/12/49 

0.56 ' 

260 





8/30/49 

1.42 

500 

7S/1W-9C1 



Irrigation 

9/12/49 

0.28 

300 

6S/1E-16P1 


400 

Irrigation „ . _ 

5/10/49 

1.69 

600 

7S/1W-9J1 


360 

Irriga tion 

5/17/49 

0.85 

330 





9/ 7/49 

1.97 

500 





■ 9/20/49 

0.56 

280 



118 


SANTA CLARA VALLEY INVESTIGATION 


PARTIAL MINERAL ANALYSES OF GROUND WATERS IN SANTA CLARA VALLEY-Continued 


Well number 

Depth, 

in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

Well number 

Depth, 

in 

feet 

Use 

I 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

Division 
of Water 
Resources 

Poland* 

Division 
of Water 
Resources 

Poland* 

7S/1W-9M1 


281 

Irrigation 

5/17/49 

0,56 

300 

7S/1E-9D1, 


325 

Dairy 

10/ 4/49 

0.56 

400 





9/20/49 

0.28 

270 

7S/1E-10B1 



Irrigation and 

5/15/49 

0.85 

580 

7S/1W-11N1 




5/19/49 

1.13 









7S/1W-13K1 . 


634 

Municipal 

10/ 4/49 

0.56 

300 

7S/1E-14C2- 


187 


5/12/49 

1.13 

520 

7S/1W-14G1 




10/ 3/49 

0.85 

370 





7/12/49 

0.56 

430 

7S/1W-14M1 




9/ 7/49 


300 





8/24/49 


400 

7S/1W-16A1 




5/18/49 

0.85 

325 

7S/iE-14R2- 


204 


5/12/49 

1.67 

630 





9/23/49 

0.56 

280 




domestic 

9/ 6/49 

1.40 

490 

7S/lW-lt5Dl ___ . 


312 


5/13/49 

0.85 

315 

7IS/1E-15J2 




5/12/49 

0.85 

580 





9/20/49 

0.56 

270 




domestic 



7S/1W-16H1 


313 


5/20/49 

0.85 

325 

7S/1E-20Q6 




10/ 4/49 

0.56 

300 





7/12/49 

0.56 

285 

7S/1E-21K2 _ 


300 


10/ 4/49 

0.56 

400 





8/26/49 

0,56 

310 

7S/1E-22P1 



Irrigation and 

10/ 4/49 

n ■ 8 .^ 

380 

7S/lW-17rD_. 




5/18/49 

0.28 

305 








7S/1W-18G1 


420 


5/18/49 

0.85 

340 

7S/1E-23K1 




5/11/49 

0.56 

470 





8/31/49 

0.85 

320 





8/25/49 

0.56 

380 

7S/1W-18N1 


525 

Irrigation 

5/18/49 

1.13 

340 

7S/1E-24R1 



Irrigation 

5/12/49 

0.S5 

450 





8/26/49 

0.85 

290 





7/12/49 

3.95 

710 

7S/1W-19E1 


400 

Irrigation 

5/18/49 

1.13 

340 





8/24/49 

4.23 

760 





9/20/49 

0.85 

310 

7S/1E-25E4 


268 

Irrigation _ , 

5/11/49 

0.85 

460 

7S/iW-19Kl 


560 

Irrigation and 

5/19/49 

0.56 

290 





7/12/49 

1.13 

390 




domestic 








8/25/49 

0.85 

400 

7S/1W-20B1 


285 

Irrigation 

5/18/49 

0.85 

325 

7S/1E-26E2 


164 

Irrigation and 

10/ 4/49 

0.85 

400 





9/ 7/49 

0.56 

340 




domestic 




7S/1W~20K2 


450 

Irrigation „ 

5/19/49 

0.85 

320 

7S/1E-27A2 



Irrigation , 

5/11/49 

1.67 

630 





9/ 7/49 

0.56 

300 

7S/1E-31R1 



Irrigation 

5/15/49 

0.56 

350 

7S/UV-21P2__ __ 



Irrigation and 

10/ 3/49 

0.56 

300 





7/12/49 

0.56 

315 




domestic 








8/25/49 

0.85 

310 

7S/1W-22G1 


390 

Irrigation 

9/21/49 

0.28 

230 

7S/1E-32B2 


400 


5/15/49 

0 . 56 

340 

7S/1W-23J1 



Irrigation 

5/18/49 

1.13 

370 





7/12/49 

0.56 

295 





10/ 4/49 

0.56 

350 





8/25/49 

0.28 

290 

7S/1W-23P1 



Irrigation 

5/18/49 

0.56 

250 

7S/1E-32R1 



Irrigation 

5/15/49 

0.28 

270 

7S/1W-24H2 



Irrigation 

5/17/49 

0.85 

490 





7/13/49 

0.28 

255 





8/26/49 

0.85 

430 





8/25/49 

0.28 

280 

7a/1W-9-^F,1 



Irrigation 

5/15/49 

0.56 

340 





10/ 4/49 

0.28 

270 





7/12/49 

0.56 

295 

7S/1E-33Q2 



Irrigation and 

10/ 4/49 

0.56 

310 





8/25/49 

0 . 56 

310 




domestic 




7S/1W-27A1 



Irrigation 

5/19/49 

0.85 

335 

7S/1E-35G2 



Irrigation and 

5/11/49 

0.85 

400 

7S/1W-28G1 



Irrigation and 

5/19/49 

0.85 

290 




domestic 

8/25/49 

0.56 

370 




domestic 

10/ 3/49 

0.56 

270 





10/ 4/49 

0.56 

350 

7S/XW-29Ki 


1065 

Irriga.tion 

5/18/49 

0.85 

335 

7S/1E-36L2 




5/11/49 

1.41 

520 





7/12/49 

0.56 

285 





9/20/49 

1.13 

430 





8/26/49 

0 56 

320 

7S/1E-7K3 



Irrigation 

- /I 9 /40 

1 . 07 

730 

7S/1W-29M2_ ___ 


; 607 


9/ 7/49 

0.28 

250 





9/26/49 

1.41 

550 

7 ^ /i 1 



Irrigation 

9/20/49 

0 . oG 

300 

7S/1E-18HX 


40 u 

Irrigation 

5/12/49 

1.41 

o30 

7sWw-3lA3 



Irrigation- 

9/ 2/49 

0.56 

270 





9/20/49 

1.41 

550 

7S/1W-32K2 


202 

Irrigation and 

5/19/49 

0.85 

265 

7S/2E-19F4 




10/ 5/49 

1,13 

460 




domestic 

9/20/49 

0.28 

240 

7S/2E-‘:>0C1 


327 

Irrigation and 

10/ 4/49 

1 . 13 

500 

7S/1W-34D1 



Irrigation 

5/18/49 

0.85 

290 




domestic 








9/18/49 

0.28 

220 

8 S/iW-lNl 


775 

Irrigation 

5/17/49 

2.82 

560 

7S/1W-34P1 




5/17/49 

0.85 

370 

8S/1W-3D1 


818 


5/17/49 

1.13 

350 





7/14/49 

0.56 

315 





9/21/49 

1.67 

400 





9/22/49 

0.85 

i 370 

8S/1W-10M1, 



Irrigation 

5/17/49 

1.13 

380 

7S/2W-1D1 



Irrigation and 

5/11/49 

1.13 

405 





10/ 3/49 

1.97 

460 




domestic 

9/ 6/49 

0.85 

230 

8S/1W-12M1 


290 

Trri£’'ation 

5/17/49 

1.97 

560 

7S/2W-1G2 



Irrigation and 

5/17/49 

0.85 

340 





9/26/49 

2.82 

620 




domestic 

8/23/49 

0.85 

370 

8S/1W-15B1 


144 

Irrigation 

5/17/49 

1.13 

380 

7S/2W-2P1 


205 

Irrigation 

5/17/49 

0.56 

340 





7/12/49 

0.85 

350 





9/ 6/49 

0.56 

290 

8S/1W-16K1 


Pumps 


7/12/49 

0.85 

350 

7S/2W-3A1 


550 


5/17/49 

0.85 

380 



from 









S/23/49 

0.56 ; 

280 1 



Los 





7S/2W-3E1__. 



Irrigation 

9/20/49 

0 . 56 

270 



; Gatos 





7S/2W-3K1 


770 

Irrigation 

8 / 3/49 

0.85 : 

315 



Creek 





7S/2W-4H1 



Domestic, 

5/19/49 

0 . 85 i 

290 

8 S/ 1 E- 1 H 1 




5/11/49 

1.13 

560 

7S/2W-11G2 



Irrigation 

5/17/49 

0.56 

365 





10/ 4/49 

1.13 

430 





9/23/49 

0.56 

300 

8S/1E-1Q1 


120 

Irrigation and 

5/11/49 

0.85 

580 

7S/2W-11R1 


552 

Irrigation 

5/17/49 

0.56 

380 




domestic 

9/20/49 

0.85 

460 





9/ 8/49 

0.85 

370 





9/21/49 

1.13 

470 





9/20/49 

0.85; 

370 

8S/1E-3N1_,, . 


176 

Irrigation 

10/ 4/49 

0.28 

270 

7S/2W-12K1 


510 

Irrigation 

5/17/49 

1.13 : 

420 

8S/lE-5Ml_-_ 




5/15/49 

0.56 

315 





9/ 6/49 

0.85 

370 

8S/1E-6N2, _ 


400 

Irrigation 

5/15/49 

0.85 

290 

7S/2W-14G1 


500 

Irrigation 

10/ 3/49 

0.85 

370 





9/ 7/49 

0.28 

250 

7S/2W-14H2 


1405 

Irrigation 

5/19/49 

1.41 

570 

8S/1E-8A1 



Irrigation 

5/12/49 

0.56 

250 

7S/1E-2B1__ 



Irrigation 

9/ 6/49 

2.54 

690 





8/24/49 

0.28 

240 

7S/1E-7R1 


865 

Municipal 

10/ 5/49 

0 . 56 

260 

8S/1E-9H1 I 


245 

Irrigation — 

10/ 4/49 

0.28 

290 



APPENDIX G 


119 


PARTIAL MINERAL ANALYSES OF GROUND WATERS IN SANTA CLARA VALLEY-Continued 


Weli number 


Division 
of Water 
Resources 


8S/1E-9J1 

8S/1E-10J2 

8S/1E-11C1 

8S/1E-13A1 

8S/1E-14G1 

8S/1E-17R3 

8S/1E-21B1 

8S/1E-25M1 

8S/1E-25M2 

8S/1E-26H1 

8S/2E-7A3 

8S/2E-8M1 

8S/2E-17B2 

8S/2E-17J2 

8S/2E*18E1 

8S/2E-21B1 

8S/2E-22D1 

8S/2E-26D1 

8S/2E-26M2 

8S/2E-31E4 

8S/2E-31L1 

8S/2E-34Ri 

8S/2E-35E3 

8S/2E-35Q1 

9S/2E-1K2 

9S/2E-12H1_. 

9S/3E-4B1 

9S/3E-7C1 

9S/3E-7F1 

9S/3E-9R1 

9S/3E-9R2 

9S/3E-15R2 

9S/3E-16C2 

9S/3E-16C3 

9S/3E-16G1 

9S/3E-16M1 

9S/3E-16R2 

9S/3E-17C1 

9S/3E-21H2 

9S/3E-22F3 


Poland* 


Well number 


Depth , 
in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
eprn 

Solids, 

in 

ppm 


Depth, 

in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

Division 
of Water 
Resources 

Poland* 


Irrigation 

5/15/49 

1.67 

630 

9S/3E-22P1 


209 

Irrigation 

5/13/49 

0.85 

380 

183 

Irrigation 

5/12/49 

3.10 

900 





9/ 8/49 

0.28 

330 



7/ 7/49 

2.26 

650 

9S/3E-23F1 



Irrigation 

10/ 4/49 

0.56 

310 

180 

Irrigation 

5/12/49 

0.56 

500 

9S/3E-26B1 



Irrigation 

5/13/49 

0.85 

315 



7/ 7/49 

1.13 

430 





7/ /49 

0.85 

315 



9/26/49 

0.85 

400 





10/ 4/49 

0.56 

260 



5/12/49 

0.85 

430 

9S/3E-26N3 



Irrigation- 

5/13/49 

0.28 

340 



10/ 4/49 

0.85 

310 





9/19/49 

0.56 

280 


Irrigation^ 

9/ 7/49 

3.38 

680 

9S/3E-29B1 



Abandoned 

10/ 4/49 

0.28 

250 


Irrigation and 

9/ 7/49 

1.41 

470 

9S/3E-32N1 


67 

Irrigation and 

5/13/49 

0.56 

340 


domestic 







domestic 

9/ 2/49 

0.28 

290 



5/12/49 

0.85 

430 

9S/3E-35N1 


160 


5/12/49 

0.56 

270 



8/24/49 

0.56 

330 





7/ /49 

0.28 

235 

48 

Irrigation and 

5/11/49 

0.85 

400 





8/23/49 

0.28 

220 


domestic 

9/ 7/49 

0.85 

330 

9S/3E-35Q1 



Irrigation 

9/ 2/49 

0.56 

230 

20 


5/11/49 


230 

9S/3E-36F1_ 


179 

Irrigation and 

5/13/49 

0.56 

320 



10/ 3/49 

0.85 

300 




domestic 

9/ 2/49 

0.56 

250 

25 

Irrigation. 

5/11/49 

0.28 

210 

10S/3E-1L1 



Irrigation 

5/13/49 

0.56 

270 



8/24/49 

0.85 

250 

10S/3E-2L2 


340 


5/12/49 

0.85 

315 

203 

Irrigation. 

