i The California Water Plan Update B ULLETIN 160-98

D E P A R T M E N T O

F W A

T E R R E S O U R C E S

S T A T E O

F C A

L I F O R N I A 

# C ALIFORNIA 

# W ATER 

# P LAN 

# U PDATE 

# B ULLETIN 

# 160-98

Executive Summary
November 1998

Pete Wilson

Governor

Douglas P. Wheeler Secretary for Resources The Resources Agency

David N. Kennedy
Director Department of Water ResourcesThe California Water Plan Update B ULLETIN 160-98

ii Department of Water Resources, Sacramento, 1998

Copies of Bulletin 160-98 may be purchased for $25 from: California Department of Water Resources P. O. Box 942836 Sacramento, CA 94236-0001

Make checks payable to: Department of Water Resources California residents add current sales tax Ciii The California Water Plan Update B ULLETIN 160-98



# I n 1957, the Department published Bulletin 3, the California Water Plan . Bulletin 3 was followed by the Bulletin 160 series, published six times between 1966 and 1993, updating the California Water Plan . A 1991 amendment to the California Water Code directed the Department to update the plan every five years. Bulletin 160-98 is the latest in the series. The Bulletin 160 series assesses California’s water needs and evaluates water supplies, to quantify the gap between future water demands and water supplies. The series presents a statewide overview of current water management activities and provides water managers with a framework for making decisions. In response to public comments on the last update, Bulletin 160-93, this 1998 update evaluates water management options that could improve California’s water supply reliability.Water management options being planned by local agencies form the building blocks for evaluations performed for each of the State’s ten major hydrologic regions. Local options are integrated into a statewide overview that illustrates potential progress in reducing the State’s expected future water shortages.When the previous water plan update was released, California was just emerging from a sixyear drought. This update follows the largest and most extensive flood disaster in California’s history, the January 1997 floods. These two hydrologic events fittingly illustrate the complexity of water management in the State.The Department appreciates the assistance provided by the Bulletin 160-98 public advisory committee, which met with the Department over a three-year period as the Bulletin was being prepared. The Department also appreciates the assistance provided by the many local water agencies who furnished information about their planned water management activities.

David N. Kennedy
Director 

# Foreword

. . .The California Water Plan Update B ULLETIN 160-98

ivv The California Water Plan Update B ULLETIN 160-98

Chapter ES1. Introduction Overview of California’s Water Needs ............................................................................................... ES1-2 Bulletin 160-98 Hydrologic Regions ................................................................................................ ES1-4 Changes Since the Last California Water Plan Update ...................................................................... ES1-4 Changes in Response to Bulletin 160-93 Public Comments....................................................... ES1-4 Changes in Future Demand/Shortage Forecasts ......................................................................... ES1-6 Preparation of Bulletin 160-98 ......................................................................................................... ES1-7
Public Comments on Draft........................................................................................................ ES1-7 Works in Progress and Uncertainties .......................................................................................... ES1-8
Presentation of Data in Bulletin 160-98..................................................................................... ES1-9

Chapter ES2. Current Events in California Water Management Facilities ........................................................................................................................................... ES2-1 Legislation ........................................................................................................................................ ES2-4 Proposition 204 ......................................................................................................................... ES2-4 Proposition 218 ......................................................................................................................... ES2-4

MTBE ....................................................................................................................................... ES2-4 Safe Drinking Water Act ............................................................................................................ ES2-5 Reclamation, Recycling, and Water Conservation Act of 1996 ................................................... ES2-6
Water Desalination Act of 1996 ................................................................................................. ES2-6 Major Water Management Issues and Programs................................................................................ ES2-6 Bay-Delta Accord and CALFED ................................................................................................ ES2-6
Colorado River .......................................................................................................................... ES2-8 Recent ESA Listings ................................................................................................................... ES2-9 January 1997 Central Valley Floods ......................................................................................... ES2-10 CVPIA Implementation........................................................................................................... ES2-12 SWP Monterey Agreement Contract Amendments .................................................................. ES2-14
Environmental Restoration Activities ....................................................................................... ES2-14 Implementation of Urban Water Conservation MOU ............................................................. ES2-17 Implementation of Agricultural Efficient Water Management Practices MOU......................... ES2-17 Klamath River Fishery Issues.................................................................................................... ES2-17 Truckee-Carson River System .................................................................................................. ES2-17 City of Los Angeles’ Water Supply from Owens Valley ............................................................. ES2-18

Mono Basin ............................................................................................................................. ES2-19
Salton Sea ................................................................................................................................ ES2-19 

# Contents

. . .The California Water Plan Update B ULLETIN 160-98

vi Chapter ES3. Water Supplies Water Supply Calculation ................................................................................................................. ES3-1 Definition of Bulletin 160 Water Supplies ................................................................................. ES3-1 Applied Water Methodology ...................................................................................................... ES3-2
Normalized Data ....................................................................................................................... ES3-2 Water Supply Scenarios .............................................................................................................. ES3-3 Sources of Water Supply ................................................................................................................... ES3-4 Surface Water Supplies ............................................................................................................... ES3-5 Groundwater Supplies ............................................................................................................... ES3-5 Water Marketing ........................................................................................................................ ES3-7 Water Recycling and Desalting Supplies..................................................................................... ES3-8 Water Supply Summary by Hydrologic Region .......................................................................... ES3-9 Water Quality................................................................................................................................... ES3-9

Chapter ES4. Urban, Agricultural, and Environmental Water Use Urban Water Use .............................................................................................................................. ES4-1 Population Growth .................................................................................................................... ES4-2 Factors Affecting Urban Per Capita Water Use ........................................................................... ES4-2 Urban Water Use Forecasting ..................................................................................................... ES4-4 Summary of Urban Water Use ................................................................................................... ES4-4 Agricultural Water Use ..................................................................................................................... ES4-5 Crop Water Use ......................................................................................................................... ES4-5 Quantifying Base Year Irrigated Acreage ..................................................................................... ES4-6 Forecasting Future Irrigated Acreage .......................................................................................... ES4-7 Summary of Agricultural Water Use......................................................................................... ES4-11
Environmental Water Use............................................................................................................... ES4-11
Wild and Scenic River Flows ................................................................................................... ES4-12
Instream Flows......................................................................................................................... ES4-12 Bay-Delta Outflow .................................................................................................................. ES4-14
Wetlands .................................................................................................................................. ES4-14 Summary of Environmental Water Use .................................................................................... ES4-15 Water Use Summary by Hydrologic Region ................................................................................... ES4-15

Chapter ES5. Balancing Supply and Demand Future with Existing Facilities and Programs .................................................................................... ES5-2 Water Supply ............................................................................................................................. ES5-2
Water Demand .......................................................................................................................... ES5-3 Water Shortages ......................................................................................................................... ES5-3 The Bulletin 160-98 Planning Process .............................................................................................. ES5-3 Major Steps in Planning Process ................................................................................................ ES5-5vii The California Water Plan Update B ULLETIN 160-98

Shortage Management ............................................................................................................... ES5-7 Using Applied Water Budgets to Calculate New Water Needs .................................................... ES5-7 Summary of Options Likely to be Implemented ............................................................................... ES5-8 Implementing Future Water Management Options ........................................................................ ES5-10 Bulletin 160-98 Findings................................................................................................................ ES5-11

Appendix ES5A. Regional Water Budgets with Existing Facilities and Programs ....................................................................................................................................... ES5A-1

Appendix ES5B. Regional Water Budgets with Options Likely to be Implemented............................................................................................................................... ES5B-1

Abbreviations and Acronyms ................................................................... ESA-1

Tables Table ES2-1. Major Water Conveyance Facilities Since 1992 .................................................................. ES2-2 Table ES2-2. Large Structural Fishery Restoration Projects ..................................................................... ES2-3 Table ES2-3. Proposition 204 Funding Breakdown................................................................................. ES2-5 Table ES3-1. California Water Supplies with Existing Facilities and Programs......................................... ES3-5 Table ES3-2. 1995 and 2020 Level Overdraft by Hydrologic Region ...................................................... ES3-7 Table ES3-3. Recently Completed Long-Term Water Marketing Agreements.......................................... ES3-8 Table ES3-4. 2020 Level Total Water Recycling and New Water Supply ................................................. ES3-9 Table ES3-5. California Average Year Water Supplies by Hydrologic Region ......................................... ES3-10 Table ES3-6. California Drought Year Water Supplies by Hydrologic Region........................................ ES3-10 Table ES4-1. California Population by Hydrologic Region...................................................................... ES4-2 Table ES4-2. Effects of Conservation on Per Capita Water Use by Hydrologic Region ............................ ES4-4 Table ES4-3. Applied Urban Water Use by Hydrologic Region ............................................................... ES4-5 Table ES4-4. California Crop and Irrigated Acreage by Hydrologic Region, 1995 Level ......................... ES4-8 Table ES4-5. California Crop and Irrigated Acreage by Hydrologic Region, 2020 Level ....................... ES4-10 Table ES4-6. Applied Agricultural Water Use by Hydrologic Region .................................................... ES4-11 Table ES4-7. Wild and Scenic River Flows by Hydrologic Region ........................................................ ES4-12 Table ES4-8. Instream Flow Requirements by Hydrologic Region ........................................................ ES4-14 Table ES4-9. Wetlands Water Use by Hydrologic Region ...................................................................... ES4-15 Table ES4-10. Applied Environmental Water Use by Hydrologic Region .............................................. ES4-15 Table ES4-11. California Average Year Water Use by Hydrologic Region .............................................. ES4-16 Table ES4-12. California Drought Year Water Use by Hydrologic Region ............................................. ES4-16 Table ES5-1. California Water Budget with Existing Facilities and Programs .......................................... ES5-2 Table ES5-2. Summary of Options Likely to be Implemented by 2020, by Option Type ........................ ES5-9 Table ES5-3. California Water Budget with Options Likely to be Implemented .................................... ES5-11 Table ES5A-1. North Coast Region Water Budget with Existing Facilities and Programs ..................... ES5A-2 Table ES5A-2. San Francisco Bay Region Water Budget with Existing Facilities and Programs............. ES5A-2The California Water Plan Update B ULLETIN 160-98

viii Table ES5A-3. Central Coast Region Water Budget with Existing Facilities and Programs ................... ES5A-2 Table ES5A-4. South Coast Region Water Budget with Existing Facilities and Programs ..................... ES5A-3 Table ES5A-5. Sacramento River Region Water Budget with Existing Facilities and Programs ............. ES5A-3 Table ES5A-6. San Joaquin River Region Water Budget with Existing Facilities and Programs............. ES5A-3 Table ES5A-7. Tulare Lake Region Water Budget with Existing Facilities and Programs....................... ES5A-4 Table ES5A-8. North Lahontan Region Water Budget with Existing Facilities and Programs ............... ES5A-4 Table ES5A-9. South Lahontan Region Water Budget with Existing Facilities and Programs ............... ES5A-4 Table ES5A-10. Colorado River Region Water Budget with Existing Facilities and Programs............... ES5A-5 Table ES5B-1. North Coast Region Water Budget with Options ......................................................... ES5B-2 Table ES5B-2. San Francisco Bay Region Water Budget with Options ................................................. ES5B-2 Table ES5B-3. Central Coast Region Water Budget with Options ....................................................... ES5B-2 Table ES5B-4. South Coast Region Water Budget with Options .......................................................... ES5B-3 Table ES5B-5. Sacramento River Region Water Budget with Options.................................................. ES5B-3 Table ES5B-6. San Joaquin River Region Water Budget with Options ................................................. ES5B-3 Table ES5B-7. Tulare Lake Region Water Budget with Options ........................................................... ES5B-4 Table ES5B-8. North Lahontan Region Water Budget with Options ................................................... ES5B-4 Table ES5B-9. South Lahontan Region Water Budget with Options .................................................... ES5B-4 Table ES5B-10. Colorado River Region Water Budget with Options ................................................... ES5B-5

Figures Figure ES1-1. California’s Expected Population Growth Versus Neighboring States’ Populations ............ ES1-3 Figure ES1-2. California’s Hydrologic Regions ........................................................................................ ES1-5 Figure ES3-1. Disposition of California’s Average Annual Precipitation .................................................. ES3-3 Figure ES3-2. California’s Major Water Projects ...................................................................................... ES3-6 Figure ES4-1. Projected Growth Rates by County, 1995-2020................................................................ ES4-3 Figure ES4-2. California Wild and Scenic Rivers .................................................................................. ES4-13 Figure ES5-1. 2020 Shortages by Hydrologic Region with Existing Facilities and Programs .................... ES5-4 Figure ES5-2. 2020 Shortages by Hydrologic Region with Likely Options ............................................ ES5-12

Sidebars Summary of Key Statistics ....................................................................................................................... ES1-2 California’s Hydrologic Regions .............................................................................................................. ES1-6
American River Flood Protection .......................................................................................................... ES2-11 Sacramento River Flood Control Project ............................................................................................... ES2-12
CVPIA’s Dedicated Water ..................................................................................................................... ES2-13 Key Water Supply and Water Use Definitions ......................................................................................... ES3-2 Procedures for Normalizing Water Supply and Water Use Data .............................................................. ES3-4 Initial Screening Criteria ......................................................................................................................... ES5-5 Options Category Evaluation .................................................................................................................. ES5-6ix The California Water Plan Update B ULLETIN 160-98



### STATE OF CALIFORNIA

Pete Wilson, Governor

THE RESOURCES AGENCY Douglas P. Wheeler, Secretary for Resources

DEPARTMENT OF WATER RESOURCES David N. Kennedy, Director

Raymond D. Hart Robert G. Potter Stephen L. Kashiwada

Deputy Director Chief Deputy Director Deputy Director

L. Lucinda Chipponeri Susan N. Weber Assistant Director for Legislation Chief Counsel

DIVISION OF PLANNING AND LOCAL ASSISTANCE
William J. Bennett, Chief

This Bulletin was prepared under the direction of Jeanine Jones . .......................................................................................................... Chief, Statewide Planning

by Naser Bateni ...................................................................................Former Chief, Water Resources Evaluation Paul Hutton ................................................................................................ Chief, Water Resources Evaluation Waiman Yip ..................................................................................................................... ........ Senior Engineer Bob Zettlemoyer ......................................................................................................................Senior Engineer

assisted by
Barbara Cross Tom Hawkins Dick Neal Steve Cowdin Ray Hoagland Virginia Sajac Dan Fua Scott Matyac Clara Silva

with assistance on special topics or studies by
Manucher Alemi Marla Hambright Richard Le
Linton Brown Darryl Hayes Claire LeFlore Randy Brown Dale Hoffman-Floerke Jim Rich Ed Craddock Steve Kasower Maurice Roos Baryohay Davidoff John Kramer Ray Tom Farhad FarnamThe California Water Plan Update B ULLETIN 160-98

x Data collection and regional information provided by Department District offices

Northern District Naser Bateni, Chief
assisted by
X. Tito Cervantes Douglas Denton Glen Pearson Andrew Corry Todd Hillaire Eugene Pixley

Central District Karl Winkler, Chief
assisted by Alan Aguilar Al Lind Doug Osugi Emil Calzascia Ed Morris James Wieking Toccoy Dudley

San Joaquin District Lou Beck, Chief
assisted by Jack Erickson Brian Smith Ernie Taylor Robert Polgar Arvey Swanson Iris Yamagata David Scruggs

Southern District Charles White, Chief
assisted by Glenn Berquist Vern Knoop Mark Stuart Sergio Fierro Kelly Lawler Garret Tam Sing David Inouye Michael Maisner

Editorial, design, and production services were provided by Nikki Blomquist Teresa Chaney Joanne Pierce John Carter Mike Miller Therese Tynan

Photography provided by Department of Water Resources, Photography Unit Peter Stoiber, Supervising Photographer

Paul Hames Dale Kolke Stephen Payer Norm Hughesxi The California Water Plan Update B ULLETIN 160-98



### State of California The Resources Agency Department of Water Resources



### CALIFORNIA WATER COMMISSION

Daniel F. Kriege Stanley M. Barnes Chair, Capitola Vice Chair, Visalia

Donald C. Cecil ................................................................................................................................... Willows

George Gowgani, Ph.D........................................................................................................... San Luis Obispo

Homer F. Lundberg ............................................................................................................................ Richvale

Michael D. Madigan ............................................................................................................. ........... San Diego

Martin A. Matich............................................................................................................... ...... San Bernardino

Sayre M. Miller ....................................................................................................................................... Clovis



### Raymond E. Barsch, Executive Officer

The California Water Commission serves as a policy advisory body to the Director of the Department of Water Resources on all California water resources matters. The nine-member citizen commission provides a water resources forum for the people of the State, acts as a liaison between the legislative and executive branches of State government, and coordinates federal, State, and local water resources efforts.ES1-1 I NTRODUCTION The California Water Plan Update B ULLETIN 160-98



# I n 1957, the Department published Bulletin 3, the California Water Plan. Bulletin 3
was followed by the Bulletin 160 series, published six times between 1966 and 1993,
updating the California Water Plan. A 1991 amendment to the California Water
Code directed the Department to update the plan every five years. Bulletin 160-98 is the

latest in the series.
The Bulletin 160 series assesses California’s agricultural, environmental, and urban
water needs and evaluates water supplies, in order to quantify the gap between future water
demands and the corresponding water supplies. The series presents a statewide overview of
current water management activities and provides water managers with a framework for
making water resources decisions.
While the basic scope of the Department’s water plan updates has
remained unchanged, each update has taken a distinct approach to water
resources planning, reflecting issues or concerns at the time of its
publication. In response to public comments on the last update, Bulletin
160-93, the 1998 update evaluates water management actions that could
be implemented to improve California’s water supply reliability. Bulletin
160-93 analyzed 2020 agricultural, environmental, and urban water
demands in considerable detail. These demands, together with water supply
information, have been updated for the 1998 Bulletin, which also uses a 

# Introduction Executive Summary

The Department’s Bulletin

160 series quantifies only

California’s managed or

dedicated water uses— urban, agricultural, and

environmental uses. Unmanaged uses, such as the precipitation consumed

by native plants, are not quantified.ES1-2 I NTRODUCTION The California Water Plan Update B ULLETIN 160-98

1995 2020

Agricultural Environmental Urban

Agricultural Environmental Urban

11% 15%

43% 39% 46% 46% 2020 planning horizon. However, much of Bulletin160-98 is devoted to identifying and analyzing options for improving water supply reliability. Watermanagement options available to, and being considered by, local agencies form the building blocks of evaluations prepared for each of the State’s ten major hydrologic regions. (Water supplies provided by local agencies represent about 70 percent of California’sdeveloped water supplies.) These potential local options are integrated with options that are statewide in scope, such as the CALFED Bay-Delta program, to create a statewide evaluation. The statewide evaluation represents a snapshot, at an appraisal level of detail, of how actions planned by California water managers could reduce the gap between supplies and demands. The evaluation does not present potential measures to reduce all shortages statewide to zero in year 2020. Such an approachwould not reflect economic realities and current planning by local agencies. Not all areas of the State and not all water users can afford to reduce drought yearshortages to zero. Bulletin 160-98 focuses on compiling those options that appear to have a reasonable chance of being implemented by water suppliers, toillustrate potential progress in reducing the State’s future shortages.