5/11/49 

0.56 

350 





9/30/49 

0.28 

250 



9/ 6/49 

0.56 

320 

10S/3E-3C2 


220 

Irrigation and 

5/12/49 

0.56 

350 

200 

Irrigation 

5/11/49 

0.56 

370 




domestic 

9/ 2/49 

0.28 

290 



9/20/49 

0.56 

290 

10S/3E-9E1 __ _ 


55 

Irrigation 

5/12/49 

0.56 

210 


Irrigation 

5/11/49 

0.56 

350 

10S/3E-12D1 _ _ 


182 

Irrigation, stock 

5/13/49 

0.56 

290 



9/ 6/49 

0.28 

280 




and domestic 

10/ 4/49 

0.56 

230 

220 


5/10/49 

0.58 

380 

10S/3E-13J1 



Irrigation 

5/12/49 

0.56 

270 



9/26/49 

0.28 

280 





10/ 4/49 

0.28 

210 

170 


5/11/49 

0.85 

420 

10S/3E-14B1 


175 

Irrigation 

5/12/49 

0.56 

300 



9/ 7/49 

0.56 

350 





7/ /49 

0.85 

295 

100 

Irrigation 

5/10/49 

0.56 

320 





9/30/49 

0.56 

250 



9/ 6/49 

0.28 

260 

10S/3E-25K1 


141 

Irrigation- 

5/12/49 

0.56 

300 


Irrigation and 

5/10/49 

0.56 

270 





7/ /49 

0.56 

265 


domestic 

9/ 8/49 

0.28 

290 





8/23/49 

0.56 

260 

140 

Irrigation and 

5/10/49 

0.56 

450 

10S/3E-35J1 


289 


5/12/49 

1.97 

670 


domestic 

9/ 6/49 

0.56 

350 





8/23/49 

1.97 

570 

150 

Irrigation 

5/10/49 

0.28 

350 

10S/3E-36C1 


250 

Irrigation 

5/12/49 

0.56 

320 



10/ 4/49 

0.56 

320 





9/ 8/49 

0.85 

340 

40 

Irrigation 

5/11/49 

1.13 

380 

10S/4E-7B2 


185 

Irrigation 

5/13/49 

0.85 

520 



8/24/49 

0.56 

300 





10/ 4/49 

1.13 

420 

30 

Irrigation and 

5/11/49 

0.28 

230 

10S/4E-17E2 



Irrigation and 

5/12/49 

1.13 

380 


domestic 

9/ 7/49 

0.56 

300 




domestic 

8/24/49 

0.85 

330 

150 

Irrigation 

5/10/49 

0.56 

380 

10S/4E-18G2 


185 

Irrigation and 

5/13/49 

0.56 

300 



8/24/49 

0.56 

330 




domestic 

7/ /49 

0.28 

265 



5/10/49 

0.56 

350 





10/ 4/49 

0.56 

240 



9/ 6/49 

0.56 

300 

10S/4E-20J1 


210 

Irrigation 

5/1 1 /49 

0.85 

420 


Irrigation and 

5/16/49 

0.56 

370 





7/ /49 

0.56 

430 


domestic 

9/ 2/49 

0.56 

320 





8/23/49 

1.13 

370 


Irrigation 

5/16/49 

0.56 

370 

10S/4E-27B1 


412 

Irrigation 

5/11/49 

0.85 

520 



9/ 2/49 

0.56 

330 





8/23/49 

1.13 

430 

125 

Irrigation 

5/16/49 

0.56 

330 

10S/4E-28K2 




5/11/49 

0.85 

320 



9/ 8/49 

0.28 

260 





7/ /49 

0.85 

280 



5/13/49 

0.28 

350 





8/23/49 

1.13 

430 



9/ 2/49 

0.56 

290 

10S/4E-28N2 


322 

Irrigation 

5/11/49 

0.28 

315 

170 

Irrigation.. 

5/16/49 

0.56 

320 





8/23/49 

0.56 

270 



9/ 2/49 

0.56 

310 

10S/4E-29D1 



Irrigation and 

5/11/49 

0.56 

300 


Irrigation 

5/16/49 

0.56 

380 




domestic 

7/ /49 

0.56 

265 



10/ 3/49 

0.56 

330 





8/24/49 

0.28 

250 

180 

Irrigation 

10/ 4/49 

0.56 

390 

10S/4E-30J3 _ 



Irrigation and 

5/12/49 

0.56 

250 


Irrigation 

5/16/49 

5.08 

800 




domestic 

8/23/49 

0.28 

240 

235 


5/13/49 

0.56 

450 

10S/4E-31H2 



Irrigation and 

5/12/49 

0.56 

270 



9/ /49 

0.85 

370 




domestic 

8/23/49 

0.28 

240 



10/ 4/49 

0.56 

330 

10S/4E-35E1 


447 

Irrigation - 

5/11/49 

0.85 

420 



10/ 4/49 

0.56 

330 





10/ 4/49 

0.85 

360 


Irrigation . . 

5/16/49 

0.56 

380 

10S/4E-35Q1 




5/11/49 

1.13 

500 



8/30/49 

0.56 

330" 





7/ /49 

1.13 

430 

301 

Irrigation and 

5/16/49 

0.85 

420 





10/ 4/49 

0.85 

390 


domestic 

9/ 2/49 

1.13 

350 

11S/3E-1Q1 




7/ /49 

0.56 

215 

301 

Irrigation 

5/13/49 

0.56 

315 

11S/4E-1B1 




5/11/49 

0.56 

300 



7/ /49 

0.56 

295 

11S/4E-3G1_. 



Irrigation - - 

5/11/49 

0.56 

320 

425 


10/ 4/49 

0.85 

340 

11S/4E-3N3 


103 


5/11/49 

1.67 

780 



5/16/49 

0.56 

340 





9/ 8/49 

1.41 

700 


Irrigation and 

10/ 4/49 

0.85 

310 

11S/4E-3R2_ 


220 

Irrigation 

5/11/49 

1.13 

460 


domestic 







9/ 2/49 

1.13 

430 



10/ 4/49 

0.56 

340 1 

11S/4E-4K4 



Irrigation _ 

5/11/49 

0.56 

440 



120 


SANTA CLARA VALLEY INVESTIGATION 


PARTIAL MINERAL ANALYSES OF GROUND WATERS IN SANTA CLARA VALLEY-Continued 


Well number 

Depth, 

in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

! 

1 Well number 

1 

Depth, 

in 

feet 

Use 

Date 

of 

sample 

Chlo- 
rides, in 
epm 

Solids, 

in 

ppm 

Division 
of Water 
Resources 

Poland* 

Division 
of Water 
Resources 

Poland* 

11S/4E-4N1 



Irrigation 

5/10/49 

0.56 

340 

11S/4E-HJ1. 


598 


5/11/49 

1 . 13 

420 





8/23/49 

0.56 

310 





8/31/49 

0.85 

370 

11S/4E-5D1 



Irrigation 

5/12/49 

0.56 

320 

11S/4E-13B1 


673 

Irrigation . 

5/11/49 

2.82 

580 





S/23/49 

0.56 

260 





if /49 

2.26 

540 

11S/4E-6N1 


178 


5/12/49 

0.56 

220 





9/ 8/49 

2.54 

500 





8/ 3/49 

0.28 

200 

11S/4E-16L1 


130 

Irrigation 

5/10/49 

0.85 

500 

11S/4E-7G2 



Irrigation. 

5/12/49 

0.28 

250 





8/23/49 

0.56 

310 





8/23/49 

0.28 

210 

11S/4E-17A1 


280 

Irrigation 

5/10/49 

0.56 

340 

11S/4E-7R1 


77 

Irrigation 

5/11/49 

0.56 

250 





8/23/49 

0.28 

290 

11S/4E-8L1 



Irrigation 

5/10/49 

0.85 

320 

11S/4E-17F1. 


406 

Irrigation 

5/10/49 

0.28 

260 





9/ 8/49 

0.56 

310 

11S/4E-17Q2. __ 


183 

Irrigation 

5/11/49 

0.28 

315 

11S/4E-9A2 


71 

Irrigation 

5/11/49 

0.56 

730 

11S/4E-21H1 


90 

Irrigation 

5/10/49 

0.56 

570 





9/ 8/49 

0.56 

600 

11S/4E-22B1 _ 


350 

Irrigation . 

5/10/49 

1.13 

380 

11S/4E-9G1 


60 

Irrigation 

5/11/49 

1.13 

! 520 





9/ g/49 

0 . 56 

290 





8/23/49 

0.56 

1 460 

11S/4E-22D1 


185 

Irrigation . . 

7/ /49 

0.85 

300 

11S/4E-9P3 



Irrigation 

5/10/49 

0.85 

450 





8/30/49 

0.28 

240 





9/ 1/49 

0.56 

310 

11S/4E- 8J1 


300 

Irrigation ... 

7/ /49 

0.56 

350 

11S/4E-10L1 


220 

Irrigation 

5/11/49 

1.13 

600 





8/30/49 

0.28 

290 





8/31/49 

1.13 

430 

11S/4E-29G1 


120 

Irrigation. 

5/10/49 

0.85 

380 

US/4E-11C1 



Irrigation and 

5/11/49 

0.85 

460 





8/30/49 

0.28 

290 




domestic 

8/ 3/49 

0.85 

370 

11S/4E-33N1 


190 

Irrigation 

5/10/49 

2.26 

490 












9/ 2/49 

1.67 

400 


* Samples collected and analyzed in 1938-39 as a program of Stanford University, Geology Department, under direction of Joseph F. Poland. 



APPENDIX H 

APPLICATIONS TO APPROPRIATE WATER 
IN SANTA CLARA VALLEY 

(Filed with Division of Water Resources, Department of Public Works, under provisions of 

Water Code, State of California) 


( 121 ) 



8—19273 


APPLICATIONS TO APPROPRIATE WATER IN SANTA CLARA VALLEY, FILED WITH DIVISION OF WATER RESOURCES, 
DEPARTMENT OF PUBLIC WORKS, UNDER PROVISIONS OF WATER CODE, STATE OF CALIFORNIA 


Location of diversion 

point, referenced to Amount of 


Appli- Mt. Diablo base diversion 


cation 

Date 

Name of 

Source of 
water supply 

and meridian 


Purpose 

Status 

ber 




Va \ 

H 

Sec- 

tion 

Town- 
ship ! 

Range 

Second- 

feet 

Acre- 

feet 



232 

3/20/16 

Aloise McPhee . — _ 

Glenovia Creek . 

SE : 

SW 

6 

lOS ' 

2E 

0.04 


Irrigation and do-- 

License 












mestic 


649 

4/23/17 

A. Lantz . - _ . 

Arroyo Seco . 


SW 

25 

8S ; 

IE 

0.075 


Irrigation 

License 

1733 

3/23/20 

Lester, Gilker, and Lester _ „„ „ 

Los Gatos Creeks* * „ --- 


SW 

10 

8S 

IW 

3.5 



License 

2153 

12/23/20 

San Jose Abstract and Title Company 

Los Gatos „ „ - 

SE 

Proj. 

16 

8S 

IW 

2.22 


Irrigation 

License 

3323 

3/24/23 

M. Kell : 

Uvas Creek.. .. .. 

SE 1 

NW 

18 

lOS 

3E 

0.27 


Irrigation and do- 

License 

4698 

7/14/25 

Montezuma Mountain Ranch School . 

Collins Creek „ ... ....... 

NE 

NW 

7 

9S 

IW 

0.13 


Irrigation and do- 

License 

5156 

4/23/30 

City of San Jose - — — 

N. Fork Penitencia Creek ...... 

NW 

SE 

21 ' 

6S ^ 

2E 


500 

Irrigation 

License 

5653 

12/ 1/26 

Santa Clara Valley Water Conservation 

Guadalupe Creek . . ... . . 

NE 

SW 

9 ; 

8S 

IE 



Irrigation and do- 

Permit 



District 


SW 

SW 

9 

8S 

IE 


10,000 

mestic 

Permit 

5654 

12/ 1/26 

Santa Clara Valley Water Conservation 

Los Gatos .. . .. ... .. 

NE 

SE 

3 

8S 1 

IW 


10,000 

Irrigation and do- 

Permit 



District 









mestic 


6167 

1/19/26 

I. Meyerholz, et al. . . „ , „ 

Stevens Creek. . . 

SE 

NE 

10 

2S i 

2W 

2.34 


Irrigation. . .. 

License 

6296 

5/22/29 

Board of Trustees Stanford University 

Los Trancos Creek ... 

SW 

NE 

28 

6S ! 

3W 

40 

900 

Irrigation and do- 

License 




! 








mestic 


6601 

3/15/30 

L. O’Neal i 

Unnamed stream . 

SE 

SW 

10 

7S 1 

3W 

8,500 

g-P-d. 

Irrigation and do- 

License 












mestic 


6753 

7/29/30 

California Water Service Company 

San Francisqui to Creek. .. . . . . .. 

NW 1 

SE 

12 

6S i 

4W 

25 

980 

Municipal . 

Permit 

7140 

12/ 9/31 

Santa Clara Valley Water Conservation 

Coyote Creek. . . 

SE 

SE 

29 

9S 1 

4E 


40,000 

Irrigation and do- 

Permit 



District 









mestic 


7141 

12/ 9/31 

Santa Clara Valley Water Conservation 

Alrnaden Creek ..... .... 

NW 

NE 

11 

9S ! 

IE 


2,500 

Irrigation and do- 

License 



District 









mestic 


7142 

12/ 9/31 

Santa Clara Valley Water Conservation 

Guadalupe Creek . _ . ... ... .. 

NE 

NE 

32 

8S 

IE 


3,500 

Irrigation and do- 

License 



District 









mestic 


7143 

12/ 9/31 

Santa Clara Valley Water Conservation 

Stevens Creek .. . . . 

NW 

NW 

27 

7S 

2W 


4,000 

Irrigation and do- 

License 



District 



j 






mestic 


7438 

11/16/32 

Grant Company ^ ^ 

Arroyo Aguague . . ... 

SE 

NW ! 

12 

7S 

2E 


500 

Irrigation. ... .. 

License 







Proj. 







7913 

4/20/34 

G. Smith ^ - - 

Uvas Creek . . . 

SW 

SE 

17 

lOS 

3E 

0.11 


Irrigation and do- 

License 












mestic 

I 

7995 

6/28/24 

C. Miller, et al. _ . . „ . 

Calero . „ 

NW 

NE 

36 

8S 

IE 

1.0 


Irrigation 

License 

8013 

7/ 6/34 

J. Marchetti. 

Uvas Creek . . . . „ . . . . 

NE 

SW 

17 

lOS 

3E 

0.3 


Irrigation 

License 

8079 

8/21/24 

F. J. Polak 

Coyote River . „ ... 

SW 

SE 

6 

9S 

3E 

5.0 


Irrigation 

License 

8098 

9/11/34 

Santa Clara Valley Water Conservation 

Calero -. .. „ . . 

NW 

NE 

6 

9S 

2E 


3,500 

Irrigation and do- 

License 



District 









mestic 

} 

8099 

9/11/34 

Santa Clara Valley Water Conservation 

Alrnaden Creek . „ . „ 

NW 

NE 

11 

9S 

IE 

100 1 

6,000 

Irrigation and do- 

License 



District 









mestic 

1 Permit 

8387 

7/10/35 

Santa Clara Valley Water Conservation 

Los Gatos Creek 

NE 

SE 

9 

8S 

IW 


4,000 

Irrigation and do- 




District 








1 

mestic 

1 

8388 

7/10/35 

Santa Clara Valley Water Conservation 

Coyote River. . 

NE 

SW 

16 

8S 

2E 


5,000 

Irrigation and do- 

1 License 



District 









mestic 


8462 

10/ 3/35 

F. G. Wool Packing 

Coyote River .. 

SW 

NE 

22 

7S 

IE 

0.47 


Irrigation . _ 

I License 

9579 

5/ 9/39 

Aloise McPhee „ - 

Swanson Creek 

NE 

NE 

12 

lOS 

IE 

0.3 


Irrigation, domestic 

Permit 












and fire protection 


11010 

3/20/45 

Santa Clara Valley Water Conservation 

Penitencia Creek 

SE 

SW 

23 

6S 

IE 


3,500 

Irrigation and do- 

Permit 



District 









mestic 


11549 

9/12/46 

A. Fries 

Arroyo Aguague _ 

SW 

SW j 

10 

7S 

2E 

1,650 

g.p.d. 

Irrigation and stock 

License 

11574 

10/ 3/46 

C. B. and G. B. Kuhn_._ 

Unnamed creek . . . 

SE 

SE 

22 

7S 

2E 


1 

Irrigation 

License 




Unnamed spring No. 1. _ 

NW 

NW 

27 

7S 

2E 

5,760 

ig.p.d. 






Unnamed spring No. 2 . 

SE 

NE 

27 ; 

7S : 

2E 

5,760 

g.p.d. 






Unnamed spring No. 3 

SE 

NE 

27 

7S 

2E 

38,880 

g-P-d. 






Unnamed spring No. 4 : ; 

NE 

NE 

27 

7S 

2E 

7,200 

g.p.d. 






Unnamed spring No. 5. 

SE 

SE 

22 

7S 

2E 

5,760 

g.p.d. 






Unnamed spring No. 6. . ... . . 

SE 

SE 

22 

7S 

2E 

7,200 

g.p.d. 






Unnamed spring No. 7 . 

SE 

SE 

22 

' 7S 

2E 

1,440 

g.p.d. 



11599 

10/31/46 

E. S. Selvage 

Two unnamed streams 

NW 

■ NE 

22 

lOS 

^ 3E 

0.75 

30 

Irrigation 

Permit 




Two unnamed streams 

SW 

NE 

22 

lOS 

3E 








, Two unnamed streams - - 

NW 

SE 

22 

lOS 

3E 






APPENDIX H 123 



APPLICATIONS TO APPROPRIATE WATER IN SANTA CLARA VALLEY, FILED WITH DIVISION OF WATER RESOURCES, 
DEPARTMENT OF PUBLIC WORKS, UNDER PROVISIONS OF WATER CODE, STATE OF CALIFORNIA-Continued 


Appli- 

cation 

num- 

ber 

Date 

filed 

Name of 
applicant 

Source of 
water supply 

Location of diversion 
point, referenced to 

Mt. Diablo base 
and meridian 

Amount of 
diversion 

Purpose 

Status 


H 

Sec- 

tion 

Town- 

ship 

Range 

Second- 

feet 

Acre- 

feet 

11600 

10/31/46 

E. S. Selvage 

Two unnamed streams - . .. - 

NW 

SE 

22 

lOS 

3E 

0.3 

25 

Irrigation _ 

Permit 




Two unnamed streams 

SW 

SE 

22 

lOS 

3E 








Two unnamed streams . . _ . 

SE 

SE 

22 

lOS 

3E 





11601 

10/31/46 

E. S. Selvage 

Unnamed stream 

NW 

SW 

22 

lOS 

3E 

0.083 

6.0 

Irrigation and do- 

License 












rnestic 


11727 

2/13/47 

B. Cribari and Sons 

Unnamed stream 

NE 

NE 

34 

7S 

2E 


10 

Irrigation- - 

Permit 

11751 

3/ 3/47 

Santa Clara Valley Water Conservation 

Los Gatos Creek 

SE 

SE 

29 

8S 

IW 


30,000 

Irrigation and do- 

Permit 



District 









mestie 


11806 

4/ 1/47 

H. Riedel, et al 

Dr^^' Creek .. . . . 

NE 

NW 

19 

2S 

2E 

0.5 


Irrigation „ 

Permit 

11825 

4/16/47 

State Division of Forestry 

IjOS Aland tos Creek- . . _ 

NE 

SW 

2 

9S 

IE 

15,000 

g.p.d. 

Domestic and fire 

License 












protection 


12066 

6/15/50 


Moddy Gulch „ . _ _ _ 

SW 

NW 

9 

9S 

IW 

0.04 




12134 

10/20/47 

San Jose Water Works. - 

Saratoga (Campbell) Creek . . 

SE 

NW 

11 

8S 

2W 

1.96 


Domestic, municipal, 

Permit 












industrial 


12201 

7/21/47 

E. Weld. 

Silver Creek _ .. _ 

SW 

NW 

30 

7S 

2E 


11 

Irrigation- 

Permit 




Unnamed stream 

NE 

SE 

25 

7S 

IE 


1 

Stock water „ 


12208 

12/22/47 

C. B. and G. B. Kuhn 

Unnamed spring 



27 

7S 

2E 

7,200 

g.p.d. 

Irrigation and stock- 

Permit 












wafer 


13016 

4/ 4/49 

Santa Clara Valley Water Conservation 

Coyote Creek - . . . 

SW 

NE 

10 

9S 

3E 


75,000 

Irrigation, domestic 

Permit 



District 









and industrial 


13020 

4/ 5/49 

R. V. and E. S. Garrod 


NE 

SE 

34 

7S 

2^^ 




Permit 











rnestic 

13021 

4/ 5/49 

E. I. and L. B. Poor . 

Unnamed creek 

NW 

SE 

34 

7S 

2W 


5 

Irrigation aEd do- 

Permit 












rnestic 


13223 

7/ 8/49 

George Britton 

Unnamed stream- 

SW 

SW 

5 

lOS 

3E 


10 

Irrigation and stock. 

Permit 

13224 

7/ 8/49 

George Britton 

Unnamed stream. 

SE 

SW 

5 

lOS 

3E 


50 

Irrigation, stock and 

Permit 












domestic 


13352 

9/14/49 

P. Peabody. 

Unnamed creek 

SW 

SW 

23 

lOS 

4E 


56 

Irrigation and stock. _ 

License 

13375 

10/ 3/49 

F. Metzger 

Dry Creek . 

NW 

SW 

34 

7S 

2E 


4.5 

Irrigation 

Permit 

13409 

10/21/49 

N. W. and P. H. Mancuso 

Unnamed ravine 

NW 

NE 

15 

7S 

2E 

15,000 

g.p.d. 

Irrigation and do- 

Permit 







Proj. 





mestic 


13444 

11/ 4/49 

J. A. Besson, Et ux 

Bodfish Creek - . _ , . 

SW 

NE 

5 

ns 

3E 

1.0 

100.0 

Irrigation and do- 

Permit 












mestic 


13584 

2/16/50 

G. and R. Mancuso 

Unnamed ravine . . . . . 

NE 

NE 

28 

7S 

2E 


10 

Irrigation 

Permit 

13641 

3/21/50 

P. Peabody 

Unnamed spring 

SW 

SW 

23 

lOS 

4E 


20 

Irrigation. 

Permit 

13719 

5/ 3/50 

B, Greef... 

Eastman Creek 

SW 

SE 

12 

lOS 

2E 

0.16 

30 . 0 

Irrigation and do- 

Permit 












mestic 


13791 

6/14/50 

South Santa. Clara Valley Water Conserva- 

Llagas Creek 

SW 

SW 

30 

9S 

3E 


7,500 

Irrigation and do- 

Permit 



tion District 









mestic 


13886 

8/ 8/50 

South Santa Clara Valley Water Conserva- 

Uvas Creek 

SE 

SE 

12 

lOS 

2E 

100 

30,000 

Irrigation and do- 

Permit 



tion District 









mestic 


13892 

8/11/50 

Santa Clara Valley Water Conservation 

Silver Creek 

NE 


32 

7S 

2E 


2,000 

Domestic 

Incomplete 



District 











13900 

8/17/50 

F. M. and C. M. Shay 

Uvas Creek _ 

NW 

SW 

: 28 

lOS 

3E 

2,000 

g.p.d. 

Domestic and stock ... 

Permit 

13970 

9/29/50 

Ruth M. Weston 

Uvas Creek. 

SE 

NE 

29 

lOS 

3E 

0 . 250 


Irrigat.ioM 

Permit 

14013 

10/23/50 

Fred 0. Scheidegger 

Little Uvas Creek- .. 

SW 

NE 

34 

9S 

2E 

0.25 


Irrigation 

Permit 

14021 

10/26/50 

R. H. Bickel 

Uvas Creek . : 

NW 

i NW 

33 

lOS 

3E 1 

0,25 


Irrigation and do- , 

Permit 












rnestic 





Uvas Creek .. 

SW 

NW 

33 

lOS 

3E 

' 0,085 


Irrigation and do- 

Permit 










j 


mestic 


1 ■ 



. Uvas Creek 

N'W 

■ NW 

33 

lOS 

3E 

0 . 67 


Irrigation and do- 

Permit 












mestic 


14037 

11/ 8/50 

W . Quadros - - 

Dry Creek- - 

NW 

NW ' 

15 

7S 

2E 

1,500 

g.p.d. 

Irrigation and do- 

Permit 












mestic 


14111 

12/26/50 

A. Tomkin. 

Little Uvas Creek 

SE 

SW 

28 

9S 

2E 

0.38 


Irrigation 

Permit 

14140 

1/25/51 

J. Lowe... - - - 

Little Uvas Creek 

SW 

SE , 

35 

9S 

2E 


40 

Irrign.tion 

PeiTTiit 

14163 

2/16/51 

R. Holland- -- 

Little Uvas Creek 

NW 

NE ' 

32 

9S 

2E 

0.175 


Irrigation 

Permit 


I. 


124 SANTA CLARA VALLEY INA^BSTIGATION 



Appli” 

cation, 

num- 

ber 


14170 

14288 

14313 

14468 

14503 

14587 

14655 

14687 

14922 

15081 

15144 

15349 

15412 


15547 

15817 

16146 


APPLICATIONS TO APPROPRIATE WATER IN SANTA CLARA VALLEY, FILED WITH DIVISION OF WATER RESOURCES, 
DEPARTMENT OF PUBLIC WORKS, UNDER PROVISIONS OF WATER CODE, STATE OF CALIFORNIA-Continued 


Date 

filed 

Name of 
applicant 

Source of 
water supply 

Location of diversion 
point, referenced to 

Mt. Diablo base 
and meridian 

Amount of 
diversion 

Purpose 

Status 



Sec- 

tion 

Town- 

ship 

Range 

Second- 

feet 

Acre- 

feet 






Proj. 







2/23/51 



SE 

SW 

28 

7S 

2E 


8.7 

Irrigation . 


5/ 2/51 

J. DeBell 


NE 

SW 

3 

IIS 

3E 


138 


Permit 










reation 


5/17/51 

California Water Service Company 

San Francisquito Creek . . 

NE 

NW 

14 

6S 

4W 

75 

2,500 

Municipal ... 

Permit 

9/ 6/51 

G. Bender^ 


NE 

NE 

29 

7S 

2E 

0.2 

3 

Irrigation 

Permit 





Proj. 







9/27/51 

F. M. and C. M. Shay- 


NW 

SW 

28 

lOS 

3E 

0.09 


Irrigation and stock 

Permit 

11/26/51 



SW 

NW 

28 

7S 

2W 

85,000 


Irrigation 

Permit 

1/25/52 

F. Metzger 

Dry Creek . 

NW 

SW 

34 

7S 

2E 

5.5 

Irrigation 

Permit 

2/26/52 

G. Smith 

Uvas Creek . 

gw 

SE 

17 

lOS 

3E 

0.11 


Irrigation and do- 

Permit 










mestic 


7/22/52 

C. Swenson 

Silver Creek 

SE 

NE 

25 

7S 

IE 

0.33 


Irrigation 

Permit 





Proj. 







11/14/52 

Blacks Alrnaden Water System.. _ 

Los Alamitos Creek 

SW 

SE 

10 

9S 

IE 

3 


Domestic, municipal 

Permit 











and industrial 


1/ 5/53 

V. Guluzzo 

Unnamed spring 

NE 

NE 

7 

7S 

2E 

0.39 


Irrigation 

Permit 





Proj. 







5/18/53 

F. M. and Cecilia M. Shay . 

Uvas Creek . _ .. 



28 

lOS 

3E 

0.04 


Domestic and stock- 

i Permit 










water 


7/14/53 

San Jose Water Works 

Saratoga (Campbell) Creek ._ 

SE 

NW 

11 

8S 

2W 


2,000 

Domestic, municipal 

Pending 









and industrial 







Proj. 







9/21/53 

Anthony and Carmelita Peters. . 

Unnamed ravine 

NW 

NW 

15 

7S 

2E 


5 

Irrigation 

Permit 





Proj. 






4/ 6/54 

Donald Williams - . 

Unnamed stream. . 



4 

7S 

2E 

0.11 


Irrigation 

Permit 





Proj. 







11/19/54 

E. P. Hockenbeainer. . 

Unnamed stream. .... . 



34 

lOS 

3E 

0.75 


Irrigation. 

Pending 












APPENDIX H 125 



APPENDIX I 

DAMS UNDER STATE SUPERVISION IN AND ADJACENT 
TO SANTA CLARA VALLEY, 1954 


( 127 ) 



DAMS UNDER STATE SUPERVISION IN AND ADJACENT TO SANTA CLARA VALLEY, 1954 






jocatioi 












M. 