Overview of California’s Water Needs

Bulletin 160-98 estimates that California’s water shortages at a 1995 level of development are 1.6 maf in average water years, and 5.1 maf in drought years. (As described later in the Bulletin, shortages represent the difference between water supplies and water demands.) The magnitude of shortages shown fordrought conditions in the base year reflects the cutbacks in supply experienced by California water users during the recent six-year drought. Bulletin 160-98 forecasts increased shortages by 2020—2.4 maf in an average water year and 6.2 maf in drought years. The water management options identified as likely to be implemented could reduce those shortages to 0.2 maf in average water years and 2.7 maf in drought years. Population growth is expected to drive the State’sincreased water demands. To put California’s population into perspective, about one of every eight U.S.

Summary of Key Statistics Shown below for quick reference are some key statistics presented in the Bulletin. Water use information is based on average water year conditions. The details behind the statistics are discussed in Chapter ES4.

1995 2020 Forecast Change Population (million) 32.1 47.5 +15.4 Irrigated crops (million acres) 9.5 9.2 -0.3 Urban water use (maf) 8.8 12.0 +3.2 Agricultural water use (maf) 33.8 31.5 -2.3 Environmental water use (maf) 36.9 37.0 +0.1ES1-3 I NTRODUCTION The California Water Plan Update B ULLETIN 160-98

+15.4 million

The anticipated growth in California's population by the year 2020 is approximately equivalent to the combined 1995 population of these eight neighboring states. Anticipated Population Growth In California By 2020: New Mexico Arizona Nevada Oregon Idaho Wyoming Utah Montana

TOTAL: 1.7 4.3 1.5 3.1 1.2 0.5 2.0 0.9

15.2 million

Oregon

Idaho Montana

Wyoming

Nevada

Utah

Arizona New Mexico F IGURE ES1-1. California’s Expected Population Growth Versus Neighboring States’ PopulationsES1-4 I NTRODUCTION The California Water Plan Update B ULLETIN 160-98

residents now lives in California. During the time period covered in the Bulletin (the 25 years from 1995 to 2020), California’s population is forecast to increaseby more than 15 million people, the equivalent of adding the present populations of Arizona, Nevada, Oregon, Idaho, Montana, Wyoming, New Mexico, and Utah to California, as shown in F igur e ES1-1 . Today, four of the nation’s 15 largest cities (Los Angeles, San Diego, San Jose, and San Francisco) are located in the State. The sidebar on page ES1-2 summarizes key statistics developed later in the Bulletin.

Bulletin 160-98 Hydrologic Regions

F igur e ES1-2 shows California’s ten hy dr ologic r egions , corresponding to the State’s major drainagebasins. The Department subdivides the State into regions for planning purposes. The largest planning unit is the hydrologic region, a unit used extensively in thisBulletin. The next level of delineation below hydrologic regions is the planning subarea. Some of theBulletin’s regional water management evaluations discuss information at the PSA level. The smallest study unit used by the Department is the detailed analysis unit. California is divided into 278 DAUs. Most of the Departments’ Bulletin 160 analyses begin at theDAU level, and the results are aggregated into hydrologic regions for presentation. Changes Since the Last California Water Plan Update

The last California Water Plan update, Bulletin 160-93, was published in 1994 and used 1990-level information to represent base year water supply anddemand conditions. At that time, California had recently emerged from the six-year drought and Bay-Delta issues were in a state of flux. Bulletin 160-98 uses 1995-level information to represent base year conditions, including new (interim) Bay-Delta standards. Changes in Sacramento-San Joaquin River Deltaconditions are a major difference between the two bulletins. Bulletin 160-93 was based on State Water Resources Control Board Decision 1485 regulatory conditions in the Delta, and used a range of 1 to 3 maf for unspecified future environmental water needs—arange that reflected uncertainties associated with BayDelta water needs and Endangered Species Actimplementation. Bulletin 160-98 uses SWRCB’s Order WR 95-6 as the base condition for Bay-Delta operations, and describes proposed CALFED actions for the Bay-Delta. Bulletin 160-93 was the first California Water Plan update to examine the demand/supply balance for drought water years as well as for average water years, a response to water shortages experienced during the then-recent drought. Bulletin 160-98 retains the drought year analysis and also considers the other end of the hydrologic spectrum—flooding. Traditionally, water supply has been the dominant focus of the water plan updates. In response to the January 1997 flooding in Northern and Central California, Bulletin 160-98 highlights common areas in water supply and flood control planning and operations and emphasizes the benefits of multipurpose facilities.
Changes in Response to Bulletin 160-93 Public Comments Other changes between the two reports resultedfrom public comments on Bulletin 160-93. The dominant public comment on Bulletin 160-93 was that it should show how to reduce the gap between existing supplies and future demands, in addition to makingsupply and demand forecasts. Bulletin 160-98 addresses that comment by presenting a compilation oflocal agencies’ planning efforts together with potential water management options that are statewide inscope. Local agencies’ plans form the base for this effort, since it is local water purveyors who have the Agreements reached in the 1994 Bay-Delta Accord were widely hailed as a truce in California’s water wars. The approach taken in the Bay-Delta exemplifies some hallmarks of today’s water management activities—increased participation by local governments and other stakeholders in statewide water management issues, and significant efforts to carry out ecosystem restoration actions.ES1-5 I NTRODUCTION The California Water Plan Update B ULLETIN 160-98

North Coast

Sacramento River

San Joaquin River San Francisco Bay

Central Coast Tulare Lake

South Lahontan

South Coast Colorado River North Lahontan F IGURE ES1-2. California’s Hydrologic RegionsES1-6 I NTRODUCTION The California Water Plan Update B ULLETIN 160-98

ultimate responsibility for meeting their service areas’ needs. Bulletin 160-98 excludes groundwater overdraft from the Bulletin’s base year water supply estimate andis therefore the first water plan update to show an average water year shortage in its base year. (Both of the bulletins excluded future groundwater overdraft from future water supply estimates.) About 1.5 maf of the1.6 maf base year shortage is attributable to groundwater overdraft. Finally, Bulletin 160-98 uses applied water data, rather than the net water amounts historically used in the water plan series. This change was made in response to public comments that net water data were more difficult to understand than applied water data. This concept is explained in Chapter ES3. Changes in Future Demand/Shortage Forecasts Bulletin 160-93 used a planning horizon of 1990- 2020. Bulletin 160-98 uses a planning horizon of 1995-2020. Bulletin 160-98 uses the 2020 planninghorizon because no major data changes occurred between the two reports that would justify extending the planning horizon. Urban water demands dependheavily on population forecasts—the next U.S. Census will not be conducted until 2000. The water plan series uses population forecasts from the Department of Finance. DOF reduced its 2020 forecast for California in the period between Bulletin 160-93 and Bulletin 160-98. The reductionreflects the impacts of the economic recession in California in the early 1990s. California experienced a record negative net domestic migration then, as more California’s Hydrologic Regions

North Coast Klamath River and Lost River Basins, and all basins draining into the Pacific Ocean from the Oregon stateline southerly through the Russian River Basin.

San Francisco Bay Basins draining into San Francisco, San Pablo, and Suisun Bays, and into Sacramento River downstream from Collinsville; western Contra Costa County; and basins directly tributary to the Pacific Ocean below the Russian River watershed to the southern boundary of the Pescadero Creek Basin.

Central Coast Basins draining into the Pacific Ocean below the Pescadero Creek watershed to the southeastern boundary of Rincon Creek Basin in western Ventura County.

South Coast Basins draining into the Pacific Ocean from the southeastern boundary of Rincon Creek Basin to the Mexican boundary.

Sacramento River Basins draining into the Sacramento River system in the Central Valley (including the Pit River drainage), from the Oregon border south through the American River drainage basin.

San Joaquin River Basins draining into the San Joaquin River system, from the Cosumnes River basin on the north through the southern boundary of the San Joaquin River watershed.

Tulare Lake The closed drainage basin at the south end of the San Joaquin Valley, south of the San Joaquin River watershed, encompassing basins draining to Kern Lakebed, Tulare Lakebed, and Buena Vista Lakebed.

North Lahontan Basins east of the Sierra Nevada crest, and west of the Nevada stateline, from the Oregon border south to the southern boundary of the Walker River watershed.

South Lahontan The closed drainage basins east of the Sierra Nevada crest, south of the Walker River watershed, northeast of the Transverse Ranges, north of the Colorado River Region. The main basins are the Owens and the Mojave River Basins.

Colorado River Basins south and east of the South Coast and South Lahontan regions; areas that drain into the Colorado River, the Salton Sea, and other closed basins north of the Mexican border.ES1-7 I NTRODUCTION The California Water Plan Update B ULLETIN 160-98

people moved out of the State than moved in. This reduction in the population forecast translates to areduction in forecasted urban water use in Bulletin 160-98. The 2020 forecasted agricultural water demands increased from Bulletin 160-93 to Bulletin 160-98, even though the forecasted crop acreage decreased slightly. This increase resulted from elimination of the “other” category of water use shown in Bulletin 160- 93, which included conveyance losses. For Bulletin 160-98, water in the “other” category was reallocatedback to the major water use categories to simplify information presentation. Most of the conveyance losses are associated with agricultural water use. Combiningthe “other” category into the major water use categories most affected the agricultural water demand forecast. When conveyance losses are factored out ofthe Bulletin 160-98 forecast, agricultural water use decreases between Bulletin 160-93 and Bulletin 160-98. Bulletin 160-93 was the first water plan update to quantify environmental water use, recognizing theimportance of the water that is dedicated to environmental purposes for maintaining those resources and that this water is unavailable for future developmentfor other purposes. As illustrated earlier, the environmental sector is California’s largest water using sector.Bulletin 160-98 uses the same definition and quantification procedure for environmental water use as did Bulletin 160-93. The 2020 environmental water demand forecastincreased substantially from Bulletin 160-93 to Bulletin 160-98. This increase results from implementation of the Bay-Delta Accord, inclusion of additional wildand scenic river flows, and increased instream flow requirements. The shortage shown in Bulletin 160-98 is similarin magnitude to the low end of the shortage range reported in Bulletin 160-93. The treatment of forecasted Bay-Delta environmental water demands accounts for much of the difference. The range of potential future environmental water demands of 1 to 3 maf used inBulletin 160-93 was added to that Bulletin’s base environmental water demand forecast, rather than beingevaluated through operations studies, because BayDelta regulatory assumptions could not be determinedthen. This conservative approach yielded higher demands than operations studies would have provided.

Preparation of Bulletin 160-98 Although the water plan updates are published only every five years, the Department continuously compiles and analyzes the annual data used to prepare them. After publication of Bulletin 160-93 in 1994, the remainder of that year was devoted to finishingdata evaluation deferred during the Bulletin’s production. Work on Bulletin 160-98 began in 1995. Acitizens’ advisory committee with more than 30 members, representing a wide range of interests, was established to assist the Department in its preparationof the next water plan update. The advisory committee met with Department staff 17 times duringBulletin 160-98 preparation, and in August 1997 reviewed an administrative draft that preceded release of the public review draft at the end of January 1998. The review period for the public draft extended through mid-April 1998, during which time public meetings were held and presentations were made to interested parties. The draft was also made available on the World Wide Web. Over 4,000 copies of the public review draft were distributed.

Public Comments on DraftThe Department received over 200 comment letters on the draft and additional comments from public meetings. Many comments were provided by local agencies whose facilities and projects are described in the public draft, and dealt with edits or corrections regarding those facilities or projects. Another major class of comments dealt with policy, conceptual, oranalytical subjects. Many of these comments were influenced by discussions taking place in the CALFED Bay-Delta program and reflected the commenters’ positions on CALFED issues. For example, proponentsof CALFED’s no conveyance improvements alternative generally expressed opposition to Bulletin 160-98’s exclusion of groundwater overdraft as a supply, because this approach increases overall statewide shortages. The Department received positive public comments onBulletin 160-93 when it excluded groundwater overdraft as a supply for the first time, and also received positive comments on its treatment of overdraft for Bulletin 160-98. Often, public comments conflictedwith one another. For example, environmental organizations frequently stated that the Bulletin should include more future water conservation, while water purveyors frequently stated that levels assumed in theBulletin were overly optimistic. Some comments suggested that the Bulletin’s future water demands could be reduced by raising water prices, while others felt that the forecasted demands were too low and did notES1-8 I NTRODUCTION The California Water Plan Update B ULLETIN 160-98

take into account future needs of California’s population and agricultural economy. Likewise, somecomments expressed philosophical opposition to constructing more reservoirs in California, while othersemphasized the need for more storage and flood control reservoirs. The Department considered thesecomments in the context of the Bulletin’s goal of accurately reflecting actions that water purveyors statewide would be reasonably likely to implement by year 2020. Some comments suggested that Bulletin 160-98(or the Department, or the State of California) advocate or express a vision on a variety ofsubjects—including State-funded water supply development, sustainable development, nonpoint source pollution, flood control, food production security, mandatory water pricing, and greater use of desalting(by entities other than the commenter). Such an approach is outside the scope of the Department’s water plan update series. The role of the Bulletin 160 series is to evaluate present and future water supplies and demands given current social/economic policies, andto evaluate progress in meeting California’s future water needs. As appropriate, the Bulletin discusses how other factors such as flood control may relate to water supply planning. To develop 2020-level conditions, the Departmentmakes a fundamental assumption that today’s conditions—facilities, programs, water use patterns, and other factors—are the basis for predicting the future.(And, as one commenter correctly pointed out, Bulletin 160-98 also assumes that California’s climate will remain unchanged over the Bulletin’s 25-year planning horizon.) This approach differs distinctly from theapproach of establishing a desired future goal or vision, and then preparing a plan that would implement that goal or vision. Such a plan would require broad public acceptance that simply does not exist today.Many of the advocacy or vision comments described above are also not within the Department’s jurisdiction or the jurisdiction of other State agencies.For example, the Department’s role in developing water supply for local agencies is limited to fulfilling itsState Water Project contractual obligations. (The Department may provide financial assistance to local agencies for various water management programs asauthorized under bond measures enacted by the Legislature and approved by the voters.) The Departmenthas no regulatory authority to mandate how local water agencies price their water supplies, or to requirethat local agencies adopt one type of water management option over another. Comments such as those suggesting that the Department plan for control of nonpoint source pollution or food production address the jurisdictional areas of other State agencies.The subject of flood control merits special mention because of the direct relationship between operation of water supply projects and flood control projects. The purpose of the water plan update series is to evaluate water supplies, but those supplies can be affected by flood control actions such as increasing the amount of reservoir storage dedicated to flood control purposes. With memories of the disastrous January 1997 floods still fresh in people’s minds, somecommenters recommended that Bulletin 160-98 devote more attention to flood control needs, such asfloodplain mapping programs, that are not directly related to water supply considerations. The 1997 Final Report of the Governor’s Flood Emergency Action Team describes recommended actions to be taken based on the damages experienced in January 1997. Sections ofthat report are referenced throughout the Bulletin. Bulletin 160-98 emphasizes the interaction between water supply and flood control planning, and points out the benefits associated with multipurpose water projects.As discussed in the following section, the Department received a number of comments requesting thatBulletin 160-98 quantify future water supply uncertainties associated with ongoing programs or regulatory actions, such as the CALFED Bay-Delta program, Federal Energy Regulatory Commission hydroelectric plant relicensing, and Endangered Species Act listings. Text has been added that quantifies those actions for which data are available. The Department received some comments that could not be incorporated in Bulletin 160-98 because they suggested substantial changes in the scope or content of the Bulletin that could not be addressed before the Bulletin’s due date to the Legislature, or suggested changes for the next update of the water plan.The scope of Bulletin 160-98 was established in coordination with the Bulletin’s advisory committee in 1995, just as the scope of the next plan update (five years hence) will be established early in the process of preparing that update. The Department will consider these long-term comments when work begins on the next update.
Works in Progress and UncertaintiesThe descriptions of major California water management activities provided in the Bulletin are generallyES1-9 I NTRODUCTION The California Water Plan Update B ULLETIN 160-98

current through July 1998. There are several pending activities that could be characterized as works in progress, including the CALFED Bay-Delta programand Colorado River water use discussions. For programs such as these, the Bulletin describes their current status and potential impacts, if known, on future water supplies. There are uncertainties associated with the outcomes of these activities, just as there are with any process that is evaluated in mid-course. As noted at the beginning of this chapter, each water plan update focused on issues or concerns of special interest at the time of its publication. As an example of this focus, Bulletin 160-83 was the last water plan update to review water use for hydropower generation. No major changes have occurred since the late 1970s/early 1980s, when high energy prices and favorable tax treatment for renewable energy spurred a boom in small hydropower development. Today,uncertainties about water supply and water use associated with hydropower production are increasing, withthe 1998 initiation of deregulation for California investor-owned power utilities and the prospect of FERC relicensing of several powerplants on major Sierra Nevada rivers between 2000 and 2010. Although there is presently little information available on which to base forecasts of resultant changes in water supplies, more information is likely to be available for the next water plan update.Colorado River interstate issues are a new addition to a statewide water picture largely dominated by Delta and Central Valley Project Improvement Act issues in the recent past. Achieving a solution to California’s need to reduce its use of Colorado River water to the State’s basic apportionment (a reduction of as much as 900 taf from historical uses) requires consensus among California’s local agencies that use the river’s water, as well as concurrence in the plan by the other basin states.
Presentation of Data in Bulletin 160-98 Water budget and related data are tabulated byhydrologic region throughout the Bulletin. The statewide totals in these tables are generally presented as rounded values. As a result, individual table entries will not necessarily sum exactly to the rounded totals.In the Chapter ES5 water budget appendices, regional water use/supply totals and shortages are not rounded. Individual table entries may not sum exactly to the reported totals due to rounding of individual entries for presentation purposes.ES2-1 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

California’s

increasing population is a

driving factor in future water

management planning. 

# Current Events in California Water Management 

# T his chapter highlights some significant infrastructure and institutional changes
that have occurred since the publication of Bulletin 160-93, and reviews the
status of selected high-profile programs.

A common theme in previous California Water Plan updates has been the need
to respond to the State’s continually increasing population. Population growth brings with
it the need for new or expanded infrastructure. California’s water purveyors have made
significant infrastructure improvements—including reservoirs, conveyance facilities, recycling
and desalting facilities, and structural environmental restoration projects—since publication

of the last C alifornia Water Plan update.
In 1998, Contra Costa Water District completed its 100 taf Los Vaqueros Reservoir,
improving water quality and providing emergency storage for its service area. Metropolitan
Water District of Southern California is constructing its Eastside Reservoir in Riverside
County. When completed in 1999, this 800 taf reservoir will nearly double the region’s
existing surface storage capacity and will provide increased terminal storage for
SWP and Colorado River supplies. Eastside Reservoir would provide the entire
region with a six-month emergency supply after an earthquake or other disaster
and would also provide water supply for drought protection and peak summer

demands. 

# Executive Summary

FacilitiesES2-2 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

Several major conveyance projects were completedor began construction since the last water plan update. For example, the Department’s Coastal Aqueduct, completed in 1997, now carries SWP water to San Luis Obispo and Santa Barbara Counties. Mojave Water Agency recently completed a major conveyance facility (71 miles long) and is constructing another of similar length to import surface water to its service area to alleviate longstanding groundwater overdraftproblems. Large conveyance projects under construction or recently completed are listed in Table ES2-1. Water recycling and desalting are becoming largercomponents of existing and potential future water supplies, especially for urban areas. Bulletin 160-98 estimates 1995-level total statewide water recycling to be 485 taf/yr, considerably higher than the Bulletin 160-93 total water recycling estimate of 384 taf/yr. Groundwater recharge and agricultural and landscape irrigation constitute the greatest uses of recycled waterin the State. As advanced treatment technologies become more cost-effective, and as public acceptance increases, augmentation of surface water supplies may become another application for recycled water. The San Diego water repurification program, a proposed project to repurify 16 taf/yr of wastewater, would bethe first example of highly treated recycled water being discharged directly into a surface reservoir. Today, California has more than 150 desaltingplants producing fresh water from brackish groundwater, municipal and industrial wastewater, and seawater. The capacity of these plants totals about 66 taf/ yr; seawater desalting capacity accounts for only 8 taf/ yr of total capacity. Most existing plants are small (less than 1 taf/yr) and have been constructed in coastal communities with limited water supplies. The Santa

DWR’s extension of the Coastal Branch to serve San Luis Obispo and Santa Barbara Counties provides an imported surface water supply that can help reduce overdraft of coastal groundwater basins. T

ABLE ES2-1 Major Water Conveyance Facilities Since 1992

Facility Constructing Status Length Maximum Agency (miles) Capacity (cfs) Coastal Branch Aqueduct Department of Water Resources completed 1997 100 100
Eastside Reservoir Pipeline Metropolitan Water District completed 1997 8 1,000 of Southern California
East Branch Enlargement Department of Water Resources completed 1996 100 2,880
Mojave River Pipeline Mojave Water Agency started 1997 71 94
Old River Pipelines Contra Costa Water District completed 1997 20 400

(Los Vaqueros Project)
East Branch Extension Department of Water Resources started 1998 14 104
Inland Feeder Project Metropolitan Water District started 1997 44 1,000 of Southern California
Morongo Basin Pipeline Mojave Water Agency completed 1994 71 100

New Melones Water Stockton East Water District and completed 1993 21 500

Conveyance Project Central San Joaquin Water Conservation DistrictES2-3 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

Barbara desalting plant, with a capacity of 7.5 taf/yr, is the largest seawater desalting plant in California. The plant was constructed during the 1987-92 drought and is now on long-term standby. In 1997, the MarinaCoast Water District completed construction on a reverse osmosis seawater desalting plant. This $2.5 million plant produces about 340 af/yr. Many large-scale environmental restorationprojects and programs are being implemented. Facilities associated with these programs include the UnitedStates Bureau of Reclamation’s Shasta Dam Temperature Control Device, USBR’s Red Bluff Diversion Dam Research Pumping Plant, and many fish screens or fishpassage improvements at local agency and privatelyowned diversions. Financial assistance provided byprograms such as CVPIA’s anadromous fish restoration program and CALFED’s Category III programhas resulted in a major expansion of local agency screening and fish passage projects. Table ES2-2 lists some of the largest examples of recently completed structural fishery restoration projects. Several more large fish screen facilities are nearing the final phases of design or construction, includingdiversions on the Sacramento River at the GlennColusa Irrigation District, Reclamation District 108 near Grimes, Reclamation District 1004 near Princeton, the Princeton-Codora-Glenn Irrigation District and Provident Irrigation District consolidated diversion, and others. Construction of GCID’s Hamilton City Pumping Plant screen began in spring 1998. This $70 million project will minimize fish losses near the pumping plant and will maximize GCID’s ability to meet its water supply delivery obligations. Reclamation District 108 began construction in 1997 USBR is evaluating the fishery impacts of different types of pump diversions to the Tehama-Colusa Canal. One alternative for improving fish passage at Red Bluff Diversion Dam would be to leave the dam’s gates in the raised position and use a pumping plant to make TCC diversions. The research plant contains three pumps—one helical pump and two Archimedes screw pumps (right side of photo).

Shasta Dam Temperature Control Device T ABLE ES2-2 Large Structural Fishery Restoration Projects

Project Owner Description

USBR An approximately $83 million modification to the dam’s outlet works to allow temperature-selective releases of water through the dam’s powerplant was completed in 1997.

Red Bluff Diversion Dam Research Pumping Plant USBR A $40 million experimental facility to evaluate fishery impacts of different types of pumps diverting Sacramento River water into the Tehama-Colusa and Corning Canals was constructed in 1995.
Butte Creek fish passage Western Canal Water District and others A multi-component project to improve fish passage by removing small irrigation diversion dams from the creek. By 1998, five diversion dams will have been removed.
Maxwell Irrigation District fish screen Maxwell ID An 80 cfs diversion on the Sacramento River was screened in 1994.
Pelger Mutual Water Company fish screen PMWC A 60 cfs diversion on the Sacramento River was screened in 1994.ES2-4 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

on a new $10 million fish screen. The project, located at the district’s Wilkens Slough diversion, will protectmigrating winter-run chinook salmon. The district anticipates completing the project by the 1999 irrigation season. Reclamation District 1004 began construction of its $8 million fish screen in 1998. In addition to a fish screen, the project includes relocation of the Princeton Pumping Plant and conveyance facilities. In 1998, the Princeton-Codora-Glenn and ProvidentIrrigation Districts are expected to complete construction of an $11 million fish screen and pump consolidation project. The 600 cfs project eliminates three unscreened diversions.

Legislation

Proposition 204 In 1996, California voters approved Proposition 204, the Safe, Clean, Reliable Water Supply Act. The act authorized the issuance of $995 million in general obligation bonds to finance water and environmentalrestoration programs throughout the State. Approximately $600 million of these bonds would provide theState share of costs for projects benefitting the BayDelta and its watershed, including $390 million of thisamount to implement CALFED’s ecosystem restoration program for the Bay-Delta. These latter fundswould be available after final federal and State environmental documents are certified and a cost-sharing agreement is executed between the federal and State governments. Table ES2-3 summarizes all programs authorized for Proposition 204 funding.

Proposition 218 Voter approval of Proposition 218 in November 1996 changed the procedure used by local governmentagencies for increasing fees, charges, and benefit assessments. Benefit assessments, fees, and charges that are imposed as an “incident of property ownership” are now subject to a majority public vote. Proposition 218 defines “assessments” as any levy or charge on realproperty for a special benefit conferred to the real property, including special assessments, benefit assessments, and maintenance assessments. Proposition 218 further defines “fee” or “charge” as any levy (other than an advalorem tax, special tax, or assessment), which is imposed by an agency upon a parcel or upon a person as an incident of property ownership, including a user fee or charge for a property-related service. Although there are many tests to determine if afee or charge is subject to the provisions of Proposition 218, the most significant one is whether the agency has relied upon any parcel map for the imposition of the fee or charge. There is currently uncertainty in theinterpretation of Proposition 218 requirements, especially as they relate to certain water-related fees and charges. From one point of view, Proposition 218 couldbe interpreted as a comprehensive approach to regulate all forms of agency revenue sources. This broad interpretation would include all fees and charges forservices provided to real property. Types of water-related charges and fees that may be affected by Proposition 218’s requirements include meter charges, acreage-based irrigation charges, and standby charges. Additional legislation or judicial interpretation may be needed to clarify the application of Proposition 218 to fees and charges used by water agencies. Several waterindustry groups are working on proposals for clarifying legislation. To date, there has been one water-relatedlegislative clarification of Proposition 218. A 1997 statute clarified that assessments imposed by water districts and earmarked for bond repayment are not subject to the proposition’s voter approval requirements. Municipalities and special districts are beginning to seek voter approval of assessments as required by Proposition 218. Many assessments to fund existing programs have been receiving voter approval. There is at least one example, however, of a water agency whose proposed assessment was not approved. Monterey County Water Resources Agency did not receive voterapproval for an assessment to support existing programs—groundwater quality monitoring, water conservation, and nitrate management outreach— funded by water standby charges. Examples of MCWRA’s proposed assessment charges were $1.67 per irrigated acre for agricultural land use and $2.26 per parcel for single-family dwellings.

MTBE Detection of methyl tertiary butyl ether in water supplies soon after it was approved for use as an airpollution-reducing additive in gasoline has raised concerns about its mobility in the environment. Legislation enacted in 1997 included several provisions dealing with MTBE regulation, monitoring, and studies. One provision required the Department of Health Services to establish a primary (health-based) drinking water standard for MTBE by July 1999, and a secondary (taste and odor) drinking water standard by July 1998.ES2-5 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

MTBE can be detected by taste at very low concentrations, hence the early requirement for a secondary drinking water standard.
Safe Drinking Water Act The Safe Drinking Water Act, administered by theU.S. Environmental Protection Agency in coordination with the states, is the chief federal regulatory legislation dealing with drinking water quality. The 104th Congress reauthorized and made significantchanges to the SDWA, which had last been reauthorized in 1986. Major changes included: • Establishing a drinking water state revolving loan fund, to be administered by states in a manner similar to the existing Clean Water Act State Revolving Fund. Loans would be made available to public water systems to help them comply with national primary drinking water regulations and to upgrade water treatment systems. • The standard-setting process for drinking water contaminants established in the 1986 amendments was changed from a requirement that EPA adopt standards for a set number of contaminants on a fixed schedule to a process based on risk assessment and cost/benefit analysis. The 1996 amendments require EPA to publish (and periodically update) a list of contaminants not currently subject to national primary drinking water regulations, and to periodically determine whether to regulate at least five contaminants from that list, based on risk and benefit considerations. • A requirement that states conduct vulnerability assessments in priority source water areas expanded existing source water quality protection provisions. States are authorized to establish voluntary, incentive-based source protection partnerships with local agencies. This activity may be funded from the new SRF. • As a result of the 1996 amendments, EPA adopted a more ambitious schedule for promulgating the

T

ABLE ES2-3 Proposition 204 Funding Breakdown

Program Dollars (in millions)

Delta Restoration 193

CVPIA State share 93 Category III State share 60 Delta levee rehabilitation 25 South Delta barriers 10 Delta recreation 2 CALFED administration 3 Clean Water and Water Recycling 235
State Revolving Fund Clean Water Act loans 80 Clean Water Act grants to small communities 30 Loans for water recycling projects 60 Loans for drainage treatment and management projects 30 Delta tributary watershed rehabilitation grants and loans 15 Seawater intrusion loans 10 Lake Tahoe water quality improvements 10
Water Supply Reliability 117
Feasibility investigations for specified programs 10 Water conservation and groundwater recharge loans 30 Small water project loans and grants, rural counties 25 Sacramento Valley water management and habitat improvement 25 River parkway program 27 CALFED Bay-Delta Ecosystem Restoration Program 390

Flood Control Subventions 60

Total 995ES2-6 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

Disinfectant/Disinfection By-Products Rule and the Enhanced Surface Water Treatment Rule. The first phase of the D/DBP Rule is proposed to take effect in late 1998, as is an interim ESWTR. More stringent versions of both rules are proposed to follow in 2002.
Reclamation, Recycling, and Water Conservation Act of 1996 This act amended Title 16 of PL 102-575 byauthorizing federal cost-sharing in additional wastewater recycling projects. (PL 102-575 had authorized federal cost-sharing in specified recycling projects.) The additional California projects are shown below, along with the nonfederal sponsors identified in the statute. • North San Diego County area water recycling project (San Elijo Joint Powers Authority, Leucadia County Water District, City of Carlsbad, Olivenhain Municipal Water District) • Calleguas Municipal Water District recycling project (CMWD) • Watsonville area water recycling project (City of Watsonville) • Pasadena reclaimed water project (City of Pasadena) • Phase 1 of the Orange County regional water reclamation project (Orange County Water District and County Sanitation Districts of Orange County) • Hi-Desert Water District wastewater collection and reuse facility (HDWD) • Mission Basin brackish groundwater desalting demonstration project (City of Oceanside) • Effluent treatment for the Sanitation Districts of Los Angeles County with the City of Long Beach (Water Replenishment District of Southern California, OCWD) • San Joaquin area water recycling and reuse project (San Joaquin County, City of Tracy) Federal cost-sharing in these projects is authorized at a maximum of 25 percent for project construction and federal contributions for each project are capped at $20 million. Funds are not to be appropriated for project construction until after a feasibility study andcost-sharing agreement are completed. Federal costsharing may not be used for operations and
maintenance.The act also authorizes the Department of Interior to cost-share up to 50 percent (planning and design) in a Long Beach desalination research and development project. Local sponsors are the City of Long Beach, Central Basin Municipal Water District, and MWDSC.
Water Desalination Act of 1996
This act authorizes DOI to cost-share in non-federal desalting projects at levels of 25 percent or50 percent (for projects which are not otherwise feasible unless a federal contribution is provided).Cost-shared actions can be research, studies, demonstration projects, or development projects. The authorization provides $5 million per year for fiscal years 1997 through 2002 for research and studies, and$25 million per year for demonstration and development projects. The act requires DOI to investigate at least three different types of desalting technology and to report research findings to Congress.