D. B. & 

M. 


Crest 

Crest 

Crest 

Capac- 

Date 


Name 

Owner 

Stream 




Type 

length. 

height, 

eleva- 

ity, in 

con- 

Use 







in 

in 

tion, 

acre- 

structed 





tion 

ship 

Range 


feet 

feet 

in feet 

feet 


Alma den - _ . 

Santa Clara Valley Water Conser- 

Alamitos Creek 

11 

9S 

IE 

Earth . 

500 

no 

615 

2,000 

1936 

Irrigation, domestic 


vation District 












Anderson 

Santa Clara Valley Water Con- 

Coyote River. 

10 

9S 

3E 

Earth _ 

1,200 

235 

640 

75,000 

1950 

Irrigation, domestic, in- 


servation District 











dustrial 

Austrian _ _ 

San Jose Water Works .. ._ 

Los Gatos Creek 

24 

9S 

IW 

Earth-- 

700 

185 

1,125 

6,140 

1950 

Domestic 

Calero _ 

Santa Clara Valley Water Con- 

Calero Creek 

6 

9S 

2E 

Earth- _ 

845 

94 

490 

9,300 

1935 

Irrigation, domestic 


servation District 












Cherry Flat _ 

City of San Jose 

Penitencia Creek-. 

21 

6S 

2E 

Earth 

230 

60 

1,700 

500 

1936 

Irrigation 

Coyote 

Santa Clara Valley Water Con- 

Coyote Creek- 

1(5 

8S 

2E 

Earth, rock 

980 

140 

803 

27,770 

1936 

Irrigation, domestic 


servation District 












Coyote Percolation 

Santa Clara Valley Water Conser- 

Coyote Creek- 

29 

9S 

4E 

Concrete sill, flash- 

204 

24 

238 

72 

1934 

Irrigation, domestic 


vation District 





boards 







DeBell 

Jack DeBell . . 

Tributary of Bodfish Creek 

3 

IIS 

3E 

Earth . 

616 

53 

493 

120 

1952 

Irrigation, recreation 

Elmer J. Chesbro 

South Santa Clara Valley Water 

Llagas Creek- .. 

30 

9S 

3E 

Earth, rock 

650 

95 

535 

7,500 

Under 

Irrigation, domestic 


Conservation District 










con 













struc- 
1 tion 


Felt Lake- 

Leland Stanford Jr. University 

Tributary of Los Trancos 

22 

6S 

3W 

Earth 

590 

67 

367 

900 

i 1930 

Irrigation, domestic 



Creek 











Grant Company No. 2- 

Grant Ranch-- -. . 

Arroyo Aguague. _ 

2 

7S 

2E 

Earth _ _ . . 

80 

27 

1,596 

600 

1927 

Irrigation 

Guadalupe 

Santa Clara Valley Water Conser- 













vation District _ 

Guadalupe Creek. . 

32 

8S 

IE 

Earth-- 

695 

142 

623 

3,500 

1935 

; Irrigation, domestic 

Higvera - .. - 

Marion Cortner Weller _ . 

South Calera Creek. 

32 

5S 

IE 

Earth.. 

515 

44 

1 195 

81 

1953 

Irrigation 

Kuhn 

Charles B. and George B. Kuhn 

Tributary of Dry Cr ek_ . 

27 

7S 

' 2E 

Earth 

312 

67 

760 

85 

; 1947 

Irrigation 

Lagunita . - 

Leland Stanford Jr., University 

Tributary of San Francisco Bay 

10 

6S 

3W 

Earth 

2,500 

15 

134 

260 

1900 

Irrigation, reclamation 

Lake Ranch (east). . 

San Jose Water Works . . 

Beardsley Creek _ _ . 

, 23 

8S 

2W 

Earth- . _ 

160 

38 

1,809 

1 323 

1877 

1 Domestic 

Lexington . _ . 

Santa Clara Valley Water Conser- 

Los Gatos Creek 

i 29 

8S 

IW 

Earth 

1 685 

205 

1 665 

25,000 

1953 

Irrigation, domestic 


vation District 












Lower Howell. , „ 

San Jose Water Works 

Rundell Creek _ 

31 

8S 

IW 

1 Earth 

475 

I 38 

1,387 

153 

1877 

Domestic 

North Fork.. _ . 

Pacheco Pass Water District . 

Pacheco Creek 

22 

lOS 

; 6E 

Earth . „ _ 

600 

100 

483 

6,150 

1939 

Irrigation 

Peabody . 

Porter T. Peabody... 

Tributary of Llagas Creek 

23 

lOS 

4E 

Earth 

296 

64 

650 

76 

1950 

Irrigation 

Rickey . 

J. H. Rickey . . 

Peter’s Creek _ . 

' 22 

7S 

' 3E 

Earth 

175 

64 

1 104 


1950 

Irrigation 

Selvage No. 2 . . 

Eugene G, Selvage . 

Tributary of Llagas Creek 

22 

lOS 

3E 

Earth .. _ _ 

440 

42 

400 

24 I 

1948 

Irrigation, domestic 

Stevens Creek 

Santa Clara Valley Water Conser- 

Stevens Creek 

27 

7S 

2W 

Earth 

1,080 

120 

545 

4,000 

1935 I 

Irrigation, domestic 


vation District 












Upper Howell- .. 

San Jose Water Works. 

Rundell Creek 

i 31 

1 8S 

IW 

Earth 

I 640 

36 

1,412 ' 

243 

1878 

Domestic 

Vasona Percolating. 

Santa Clara Valley Water Conser- 

Los Gatos Creek 

10 

8S 

IW 

Earth 

980 

32 

305 

660 ! 

1935 

Irrigation, domestic 


vation District 












Williams . . . .. 

San Jose Water Works . . 

Los Gatos Creek . 

30 

9S 

IE 

Gravity straight- 

87 

70 

1 1,222 

! 

160 

1895 ^ 

Domestic 


to 


APPENDIX I 



APPENDIX J 


RECORDS OF APPLICATION OF GROUND WATER TO 
REPRESENTATIVE CROPS IN SANTA CLARA VALLEY 



TABLE OF CONTENTS 

RECORDS OF APPLICATION OF GROUND WATER TO 
REPRESENTATIVE CROPS IN SANTA CLARA VALLEY 

Page 


Application of Ground Water to Representative Crops in North Santa Clara 
Valley, Pressure Zone 133 

Application of Ground Water to Representative Crops in North Santa Clara 
Vallej^j For ebay Zone 135 

Application of Ground Water to Representative Crops in South Santa Clara 
y alley j Pressure Zone 136 

Application of Ground Water to Representative Crops in South Santa Clara 
Valley, Porebay Zone 137 


( 182 ) 



APPENDIX J 


133 


APPLICATION OF GROUND WATER TO REPRESENTATIVE CROPS IN 
NORTH SANTA CLARA VALLEY 


Pressure Zone 


Crop 

Season 

Map 

num- 

ber 

Well 

number 

Method of 
irrigation 

Acres 

Depth per irrigation, in inches 

Total 

depth, 

in 

inches 

1st 

2nd 

3rd 

4th 

5th 

^ 6th 

7th 

8th 

9th 

10th 

Alfalfa 

1948 

1 

7S/1E-14C2 

Check 

30 

2.31 

8,59 

9.41 

7.67 

8.50 







36.48 


1949 

2 

7S/1E-HG1 

Border check 

6 

6.46 

3.80 

7.80 

4.06 

3.74 

5. 

10 





30.96 








Weighted mean depth 

: 1948 

-49 

35.56 inches (2.96 feet) 


Beans _ 

1948 

3 

6S/1W~26D1 

Contour check _ _ 

77 

4.25 

2,16 

2.56 

2.25 








11.22 


1948 

4 

6S/1W-29C1 

Furrow 

19.75 

7.42 

8.66 

7.82 









23.90 


1948 

5 

6S/1W-36G1 

Furrow _ , 

20 












40.2 


1948 

6 

6S/1E-30M1 

Furrow 

10 












13.32 


1949 

/ ^ 

6S/1E-30L1 \ 

Furrow 

45 

1.86 

2.99 

2.82 

2.60 








10.27 



1 ^ 

6S/1E-30M1 / 
















1949 

/ ^ 

6S/1W-26D1 1 

Furrow 

72 

5.48 

3.09 

6.15 









14.72 



1 8 

6S/1W-12M2 / 
















1949 

9 

6S/2W-24C1 

Furrow 

51 

5.52 

7.63 

3.88 

2.62 








19.65 








Weighted mean depths: 1948 

17.93 inches (1.49 feet) 












1949 

15.02 inches (1.25 feet) 












1948-49 

16,28 inches (1,36 feet) 



1948 

6 

6S/1E-30M1 

F urrow 

9 












29.80 


1948 

10 

7S/1W-16H1 

Contour check. _ 

4 












44.51 


1949 

11 

6S/1W-UN1 

Furrow _ . 

10 












26.20 








Weighted mean depths : 1948 

34 . 33 inches (2 . 86 feet) 












1949 

26 , 20 inches (2 . 18 feet) 












1948-49 

30.79 inches (2.57 feet) 


Orchard 


















1948 

12 

6S/2W-27F1 

Furrow 

2.5 

2.94 

3.15 










6.09 


1948 

13 

6S/2W-29D2 

Contour check __ 

10 

13.84 

8.83 

11.40 









34.07 


1948 

13 

6S/2W-29D2 

Contour check. _ 

17.5 

13.84 

11.40 










25,24 


1948 

14 

7S/1W-6P1 

Contour cheek.. 

35 

1.62 

3.23 

3.28 

5.20 








13.33 


1948 

14 

7S/1W-6P1 

Contour check.. 

65 


4.10 

4.17 









8.27 


1948 

15 

7S/1W-7F1 

Contour.. 

14 

7.50 


6.48 









13,98 


1948 

15 

7S/1W-7F1 

Contour 

16 

7.50 

4.17 

6.48 









18.15 


1949 

16 

6S/2W-36H2 

Contour check. _ 

12 

9.36 

9.60 










18.96 








Weighted mean depths: 1948 

14 . 30 inches (1.19 feet) 












1949 

18.96 inches (1.58 feet) 












1948-49 

14.62 inches (1.22 feet) 


Cherries 

1948 

12 

6S/2W-27F1 

Furrow 

1.5 

3.62 

3.42 










7.04 


1948 

10 

7S/1W-16H1 

Contour check.. 

3 

4.26 

4.01 



. 







1 8.27 


1948 

17 

7S/2W-3A1 

Contour check. . 

24 

6.89 

7.08 

7.53 

10.24 








1 31.74 


1949 

16 

6S/2W-36H2 

Contour check. . 

n 

9.20 

4.85 

8.45 

6.91 

2.51 







1 31.92 








Weighted mean depths: 1948 

27.97 inches (2.33 feet) 












1949 

31.92 inches (2.66 feet) 

i 











1948-49 

29.07 inches (2.42 feet) 

! 

Mixed 

1948 

18 

6S/1W-32Q1 


10 

7.08 

5.66 

5.30 









18.04 


1948 

19 

6S/1E-33L2 


4.5 

5.17 

8.73 

7.21 

3.68 








1 24.79 


1948 

19 

6S/1E-33L2 


4.5 

3.73 

5.30 

3.22 

5.21 

1.12 







t 18.58 


1948 

14 

7S/1W-6P1 

Contour check. . 

38.5 

2.05 

4.10 

4.17 

4.79 








i 15.11 


1948 

17 

7S/2W-3A1 

ContOLir check . _ 

75 

7.11 

8.63 

8.14 

7.47 








31.35 


1949 

13 

6S/2W-29D2 

Contour check _ . 

30 

10.46 

6.06 










16.52 


1949 

16 

6S/2W-36H2 


12 

7.75 

8.42 










, 16.17 


1949 

20 

7S/1W-8F1 


4 

7.75 

9.85 

5.01 

3.66 

5.04 







31.31 








Weighted mean depths : 1948 

24,97 inches (2.08 feet) 












1949 

17.71 inches (1.48 feet) 












1948-49 

23 . 10 inches (1.93 feet) 


Pears 

1948 

21 

6S/1W-11K1 

Contour check . . 

60 

4.91 1 

6.13 

5.60 

7.44 








24,08 


1948 

22 

6S/1W-14P2 


22 

6.53 

5.91 

4.58 

6,10 








23.12 


1948 

23 

6S/1W-24H3 


10 

3.98 

3.98 

3.98 

3.58 

3.46 

2. 

77 





21.75 


1949 

24 

6S/1W-11C1 

Furrow. _ 

22 

4.61 

4.22 

5.14 









13.97 


1949 

21 

6S/1W-11K1 

Furrow. 

60 

8.82 

13.84 

12.86 









35.52 


1949 

22 

6S/1W-14P2 

Check 

22 

5.68 

8.19 

5.88 









19.75 








Weighted mean depths: 1948 

23.60 inches (1.97 feet) 












1949 

27 . 63 inches (2 . 30 feet) 












1948-49 

25.73 inches (2.14 feet) 


Prunes 

1948 

25 

6S/2W-29A1 

Contour check.. 

12 

4.24 

7.52 

5,61 









17.37 


1948 

25 

6S/2W-29A1 

Contour check . . 

10 

3.80 

5.13 

6.55 









15.48 


1948 

25 

6S/2W-29A1 

Contour check . _ 

10 

3.35 

5.80 

4.55 









13.70 


1948 

25 

6S/2W-29A1 

Contour check . _ 

10 

2.99 

4.18 

4.92 









12.09 


1948 

25 

6S/2W-29A1 

Contour check . . 

3 

0 

5.85 

7.05 









12.90 


1948 

18 

6S/1W-32Q1 


20 

7.08 

5.85 

4.34 









17.27 


1948 

20 

7S/1W-8F1 

Contour. . . 