Major Water Management Issues and Programs

Bay-Delta Accord and CALFED Representatives from the California Water Policy Council, created to coordinate activities related to State long-term water policy, and the Federal Ecosystem Directorate, created to coordinate actions of federalagencies involved in Delta programs, signed a Framework Agreement for the Bay-Delta estuary in June 1994. Together, these agencies are known as CALFED. The Framework Agreement improved coordinationand communication between State and federal agencies with resource management responsibilities in the estuary. It covered the water quality standards setting process; coordinated water project operations with requirements of water quality standards, endangeredspecies laws, and CVPIA; and provided for cooperation in planning long-term solutions to problems affecting the estuary’s major public values. In December 1994 State and federal agencies, working with stakeholders, reached agreement on the “Principles for Agreement on Bay-Delta StandardsBetween the State of California and the Federal Government” (referred to as the Bay-Delta Accord) that would remain in effect for three years. Provisions of the Bay-Delta Accord covered water quality standard setting and water project operational constraints, ESA implementation and use of real-time monitoring data, and improvement of conditions not directly related to Delta outflow. Parties to the Accord committed to fundES2-7 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

“non-flow Category III” measures at $60 million per year for the agreement’s three-year term. The Accord was subsequently extended for a fourth year. An Operations Group composed of representatives from the State and federal water projects and the other CALFED agencies was established to coordinate project operations. Stakeholders from water agencies, and environmental and fishery groups participate in Operations Group meetings. Water Quality Standard Setting. SWRCB adopted a water quality control plan for the Bay-Delta in May 1995, incorporating agreements reached in the Accord. In June 1995, SWRCB adopted Order WR 95-6, an interim order amending terms and conditionsof SWRCB’s Decision 1485 and the SWP’s and Central Valley Project’s water right permits to resolve inconsistencies with D-1485 requirements and theprojects’ voluntary implementation of Accord standards. The interim order will expire when a water right decision allocating final responsibilities for meeting the 1995 objectives is adopted, or on December 31, 1998, whichever comes first. SWRCB released a revised draft EIR for implementing the water quality control plan in 1998, and intends to issue a water right decision implementing the order by the end of 1998. The DEIR has eight flow alternatives: (1) SWP and CVP Responsible for D-1485 Flow Objectives (2) SWP and CVP Responsible for 1995 Bay-Delta Water Quality Control Plan Flow Objectives (3) Water Right Priority Alternative—the CVP’s Friant Unit is assumed to be an in-basin project. (4) Water Right Priority Alternative—the CVP’s Friant Unit is assumed to be an export project. (5) Watershed Alternative—monthly average flow requirements are established for major watersheds based on Delta outflow and Vernalis flow objectives and the watersheds’ average unimpaired flow. The parties responsible for providing the required flows are water users with storage in foothill reservoirs that control downstream flow to the Delta, and water users with upstream reservoirs that have a cumulative capacity of at least 100 taf who use water primarily for consumptive uses. (6) Recirculation Alternative—USBR is required to make releases from the Delta-Mendota Canal to meet the Vernalis flow objectives. (7) San Joaquin Basin Negotiated Agreement—San Joaquin Basin water right holders’ responsibility to meet the plan objectives is based on an agreement titled “Letter of Intent among Export Interests and San Joaquin River Interests to Resolve San Joaquin River Issues Related to Protection of Bay-Delta Environmental Resources.” (8) San Joaquin Basin Negotiated Agreement— Vernalis flow objectives are replaced by target flows contained in the agreement. CALFED Long-Term Solution-Finding Process for Bay-Delta. The June 1994 Framework Agreement called for a State-federal process to develop long-term solutions to Bay-Delta problems related to fish and wildlife, water supply reliability, natural disasters, and water quality. The CALFED program is managed by an interagency team under the policy direction ofCALFED member agencies, with public input provided by the Bay-Delta Advisory Council. BDAC is a 31-member advisory panel representing California’s agricultural, environmental, urban, business, fishing, and other interests who have a stake in the long-term solution to Bay-Delta problems. The CALFED program’s first phase identified problems and goals for the Bay-Delta, and developed a range of alternatives for long-term solutions. Thisphase concluded with a September 1996 report identifying three broad solutions, each of which included

Actions funded by the Category III program include fish screening, fish passage improvements, habitat acquisition, and control of non-native invasive species. The zebra mussel has caused millions of dollars of increased operations and maintenance costs to Great Lakes water users. Preventing the mussels’ spread is a priority in invasive species management.ES2-8 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

a range of water storage options, a system for conveying water, and some programs that were common toall alternatives. The second phase consisted of preparing a programmatic EIR/EIS covering three main alternatives for conveyance of water across the Delta— an existing system alternative, a through-Delta alternative, and a dual Delta conveyance alternative. The first public review draft of the PEIR/PEIS was released in March 1998. CALFED expects to issue a second draft PEIR/PEIS by the end of 1998. The revised draft would identify CALFED’s draft preferred alternative.The third phase would involve staged implementation of the preferred alternative over a time periodof several decades and will require site-specific environmental documents. Current plans are for an initial implementation period of 7 to 10 years, during whichonly common program elements would be implemented (water conservation measures, ecosystem restoration, levee improvements). Any conveyance or storage facilities would be constructed in a later phase of implementation. ESA Administration. The December 1994 BayDelta Accord established several principles governing ESA administration in the Bay-Delta during the agreement’s term. • The Accord is intended to improve habitat conditions in the Bay-Delta to avoid the need for additional species listings during the agreement’s term. If additional listings do become necessary, the federal government will acquire any additional water supply needed for those species by buying water from willing sellers. • There is intended to be no additional water cost to the CVP and SWP resulting from compliance with biological opinion incidental take provisions for presently listed species. The CALFED Operations Group is to develop operational flexibility by adjusting export limits. • Real-time monitoring is to be used to the extent possible to make decisions regarding operational flexibility. CALFED commits to devote significant resources to implement real-time monitoring.

Colorado RiverA major issue facing California is its use of Colorado River water in excess of the amount apportioned to it by the existing body of statutes, court decisions, and agreements controlling use of the water supplyamong the seven basin states. California’s basic apportionment of river water is 4.4 maf of consumptive use per year (plus a share of surplus flows, when available), as compared to its present consumptive use of up to 5.3 maf/yr. California’s use has historically exceeded the basic apportionment because California has been able to divert and use Arizona’s and Nevada’s unused apportionments, and to divert surplus water. With completion of the Central Arizona Project andthe 1996 enactment of groundwater banking legislation, Arizona projects that it will use almost all of its 2.8 maf apportionment for the first time in 1998. Nevada is projected to use about 280 taf of its 300 taf apportionment in 1998. California local agencies, working through theColorado River Board of California, have been developing a proposal for discussion with the other basin states to illustrate how, over time, California would reduce its use to the basic apportionment of 4.4 maf/yr. Drafts of the proposal, known as the draft Colorado River Board 4.4 Plan, have been shared with theother states. Efforts are being made to reach intrastate consensus on the plan in 1998. As Bulletin 160-98 CALFED’s Ecosystem Restoration Program calls for extensive creation of new habitat in the Delta. Construction of setback levees would allow restoration of riparian and riverine aquatic habitats, benefitting fish and wildlife.ES2-9 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

goes to press, the most current version of the draft plan is the December 1997 version.As formulated, the draft plan would be implemented in two phases. The first phase (between thepresent and 2010 or 2015) would entail implementing already identified measures such as waterconservation and transfers to reduce California’s Colorado River water use to about 4.6 to 4.7 maf/yr. The second phase would implement additional measures to reduce California’s use to its basic annual 4.4 maf apportionment in those years when neither surplus water nor other states’ unused apportionments were available. One of the fundamental assumptions madein the plan is that MWDSC’s Colorado River Aqueduct will be kept full by making water transfers fromagricultural users in the Colorado River Region to urban water users in the South Coast Region. Actions included in the first phase were: core water transfers such as the existing Imperial IrrigationDistrict/MWDSC agreement and the proposed Imperial Irrigation District/San Diego County WaterAuthority transfer; seepage recovery from unlined sections of the All American and Coachella Canals; drought year water transfers similar to the Palo VerdeIrrigation District/MWDSC pilot project; groundwater banking in Arizona; and conjunctive use of groundwater in areas such as the Coachella Valley. The draft plan recognizes that transfers of conserved water must be evaluated in the context of preserving the Salton Sea’s environmental resources, and also that plan elements must address environmental impacts on the lower Colorado River and its listed species. Other actions to occur as part of the first phase would include implementation of the San Luis Rey Indian water rights settlement authorized in PL 100- 675 and implementation of measures to administer agricultural water entitlements within the first threepriorities of the Seven Party Agreement. An important element of the draft CRB 4.4 Plan is the concept that existing reservoir operating criteria be changed by USBR to make optimum use of the river’s runoff and available basin storage capacity. California agencies developed new proposed operating criteria that are included in the draft CRB 4.4 Plan. The draft plan contemplates that changes in operating criteria would be part of both the first and second phases. The other basin states have been cautious in their reaction to California’s proposals for reservoir reoperation, and have suggested, for example, that new criteria should not be implemented until California has prepared the environmental documents and executed the agreements that would be needed to begin implementation of the draft CRB 4.4 Plan. The second phase of the draft CRB 4.4 Plan wouldinclude additional average year and drought year water transfers. Specifics on these transfers would bedeveloped during the first phase of plan implementation. Other components of the second phase wouldinclude further transfers of conserved agricultural water to the South Coast and further work on reservoir operating criteria. Implementation of some elementsof phase two of the plan may extend beyond the Bulletin 160-98 planning horizon.

Recent ESA Listings Since publication of Bulletin 160-93, there has been action on federal listing of several fish species having statewide water management significance. In August 1997, the National Marine Fisheries Service listed two coastal steelhead populations as threatened (from the Russian River south to Soquel Creek, and from the Pajaro River south to the Santa Maria River), and one population as endangered (from the Santa Maria River south to Malibu Creek). NMFS deferred listing decisions for six months for other California populations—from the Elk River in Oregon to the Trinity River in California, from Redwood Creek to

USBR’s Parker Dam on the Colorado River impounds Lake Havasu. At this location, the Colorado River forms the stateline between California and Arizona. MWDSC’s Colorado River Aqueduct and the Central Arizona Project divert from Lake Havasu.ES2-10 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

the Gualala River, and in the Central Valley—due toscientific disagreement about the sufficiency and accuracy of the data available for listing determinations.In March 1998, NMFS listed the Central Valley population as threatened, and deferred listing of the twonorth coast populations in favor of working with California and Oregon on state conservation plans. Also in 1997, NMFS listed the Southern Oregon/ Northern California coast evolutionarily-significant unit of coho salmon as threatened. In 1996, NMFS listed coho salmon in the central coast ESU (from Punta Gorda in Humboldt County south to the San Lorenzo River) as threatened. In 1998, NMFS proposed several runs of chinooksalmon for listing—the spring-run in the Central Valley ESU as endangered, the fall and late-fall runs in the Central Valley ESU as threatened, and the spring and fall runs in the Oregon/California coastal ESU as threatened. (The spring-run chinook salmon has been listed as a candidate species under the California ESA.) NMFS expects to make its decision on listing in 1999. USFWS proposed in 1994 to list a resident Deltafish species, the Sacramento River splittail, but a congressional moratorium on listing of new speciesprevented USFWS from working on the proposal until 1996. USFWS again proposed to list splittail in 1996, but received significant public comments on newscientific information for splittail. The extended public comment period ended July 1998. USFWS is expected to make a decision after reviewing comments.USFWS has also listed or proposed for listing species whose limited range would result in localized water management impacts. For example, the red legged frog, found primarily in the Central Coast area, was listed as threatened in 1996. Another example is the Santa Ana sucker, found in the Santa Ana River, proposed for listing in 1998.
January 1997 Central Valley Floods The January 1997 flood event was notable for its sustained rainfall intensity, the volume of floodwater,and the extent of the storm pattern—from the Oregon border down to the southern end of the Sierra. Over a three day period, warm moist winds from the southwest blew over the Sierra Nevada, pouring over 30 inches of rain on watersheds already saturated by one of the wettest Decembers on record. In many major river systems, flood control dams reduced flood flowsby half or more, saving lives and significantly reducing property damage. However, in some areas, leveed flood control systems were overwhelmed, causing approximately $2 billion in damages.Most of the large reservoirs in Northern California were full or nearly full within the first days inJanuary. Several Sacramento Valley reservoirs—including Shasta, Oroville, and New Bullards Bar—experienced record inflows during the January 1997 flood event. American River inflow to Folsom Reservoir was similar to the amount recorded duringthe February 1986 flood. Levees of the federal Sacramento River Flood Control Project (see sidebar) sustained moderate to heavy damage, including two major levee breaks (one near the town of Arboga) and several relief cuts. Flooding in the Marysville-Yuba City area resulted in 35,000 people being evacuated fromthe Marysville area and 75,000 people being evacuated downstream in Sutter County. The volume of runoff exceeded the flood control capability of New Don Pedro Reservoir on the Tuolumne River and Millerton Lake on the Upper San Joaquin River. While the peak flood release from New Don Pedro Dam was less than half the peak Tuolumne River inflow of 120,000 cfs, it was more than six times the downstream channel’s flow restrictions of 9,000 cfs. In all, 36 levee failures occurred along the San Joaquin River system, along with extensive damagerelated to high flows and inundation. Most of the damage occurred downstream of the Tuolumne River confluence. The January 1997 floods demonstrated the need for increased Central Valley flood protection. The 1997 Final Report of the Governor’s Flood Emergency Action Team identified many actions that could be taken toincrease valley flood protection, including better emergency preparedness, floodplain management actions,levee system improvements, construction of new floodways, temporary storage of floodwaters on wildliferefuges, reoperation or enlargement of existing reservoirs to increase flood storage, and construction of new
reservoirs. The Sacramento River Flood Control Project’s ability to provide protection for growing urban areas is the primary flood control issue facing the Sacramento Valley. Additional flood protection is needed in theYuba River Basin, particularly in the greater MarysvilleYuba City area. Additional flood protection is also needed in the American River Basin for the Sacramento metropolitan area, as discussed in the accompanyingsidebar. The 1997 FEAT report detailed several recommendations and possible actions for the SacramentoES2-11 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

The Sacramento metropolitan area has one of the lowest flood protection levels in the nation, for a community of

its size. Without interim reoperation of Folsom Dam, the community is estimated to have only a 1- in-60 year level of protection. (With reoperation, the level of protection is 1-in-77 years). This photo shows the American River in January 1997, and the high-density urban development adjacent to the levee.

American River Flood Protection

Following the floods of February 1986, the United States Army Corps of Engineers reanalyzed American River Basin hydrology and concluded that Folsom Dam did not provide an adequate level of flood protection to the downstream Sacramento area, significantly less than the 250-year protection estimated in the late 1940s when the dam was designed. The 977 taf reservoir has a normal winter flood control reservation of 400 taf (estimated to provide theSacramento area with protection from a storm having a 1-in60-year return period).

Three main flood protection alternatives have been evaluated by USACE. Two of the alternatives would increase flood control storage in Folsom, modify the dam’s spillway and outlet works, and improve downstream levees. The third alternative would construct a detention dam at Auburn, with downstream levee improvements. USACE studies identified the detention dam as the plan that maximized national economic benefits. The State Reclamation Board endorsed the detention dam as the best long-term solution to reliably provide greater than 1-in-200 year flood protection.