40 

4.00 

4.00 

5.63 

7.93 








21.56 


1948 

10 

7S/1W-16H1 


5 

4.66 

5.26 

5.48 









15.40 


1948 

10 

7S/1W-16H1 


5 

4.22 

3.68 

2.55 









10.45 


1948 

10 

7S/1W-16H1 


5 

8.11 

7.06 










15.17 


1948 

10 

7S/1W-16H1 


12 

8.52 

6.07 










14.59 


1948 

10 

7S/1W-16H1 


5 

7.89 

5.64 










13.53 



134 


SANTA CLARA VALLEY INVESTIGATION 


APPLICATION OF GROUND WATER TO REPRESENTATIVE CROPS IN 
NORTH SANTA CLARA VALLEY-Continued 


Pressure Zone 


Crop 

Season 

Map 

num- 

ber 

V/cll 

number 

Method of 
irrigation 

Acres 

Depth per irrigation, in inches 

Total 

depth, 

in 

inches 

1st 

2rid 

3rd 

4th 

: 5th 

' 

6th 

7th 

8th 

9th 

10th 

Orchard 


















Prunes 

1948 

10 

7S/1W-16H1 


20 

6.36 

7.04 










13.40 

(Continued) 

1948 

10 

7S/1W-16H1 


15 

5.16 

3.91 

2.60 









11.67 


1948 

10 

7S/1W-16H1 


5 

6.92 

5.71 










12.63 


1948 

10 

7S/1W-16H1 


10 

6.96 

6.84 

6.54 

3,34 








23.68 


1949 

16 

6S/2W-36H2 

Contour check __ 

10 

5.27 

8.67 










13.94 


1949 

20 

7S/1W-8F1 


36 

5.90 

3.27 

8.21 









17.38 








Weighted mean depths: 1948 

16.36 inches (1.36 feet) 












1949 

16 . 63 inches G - 39 feet) 












1948-49 

16.41 inches (1.37 feet) 



1948 

12 

6S/2W-27F1 


9 

1.03 

1.60 










*2.63 


1948 

13 

6S'/2W-29D2 


2.5 

13.84 











13.84 


1948 

10 

7S/1W-16H1 


1.5 

6.10 

6.26 










12.36 


1948 

10 

7S/1W-16HI 


1.5 

18.28 











IS. 28 


1949 

26 

7S/1E=14P3 

Furrow and 

19 

10.2 

10.1 










20.3 





contour check 





















Weighted mean depths: 1948 

14 

.65 inches (1.22 feet) 












1949 

20 . 30 inches (1.69 feet) 












1948-49 

19,03 inches (1.59 feet) 


Total 







Weighted mean depths: 1948 

19.33 inches (1.61 feet) 


Orchard 










1949 

22.76 inches (1.90 feet) 












1948-49 

20.30 inches (1.69 feet) 









* Omitted from w'eighted mean. 







1948 

27 

7S/1E-10H2 



4.18 

1.31 

6.04 

4.27 

3.26 

6. 

07 

1.41 






1948 

1 

7S/1E-14C2 

Check,. 

40 

6.40 

5.51 

3.19 

2.68 

7.22 

3. 

27 

3.08 

3.59 



34.94 


1949 

1 

7S/1E-14C2 

Rectangular 

70 












30.92 





check 





















Weighted mean depths; 1948 

30.49 inches (2.54 feet) 












1949 

30.92 inches (2,58 feet) 












1948-49 

30.69 inches (2.56 feet) 


Sugar beets 

1948 

22 

6S/iW-14P2 


30 

2.19 

2.54 

6.24 









' 10.97 


1948 

3 

6S/1W-26D1 

Contour 

45 

6.68 

4.37 










11.05 


1948 

2 

7S/1E-11G1 

Furrow 

21 

9.80 

5.47 

4.10 









19.37 


1949 

/ ^ 

6S/1W-12M2 \ 

Furrow. 

48 

5.45 

6.45 

5.80 









17.70 



1 3 

6S/lW-26Di / 
















1949 

22 

6S/1W-14P2 

Furrow — 

11 












19,85 


1949 

9 

6S/2W-24C1 

Furrow^ 

48 

4.13 

3.77 

4.94 

2.93 

3.28 







19.05 


1949 

2 

7S/1E-11G1 

Furrow 

24 

9.73 

5.21 

5.15 

4.80 

1.01 







25.90 








Weighted mean depths: 1948 

12 

. 85 inches (1 . 07 feet) 












1949 

19.88 inches (1.66 feet) 












1948-49 

16.90 inches (1.41 feet) 


Truck 

1948 

12 

6S/1W-27F1 

Furrow 

6.5 

8.68 










8.68 


1948 

4 

6S/1W-29C1 

Furrow 

7 












5.11 


1948 

4 

6S'/1W-29C1 

Furrow' 

10 












7.75 


1948 

18 

6S/1W-32Q1 


12 

11.20 











11.20 


1948 

5 

6S/1W-36G1 

Furrow'.. 

40 












35.1 


1948 

5 

6S/1W-36G1 

Furrow. „ 

40 












4.7 


1948 

28 

6S/2W-29J1 


35 

1 











69.5 


1948 

29 

6S/lE-17Ri 

Furrow'.. 

23 












36.8 


1948 

6 

6S/1E-30M1 


10 












7.23 


1948 

1 ^ 

6S/1E-30M1 \ 

Furrow' 

21 












15.07 



\ 2 

7S/1E-11G1 j 
















1948 

19 

6S/1E-33L2 


9 












15.26 


1948 

10 

7S/1W-16H1 


3 

13.02 











13.02 


1949 

24 

6S/1W-11C1 

Furrow' 

73 












16.24 


1949 

22 

6S/1W-14P2 

Furrow' 

19 












21.68 


1949 

29 

6S/1E-17R1 

F urrow' 

23 

2.17 

5.22 

5.95 

7.68 

6.15 

5, 

66 

4.38 




37.21 


1949 

f 7 

6S/1E-30L1 


25 

2.80 

5.33 

4.53 

5.03 








17.69 



1 6 

6S/1E-30M1 / 
















1949 

I 7 

6S/1E-30L1 1 


10 

5.70 

2.66 

5.72 

2,68 

3.94 

3. 

87 





24.57 



1 6 

6S/1E-30L1 / 
















1949 

rr 

6S/1E-30E1 


9 

6.92 

3.6? 

5.61 

2.93 

5.20 

c 

80 





26.03 








Weighted mean depths: 1948 

26.51 inches (2.21 feet) 












1949 

21.23 inches (1.77 feet) 












1948-49 

24 . 28 inches (2 . 02 feet) 




APPENDIX J 


135 


APPLICATION OF GROUND WATER TO REPRESENTATIVE CROPS IN 
NORTH SANTA CLARA VALLEY 


Forebay Zone 


Crop 

Season 

Map 

num- 

ber 

Well 

number 

Method of 
irrigation 

Acres 

Depth per irrigation, in inches 

Total 

depth, 

in 

inches 

1st 

2nd 

3rd 

4th 

5th 

6th 

7th 

8th 

9th 

10th 

Orchard 

















Apricots 

1948 

30 

6S/2W-34M1 

1st irrigation by 

32.5 

3.86 

5.79 

3.44 

4.95 

5.76 






23.80 





furrow, others 

















by check 














1948 

r 31 

7S/1W-19E1 \ 

Contour check 

5 

5.51 

3.71 

5.38 








14.60 



\ 32 

7S/1W-19F1 / 




Weigh 

ted mea 

n depth 

1948 

22 

.57 incl 

les (1.8 

8 feet) 



Cherries _ „ 

1948 

30 

6S/2W-34MI 

1st irrigation by 

5 

5.42 

8.18 

7.86 

6.67 

6.34| 






34.47 





furrow, others 

















by check 














1948 

33 

7S/1W-20K2 


23 

5.55 

5.07 

4.67 








1.5 29 


1948 

33 

7S/1W-20K2 


20 

6.15 

6.10 









12.25 








Weigh 

ted mea 

n depth 

1948 

13 

. 88 incl 

es (1 . 1€ 

feet) 



Pears ~ _ 

1948 

33 

7S/1W-20K2 


3 

4.64 

6.63 

8.47 

6.63 







26 37 

Prunes 

1948 

/ 31 

7S/1W-19E1 \ 


40 

11.70 

13.57 

9.95 








35.22 



i 32 

7S/1W-19F1 / 














1948 

/ 31 

7S/1W-19E1 \ 


37 

5.00 

5.80 

5.38 








1 16.18 



\ 32 

7S/1W-19F1 j 















1948 

/ 31 

7S/1W-19E1 \ 


15 


3.78 

5.55 








9.33 



\ 32 

7S/1W-19F1 j 










1 





1948 

/ 

7S/1W-19E1 \ 


18 

4.72 1 




I 



! 1 



1 4.72 



\ 32 

7S/1W-19F1 J 















1948 

/ 31 

7S/1W-19E1 \ 


10 


4.11 






1 



4.11 



\ 32 

7s/iw-i9Fi r 















1948 

33 

7S/1W-20K2 


10 

7.19 

6.91 






1 



14.10 


1948 

34 

8S/1E-8C1 

Contour and 

85 

7.92 

10.68 ^ 









j 18.60 





sprinkler 

















S5^stem 





1 









1948 

/ 35 

8S/1E-21C3 \ 


20 

5.76 

7.17 : 

1 








12.93 



\ 36 

8S/1E-21H1 / 





1 

1 










1948 

/ 35 

8S/1E-21C3 \ 


58 

7.04 

13.53 









20.57 



\ 36 

8S/1E-21H1 / 





















Weighted mean depth 

: 1948 

; 18 

.59 inches (1.55 feet) 


Total 










i 




1 


Orchard 







Weighted mean depth: 1948 

I I 1 

! 18 
I 

.72 inches (1.56 feet) 

) I 1 


Vineyard 

1948 

34 

8S/1E-8C1 


50 

9.07 1 





1 1 



! 

i 

9.07 



136 


SANTA CLARA VALLEY INVESTIGATION 


APPLICATION OF GROUND WATER TO REPRESENTATIVE CROPS IN 
SOUTH SANTA CLARA VALLEY 


Pressure Zone 


Crop 

Scso. 

Map 

num- 

ber 

Well 

number 

Method of 
irrigation 

Acres 

1st 

2nd 

3rd 

Depth 

4th 

per irrigation, ir 

5th 1 6th 

! 

inches 

7th 

8th 

9th 

lOth 

Total 

depth, 

in 

inches 

Alfalfa 

1948 

37 

10S/4E-19N1 

Flood by ditch . . 

15 

3.43 

2.74 

3.47 

1.35 

2.88 

2.61 

2.61 




19.09 


1948 

38 

10S/4E-30A2 


18 

3.45 

6.71 

10.25 

10.25 







30.66 


1948 

39 

11S/4E-10A1 


33 

6.40 

5.10 

5.29 

4.62 

3.42 

3.45 

2.66 

2.79 



33.73 


1948 

40 

11S/4E-11J1 

Border check 

35 

4.25 

3.94 

2.66 

2.71 

2.66 

2.33 

1.96 

1.76 

0.90 


23.17 


1949 

37 

10S/4E-19N1 

Border check 

18 

3,94 

3.67 

4.10 

3.76 

2.32 

3.14 

3.15 

3.10 



27.18 








WTr.; .vK 

T T 

ted mca 

n depths: 1948 

O'T 

.35 inches (2.28 

feet) 












1948 

27 

. 18 inches (2.27 feet) 












1948 

-49 27 

. 32 inches (2 . 28 feet) 


Barley. „ _ 

1948 

38 

10S/4E-30A2 


12 

3.45 

3.45 







1 

6.90 








Weighted mean depth 

1948 

6 

.90 inches (0.58 foot) 


Beans 

1948 

41 

liS/4E-9A2 

Flood by ditch. _ 

26 

10.48 

13.20 









23.68 


1948 

42 

11S/4E-22B1 

Flood bv ditch. _ 

80 

4.58 

1.11 









5.69 








Weigh 

ted rnea 

11 

1948 

10 

. 10 iiiclies (0.84 foct) 


Berries 

1948 

43 

10S/4E-19C1 

Flume ditch 

3.5 

147.30 







. 

1 

47.30 








Weighted mean depth 

1948 

47 

.30 inches (3.94 feet) 


Orchard 

















Mixed 

1948 

44 

liS/4E-17Cl 

Flood by ditch.. 

10 

6.10 

11.30 

5.98 








23.38 








Weighted mean depth 

1948 

23 

. 38 inches (1.95 feet) 


Prunes.. 

1948 

45 

10S/4E-28EI 

Basin check 

26 

2 .34 

5 . 68 

2.56 

2.23 





1 

12,81 








Weighted mean depth 

1948 

12 

.81 inches (1.07 feet) 


Waimits 

1948 

46 

liS/4E-3Ll 

Contour check. . 

4 

12.00 








1 

12.00 


1949 

47 

llS/4E-2iJ2 

Contour check. . 

90 

6.53 

4.03 

4.36 






1 

34.92 


1949 

46 

11S/4E-3L1 

Contour check . _ 

4 

8.25 








1 

8.25 








Weigh 

ted mea 

n depths: 1948 

12 

. 00 iliCi 

ies (1.0{ 

^ r ^ . ^ i. \ 

J luOt; 












1949 

14 

.64 inches (1,22 feet) 












1948 

-49 14 

.53 inches (1.21 feet) 


Total 
















Orchard 







Weighted mean depths: 1948 

15 

.37 inches (1.28 feet) 












1948 

14 

.64 inches (1,22 feet) 












1948 

-49 14 

. 86 inches (1.24 feet) 


Pasture 

1948 

37 

10S/4E-i9Nl 

Flood by ditch.. 

3 

1.40 

2.65 

1.53 

2.43 

1.99 

0.88 



! 

10.88 


1948 

38 

10S/4E-30A2 


10 

2.30 

2.30 

1.84 

1.26 

1.84 

1.83 

4.60 

4.60 


20.57 


1948 

48 

10S/4E-30P4 

Flood by ditch. _ 

18 

3.36 

2,24 

2.78 

3.93 

3.81 

5.19 

5 . OS 

4.67 

3.12 

4.26 

41.30 








Additional irrigation; 11th, 2.86 






1949 

40 

11S/4E-1 IJl 

Border check 

35 

3.26 

2.30 

2.44 

1.86 

1.77 

1.99 

2.14 

2.38 

2.38 

2.60 

23.12 


1949 

48 

10S/4E-30P4 

Rectangular 

18 

3.45 

4.72 

4.87 

4.28 

2.97 

2.49 

2.89 

3.37 

5.07 

3.17 

46.63 





check 



Additi 

onal irri 

nation ; 

1th 3 2 

7‘ 12th 

2.41: 13th, 3.67 










Weighted mean depths. 1948 

31 

.67 inches (2.64 feet) 












1949 

31 

. 10 inches (2 . 59 feet) 












194S 

-49 31 

.31 inches (2.61 feet) 


Tomatoes 

1948 

42 

11S/4E-22B1 

Flood by ditch _ _ 

20 

2.21 

2.16 

2.11 

0.40 






6.88 


1949 

46 

11S/4E-3L1 

Furrow 

17 

3.48 

2.83 

5.78 

1.94 

3.24 

1.78 




19 . 05 








Weighted mean depths: 194S 

6 

. 88 inches (0 . 57 foot) 












1949 19.05 inches (1 . 59 feet) 












1948-49 12 

,47 inches (1.04 feet) 


Truck.... 

1948 

38 

10S/4E-30A2 


8 

7.20 

17.50 

8.13 

10.17 







43.00 


1948 

46 

US/4E-3L1 


15 

10.09 

7,58 

5.33 








23.00 


1948 

46 

11S/4E-3L1 


10 

9.60 

3.77 









13.37 


1948 

46 

11S/4E-3L1 


13 

8.24 

7.62 

5.44 

3.00 

2.22 






26.52 


1948 

46 

11S/4E-3L1 


12 

10.45 

3.21 

3.67 








17.33 


1948 

49 

11S/4E-10Q1 


30 

17.20 










17.20 


1948 

49 

1 1S/4E-10Q1 


14 

8.90 

10.83 

8.18 

9.42 

5.74 






43.07 


1948 

49 

■i ^ a /ATT i nr \ t 

i ±i^/ 


a 

12 . 85 

1 G , 09 

12 . 02 








4G . 96 


1948 

49 

11S/4E-10Q1 


30 

32.40 










32.40 


1949 

46 

11S/4E-3L1 


10.5 

7.58 

7.25 









14.83 


1949 

41 

11S/4E-9A2 


26 

15.2 

11.3 









26.50 








Weighted mean depths; 194J 

2( 

. 80 inches (2 . 23 feet) 












1949 23.14 inches (1,93 feet) 












1948-49 26 . 03 inches (2 . 17 feet) 




APPENDIX J 


137 


APPLICATION OF GROUND WATER TO REPRESENTATIVE CROPS IN 
SOUTH SANTA CLARA VALLEY 


Forebay Zone 


Crop 

Season 

Map 

num- 

ber 

Well 

number 

Method of 
irrigation 

Acres 

Orchard 







1948 

50 

9S/3E-36N1 




1948 

51 

11S'/4E-7R1 

Contour cheGk_ _ 

30 


1948 

52 

11S/4E-17M1 

Basin check 

10 


1949 

50 

9S/3E-36N1 

Contour check _ _ 

13.5 


1949 

53 

10S/4E-6P1 

F urro W- . 

17 


1949 

52 

11S/4E-17M1 

Contour check _ _ 

30 


1949 

54 

10S/4E-18K1 

Contour checks „ 

30 


1949 

55 

11S/4E-6N1 

Basin cheek 

158 


1949 

51 

11S/4E-7R1 

ContoLir check. _ 

30 

1 

Walnuts 

^ 1948 

I 56 

i 9S/3E-22R2 

Basin check 

18 

1 

Total 1 





Orchard _ j 






Tomatoes - I 

1948 

57 

: 9S/3E-25P1 

1 Ditch to row 

1 

0.5 

Truck i 

1948 

57 

9S/3E-25P1 

Ditch to row 

9 


1948 

57 

9S/3E-25P1 


2 


1st 


6.15 

8.32 

5.60 

6.49 

2.92 

12.10 

7.55 

5.09 

17.43 


Depth per irrigation, in inches 


Total 


1 

2nd 

3rd ^ 

4th 1 

5th 

1 

6th 1 

7th j 8th 

3.15 i 

4.44 

5.55 

4.76 


1 



! 



depth. 


1 9th 

1 

10th 

in 

inches 



9.30 

8.32 

5.60 

10.93 

='=2.92 

12.10 

13.10 

9.85 

17.43 


Weighted mean depths: 


1948 

1949 
1948-49 


8.06 inches (0.67 foot) 
10.71 inches (0.89 foot) 
10.28 inches (0.86 foot) 


^Omitted from weighted mean. 


3.16 

2.56 1 3.08 j 2.47 | 
Weighted mean depth: 

1 

1948 

1 1 1 1 

11.27 inches (0.94 foot) 

11.27 


Weighted mean depths: 

1948 

1949 
1948-49 

8.87 inches (0.74 foot) 

10.71 inches (0.89 foot) 

10.33 inches (0.86 toot) 


6.40 1 

i 1 1 

Weighted mean depth: 

1 

1948 

1111 

6.40 inches (0.53 foot) 

6.40 

11.80 1 
6.18 

Weighted mean depth: 

! 

1948 

10.78 inches (0.90 foot) 

11.80 

6.18 



APPENDIX K 

SEASONAL SUMMARIES OF MONTHLY YIELD STUDIES 


( 139 ) 



TABLE OF CONTENTS 

SEASONAL SUMMARIES OF MONTHLY YIELD STUDIES 

Page 

Anderson Reservoir on Coyote Creek 141 

Combined Operation of Alamitos Diversion and Lexington Reservoir on Los 
Oat os Creek 141 

Little Francis Reservoir on San Franeisquito Creek 142 

Zaj'ante Reservoir on Zayante Creek , 142 

Uvas Reservoir on Uvas Creek 143 


( 140 ) 



APPENDIX K 


141 


SEASONAL SUMMARY OF MONTHLY YIELD STUDY, ANDERSON 
RESERVOIR ON COYOTE CREEK 


(In acre-feet) 

Storage capacity: 75,000 acre-feet Seasonal yield: 56,000 acre-feet 


Season 

Water supply 

Distribution of water supply 

Storage, 
October 1 

Coyote Creek 
inflow 

Evaporation 

Releases to 

Spill 

Storage, 

September 

30 

Coyote Creek 

Aiamitos 

Percolation 

Pond 

Dry Creek 

1935-36 

0 

54,300 

400 

44,800 

6,400 

2,700 

0 

0 

36-37 

0 

62,800 

1,100 

48,900 

4,600 

3,600 

0 

4,600 

37-38 

4,600 

151,400 

2,700 

58,900 

7,300 

4,500 

31,500 

51,100 

38-39 - 

51,100 

20,300 

600 

52,000 

17,900 

900 

0 

0 

1939-40 

0 

65,400 

1,000 

49,900 

3,700 

4,500 

0 

6,300 

40-41 

6,300 : 

138,100 

2,500 

62,900 

7,100 

4,500 

19,800 

47,600 

41-4^ 

47,600 

76,100 

2,300 

69,400 

9,400 

4,500 

0 

1 38,100 

42-43 

38,100 

69,100 

1,500 

69,400 

14,700 

4,500 

0 

17,100 

43-44 

17,100 

51,100 

400 

56,100 

11,700 

0 

0 

0 

1944-45 

0 

51,700 

300 

45,500 

5,000 : 

900 

0 

0 

45-46 

0 

37,900 

0 

37,900 

0 

0 

0 

0 

46-47 

0 

9,000 

0 

9,000 

0 

0 

0 

0 

47-48 

0 

4,800 

0 

4,800 I 

0 

0 

0 

0 

AVERAGES 


60,900 

1,000 

46,900 

6,700 

2,400 

3,900 ! 



SEASONAL 


SUMMARY OF MONTHLY YIELD STUDY, COMBINED 
DIVERSION AND LEXINGTON RESERVOIR ON LOS 


OPERATION OF 
GATOS CREEK 


ALAMITOS 


(In acre-feet) 


Season 

Aiamitos Diversion 

Storage capacity 

Lexington Reservoir 

25,000 acre-feet Seasonal yield : 

21,900 acre-feet 

Supply 

Distribution 

Water supply 

Distribution of water supply 

Runoff 

Release 
to Los 
Gatos 
Creek 

Release 

to 

Aiamitos 
Percola- 
tion Pond 

Spill 

Storage, 
October 1 

Austrian 

Reser- 

voir 

spill 

Runoff 
less di- 
versions 
between 
Austrian 
Dam and 
Lexing- 
ton Dam 

Evapo- 

ration 

Releases to 

Spill 

Storage, 
Septem- 
ber 30 

Los 

Gatos 

Creek 

San 

Tomas 

Aquinas 

Creek 

Sara- 

toga 

Creek 

1935-36: - 

16,100 

13,100 

3,000 

0 

0 

0 

16,100 

0 

10,700 

3,500 

1,900 

0 

0 

36-37 

26,400 

20,200 

5,500 

700 

0 

0 

22,300 

600 

13,500 

5,100 

3,100 

0 

0 

37-38 

66,900 

15,700 

11,600 

39,600 

0 

13,600 

53,600 

1,100 

31,200 

8,800 

5,600 

18,900 

1,600 

38-39 

6,500 

6,500 

0 

0 

1,600 

0 

2,000 

0 

3,600 

0 

0 

0 

0 

1939-40 

33,600 

17,000 

9,000 

7,600 

0 

4,800 

38,300 

1,000 

25,600 

8,100 

5,300 

700 

2,400 

40-41 

51,000 

18,700 

8,900 

23,400 

2,400 

13,900 

52,200 

1,100 

31,000 

6,500 

4,300 

19,600 

6,000 

41-42 

35,400 

25,000 

9,700 

700 

6,000 : 

7,400 

32,400 

1,100 

26,900 

8,900 

5,600 

0 

3,300 

42-43 

25,500 

21,800 

3,100 

600 

3,300 

3,700 

20,600 

300 

17,700 

7,100 

2,500 

0 ^ 

0 

43-44 

14,800 

14,800 

0 

0 

0 

0 

8,900 

0 ; 

6,700 

1,900 

300 

0 1 

0 

1944-45 

18,500 

13,900 

2,800 

1,800 

0 

1,600 

18,000 

0 

12,400 

5,200 

1,800 

0 ^ 

0 

45-46 

12,100 

12,100 

0 

0 

0 

800 

12,500 

0 

8,800 : 

3,200 

1,000 

0 i 

0 

46-47 

3,300 

3,300 

0 

0 

0 

0 

3,000 

0 

3,000 1 

0 

0 

0 I 

0 

47-48 

5,200 

5,200 

0 

0 

0 ; 

0 

4,100 

0 

3,200 i 

900 

0 

0 ! 

0 

AVERAGES 

24,200 

14,400 

4,100 

5,700 


3,500 

21,900 

400 

14,900 ; 

4,600 

2,400 

3,000 



142 


SANTA CLARA VALLEY INVESTIGATION 


SEASONAL SUMMARY OF MONTHLY YIELD STUDY, LITTLE FRANCIS 
RESERVOIR ON SAN FRANCISQUITO CREEK 


Storage capacity: 7,300 acre-feet 


(In acre-feet) 


Seasonal yield: 3,000 acre-feet 


Season 

Water supply 

Distribution of water supply 

Storage, 
October 1 

Estimated 

runoff, 

San Fran- 
cisQuito 
Creek 

Evaporation 

Demand 

Spill 

Storage, 

September 

30 

1935-36 _ 

0 

9,800 

500 

2,400 

1,800 

5,100 

36-37 

5,100 

15,800 

600 

3,000 

12,100 

5,200 

37-38 

5,200 

27,200 

600 

3,000 

23,500 

5,300 

38-39 

5,300 

500 

500 

3,000 

0 

2,300 

1939-40 

2,300 

18,400 

600 

3,000 

12,000 

5,100 

40-41 __ 

5,100 

23,300 

600 

3,000 

19,300 

5,500 

41-42 

5,500 

18,400 

600 

3,000 

15,100 

5,200 

42-43 

5,200 

13,100 

600 

3,000 

9,500 

5,200 

43-41 

5,200 

3,000 

500 

3,000 

0 

4,700 

1944-45. 

4,700 

9,000 

600 

3,000 

4,900 

5,200 

45-46 

5,200 

5,900 

600 

3,000 

2,400 

5,100 

46-47.. 

5,100 

700 

400 

3,000 

0 

2,400 

47-48 

2,400 

1,300 

300 

3,000 

0 

400 

AVKilAUES 


11,200 

500 

3,000 

7,700 



YIELD STUDY, ZAYANTE RESERVOIR ON ZAYANTE CREEK 


(In acre-feet) 

Storage capacity: 6,900 acre-feet Seasonal yield: 4,000 acre-feet 


Season 

November-May 

June-Ocfcober 

Storage, 
end of 
October 

Spill, 
end of 
May 

Runoff 

Demand, 

40 per cent 
of seasonal 
demand 

Storage, 
end of May 

Demand, 

60 per cent 
of seasonal 
demand 

Apparent 
storage, 
end of 
October 

Average 

summer 

storage 

Evaporation 

1935-36 

8,600 

1,600 

6,900 

2,400 

4,500 

5,700 

300 

4,200 

100 

36-37 

6,600 

1,600 

6,900 

2,400 

4,500 

5,700 

300 

4,200 

2,300 

37-38 

15,800 

1,600 

6,900 

2,400 

4,500 

5,700 

300 

4,200 

11,500 

38-39 

2,000 

1,600 

4,700 

2,400 

2,300 

3,500 

200 

2,100 

0 

1939-40 

14,800 

1,600 

6,900 

2,400 

4,500 

5,700 

300 

4,200 

8,400 

40-41 . 