The Central Valley’s January 1997 flood disaster prompted another examination of American River hydrology. Based on that hydrologic review, the 1986 and 1997 floods are now considered to be about 60-year events. The 1997 flooding also triggered payback provisions of the Sacramento Area Flood Control Agency’s agreement with USBR, under which USBR sets aside up to 270 taf of additional winter flood control space in Folsom. (This additional flood control space in the reservoir raises Sacramento’s level of protection to about a 77-year event level.) Reoperation of Folsom for additional flood control resulted in a loss of supply to USBR. SAFCA and the federal government purchased 100 taf to offset the loss of supply—50 taf from Yuba County Water Agency, 35 taf from Placer County Water Agency, and 15 taf from GCID.

In 1998, the Reclamation Board restated its conclusion that the best long-term engineering solution to reliably provide greater than 1-in-200 year flood protection is to develop additional flood detention storage at Auburn. As an incremental measure to increase the level of flood protection, the Board also resolved to support SAFCA’s plan for modifying Folsom Dam’s outlets to increase flood protection to approximately a 1-in-110 year level. As of June 1998, SAFCA was seeking congressional authorization for USACE participation in Folsom Dam modifications and downstream levee enlargements. Valley, including new flood storage, enlarged floodbypasses, and increasing channel capacity through measures such as dredging and setback levees. The primary flood control issue facing the San Joaquin River watershed is the lack of flood channel capacity. Channels and levees are generally designedfor 50-year flood protection. Insufficient channel capacity is especially problematic in the lower San Joaquin River below the Merced River. At the lower end of the system, sediment deposition continues to raise the river bed and reduce channel capacity. Sediment deposition also promotes vegetation growth, thereby increasing channel roughness and further impeding flows. As urban development occurs on lands formerly used foragriculture, the need for higher levels of flood protection becomes more important. The 1997 FEAT reportES2-12 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

detailed several recommendations and possible actions for the San Joaquin River watershed, including newflood storage, development restrictions and land acquisitions in the floodplain, and increasing channel capacity through measures such as dredging, setback levees, and improving bridge crossings.
CVPIA ImplementationCVPIA made significant changes to the CVP’s legislative authorization, amending the project’s purposes to place fish and wildlife mitigation and restorationon a par with water supply, and to place fish and wildlife enhancement on a par with power generation. Key areas of CVPIA implementation are summarizedbelow. USBR and U.S. Fish and Wildlife Service released a draft programmatic EIS on CVPIA implementation for public review in November 1997.The draft PEIS describes, among other things, estimated water supply impacts of federal implementation of the act, and illustrates the consequences ofdifferent alternatives for fish and wildlife supplemental water acquisition. A final EIS is scheduled to be released in 1999. Renewal of CVP Water Service Contracts.CVPIA prohibited execution of new CVP water service contracts (with minor exceptions), except for fishand wildlife purposes, until all of the many environmental restoration actions specified in the statute had been completed. The act also provided that existing long-term water service contracts be renewed for 25- year terms, as opposed to their previous 40-year terms. Only interim renewals (not more than three years) are allowed until the PEIS required by the act is completed. Beginning in October 1997, most existing long term contracts are subject to a monetary hammer clauseencouraging early renewal. Renewed contracts will inThe January 1997 flood disaster was the largest in the State’s history. Flooding forced more than 120,000 people from their homes, and over 55,000 people were housed in temporary shelters. Nearly 300 square miles of agricultural land were flooded. Livestock and wildlife were trapped by the flooding.

Sacramento River Flood Control Project

Congress authorized the Sacramento River Flood Control Project in 1917 after a series of major Sacramento Valley floods in the late 1800s and early 1900s. The project was built with local, State, and federal funding. The project includes levees, overflow weirs, bypass channels, and channel enlargements. Overflow weirs allow excess water in the main river channel to flow into bypasses in the Sutter Basin and Yolo Basin. The bypass system was designed to carry 600,000 cfs of water past Sacramento—110,000 cfs in the Sacramento River through downtown Sacramento and West Sacramento, and the remainder in the Yolo Bypass. The system has worked exceedingly well over the years. The capacity of the SRFCP was increased upon completion of Shasta Dam in 1945 and Folsom Dam in 1956. The Feather and Yuba River systems did not share in the SRFCP’s flood control benefits; however, supplemental protection was provided by the completion of Oroville Dam on the Feather River in 1968 and New Bullards Bar Dam on the Yuba River in 1970. These are large multipurpose reservoirs in which flood control functions share space with water supply functions.ES2-13 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

corporate new provisions required by CVPIA, such as tiered water pricing. Since USBR has not completedthe PEIS, all contract renewals to date have been interim renewals. USBR has had more than 60 interim contract renewals from the date of enactment through 1996, representing over 1 maf/yr of supply. Fish and Wildlife Restoration Actions. One ofthe most controversial elements of CVPIA implementation has been management of the 800 taf of CVPyield (see sidebar) dedicated by the act to fishery restoration purposes. This water is available for use on CVP controlled streams (river reaches downstreamfrom the project’s major storage facilities on the Sacramento River, American River, and Stanislaus River) and in the Bay-Delta. The ambiguity of the statutory language and the use of dedicated water in the Bay-Delta Accord havegenerated many questions, including whether the water may be exported from the Delta after the water has been used for instream flow needs in upstream rivers, and if the water may be used for Bay-Delta purposes beyond Accord requirements. Initially, USBR and USFWS attempted to develop guidelines or criteriafor its management. Subsequent to CALFED’s creation, the CALFED Operations Group became a forum for attempting to resolve dedicated water. In November 1997, DOI released its final administrative proposal on management of the dedicated water. The proposal’s release was subsequently challenged in legal action filed by some CVP water contractors. A main purpose of the dedicated water is meetingthe act’s goal of doubling natural production of Central Valley anadromous fish populations (from their average 1967-91 levels) by year 2002. Release of water to the San Joaquin River from Friant Dam is excluded from this program. CVPIA authorizes USBR and USFWS to acquire additional, supplemental water from willing sellers to help achieve the doubling goal. CVPIA further allocates additional CVP water supply for instream use in the Trinity River by reducing the quantity of water which the project could otherwise divert, requiring that an instream flow of 340 taf/yr be maintained through water year 1996 while USFWS finishes a long-term instream flow study. (USFWS now recommends instream flows much greater than 340 taf/yr.) CVPIA enumerates specific physical restoration measures that the federal government must completefor fishery and waterfowl habitat restoration. The largest completed measures are a temperature control device at Shasta Dam, at a cost of over $83 million, and a research pumping plant at Red Bluff DiversionDam. CVPIA allocated part of the costs of some restoration measures to the State; the remaining costs are being paid by federal taxpayers and by CVP water and power contractors. Some of the smaller restoration actions include individual fish-screening projects thatUSBR and USFWS are cost-sharing with local agencies under the anadromous fish screening program. CVPIA required USBR to impose a surcharge onCVP water and power contracts for deposit into a Restoration Fund created by the act. Monies deposited into the fund are appropriated by Congress to help fund CVPIA environmental restoration actions. The act authorizes appropriation of up to $50 million (1992 dollars) per year for the restoration actions. Annual deposits into the fund vary with water and power sales. CVPIA environmental restoration actions can be funded from the general federal treasury, as well as from the Restoration Fund. Land Retirement Program. CVPIA authorizedDOI to carry out an agricultural land retirement program for lands receiving CVP water. USBR publishedinterim guidelines for administration of a pilot program, pending formal promulgation of rules and regulations. The federal guidelines were developed in

CVPIA’s Dedicated Water

Section 3406(b)(2) describes the dedicated water as follows: Upon enactment of this title dedicate and manage annually 800,000 acre-feet of Central Valley Project yield for the primary purpose of implementing the fish, wildlife, and habitat restoration purposes and measures authorized by this title; to assist the State of California in its efforts to protect the waters of the San Francisco Bay-San Joaquin Delta Estuary; and to help meet such obligations as may be legally imposed upon the Central Valley Project under State or Federal law following the date of enactment of this title, including but not limited to additional obligations under the federal Endangered Species Act. For the purpose of this section, the term “Central Valley Project yield” means the delivery capability of the Central Valley Project during the 1928-1934 drought period after fishery, water quality, and other flow and operational requirements imposed by terms and conditions existing in licenses, permits, and other agreements pertaining to the Central Valley Project under applicable State or Federal law existing at the time of enactment of this title have been met.ES2-14 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

coordination with a State land retirement program established in 1992 under Water Code Section 14902 et seq . The State statute limited the retirement program to drainage-impaired lands. The State land retirementprogram has never been funded, and thus no State acquisitions have been made. By November 1997, thefederal land retirement program had made one purchase—about 600 acres of drainage-impaired land in Westlands Water District that would be managed for wildlife habitat. Recently, USBR solicited proposalsfrom landowners wishing to participate in the retirement program and received offers to sell lands amounting to 31,000 acres. Other Programs and Reports. From a water supply standpoint, certain CVPIA-mandated reports are of special interest. USFWS has prepared several draftdocuments relating to estimated Central Valley environmental water needs and water management actions for the AFRP. The most recent draft of the AFRP was published in May 1997. In 1995, USBR released anappraisal-level least-cost CVP yield increase plan, required by the act to identify options for replacing the water supply dedicated to environmental purposes. Although the act directed that the plan be prepared, USBR was not required to implement it.

SWP Monterey Agreement Contract Amendments The Monterey Agreement among the Department and SWP water contractors was signed in December 1994. This agreement set forth principles for making changes in SWP water supply contracts, which would then be implemented by an amendment (Monterey Amendment) to each contractor’s SWP contract. The amendment has been offered to all SWP contractors.Those contractors that sign the amendment will receive the benefits of it, while those that do not will have their water supply contracts administered such that they will be unaffected by the amendment. As of July 1998, 26 of the 29 contractors had signed the amendment. Changes to SWP Water Allocation Rules. The amendment states that during drought years projectsupplies are to be allocated proportionately on the basis of contractors’ entitlements. The amendment allocates water to urban and agricultural purposes onan equal basis, deleting a previous initial supply reduction to agricultural contractors. Permanent Sales of Entitlement. The amendment provides for transfer of up to 175 taf of entitlement from agricultural use. The first transfer made was relinquishment of 45 taf of entitlement (40,670 af from Kern County Water Agency, 4,330 af from Dudley Ridge Water District) back to the SWP,as part of the transfer of the Kern Water Bank property to these agencies. This relinquishment reduces the total SWP contractual commitment. The amendmentprovides for an additional 130 taf of existing agricultural entitlement to be sold on a permanent basis to urban contractors, on a willing buyer-willing seller basis. Storing Water Outside a Contractor’s Service Area; Transfers of Non-Project Water. This provision allows a contractor to store water in anotheragency’s reservoir or groundwater basin. Examples include water storage programs with Semitropic Water Storage District, a member agency of Kern CountyWater Agency. The amendment also provides a mechanism for using SWP facilities to transport non-project water for SWP water contractors. (The Departmentuses other contractual arrangements for wheeling water for the CVP and for other non-SWP water users.) Annual Turnback Pool. Prior to the amendment,water allocated to contractors that was not used during a year would revert to the SWP at the end of theyear. No compensation was provided to the contractor for this water, and no other contractors could make use of these supplies during the year. The turnback pool is an internal SWP mechanism which provides for pooling potentially unused supplies early in the year for purchase by other SWP contractors at a setprice. If neither the SWP nor individual SWP contractors wish to use water placed into the pool, that water may then be sold to entities that are not SWP

contractors. Other Operational Changes. The amendment established a procedure to transfer ownership of the Department’s KWB property to KCWA and DudleyRidge Water District. The amendment allows contractors repaying costs of constructing the Castaic and Perris terminal reservoirs to increase their control and management of a portion of the storage capacity of each reservoir, to optimize the operation of local andSWP facilities. This is expected, for example, to improve dry year supplies for MWDSC, Castaic Lake Water Agency, and Ventura County Flood Control and Water Conservation District.

Environmental Restoration Activities Several major environmental restoration activities are ongoing throughout the State, in addition to theES2-15 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

intensive effort focused on the Bay-Delta. Projects focused on fishery and habitat restoration on the State’s three most important river systems—the Sacramento,San Joaquin, and Colorado Rivers—are described below, followed by a brief mention of restoration and mitigation projects in other watersheds. Sacramento River System. The extensive structural environmental restoration actions beingperformed in the Sacramento River system were described earlier in this chapter. These actions includemajor projects such as USBR’s Shasta Dam Temperature Control Device and research pumping plant atRed Bluff Diversion Dam, as well as fish screen installations at many of the larger irrigation diversions onthe Sacramento River mainstem. Many more restoration actions are being planned, such as additional fish passage improvements on Butte and Clear Creeks andat Anderson-Cottonwood Irrigation District’s diversion dam. Many of the actions on the river’s mainstemwere in response to the need to protect listed winterrun chinook salmon. Actions are also being taken to protect spring-run chinook salmon, a species proposed for listing under the federal ESA and a State candidate species. In 1995, State legislation restricted future water development on Mill and Deer Creeks to protect springrun chinook salmon habitat. In addition, local landowners formed the Mill and Deer Creek WatershedConservancies. The conservancies have begun a watershed planning and management process, withfunding assistance from an EPA grant. The Department has participated with Mill Creek landowners in a test project to construct wells to provide groundwater supplies in lieu of creek diversions for irrigation during spring fish migration periods. A similar project is being negotiated with Deer Creek water users. San Joaquin River System. One of the first overviews of San Joaquin River restoration needs was provided by the Resources Agency’s 1995 San Joaquin River Management Program Plan, which evaluated potential actions on part of the river’s mainstem and on the lower reaches of its main tributaries. Structural restoration work performed to date has focused largelyon spawning gravel placement and related habitat improvements. Several other projects are now in planning, including replacement of Central California IrrigationDistrict’s Mendota Dam and a potential new fish hatchery on the Tuolumne River. Increased instream flows have been provided in the river system through SWRCB Order WR 95-6 requirements and through a FERC settlement agreement for the Tuolumne River. The San Joaquin River Conservancy, a State agency charged with acquiring and managing public lands within the San Joaquin River Parkway, is working to expand lands preserved by the parkway. The parkway includes the San Joaquin River and about 5,900 acres of land on both sides of the river, extending about22 miles from Friant Dam downstream to the Highway 99 crossing of the river. The parkway is planned as a riparian corridor with public access trails, boatingaccess points, wildlife areas, and education areas. Approximately 1,900 acres are located in Madera County and 4,000 acres in Fresno County, of which approximately 1,600 acres are now in public owner ship.