22,800 

1,600 

6,900 

2,400 

4,500 

5,700 

300 

4,200 

18,500 

41-42 

13,600 

1,600 

6.900 

2,400 

4,500 

5,700 

300 

4,200 

9,300 

42-43 

10,300 

1,600 

6,900 

2,400 

4,500 

5,700 

300 

4,200 

6,000 

43-44 

4,100 

1,600 

6,700 

2,400 

4,300 

5,500 

300 

4,000 

0 

1944-45 

7,500 

1,600 

6,900 

2,400 

4,500 

5,700 

300 

4,200 

3,000 

45-46 

5,500 

1,600 

6,900 

2,400 

4,500 

5,700 

300 

4,200 

1,200 

46-47 

2,500 

1,600 

5,100 

2,400 

2,700 

3,900 

200 

2,500 

0 

47-48 -- . - 

2,700 

1 ,600 

3,600 

2,400 

1,200 

2,400 

200 

1,000 

0 

AvEhaviEB . - 

9 ,0uu 

1 jUUU 


2,400 



300 


4.600 



APPENDIX K 


143 


SEASONAL SUMMARY OF MONTHLY YIELD STUDY, UVAS RESERVOIR ON UVAS CREEK 


(!n acre-feet) 

Storage capacity: 34,000 acre-feet Seasonal yield: 17,400 acre-feet 


Season 

Water supply 

Distribution of water supply 

Storage, 
October 1 

Runoff, 

Uvas Creek 

Evaporation 

Releases to 

Spill 

Storage, 
September 30 

Uvas Creek 

Llagas Creek 

1932-33 

0 

5,600 

0 

1,800 

3,900 

0 

0 

33-34- 

0 

10,100 

200 

1,700 

8,100 

0 

0 

1934-35 

0 

15,500 

400 

3,500 

11,600 

0 

0 

35-36 

0 ! 

25,300 

1,200 

3,800 

12,500 

0 

7,800 

36-37 

7,800 

31,400 

1,400 

5,300 

16,500 

0 

I 16,000 

37-38 

16,000 

68,000 

1,600 

4,600 

14,100 

40,700 

1 23,000 

38-39 

23,000 

4,600 

200 

4,700 

22,700 

0 

1 0 

1939-40 

0 

44,500 

1,600 

3,400 

8,400 

8,700 

22,400 

40-41 

22,400 

57,500 

1,600 

4,500 

12,000 

36,600 

25,200 

41-4^ 

25,200 

38,800 

1,600 

1 4,500 

13,900 

18,200 

25,800 

42-43 

25,800 

27,800 

1,500 

I 4,800 

23,000 

8,100 

16,200 

43-44 

16,200 

17,300 ! 

900 

1 6,100 1 

26,500 

0 

0 

1944-45 

0 

25,000 

1,000 

4,500 

17,500 

0 

2,000 

45-46 

2,000 

15,200 

0 

3,400 

13,800 

0 

0 

46-47 _ 

0 

10,000 

0 

1,900 1 

8,100 

0 

0 

47-48 

0 

6,000 

0 

1,900 

4,100 

0 

0 

AVERAGES . 


25,200 

800 

3,800 

13,600 

7,000 





APPENDIX L 

ESTIMATES OF COST 


( 145 ) 



TABLE OF CONTENTS 

ESTIMATES OF COST 

Page 

Estimated Cost of Coyote Valley Well Field and Co^mte Valley — San Jose 
Pipe Line 147 

Estimated Cost of Calero-Los Gatos Creek Conduit 148 

Estimated Cost of Little Francis Dam and Reservoir 149 

Estimated Cost of Little Francis Treatment Plant and Conveyance System 150 

Estimated Cost of Za^'ante Dam and Reservoir 151 

Estimated Cost of Zayante-Los Gatos Pumping- Plant and Pine Line 152 

Estimated Cost of Uvas Dam and Reservoir 153 

Estimated Cost of Uvas-Llagas Conduit 154 

Estimated Cost of Llagas Creek Percolation Dams 154 


( 146 ) 



APPENDIX L 


147 


ESTIMATED COST OF COYOTE VALLEY WELL FIELD AND COYOTE VALLEY-SAN JOSE PIPE LINE 

(Based on prices prevailing in fall, 1954) 


Average elevation of well field: 270 feet, U.S.G.S. datum Number of wells: 7 

Elevation of pipe outlet at 12th and Martha Streets, San Jose: 100 feet. Capacity of pipe line: Variable from 2.1 to 15 second-feet 
U.S.G.S. datum Length of pipe line; 12.8 miles 


Item 

Quantity 

Unit price 

Cost 

Item 

Quantity 

Unit price 

Cost 

Capital Costs 




Capital Costs — Continued 




Drilling, casing and de- 








veloping 16-inch diame- 




Administration and en- 




ter wells, 250 feet deep _ 

7 ea. 

$4,000.00 

$28,000 

gineering, 10% __ _ 



$96,300 

1,000 gpm units including 




Contingencies, 15% 



144,500 

pump, motor, starter. 




Interest during construe- 




and installation 

7 ea. 

4,400.00 

30,800 

tion, none 




Increased pump cost for 








existing weUs due to 




TOTAL 



$1,204,000 

lowering of water table. 


lump sum 

95,000 $153,800 





Reinf orced-concrete cylin- 




Annual Costs 




der pipe in place 










14.80 

202,800 




$42,100 

27-inch diameter 

9,200 lin.ft. 

12.80 

117,800 320,600 

Repayment, 0.763% 



9*200 

Reinforced-concrete pipe 


Replacement, 1.0% 



12,000 

in place 




General expense, 0.32% _ _ 



3,900 

30-inch diameter 

6,600 lin.ft. 

13.35 

88,100 

Operation and mainte- 




27-inch diameter 

30,400 lin.ft. 

10.80 

328,300 

nance, 0 . 5% _ 



6,000 

24-inch diameter 

2,600 lin.ft. : 

8.60 

22,400 

Electric energy 



21-inch diameter 

1,300 lin.ft. 

7.00 

9,100 

For 7 — 1,000 gpm wells. 



6,800 

18-inch diameter ... 

2,600 lin.ft. 

6.05 

15,700 

For existing wells i 



10,800 

14_iriph Hiamfttpr 

1,300 lin.ft. 

4.35 

5,700 469,300 





Pavement excavation and 


TOTAL 



$90,800 

repair . 


lump sum 

3,300 





Pipe jacking .... 


lump sum 

4,000 





Rights of way . . 

3 ac. 

4,000 

12,000 





Clearing . ... 

2 ac. 

100.00 

200 19,500 





Subtotal 



$963,200 






148 


SANTA CLARA VALLEY INVESTIGATION 


ESTIMATED COST OF CALERO-LOS GATOS CREEK CONDUIT 


(Based on prices prevalfing in fall, 1954) 


Main conduit 

Elevation of crest of weir on Arroyo Calero: 383 feet, U.S.G.S. datum 
Elevation of crest of weir on Alamitos Creek: 372 feet, U.S.G.S. datum 
Elevation of outlet of Vasona Dam: 305 feet, U.S.G.S. datum 
Capacity of conduit: 50 second-feet 
length of conduit 

Unlined canal: 9.1 miles 
Reinforced-concrete pipe; 4.8 miles 


Guadalupe Creek Intercepting conduit 

Elevation of crest of weir: 347 feet, U.S.G.S. datum 
Capacity of conduit; 25 second-feet 
Length of conduit 

Unlined canal: 1.2 miles 


Item 

Quantity 

Unit price 

Cost 

Item 

Quantity 

Unit price 

Capital Costs 




Capital Costs — Continued 



Main conduit 




Administration and en- 



Diversion structure 




gineering, 10% _ 



Arroyo Calero 


lump sum 

$17,000 

Contingencies, 15%_ = _ 



Alamitos Creek „ _ _ 


lump sum 

8,000 

Interest during construe- 



Canal excavation 

62,500 cu.yd. 

$0.45 

28,100 

tion, none 



48=inch diameter re- 







forced -concrete 




TOTAL____ = 



pipe in place: (in- 







eluding blowoff 




Annual Costs 



and air valves) 







12o-foot maximum 




Interest, 3.5% . 



liead 

700 lin.ft. 

‘>5.90 

18,100 

Repayment, 0.763% 



100-foot maximum 



Replacement 





OO 

■! "00 




75=foot maximum 




Canal, 0.02% (negligi- 



head „ ^ 

10,100 iin.ft. 

21.90 

221,200 

ble) 



50-foot maximum 




General expense, 0.32% __ 



head 

9,000 lin.ft. 

20.35 

183.200 

Operation and mainte- i 



25-foot maximum 




nance 



head 

3,800 lin.ft. 

19.10 

72,600 

Pipe line, 0.5% 



Pavement excavation 


Canal, 1.0% 



and repair ^ 


lump sum 

3,000 




Transitions 

19 ea. 

100.00 

1,900 

TOTAL 



Farm crossings 

20 ea. 

400.00 

8,000 




Fence 

18.2 mi. 

1,200.00 

21,800 




Rights of wav 


lump sum 

68,000 




Clearing 

29 ac. 

100.00 

2,900 $791,300 




Guadalupe Creek inter- 







cepting canal 







Diversion structure. 


lump sum 

12,000 




Canal excavation 

5,100 cu.yd. 

0.80 

4,100 




Culverts. 

3 ea. 

400.00 

1,200 




Rights of wav 


lump sum 

5,000 




Clearing 

5 ac. 

100.00 

500 22,800 




Subtotal, ail items _ 



$814,100 

i 




Cost 


$81,400 

122,100 

$1,017,600 

$35,600 

7,800 

8,000 

3,300 

4,000 

2,100 

$60,800 




APPENDIX L 


149 


ESTIMATED COST OF LITTLE FRANCIS DAM AND RESERVOIR 


(Based on prices prevailing in fall, 1954) 


Elevation of crest of dam: 300 feet, U.S.G.S. datum Capacity of reservoir to crest of spillway: 7,300 acre-feet 

Elevation of crest of spillway: 290 feet Capacity of spillway with 4-foot freeboard: 9,000 second-feet 

Height of dam to spillway crest, above stream bed: 81 feet 


Item 

Quantity 

Unit price 

Cost 

Item 

Quantity 

Unit price 

Cost 

Capital Costs 




Capital Costs— Continued 




Dam 




Outlet works — Continued 




Diversion and care of 




Control house 


lump sum 

$2,000 

stream , 


lump sum 

$10,000 

4-foot by 5-foot head- 




Stripping and prepara- 




gate for diversion 




tion of foundation 

62,600 cu.yd. 

SO. 50 

31,300 

conduit » 


lump sum 

500 $69,300 

Excavation for em- 








bankment 




Reservoir 





223,000 cu.yd. 

0.40 

89,200 

Improvements 


lump sum 

83,000 

Embankment 


Land _ 

350 ac. 

$2,000.00 

700,000 

Impervious . _ 

178,600 cu.yd. 

0.35 

62,500 


50 ac. 

200.00 

10,000 

Pervious, salvage 

234,300 cu.yd. 

0.40 

93,700 

Utilities 


lump sum 

4,000 



3.00 

54,300 

Road relocation 


lump sum 

53,000 

Drilling grout holes 

13 '600 lin.ft. 

3.00 

40'800 

Clearing reservoir lands^ 


lump sum 

20,000 


9,070 cu.ft. 

4.00 

36,300 $418,100 

Livestock fence 

5 mi. 

1,200.00 

6,000 876,000 

Spillway- 


Subtotal 


$1,762,100 

Excavation 








Common 

218,200 cu.yd. 

0.40 

87,300 

Administration and engi- 




Rock 

3,000 cu.yd. 

1.50 

4,500 

neering, 10% 



176,200 

Concrete 

6,350 cu.yd. 

35.00 

222,300 

Contingencies, 15% 



264,300 

Reinforcing steel 

476,000 lb. 

0.15 

71,400 

Interest during construc- 



Riprap - 

4,400 cu.yd. 

3.00 

13,200 398,700 

tion, none 




Outlet works 


TOTAL 



$2,202,600 

Excavation 








Common 

300 cu.yd. 

1.00 

300 





Rock 

700 cu.yd. 

t) . 00 

3,500 

Annual Costs 




Concrete 








Pipe encasement 

540 cu.yd. 

30.00 

16,200 

Interest, 3.5% 



$77,100 

Inlet and control box_ 

150 cu.yd. 

60.00 

9,000 

Repayment, 0.763% 



16,800 

Steel pipe, 36-inch dia- 




Replacement, 0.07% 



1,500 

meter 

47,800 lb. 

0.25 

12,000 

Operation and mainte- 




Reinforcing steel 

82,000 lb. 

0.15 

12,300 

nance 



1,500 

Gate valve, 36-inch dia- 


General expense, 0.32% __ 



7,000 

meter, and actuators^ 


lump sum 

6,300 





Hollow jet valve, 30- 




TOTAL-- 



$103,900 

inch diameter 


lump sum 

7,200 







150 


SANTA CLARA VALLEY INVESTIGATION 


ESTIMATED COST OF LITTLE FRANCIS TREATMENT PLANT AND CONVEYANCE SYSTEM 

(Based on prices prevalfing in fall, 1954) 


Capacity of conduit to treatment plant: 6.5 million gallons per day 

Capacity of treatment plant: 5 million gallons per day 

Capacity of distribution reservoir: 2 million gallons 

TotG! installed capacity of pumping plant: 10 million gallons per day 


Capacity of conduit to city distribution system: 9.7 million gallons per day 
Length of conduit to treatment plant: 8,800 feet 
Length of pump line to distribution reservoir: 3,600 feet 
Lenath of conduit to city distribution system? 8,-500 feet 


Item 


Quantity 


Unit price 


Cost 


Item 


Quantity 


Unit price 


Cost 


Capital Costs 

Conduit to treatment plantj 
Canal 

Excavation 

Trimming 

Shotcrete lining 

Fence, livestock 

Structures 

20-incli diameter 
welded steel pipe, 

No. 10 gage 

Rights of way 

Subtotal 

Administration and engi- 
neering, 10% 

Contingencies, 15% 

Interest during construc- 
tion, none 

TOTAL, conduit 
to treatment 
plant 

Treatment and pumping 
plants 

Treatment plants 

Pumping plant - - 

Rights of way 

Subtotal — = 

Administration and engi- 
neering, 10% 

Contingencies, 15% 

Interest during construc- 
tion, none 

TOTAL, treat- 
ment and pump- 
ing plants 

Pipe line, distribution res- 
ervoir, and pipe line 
to distribution system] 
Pipe line 

20-inch diameter 
welded steel pipe, 

No. 10 gage 

Pavement excava- 
tion and repair 

Stand-by reservoir 

Pipe line to distribution 
system 

22-inch diameter 
welded steel pipe. 

No. 7 gage 

Rights of way- 

Subtotal 


1,050 eu.yd. 
7,240 sq.yd. 
7,240 sq.yd. 
3.2 mi. 


300 lin.ft. 
3.9 ac. 


0.75 
2.75 
1,200.00 
lump sum 


7.90 

2,000.00 


rump sum 
lump sum 
2,000.00 


3,600 lin.ft. 
SOO lin.ft. 


8,500 lin.ft. 
6 ac. 


1.50 
lump sum 


11.60 

2 , 000.00 


5.400 
19,900 

3,800 

1.400 


2,400 

7,800 


842,000 


842,000 


4,200 

6,300 


8570,000 

42.000 

10.000 


$52,500 


622,000 


8622,000 


62,200 

93,300 


$777,500 


28,400 

1,200 

135,000 


98,600 

12,000 


275,200 


8275,200 


Capital Costs— Continued 

Administration and engi- 
neering, 10% 

Contingencies, 15% 

Interest during construc- 
tion, none 

TOTAL, pipe line, 
distribution res- 
ervoir, and pipe 
line to distribu- 
tion system 

TOTAL 

Annual Costs 

Conduit to treatment plant] 

Interest, 3.5% 

Repayment, 0.763% 

Replacement, 0.02% , 
negligible operation 
and maintenance, 

0.5% 

General expense, 0.32% _ 

TOTAL, conduit 
to treatment 
plant 

Treatment and pumping 
plants 

Interest, 3.5% 

Repayment^ 0.763% 

Replacement, 1.2% 

Operation and mainte- 
nance — 
General expense, 0,32%- 

Insurance, 0.12% 

Electrical energy 

TOTAL, treat- 
ment and pump- 
ing piaUuS 

Pipe line, distribution res- 
ervoir, and pipe line 
to distribution system] 

Interest, 3.5% 

Repayment, 0.763% 
Replacement, 1.00%__ 
Operation and mainte- 
nance, 0.5% 

General expense, 0.32% 

TOTAL, pipe line, 
distribution res- 
ervoir, and pipe 
line to distribu- 
tion system 


$27,500 

41,300 


8344,000 

81,174,000 


81,800 

400 


300 

200 


82,700 


27,200 

5,900 

9,300 

44,300 

2,500 

900 

4,100 


894,200 


12,000 

2,600 

3,400 

1,700 

1,100 


#20,800 




APPENDIX L 


151 


ESTIMATED COST OF ZAYANTE DAM AND RESERVOIR 

{Based on prices prevailing in fall, 1954) 


Elevation of crest of dam: 616 feet, U.S.G.S. datum Capacity of reservoir to crest of spillway: 6,900 acre-feet 

Elevation of crest of spillway: 603 feet Capacity of spillway with 5-foot freeboard: 8,900 second-feet 

Height of dam to spillway crest, above stream bed: 127 feet 


Item 

Quantity 

Unit price 

Cost 

Item 

Quantity 

Unit price 

Cost 

Capital Costs 




Capital Costs— Continued 




Dam 




Outlet works — Continued 




Diversion and care of 




Gate valve, 30-ineh 




stream- - 


lump sum 

$10,000 

diameter, manual 




Stripping and prepara- 




control 

1 ea. 

$3,000 

$3,000 

tion of foundation 

76,600 cu.yd. 

$1.00 

76,600 

Hollow jet valve, 24- 




Excavation for em- 




inch diameter- 


lump sum 

5,400 

bankment 




Control house 


lump sum 

2,000 $96,000 

Impervious 

147,400 cu.yd. 

0.65 

95,800 





Pervious 

212,250 cu.yd. 

0.60 

127,400 

Reservoir 




Embankment 




Land and improvements 


lump sum 

77,500 

Impervious 

128,200 cu.yd. 

0.25 

32,100 

Public utilities 


lump sum 

128,400 

Pervious 

212,250 cu.yd. 

0.20 

42,500 

Clearing reservoir lands 

168 ac. 

500 

84,000 289,900 

Per\dous, salvage 

81,850 cu.yd. 

0.30 

24,500 







3.00 

34,500 




$1,039,500 

Drilling grout holes 

2,580 lin.ft. 

3.00 

7,700 





Pressure grouting 

1,720 cu.ft. 

4.00 i 

6,900 $458,000 

Administration and engi- 








neering, 10% 



103,900 

Spillway 




Contingencies, 15% 



156,000 

Excavation 

86,300 cu.yd. 

1.50 

129,500 

Interest during construc- 




Concrete _ _ 

1,430 cu.yd. 

35.00 

50,000 

tion, none 




Reinforcing steel. _ . 

107,250 lb. 

0.15 

16,100 195,600 









TOTAL- 



$1,299,400 

Outlet works 








Excavation 

1,500 cu.yd. 

4.00 

6,000 

Annual Costs 




Concrete, pipe encase- 








ment 

902 cu.yd. 

30.00 

27,100 

Interest, 3.5% - 



$45,500 

Steel pipe, 36-inch and 


Repayment 0.763% - 



9.900 

48-inch diameter 

115,900 lb. 

0.25 

29,000 

Replacement, 0.07% 



900 

Reinforcing steel 

90,200 lb. 

0.15 

13,500 

Operation and mainte- 




Gate valve, 18-inch 




nance 



2,500 

diameter, and actu- 




General expense, 0.32%_- 



4,200 

ft 

4 0a 

2,500 

10,000 







TOTAL-- 



$63,000 



152 


SANTA CLARA VALLEY INVESTIGATION 


ESTIMATED COST OF ZAYANTEAOS GATOS PUMPING PLANT AND PIPE LINE 

(Based on prices prevailing in fall, 1954) 


Elevation of reservoir outlet: 500 feet, U.S.G.S. datum Capacity of pumping plant: 20 second-feet 

Elevation of pipe line outlet on Los Gatos Creek: 895 feet, U.S.G.S. datum Length of pipe line: 6.4 miles 


Item 

1 «-> +■* 4“^ y 

Unit price 

Cost 

licni 

Quantity 

Unit price 

Cost 

Capital Costs 




Annual Costs 




Pumping plant 




Pumping plant 




3,000 gpm units; pump, 




Interest, 3.5% 



$4,200 

motor, and electrical 




Repayment, 0.763% 



900 

equipment _ 

3 ea. 

820,800 

$62,400 

Replacement, 1.2% 



1,400 

Valves 




Operation and mainte- 




10-inch diameter, 




nance 



20,000 

check 

3 ea. 

600 

1,800 

General expenses, 0.32% 



400 

10-inch diameter, 




Insurance, 0.12% 



100 


4 ea. 

500 

2,000 

Electrical energy 



20,300 

Concrete structure 


lump sum 

32,000 $96,200 








TOTAL, pumping 







$96,200 

plant ... 



$47,300 

Administration and engi- 



Pipe line 






9,600 

Interest, 3.5%. _ 



$43,300 

Contingencies. 15% - 



14,400 

Repayment, 0.763% 



9,400 

Interest during construc- 




Replacement 




tion, none 




Pipe line, 1.0% 



6,100 





Tiinnf>l 0.02% 



100 

TOTAL, pumping 




Operation and mainte- 



plant„ 



$120,200 

Tsance - .... 



6,200 




General expense, 0.32% 



4^000 

Pipe line 








30-1 nch diameter welded 




TOTAL, pipe line. 



$69,100 

steel pipe supported 








on concrete saddles _ _ 

33,800 lin.ft. 

S14.50 

$490,100 

TOTAL 



$116,400 

Tunnel portal clearing. _ 


lump sum 

500,000 $990,100 





Subtotal.- - 



$990,100 





Administration and engi- 








neering, 10% __ 



99,000 





Contingencies, 15% 



148,500 





Interest during construc- 








tion, none 








TOTAL, pipe line. 



$1,237,600 





TOTAL 



$1,357,800 







APPENDIX L 


153 


ESTIMATED COST OF UVAS DAM AND RESERVOIR 

(Based on prices prevailing in fall, 1954) 


Elevation of crest of dam: 549 feet, U.S.G.S. datum Capacity of reservoir to crest of spillway: 34,000 acre-feet 

Elevation of crest of spillway: 534 feet Capacity of spillway with 5-foot freeboard: 20,000 second-feet 

Height of dam to spillway crest, above stream bed; 142 feet 


Item 

Quantity 

Unit price 

Cost 

Item 

Quantity 

Unit price 

Cost 

Capital Costs 




Capital Costs— Continued 




Dam 




Outlet works — Continued 




Diversion and care of 




Hollow jet valve, 30- 






lump sum 

S20,000 

inch diameter 


lump sum 

$7,200 

Stripping and prepara- 


Control house 


lump sum 

2,000 

tion of foundation. 

105,200 cu.yd. 

SO. 70 

73,600 

2-foot by 2-foot canal 




Excavation for em- 




headgate 


lump sum 

200 $95,300 

bankinent 








Impervious 

916,700 cu.yd. 

0.40 

366,700 

Reservoir 




Pervious _ _ 

1,498,000 cu.yd. 

0,35 

524,300 

Land and improvements, 




Embankment 




road relocation, and 




Impervious 

733,400 cu.vd. 

0.35 

256,700 

public utilities 


lump sum 

$512,000 

Pervious 

1,273,000 cu.yd. 

0.30 

381,900 

Clearing reservoir lands 

650 ac. 

$200 

130,000 $642,000 

Pervious, salvage 

158,700 cu.yd. 

0.30 

47,600 







3.00 

138,300 

' Subtotal 



$2,785,700 

Drilling grout holes 

8,130 lin.ft. 

3.00 

24,400 




Pressure grouting 

5,410 cu.ft. 

4.00 

21,600 $1,855,100 

Administration and en- 








gineering, 10% 



278,600 

Spillway 




Contingencies, 15% 



417,800 

Excavation 




Interest during construc- 




Common. 

15,000 cu.yd. 

0.45 

6,800 

tion, one-half of con- 




Rock . . . 

60,000 cu.yd. 

1.50 

90,000 

struction period at 




Concrete 

2,185 cu.yd. 

35.00 

76,500 

3.5% 



121,900 

"R oi Tic ftf.ppl 

133,000 lb. 

0.15 

20,000 193,300 




id VCCI _ _ - „ . 



TOTAL 



$3,604,000 

Outlet works 








Excavation 








Common 

900 cu.yd. 

1.00 

900 

Annual Costs 




Rock. 

1,000 cu.yd. 

5.00 

5,000 





Concrete 




Interest, 3.5% 



$126,100 

Pipe encasement 

700 cu.yd. 

30.00 

21,000 

Repayment, 0.763% 



27,500 

Inlet and control box 

270 cu.yd. 

60.00 

16,200 

Replacement. 0.07% 



2,500 

Steel pipe, 36-inch di- 




Operation and mainte- 




ameter. - 

71,600 lb. 

0.25 

17,900 

nance - 



5,900 

Reinforcing steel 

124,000 Ib. 

0.15 

18,600 

General expense, 0.32% _ _ 



11,500 

Gate valve, 36-inch di- 








ameter, and actuators 


lump sum 

6,300 

TOTAL 



$173,500 



154 


SANTA CLARA VALLEY INVESTIGATION 


ESTIMATED COST OF UVAS-LLAGAS CONDUIT 

(Based on prices prevailing in fall, 1954) 

Elevation of Uvas Dam outlet: 425 feet, U.S.G.S. datum Length of conduit 

Elevation of Llagas Creek stream bed at conduit outlet: 350 feet, Reinforced-concrete pipe: 1.8 miles 

U.S.G.S. datum Unlined canal: 1.5 miles 

Capacity of conduit: 50 second-feet 


Item 

Quantity 

Unit price 

Cost 

Item 

Quantity 

Unit price 

Cost 

Capital Costs 




Annual Costs 




48-inch diameter rein- 




Interest, 3.5% 



$9,600 

forced-concrete pipe, in 




Repayment, 0.763% 



2,100 

place 

9,500 Hn.ft. 

$20.35 

$193,300 

Replacement 




Canal 




Pipe line, 1.00% 



2,500 

Excavation 

6,950 cu.yd. 

0.70 

4,900 

Canal and chute, 0.02% 




Compacted embank- 




(negligible) 




ment 

6,250 cu.yd. 

0.15 

900 

General expense, 0.32% __ 



900 

Farm crossings 

8 ea. 

350.00 

2,800 

Operation and mainte- 




Chute- 


lump sum 

9,000 

nance 



1,500 

Rights of way 


lump sum 

8,000 




Clearing 

2 ac. 

100 . 00 

200 $219,100 

TOTAL 



$16,600 

Subtotal - 



$219,100 




Administration and en- 








gineering, 10% 



21,900 





Contingencies, 15% 



32,900 





Interest during construc- 








TOTAL 



$273,900 






ESTIMATED COST OF LLAGAS CREEK PERCOLATION DAMS 

(Based on prices prevoiling In fall, 1954) 


Type of dam: Rock in chain link v/ire mesh Average width: 100 feet 

Number: 23 Length of flooded area: From Llagas Avenue to Rucker Avenue, 22,200 feet 

Height: 3 feet Area flooded: 50 acres 


Item 

Quantity 

Unit price 

Cost 

Item 

Quantity 

Unit price 

Cost 

Capital Costs 




Annual Costs 




Riprap _ _ _ _ _ 

2,800 cu.yd. 

$4.00 

$11,200 

Interest, 3.5%_ 



$1,400 

Galvanized steel pipe. 2- 




Repayment, 0.763% 



300 

inch diameter 

6,000 lin.ft. 

1.00 

6,000 

Replacement, 1.0% 



400 

>^-inch galvanized steel 




Operation and mainte- 




cable (7 wire) - _ _ „ _ 

4,000 lin.ft. 

1.00 

4,000 

nance 



1,900 

M-inch chain link mesh, 




General expense, 






0.75 

6,200 

0.32% - - - 



100 

12 gH.p’ft wh“A 

500 SQ.yd. 







^8-inch steel cable _ 

4,100 lin.ft. 

1.00 

4,100 $32,000 

TOTAL 



$4,100 

Subtotal 



$32,000 





Administration and en- 








gineering, 10% 



3,200 





Contingencies. 15% 



4,800 





Interest during construc- 








tion, none 








TOTAL 



$40,000 






O 


t92T3 6-55 300 


printed in California state printing office