In February 1998, two

large cylindrical fish screens were installed

at one of the largest Delta diversions located on Sherman Island.ES2-16 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

Lower Colorado River System. In 1995, DOI executed partnership agreements with California,Nevada, and Arizona to develop a multi-species conservation program for ESA-listed species and many non-listed, but sensitive, species within the 100-year floodplain of the lower Colorado River, from Glen Canyon Dam downstream to the Mexican border. In 1996, a joint participation agreement was executed toprovide funding for the program. USFWS has designated the Lower Colorado River Multi-SpeciesConservation Program steering committee as an ecosystem conservation and recovery implementationteam pursuant to ESA. The steering committee is composed of representatives from the three states, DOI,Indian tribes, water agencies, power agencies, environmental organizations, and others.The conservation program will work toward recovery of listed and sensitive species while providing for current and future use of Colorado River water and power resources, and includes USBR’s Colorado River operations and maintenance actions for the lowerriver. Over 100 species will be considered in the program, including the southwestern willow flycatcher, Yuma clapper rail, and four fish species listed under the federal ESA: Colorado squawfish, razorback sucker, humpback chub, and bonytail chub. Developing theprogram is estimated to take three years. Costs of program development and implementation of selectedinterim conservation measures, estimated at $4.5 million, are to be split equally between DOI and the non-federal partners. USBR initiated a formal Section 7 consultationprocess with USFWS, who issued a five-year biological opinion on USBR operation and maintenanceactivities from Lake Mead to the southerly international boundary with Mexico in 1997. USBR has estimated that the cost of implementing the biologicalopinion’s reasonable and prudent alternatives and measures could be as high as $26 million. The steering committee is currently participating in funding several interim conservation measures. These include a razorback sucker recovery program at Lake Mojave, restoration of Deer Island near Parker,Arizona, and a “Bring Back the Natives” program sponsored by the National Fish and Wildlife Foundation. Other Watersheds. Major environmental restoration activities are ongoing in other watersheds throughout the State, including the Russian and Kings Rivers and Lake Tahoe. A Russian River Action Plan, prepared by Sonoma County Water Agency in 1997, provides a regional assessment of needs in the Russian River watershed and identifies fishery habitat restoration projects inneed of funding. The SWRCB is promoting a coordinated Russian River fishery restoration plan. Kings River Conservation District and the Kings River Water Association are cooperating with USACE in a feasibility study of Kings River fishery habitat improvements. One component of the study includes a new multi-level intake structure for the reservoir, to better manage downstream river temperatures. USACEis also implementing a related project to install a bypass pipe at the dam’s powerplant so that releases canbe made through the existing penstocks when the turbines are not in operation. This project will provide temperature control for the downstream trout fishery. The Tahoe Regional Planning Agency, a bi-state agency created by Congress, has identified nearly $500 million in capital improvements needed to achieve environmental targets in the Lake Tahoe watershed. Federal, state, and local governments have invested nearly $90 million in erosion control, storm water drainage, stream zone restoration, public transit, and other capital projects. The U.S. Forest Service has implemented a watershed restoration program and a land acquisition program to prevent development of sensitive private lands. The State of Nevada approveda $20 million bond measure to perform erosion control and other measures on the east side of the lake. In California, Proposition 204 provides $10 million inbond funds for land acquisition and programs to control soil erosion, restore watersheds, and preserve environmentally sensitive lands. Mitigation Projects. Significant habitat improvements are also resulting from land management ormitigation projects being carried out by water agencies. For example, the Department purchased much of Sherman and Twitchell Islands in the Delta, and is implementing management plans on them to controlsubsidence and soil erosion, while providing significant wetland and riparian habitat for wildlife. The plansalso provide recreational opportunities such as walking trails and wildlife viewing. CCWD established over 18,000 acres of preserve as part of its Los Vaqueros construction project. This land is being managed to protect listed species such as the San Joaquin kit fox. The project impacted 174 acresof valley oaks and 9 acres of alkali wetlands. To mitigate, CCWD is creating or enhancing 394 acres of woodland habitat and 49 acres of wetlands.ES2-17 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

Kern Water Bank Authority set aside about 10,000 acres for habitat purposes as part of its 20,000-acre Kern Fan Element project. ESA listed species found in the project area include the kit fox, kangaroo rat, and blunt-nosed leopard lizard. As part of its Eastside Reservoir project, MWDSC purchased 3,700 acres for the Nature Conservancy’s Santa Rosa Plateau Ecological Reserve. MWDSC also purchased 9,000 acres for the Southwestern Riverside County Multi-Species Reserve, including lands around the reservoir, Lake Skinner, and the 2,500-acre Dr. Roy E. Shipley Reserve. Behind Prado Dam in Riverside County, OrangeCounty Water District operates 465 acres of constructed freshwater wetlands to reduce the nitrogen levels in the Santa Ana River. The river provides much of the county’s coastal plain groundwater recharge. ThePrado wetlands are home to several rare and endangered bird and waterfowl species. More than 226 acres are set aside as habitat for the endangered least Bell’s vireo and southwestern willow flycatcher.
Implementation of Urban Water Conservation MOU
The 1991 Memorandum of Understanding Regarding Urban Water Conservation in California defined a set of urban best management practices and procedures for their implementation, and established a California Urban Water Conservation Council composed ofMOU signatories (local water agencies, environmental groups, and other interested parties). More than 200 entities have signed the MOU. The CUWCC has monitored implementation of BMPs and reportedprogress annually to the SWRCB. The Council developed a plan providing for ongoing review of BMPsand potential BMPs. In late 1996, the Council initiated a review of the BMPs to clarify expectations for implementation and to develop an implementation evaluation methodology. Revised BMPs were adopted in 1997.
Implementation of Agricultural Efficient Water Management Practices MOU The Agricultural Efficient Water ManagementPractices Act of 1990 (AB 3616) required the Department to establish an advisory committee to develop EWMPs for agricultural water use. Negotiations among agricultural water users, environmental interests, andgovernmental agencies on a memorandum of understanding to implement EWMPs were completed in 1996. The MOU established an Agricultural WaterManagement Council to oversee EWMP implementation, much like the organizational structure that exists for urban BMPs, and also provided a mechanism forits signatories to evaluate and endorse water management plans. By May 1998, the MOU had been signed by 31 agricultural water suppliers irrigating about3 million acres of land, as well as by over 60 other entities.
Klamath River Fishery IssuesThe primary water management issue in the interstate Klamath River basin is the restoration of fish populations that include listed species such as the LostRiver and shortnose suckers, coho salmon, and steelhead trout. The Lost River sucker is native to Upper Klamath Lake and its tributaries, and the shortnose sucker is found in the Lost River, Clear Lake, Tule Lake, and Upper Klamath Lake. Both species spawn during the spring. Higher water levels in Upper Klamath Lakehave been identified as an aid to recovery of these fisheries. Coho and steelhead were recently listed, and water supply implications will not be known until management plans are completed and recovery goals are established. To address the need for greater certainty in projectoperations, USBR began preparing a long-term Klamath Project Operations Plan in 1995. Several issues have delayed completion of the long-term plan. USBR has issued an annual operations plan each year since 1995. The Klamath River Compact Commission isfacilitating discussions on water management alternatives to address water supply needs. This three-member commission was established by an interstate compact ratified by Congress in 1957 to facilitate integrated management of interstate water resources. The KRCC, USBR, and both states are cooperatively developingwater supply options. Members include a representative from the Department, the Director of the OregonWater Resources Department, and a presidentiallyappointed federal representative.
Truckee-Carson River System The Truckee-Carson-Pyramid Lake Water Rights Settlement Act (Title II of Public Law No. 101-618)settled several water rights disputes affecting the waters of Lake Tahoe, the Truckee River, and the Carson River. Of most importance to California, the act made an interstate apportionment of these waters between the States of California and Nevada. (It was the firstES2-18 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

congressional apportionment since the Boulder Canyon Project Act of 1928.) The act addresses severalother issues, including settlement of water supply disputes between the Pyramid Lake Paiute Tribe of Indians and other users of the Truckee and Carson Rivers. Theact also addresses environmental concerns, such as recovery of listed fish species in Pyramid Lake.Many of the act’s provisions—including the interstate apportionment between California and Nevada—will not take effect until several conditionshave been satisfied, including dismissal of specified lawsuits and negotiation and adoption of a Truckee River Operating Agreement. The act requires that a TROA be negotiated among DOI and California and Nevada,after consultation with other parties as may be designated by DOI or by the two states. The TROA addresses interstate water allocation and implements an agreement between Sierra Pacific Power Companyand the United States which provides for storing water in upstream reservoirs for Pyramid Lake fish and emergency drought water supplies for the Reno-Sparks area. TROA negotiation has been ongoing since 1991. A draft TROA is analyzed in an EIS/EIR prepared by DOI. (The Department is the State lead agency for compliance with the requirements of CEQA.) The draft EIS/EIR was released for public review in 1998 and is expected to be completed in 1999.

City of Los Angeles’ Water Supply from Owens Valley In 1913, the City of Los Angeles began diverting water from Owens Valley through the Los Angeles Aqueduct. A second aqueduct, completed in 1970, increased the Los Angeles Department of Water andPower’s capacity to divert both surface and groundwater from the Owens Valley. LADWP’s water diversionshave resulted in degradation of the valley’s environmental resources. Recent issues have revolved around rewatering the lower Owens River and dust control on the Owens Lakebed. Rewatering Lower Owens River. In 1972, Inyo County initially filed suit against the city, claiming thatincreased groundwater pumping from the second aqueduct was harming the Owens Valley environment. An EIR was subsequently prepared jointly by LADWP and the county, and in 1991 both parties executed a long-term water management agreement delineatinghow groundwater pumping and surface water diversions would be managed to avoid significant decreases in vegetation, water-dependent recreational uses, and wildlife habitat. Several agencies, organizations, and individuals challenged the adequacy of the EIR and were granted amici curiaestatus by the Court of Appeals, allowing them to enter in the EIR review process. Another agreement was subsequently executed in 1997, ending 25 years of litigation between Los Angeles and Inyo County.The lower Owens River project, a major provision of the agreement, was developed to rewater approximately 60 miles of the Owens River channel from the LAA diversion downstream to Owens Lake.The project is also identified in the EIR as compensatory mitigation for impacts that occurred between 1970 and 1990 that were considered difficult to quantify or mitigate directly. Four significant physical features of the LORP and agreement are: provision of year-roundflows in the lower Owens River (with a pumpback station just above the Owens River delta to return some of the water to the LAA), provision of flows past the pumpback station to create new wetlands in the Owens Lake delta, enhancement of off-river lakes and ponds,and development of a new 1,500-acre waterfowl habitat area. The majority of planning work is expected to be completed by December 1998. Los Angeles will pay the costs of implementing the project, with the county repaying one half of the costs up to a maximum of $3.75 million. To date, the federal government has committed $300,000 for the design of the pumpback system. Congress has approved another $250,000 for planning and development work. LADWP and the county will jointly prepare an EIR on the LORP, with a draft expected by June 2000. Rewatering of the river channel will begin within 6 years after the pumpback system is completed. Dust Control on Owens Lakebed. Owens Lakebecame a dry lakebed by 1929. On windy days, airborne particulates from the dry lakebed violate air quality standards in the southern Owens Valley. In 1997, the Great Basin Unified Air Pollution Control District ordered the City of Los Angeles to implement control measures at Owens Lake to mitigate the dust problems. Under the order, 8,400 acres of lakebed would be permanently flooded with a few inches of water, another 8,700 acres would be planted with grass and irrigated, and 5,300 acres would be covered with a 4 inch layer of gravel. This order, which was appealed by the city, could reduce the city’s potential diversion by 50 taf/yr or about 15 percent of its supply. In July 1998, a compromise was reached whenES2-19 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

LADWP agreed to begin work at Owens Lake by 2001 and to ensure that federal clean air standards would be met by 2006. In turn, the APCD agreed to scale back the improvements sought in its 1997 order. Under thiscompromise, LADWP’s dust-control strategy may include shallow flooding, vegetation planting, and gravel placement. The implementation schedule requires that 6,400 acres of lakebed be treated by the end of 2001. By the end of 2006, an additional 8,000 acres would be treated, plus any additional lakebed necessary to bring particulate counts into compliance with federal air quality standards. The plan hinges on final approval from the Los Angeles City Council, the APCD’s board, and the State Air Resources Board.

Mono Basin
Mono Lake and its tributaries have been the subject of extensive litigation between the City of Los Angeles and environmental groups since the late 1970s. In 1983, the California Supreme Court ruled thatSWRCB has authority to reexamine past water allocation decisions and the responsibility to protect public trust resources where feasible. SWRCB issued a final decision on Mono Lake (Decision 1631) in 1994. Amendments to LADWP’s water right licenses are set forth in the order accompanying the decision. The order sets instream flow requirements for fishin each of the four streams from which LADWP diverts water. The order also establishes water diversion criteria to protect wildlife and other environmental resources in the Mono Basin. These water diversion criteria prohibit export of water from Mono Basin until the lake level reaches 6,377 feet, and restrict Mono Basin water exports to allow the lake level to rise to an elevation of 6,391 feet in about 20 years. Once the water level of 6,391 feet is reached, it is expected that LADWP will be able to export about 31 taf of water per year from the basin. The order requires LADWP to prepare restoration plans for the four streams from which it diverts and to restore part of the waterfowl habitat which was lost due to lake level decline. In May1997, parties to the restoration planning process presented a signed settlement on Mono Basin restoration to the SWRCB. If approved, the settlement would guide restoration activities and annual monitoring through 2014.Key features of the stream restoration plans include restoring peak flows to Rush, Lee Vining, Walker, and Parker Creeks; reopening abandoned channels in Rush Creek; and developing a monitoring plan. One of the restoration actions required by SWRCB—bypassing sediment around LADWP diversiondams—was deferred for further analysis. The waterfowl habitat restoration plan proposes that a MonoBasin waterfowl habitat restoration foundation administer a $3.6 million trust established by LADWP. Five of the parties to the agreement would serve as initial members of the foundation. Activities would includeannual monitoring, restoring open water habitat adjacent to the lake, and rewatering Mill Creek. LADWP would continue its brine shrimp productivity studies, open several channels on Rush Creek, and make its Mill Creek water rights available for rewatering MillCreek, based on the recommendations of the foundation. The plans are being considered by SWRCB and a decision is expected at the end of 1998.

Salton Sea The present day Salton Sea was formed in 1905, when Colorado River water flowed through a break ina canal that had been constructed along the U.S./Mexican border to divert the river’s flow to agricultural lands in the Imperial Valley. Over the long term, the sea’s elevation has gradually increased, going from a low on the order of -250 feet in the 1920s to its present level of about -226 feet. The Salton Sea is the largest lake located entirely within California, with a volume of about 7.5 maf at its present elevation of -226 feet. The sea occupies a closed drainage basin—if there were noinflows to maintain lake levels, its waters would evaporate. The sea receives over 1 maf annually of inflow, primarily from agricultural drainage. The largest sources of inflow (about 80 percent of the total) are the New and Alamo Rivers, which drain agricultural lands in the Mexicali and Imperial Valleys and flow into the sea’s southern end.The sea supports water-based recreational activities and has had a popular corvina fishery. During the 1950s, the highest per capita sport fishing catches in California were from the Salton Sea. Over the years, concerns about the sea’s salinity have been voiced in the context of maintaining the recreational fishery thatwas established with introduced species able to tolerate high salinities. The sea also provides important wintering habitatfor many species of migratory waterfowl and shorebirds, including some species whose diets are based exclusively on the fish in the sea. Wetlands near the sea and adjoining cultivated agricultural lands offer theavian population a mix of habitat types and food sourcES2-20 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

es. An area at the sea’s south end was established as a national wildlife refuge in 1930, although most of that area is now under water as a result of the sea’s rising elevation. Some of the 380 bird species wintering inthe area include pelicans, herons, egrets, cranes, cormorants, ibises, ducks, grebes, falcons, plovers, avocets, sandpipers, and gulls. The Salton Sea is considered to be a major stopover point for birds migrating on the Pacific flyway, and has one of the highest levels of bird diversity of refuges in the federal system. Historically, salinity has been the water quality constituent of most concern at the sea. Present levels are about 44,000 mg/L TDS (seawater is about 35,000mg/L TDS). This high level of salinity reflects longterm evaporation and concentration of salts found in its inflow. Selenium has been a more recent constituent of interest, due to its implications for aquatic species. Although selenium levels in the water column in the sea are less than the federal criterion of 5 u g/l, this concentration can be exceeded in seabed sedimentand in influent agricultural drainage water. Agricultural drain flows also contribute significant nutrient loading to the sea, which supports large algal blooms at some times of the year. Over the years, USBR and others have consideredpotential solutions to stabilize the sea’s salinity and elevation. Most recently, the Salton Sea Authority (a joint powers authority consisting of Riverside and Imperial Counties, Imperial Irrigation District, and CoachellaValley Water District) and others have been performA natural-color infrared satellite image of the Salton Sea (January 1998 Landsat 5). The irrigated areas in Imperial Valley are clearly visible to the south of the sea, as are the Algodones Dunes to the southeast. The City of Mexicali and irrigated acreage in the Mexicali Valley can also be seen.ES2-21 C URRENT E VENTS The California Water Plan Update B ULLETIN 160-98

Roadrunners are one of the bird species found year-round in the Salton Sea area. ing appraisal level evaluations of some of the frequently suggested alternatives. Maintaining a viable Salton Sea has several water management implications. First will be the actions needed to stabilize the sea’s salinity in the near-term, such as the authority’s diking proposal.Eventually, a long-term solution will need to be developed. A wide range of costs has been mentioned for along-term solution, including amounts in the billiondollar range. Some of the possible long-term solutions suggested would entail constructing facilities in Mexico, bringing a greater level of complexity to their implementation. Other water management programs in the region, such as proposals to transfer conserved agricultural water supplies, will have to be evaluated in terms of their impacts on the sea. Recent proposals to desalt water in the Alamo or New Rivers and to transport that water in the Colorado River Aqueduct to the South Coast for urban water supply have raised concernsabout maintaining the sea’s environmental productivity. Such proposals might be implemented as part of the second phase of CRB’s draft 4.4 Plan. Congressional legislation introduced in 1998 would authorize expenditure of federal funds for a multi-year study of the sea’s resources and potential solutions for managing its salinity.ES3-1 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

The SWP’s California Aqueduct is the only conveyance facility that moves water from the Central Valley to Southern California. 

# Water Supplies



# T his chapter describes how water supplies are calculated and summarized
within a water budget framework. A description of California’s existing
supplies–surface water, groundwater, recycled water, and desalted water–and
how a portion of these supplies are reallocated through water marketing follows. This chapter
concludes with a review of water quality considerations that influence how the State’s water
supplies are used.

Water Supply Calculation

Bulletin 160-98 calculates existing water supply and demand, then balances forecasted
demand against existing supply and future water management options. The balance, or
water budget, with existing supply is presented on a statewide basis in Chapter ES5 and on
a regional basis in Appendix ES5A. The water budget with future water management options
is also presented in Chapter ES5.
Definition of Bulletin 160 Water Supplies
The Bulletin 160 water budgets do not account for the State’s entire water supply and
use. In fact, less than one-third of the State’s precipitation is quantified in the
water budgets. Precipitation provides California with nearly 200 maf of total
water supply in average years. Of this renewable supply, about 65 percent
is depleted through evaporation and transpiration by trees and other plants.
This large volume of water is excluded from the Bulletin 160 water supply 

# Executive SummaryES3-2 W

ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

Key Water Supply and Water Use Definitions

Chapters ES3 and ES4 introduce California’s water supplies and urban, agricultural, and environmental water uses. Certain key concepts, defined below, provide an essential foundation for presenting and analyzing water supplies and

water use.

Applied Water: The amount of water from any source needed to meet the demand of the user. It is the quantity of water delivered to any of the following locations: • The intake to a city water system or factory. • The farm headgate or other point of measurement. • A managed wetland, either directly or by drainage flows.

For instream use, applied water is the quantity of stream flow dedicated to instream use (or reserved under federal or State wild and scenic rivers legislation) or to maintaining flow and water quality in the Bay-Delta pursuant to the SWRCB’s Order WR 95-6.

Net Water: The amount of water needed in a water service area to meet all demands. It is the sum of evapotranspiration of applied water in an area, the irrecoverable losses from the distribution system, and agricultural return flow or treated urban wastewater leaving the area.

Irrecoverable Losses: The amount of water lost to a salt sink, lost by evapotranspiration, or lost by evaporation from a conveyance facility, drainage canal, or fringe areas.

Evapotranspiration: ET is the amount of water transpired (given off), retained in plant tissues, and evaporated from plant tissues and surrounding soil surfaces.

Evapotranspiration of Applied Water: ETAW is the portion of the total ET which is provided by applied irrigation water.

Depletion: The amount of water consumed within a service area that is no longer available as a source of supply. For agricultural and certain environmental (i.e., wetlands) water use, depletion is the sum of irrecoverable losses and the ETAW due to crops, wetland vegetation, and flooded water surfaces. For urban water use, depletion is the ETAW due to landscaping and gardens, wastewater effluent that flows to a salt sink, and incidental ET losses. For environmental instream use, depletion is the amount of dedicated flow that proceeds to a salt sink.

and water use calculations. The remaining 35 percent stays in the State’s hydrologic system as runoff. (Figure ES3-1.)Over 30 percent of the State’s runoff is not explicitly designated for urban, agricultural, or environmental uses. This water is depleted from the State’s hydrologic system as outflow to the PacificOcean or other salt sinks. (Some of this non-designated runoff is captured by reservoirs, but is later released for flood control.) Similar to precipitationdepletions by vegetation, non-designated runoff is excluded from the Bulletin 160 water supply and water use calculations. The State’s remaining runoff is available as renewable water supply for urban, agricultural, andenvironmental uses in the Bulletin 160 water budgets. In addition to this supply, Bulletin 160 water budgets include a few supplies that are not generatedby intrastate precipitation. These supplies include imports from the Colorado and Klamath Rivers and new supplies generated by water recycling and desalting.
Applied Water MethodologyBulletin 160-98 water supplies are computed using applied water data. As defined in the sidebar, applied water refers to the amount of water from any source employed to meet the demand of the user. Previous editions of Bulletin 160 computed water supplies using net water data. Bulletin 160-98 switched from anet water methodology to an applied water methodology in response to public comments on Bulletin 160-93. Because applied water data are analogous to agency water delivery data, water supply data based on an applied water methodology are easier for local water agencies to review. Net water supply values are smaller than applied water supply values because theyexclude that portion of demand met by reapplication of surface and groundwater supplies. Reapplication can be a significant source of water in many hydrologic regions of California. An appliedwater budget explicitly accounts for this source. However, because of reapplication, applied water budgets do not translate directly into the supply of water needed to meet future demands. The approach used to compute the new water required to meet future demands with applied water budgets is presented in Chapter ES5.

Normalized DataWater budget data used to represent the base planning year do not necessarily match the historical conditions observed in 1995. Instead, Bulletin 160- 98’s base year applied water budget data are developedES3-3 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

from “normalized” water supply, land use, and wateruse data. Through the normalizing process, year-toyear fluctuations caused by weather and market abnormalities are removed from the data. For example, water year 1998 would greatly underestimate average annual water use, as rainfall through May and early June provided the necessary moisture needed to meet crop and landscape water demands. In most years,much of California would require applied water supplies during May and early June. The procedures usedto normalize water supply and water use data are described in the sidebar on page ES3-4.
Water Supply Scenarios California is subject to a wide range of hydrologic conditions and water supply variability. Knowledge of water supplies under a range of hydrologic conditionsis necessary to evaluate reliability needs that water managers must meet. Two water supply scenarios—average year conditions and drought year conditions—wereselected from among a spectrum of possible water supply conditions to represent variability in the regional and statewide water budgets. The average year supply scenario represents theaverage annual supply of a system over a long planning horizon. Average year supplies from the CVP and SWP are defined by operations studies for a base (1995) level of development and for a future (2020) level of development. Project delivery capabilities are defined over a 73-year hydrologic sequence. For other water supply projects, historical data are normalizedto represent average year conditions. For required environmental flows, average year supply is estimated for each of its components. Wild and scenic river flow is calculated from long-term average unimpaired flow data. Instream flow requirements are defined for an average year under specific agreements, water rights,court decisions, and congressional directives. BayDelta outflow requirements are estimated from operations studies. For many local water agencies, and especially urban agencies, drought water year supply is the critical factor in planning for water supply reliability. Traditional drought planning often uses a design drought hydrology to characterize project operations under future conditions.For a planning region with the size and hydrologic complexity of California, selecting an appropriate statewide design drought presents a challenge. The 1990-91 water years were selected to represent the drought year supply scenario for Bulletin 160-98. (The 1990-91 water years were also used to represent the drought year scenario in Bulletin 160-93.) Evapotranspiration by Trees and Other Plants

Other Runoff Designated Runoff (Bulletin 160 Water Supply)

Urban Agricultural Environmental F IGURE ES3-1. Disposition of California’s Average Annual PrecipitationES3-4 W

ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

The 1990-91 drought year scenario has a recurrence interval of about 20 years, or a 5 percent probability of occurring in any given year. This istypical of the drought level used by many local agencies for routine water supply planning. For extreme events such as the 1976-77 drought, many agencies would implement shortage contingency measures such as mandatory rationing. Another important consideration in selecting water years 1990-91 was that, because of their recent occurrence, local agencywater demand and supply data were readily available.The statewide occurrence of dry conditions during the 1990-91 water years was another key consideration in selecting them as a representative drought. Because of the size of California, droughts may or may not occur simultaneously throughout the entire state.

Sources of Water SupplyTable ES3-1 shows California’s estimated water supply, for average and drought years under 1995 and 2020levels of development, with existing facilities and programs. Facility operations in the Delta are assumed to be in accordance with Order WR 95-6. The State’s 1995- level average year water supply is about 77.9 maf,including about 31.4 maf of dedicated flows for environmental uses. As previously discussed, this supply is based on an applied water methodology and therefore includes considerable amounts of reapplication within hydrologic regions. Even with a reduction in Colorado River supplies to California’s 4.4 maf basic apportionment, annual average statewide supply is projected to increase about0.2 maf by 2020 without implementation of new water supply options. While the expected increase in average year water supplies is due mainly to higher CVP and SWP deliveries (in response to higher 2020-level demands), new water production will also result fromgroundwater and from recycling facilities currently under construction. The State’s 1995-level drought year water supplyis about 59.6 maf, of which about 16.6 maf is dedicated for environmental uses. Annual drought yearsupply is expected to increase slightly by 2020 without implementation of new water supply options. The expected increase would come from higher CVP Procedures for Normalizing Water Supply and Water Use Data On the supply side, normalized water project delivery values are computed by averaging historical delivery data. Normalized “average year” project supplies are typically computed from 3 to 5 recent non-deficient water years. Normalized “drought year” project supplies are computed by averaging historical delivery data from 1990 and 1991. A notable exception to the above procedure is the development of normalized CVP and SWP project deliveries. Supplies from these projects are developed from operations studies rather than from historical data. Operations studies provide an average project delivery capability over a multi-year sequence of hydrology under SWRCB Order WR 95-6 Bay-Delta standards. On the demand side, base year urban per capita water use data are normalized to account for factors such as residual effects of the 1987-92 drought. In any given year, urban landscape and agricultural irrigation requirements will vary with precipitation, temperature, and other factors. Base year water use data are normalized to represent ETAW requirements under average and drought year water supply conditions. Land use data are also normalized. The Department collects land use data through periodic surveys; however, the entire State is not surveyed in any given year (such as 1995). To arrive at an estimate of historical statewide land use for a specific year, additional sources of data are consulted to interpolate between surveys. After a statewide historical land use base is constructed, it is evaluated to determine if it was influenced by abnormal weather or crop market conditions and is normalized to remove such influences. Normalizing allows Bulletin 160-98 to define an existing level of development (i.e., the 1995 base year) that is compatible with a forecasted level of development (i.e., the 2020 forecast year). Future year shortage calculations implicitly rely on a comparison between future water use and existing water supply, as water supplies do not change significantly (without implementation of new facilities and programs) over the planning horizon. Therefore, the normalizing procedure is necessary to provide an appropriate future year shortage calculation. Normalizing also permits more than one water supply condition to be evaluated for a given level of development. If historical data were used to define the base year, only one specific hydrologic condition would be represented. (Historical data for 1995 would represent a wet year.) But through normalizing, a base level of development can be evaluated under a range of hydrologic conditions.ES3-5 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

and SWP deliveries and new production from surface water, groundwater, and recycling facilities currently under construction.
Surface Water Supplies Surface water includes developed supplies from the CVP, SWP, Colorado River, other federal projects, and local projects. Figure ES3-2 shows the location of the State’s major water projects. Surface water also includes the supplies for required environmental flows. Required environmental flows are comprised of undeveloped supplies designated for wild and scenic rivers, supplies used for instream flow requirements, and supplies used for Bay-Delta water quality and outflow requirements. Finally, surface water includes supplies available forreapplication downstream. Urban wastewater discharges and agricultural return flows, if beneficially used downstream, are examples of reapplied surface

water. Groundwater Supplies In an average year, about 30 percent of California’s urban and agricultural applied water is provided bygroundwater extraction. In drought years when surface supplies are reduced, groundwater supports an even larger percentage of use. The amount of water stored in California’s aquifers is far greater than that stored in the State’s surface water reservoirs, although only a portion of California’s groundwater resources can be economically and practically extracted for use.Bulletin 160-98 excludes long-term basin extractions in excess of long-term basin inflows in its definition of groundwater supply. This long-term average annual difference between extractions and recharge, defined in the Bulletin as overdraft, is not a sustainable source of water and is thus excluded from the base yearand forecast year groundwater supply estimates. (In response to public comments on the Bulletin 160-93, Bulletin 160-98 is the first water plan update to exclude overdraft from the base year groundwater supply estimate.)In wet years, recharge into developed groundwater basins tends to exceed extractions. Conversely, in dry years, groundwater basin recharge tends to be less than groundwater basin extraction. By definition, overdraft is not a measure of these annual fluctuations in groundwater storage volume. Instead, overdraft is a measure of the long-term trend associated with theseannual fluctuations. The period of record used to evaluate overdraft must be long enough to produce datathat, when averaged, approximate the long-term average hydrologic conditions for the basin. Table ES3-2 shows the Department’s estimates of 1995 and 2020- level groundwater overdraft by hydrologic region.Within some regions, overdraft occurs in some welldefined subareas, while additional groundwater development potential may exist in other subareas. For the 1995 base year, Bulletin 160-98 estimates a statewide increase in groundwater overdraft (160 taf) above the 1990 base year reported in Bulletin 160-93. Most of the statewide increase in overdraft occurred in the San Joaquin and Tulare Lake Regions, two regions T

ABLE ES3-1 California Water Supplies with Existing Facilities and Programs a (taf)

Supply 1995 2020 Average Drought Average Drought

Surface

CVP 7,004 4,821 7,347 4,889 SWP 3,126 2,060 3,439 2,394 Other Federal Projects 910 694 912 683 Colorado River 5,176 5,227 4,400 4,400 Local Projects 11,054 8,484 11,073 8,739 Required Environmental Flow 31,372 16,643 31,372 16,643 Reapplied 6,441 5,596 6,449 5,575

Groundwater b 12,493 15,784 12,678 16,010 Recycled and Desalted 324 333 415 416 Total (rounded) 77,900 59,640 78,080 59,750

a Bulletin 160-98 presents water supply data as applied water, rather than net water. This distinction is explained in a previous section. Past editions of Bulletin 160 presented water supply data in terms of net supplies.

b Excludes groundwater overdraftES3-6 W

ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

F IGURE ES3-2. California’s Major Water Projects

State

Federal

Local Trinity

Lake

Shasta Lake

Lake Oroville Tehama-Colusa Canal

Folsom Lake
Folsom South Canal
Mokelumne Aqueduct Hetch Hetchy Aqueduct

Delta-Mendota Canal

Madera

Canal Millerton Lake

Friant-Kern Canal South Bay Aqueduct North Bay Aqueduct

San Luis Reservoir

Coalinga

Canal

Cross Valley Canal Los Angeles Aqueduct California

Aqueduct

Colorado River Aqueduct

Coachella Canal San Diego Aqueducts All American Canal Lake Almanor Corning

Canal Black Butte

Reservoir Stony Gorge

Reservoir East Park Reservoir Tule Lake Clear Lake

Indian Valley Reservoir

Lake Berryessa Lake Mendocino

Lake Sonoma Glenn Colusa Canal

Contra Costa Canal

San New Bullards Bar Reservoir Englebright

Reservoir

Camanche Reservoir New Melones Lake

Lake McClure New Don Pedro Lake Lake Crowley

Pine Flat Lake

Lake Kaweah

Nacimiento

Reservoir San Antonio

Reservoir Success Lake

Twitchell Reservoir Isabella Lake

Castaic

Lake Lake Casitas Cachuma Reservoir

Lake Perris Silverwood Lake

Lake Mathews

Henshaw Reservoir

San Vicente Reservoir Grant Lake

Lower Otay Reservoir Red Bluff Diversion Dam

Luis Canal Santa Clara Conduit

Hollister Conduit Lake Tahoe Clear Lake Whiskeytown LakeES3-7 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

where surface water supplies have been reduced in recent years by Delta export restrictions, CVPIAimplementation, and ESA requirements. CVP contractors in these regions who rely on Delta exports for theirsurface water supply have experienced supply deficiencies of up to 50 percent subsequent to implementation of export limitations and CVPIA requirements. Manyof these contractors have turned to groundwater pumping for additional water supplies. This long-term increase in groundwater extractions exacerbated a short-term decline in water levels as a result of the 1987- 92 drought. As shown in Table ES3-2, groundwater overdraft is expected to decline from 1.5 maf/yr to 1.1 maf/yr statewide by 2020. Overdraft in the Central Coast Region is expected to decline as demand shifts from groundwater to imported SWP supplies, provided through the recently completed Coastal Branch of theCalifornia Aqueduct. The reduction in irrigated acreage in drainage problem areas on the west side of the San Joaquin Valley, as described in the 1990 report of the San Joaquin Valley Interagency Drainage Program, is expected to reduce groundwater demands in the San Joaquin River and Tulare Lake regions by 2020. Someincreases in groundwater overdraft are expected in Sacramento, Placer, and El Dorado Counties of the Sacramento River Region.
Water MarketingIn recent years, water marketing has received increasing attention as a tool for addressing statewideimbalances between water supply and water use. Experiences with water markets during and since the1987-92 drought bolstered interest in using marketing as a local and statewide water supply augmentation option. While water marketing does allow wateragencies to purchase additional water supply reliability during both average and drought years, watermarketing does not create new water. Therefore, water markets alone cannot meet California’s long-term water supply needs. In this update of the California Water Plan , water marketing may include: • A permanent sale of a water right by the water right holder. • A lease from the water right holder (who retains the water right), allowing the lessee to use the water under specified conditions over a specified period of time.• A sale or lease of a contractual right to water supply. Under this arrangement, the ability of theholder to transfer a contractual water right is usually contingent upon receiving approval from the supplier. An example of this type of arrangement is a sale or lease by a water agency that receives itssupply from the CVP, SWP, or other water wholesaler. Water marketing is not an actual statewide source of water, but rather is a means to reallocate existingsupplies. Therefore, marketing is not explicitly itemized as a source of water supply from existing facilitiesand programs in the Bulletin 160 water budgets. (Water marketing agreements in place by 1995 are considered to be existing programs and are implicitlypart of the water budgets.) Water marketing is identified as a potential water supply augmentation optionin the Bulletin 160 water budgets. Potential water marketing options have several characteristics that must T

ABLE ES3-2 1995 and 2020 Level Overdraft by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 0 0 0 0 San Francisco Bay 0 0 0 0 Central Coast 214 214 102 102 South Coast 0 0 0 0 Sacramento River 33 33 85 85 San Joaquin River 239 239 63 63 Tulare Lake 820 820 670 670 North Lahontan 0 0 0 0 South Lahontan 89 89 89 89 Colorado River 69 69 61 61 Total (rounded) 1,460 1,460 1,070 1,070ES3-8 W

ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

be captured in the water budgets incorporating supplies from future management options. For example,through changes in place of use, water marketing options can reallocate supplies from one hydrologic region to another. And through changes in type of use, water marketing options can reallocate supplies from one water use sector to another. Finally, for a given placeand type of use, water marketing options can reallocate supplies among average years and drought years.While several long-term agreements have been completed in recent years (see Table ES3-3), short-termagreements have made up the majority of water marketing. Short-term agreements, with terms less than one year, can be an effective means of alleviating the most severedrought year impacts. Short-term agreements can be executed on the spot market; however, water purveyors areincreasingly interested in negotiating longer-term agreements for drought year transfers. In such future agreements,specific water supply conditions may be the triggers to determine whether water would be transferred in a specific

year. Two examples of programs for acquiring waterthrough short-term agreements are the Drought Water Bank and the CVPIA interim water acquisitionprogram. Beyond these programs, data on shortterm water marketing arrangements are difficult to locate and verify. Agreements executed for less than one year do not need SWRCB approval (unless there is a change in place of use or point of diversion) and thus are not tracked by outside entities. Data are also difficult to evaluate, as it is often difficult to distinguish between ex changes and marketing arrangements. Water Recycling and Desalting Supplies Water recycling is the intentional treatment and management of wastewater to produce water suitable for reuse. Several factors affect the amount of wastewater treatment plant effluent that local agencies areable to recycle, including the size of the available market and the seasonality of demands. Local agencies must plan their facilities based on the amount of treatmentplant effluent available and the range of expected service area demands. In areas where irrigation uses constitute the majority of recycled water demands, winter and summer demands may vary greatly. (Whererecycled water is used for groundwater recharge, seasonal demands are more constant throughout the year.) Also, since water recycling projects are often planned to supply certain types of customers, the proximity of these customers to each other and to available pipeline distribution systems affects the economic viability of potential recycling projects.Technology available today allows many municipal wastewater treatment systems to produce water supplies at competitive costs. More stringent treatment requirements for disposal of municipal and industrial wastewater have reduced the incremental cost for higher levels of treatment required for recycled water. The degree of additional treatment depends on the intended use. Recycled water is used for agricultural and landscape irrigation, groundwater recharge, andindustrial and environmental uses. Some uses are required to meet more stringent standards for public health protection. An example is the City of San Diego’s planned 18 mgd wastewater repurification facility. This water project would produce about 16 taf/yr of repurified water to augment local municipal supplies. If implemented, the project would be California’s first planned indirect potable reuse project that discharges repurified water directly into a surface reservoir. The use of recycled water can lessen the demand for new water supply. However, not all water recycling produces new water supply. Bulletin 160 counts water T

ABLE ES3-3 Recently Completed Long-Term Water Marketing Agreements

Participants Region(s) Westside Water District, Colusa County Water District Sacramento River Semitropic Water Storage District, Santa Clara Valley Water District Tulare Lake, San Francisco Bay Semitropic Water Storage District, Alameda County Water District Tulare Lake, San Francisco Bay Semitropic Water Storage District, Zone 7 Water Agency Tulare Lake, San Francisco Bay Semitropic Water Storage District, Metropolitan Water District of Southern California Tulare Lake, South Coast Kern County Water Agency, Mojave Water Agency Tulare Lake, South Lahontan Arvin-Edison Water Storage District, Metropolitan Water District of Southern California Tulare Lake, South Coast Mojave Water Agency, Solano County Water Agency South Lahontan, San Francisco Bay Imperial Irrigation District, Metropolitan Water District of Southern California Colorado River, South CoastES3-9 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

that would otherwise be lost to the State’s hydrologic system (i.e., water discharged directly to the ocean or to another salt sink) as recycled water supply. If waterrecycling creates a new demand which would not otherwise exist, or if it treats water that would have otherwise been reapplied by downstream entities or recharged to usable groundwater, it is not considered new water supply. Water recycling provides multiple benefits such as reduced wastewater discharge and improved water quality. The Department, in coordination with the WateReuse Association of California, conducted a 1995 survey to update the Association’s 1993 survey of local agencies’ current and planned water recycling. By 2020, total water recycling is expected to increasefrom 485 taf/yr to 577 taf/yr, due to greater production at existing treatment plants and new productionat plants currently under construction. This base production is expected to increase new recycled supplies from 323 taf/yr to 407 taf/yr. All new recycled water is expected to be produced in the San Francisco Bay, Central Coast, and South Coast Regions. Table ES3-4 shows future potential options for water recycling. budget, 8 taf of seawater desalting is included as a drought year supply. In the 2020-level water budget, 8 taf of seawater desalting is included as average and drought year supplies.

Water Supply Summary by Hydrologic RegionTable ES3-5 summarizes average year water supplies by hydrologic region assuming 1995 and 2020levels of development and existing facilities and programs. Similarly, Table ES3-6 summarizes drought year water supplies by hydrologic region for existing and future levels of development. Regional water supplies, along with water demands presented in the followingchapter, provide the basis for the statewide water budget developed in Chapter ES5 and regional water budgets developed in Appendices ES5A and ES5B.

Water Quality A critical factor in determining the usability andreliability of any particular water source is water quality. The quality of a water source will significantly affectthe beneficial uses of that water. Water has many potential uses, and the water quality requirements for each use vary. Sometimes, different water uses may have conflicting water quality requirements. For example, water temperatures ideal for irrigation of some crops may not be suitable for fish spawning.The establishment and enforcement of water quality standards for water bodies in California fall under the authority of SWRCB and the nine regional water quality control boards. The RWQCBs protect water qualitythrough adoption of region-specific water quality control plans, commonly known as basin plans. In general, water quality control plans designate beneficial uses of water and establish water quality objectives designed to protect them. The designated beneficial uses of water may vary between individual water bodies. Water quality objectives are the limits or levels of water quality constituents or characteristics which areestablished to protect beneficial uses. Because a particular water body may have several beneficial uses,the water quality objectives established must be protective of all designated uses. When setting water quality objectives, several sources of existing waterquality limits are used, depending on the uses designated in a water quality control plan. When more thanone water quality limit exists for a water quality constituent or characteristic (e.g., human health limit vs. aquatic life limit), the more restrictive limit is used as T

ABLE ES3-4 2020 Level Total Water Recycling and New Water Supply (taf)

Projects Total New Water Water Recycling Supply

Base 577 407 Options 835 655 Total 1,412 1,062

By 2020, water recycling options could bring total water recycling potential to over 1.4 maf/yr, potentially generating as much as 1.1 maf/yr of newsupply, if water agencies implemented all projects identified in the survey. The capacity of California’s existing desalting plants totals about 66 taf annually; feedwater sources are brackish groundwater, wastewater, and seawater. Total seawater desalting capacity is currently about 8 taf/yr statewide. Most existing plants are small (less than 1 taf/yr) and have been constructed in coastal communities with limited water supplies. The Santa Barbara desalting plant, with capacity of 7.5 taf/yr, is currently the only large seawater desalting plant. The plant was constructed during the 1987-92 drought and is now on long-term standby. In the 1995-level waterES3-10 W

ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98TABLEES3-5California Average Year Water Supplies by Hydrologic Region (with existing facilities and programs, in taf)19952020Region Surface GroundwateraRecycled & TotalSurface GroundwateraRecycled & TotalDesalted (rounded)Desalted (rounded)North Coast20,3312631320,61020,3712881320,670San Francisco Bay 7,01168357,1107,06772377,180Central Coast3181,045181,3803681,041421,450South Coast3,8391,1772075,2203,6251,2432735,140Sacramento River 11,8812,672014,55012,1962,636014,830San Joaquin River 8,5622,195010,7608,4582,295010,750Tulare Lake7,8884,340012,2307,7914,386012,180North Lahontan77715789407591838950South Lahontan3222392759043724827710Colorado River4,154337154,5103,920285154,220Total (rounded) 65,09012,49032077,90064,99012,68041078,080aExcludes groundwater overdraft.TABLEES3-6California Drought Year Water Supplies by Hydrologic Region (with existing facilities and programs, in taf)19952020RegionSurface GroundwateraRecycled & TotalSurface GroundwateraRecycled & TotalDesalted (rounded)Desalted (rounded)North Coast 10,183 294 14 10,490 10,212 321 14 10,550San Francisco Bay 5,285 92 35 5,410 5,417 89 37 5,540Central Coast 160 1,142 26 1,330 180 1,159 42 1,380South Coast 3,196 1,371 207 4,780 3,130 1,462 273 4,870Sacramento River 10,022 3,218 0 13,240 10,012 3,281 0 13,290San Joaquin River 6,043 2,900 0 8,940 5,986 2,912 0 8,900Tulare Lake 3,693 5,970 0 9,660 3,593 5,999 0 9,590North Lahontan 557 187 8 750 557 208 8 770South Lahontan 259 273 27 560 326 296 27 650Colorado River 4,128 337 15 4,480 3,909 284 15 4,210Total (rounded) 43,530 15,780 330 59,640 43,320 16,010 420 59,750aExcludes groundwater overdraft.ES3-11 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

the water quality objective.Drinking water standards for a total of 81 individual drinking water constituents are in place under the mandates of the 1986 SDWA amendments. By the new SDWA standard setting process established in the 1996 amendments, EPA will select at least fivenew candidate constituents to be considered for regulation every five years. Selection of the new constituents for regulation must be geared toward contaminants posing the greatest health risks. Occasionally, drinking water regulatory goals may conflict. For example, concern over pathogens such as Cryptosporidium spurred a proposed rule requiring more rigorous disinfection. At the same time, there was considerable regulatory concern over trihalomethanes and other disinfection by-productsresulting from disinfecting drinking water with chlorine. However, if disinfection is made more rigorous, disinfection by-product formation is increased. Poor quality source waters with elevated concentrations of organic precursors and bromides further complicatethe problem of reliably meeting standards for disinfection while meeting standards for disinfection by-products. The regulatory community will have tobalance the benefits and risks associated with pursuing the goals of efficient disinfection and reduced disinfection by-products. EPA promulgated its Information Collection Rule in 1996 to obtain the data on the tradeoff posed by simultaneous control of disinfection by-products and pathogens in drinking water. The ICR requires all large public water systems to collect and report data on the occurrence of disinfection by-products and pathogens (including bacteria, viruses, Giardia , and Cryptosporidium ) in drinking water over an 18-month period. With this information, an assessment of health risks due to the presence of disinfection by-products and pathogens in drinking water can be made. EPAcan then determine the need to revise current drinking water filtration and disinfection requirements, andthe need for more stringent regulations for disinfectants and disinfection by-products.There has been growing concern over the potential human health threat of pathogens in groundwater. This concern stems from pathogens such as Giardia

, Cryptosporidium , bacteria, and viruses being found in water taken from wells. The concern about pathogens in groundwater has led to regulatory discussions ondisinfection requirements for groundwater. It is currently estimated that the Groundwater Disinfection Rule will be proposed sometime in 1999 and will become effective in 2002. The data obtained throughthe ICR will provide the necessary information to assess the extent and severity of risk. The SDWA requires states to implement wellheadprotection programs designed to prevent the contamination of groundwater supplying public drinking water wells. Wellhead protection programs rely heavily on local efforts to be effective, because communities have the primary access to information on potential contamination sources and can adopt locally-based measures to manage these potential contamination

sources.

CCWD’s Los Vaqueros Dam under construction. The reservoir does not provide new water supply, but provides terminal storage for CCWD’s existing supply and improves service area water quality.ES4-1 W ATER U SE The California Water Plan Update B ULLETIN 160-98

Nursery products are California’s third largest farm product in gross value. The nursery industry is affected by the availability of both agricultural and urban water supplies. 

# Urban, Agricultural, and Environmental Water Use 

# T his chapter describes present and forecasted urban, agricultural, and
environmental water use. The chapter is organized into three major
sections, one for each category of water use.
Water use information is presented at the hydrologic region level of detail under
normalized hydrologic conditions. Forecasted 2020-level urban and agricultural water use
have not changed greatly since publication of Bulletin 160-93. Forecasted urban water use
depends heavily on population forecasts. Although the Department of Finance has updated
its California population projections since the last Bulletin, U.S. census data are an important
foundation for the projections, and a new census will not be performed until 2000. The
Department’s forecasts of agricultural water use change relatively slowly in the short-term,
because the corresponding changes in forecasted agricultural acreage are a small percentage
of the State’s total irrigated acreage. Changes in base year and forecasted environmental
water use from the last Bulletin reflect implementation of SWRCB’s Order
WR 95-6 for the Bay-Delta.

Urban Water Use

Forecasts of future urban water use for the Bulletin are based on
population information and per capita water use estimates. Factors influencing
per capita water use include expected demand reduction due to implemen

# Executive SummaryES4-2 W

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-tation of water conservation programs. The Department has modeled effects of conservation measures and socioeconomic changes on per capita use in 20 major water service areas to estimate future changesin per capita use by hydrologic region. An urban water agency making estimates for its ownservice area would be able to incorporate more complexity in its forecasting, because the scope of its effortis narrow. For this reason, and because DOF population projections seldom exactly match population projections prepared by cities and counties, theBulletin’s water use forecasts are expected to be representative of, rather than identical to, those of local water agencies.
Population GrowthData about California’s population—its geographic distribution and projections of futurepopulations and their distribution—come from several sources. The Department works with base year and projected year population information developedby DOF for each county in the State. The decadal census is a major benchmark for population projections. DOF works from census data to calculate the State’s population in noncensus years, and to project future populations. Figure ES4-1 shows DOF’s projected growth rates by county for year 2020. (State policy requires that all State agencies use DOF population projections for planning, funding, and policymaking activities.) Population projections used in Bulletin 160-98 are based on DOF’s Interim County Population Projections (April 1997) . Table ES4-1 shows the 1995 through2020 population figures for Bulletin 160-98 by hydrologic region. DOF periodically updates its population forecaststo respond to changing conditions. Its 2020 population forecast used for Bulletin 160-93 was 1.4 million higher than the 2020 forecast used in Bulletin 160- 98. The latter forecast incorporated the effects of the recession of the early 1990s. Small fluctuations in the forecast do not obscure the overall trend—an increase in population on the order of 50 percent. The Department apportioned county population data to Bulletin 160 study areas based on watershed orwater district boundaries. Factors considered in distributing the data to Bulletin 160 study areas included population projections prepared by cities, counties, andlocal councils of governments, which typically incorporate expected future development from city andcounty general plans. The local agency projections indicate which areas within a county are expected to experience growth, and provide guidance in allocating DOF’s projection for an entire county into smaller Bulletin 160 study areas.

Factors Affecting Urban Per Capita Water Use Urban per capita water use includes residential,commercial, industrial, and institutional uses of water. Each of these categories can be examined at a greaterlevel of detail. Residential water use, for example, includes interior and exterior (e.g., landscaping) wateruse. Forecasts of urban water use for an individual community may be separated into components and forecasted individually. It is not possible to use thislevel of detail for each community in the State in Bulletin 160-98. Bulletin 160-98 modeled components of urban use for representative urban water agenciesin each of the State’s ten hydrologic regions and extrapolated those results to the remainder of each hydrologic region.Demand reduction achieved by implementing water conservation measures is important in forecasting per capita water use. Bulletin 160-98 incorporates demandreductions from implementation of urban best management practices contained in the 1991 Memorandum of Understanding Regarding Urban Water Conservation in California . Bulletin 160-98 assumes implementation of the urban MOU’s BMPs by 2020, resulting in a demand reduction of about 1.5 maf over the year 2020 demand forecast without BMP imple mentation.The relationship of water pricing to water consumption, and the role of pricing in achieving waterconservation, has been a subject of discussion in recent years. Elected board members of public water T

ABLE ES4-1 California Population by Hydrologic Region (in thousands)

Region 1995 2020

North Coast 606 835 San Francisco Bay 5,780 7,025 Central Coast 1,347 1,946 South Coast 17,299 24,327 Sacramento River 2,372 3,813 San Joaquin River 1,592 3,025 Tulare Lake 1,738 3,296 North Lahontan 84 125 South Lahontan 713 2,019 Colorado River 533 1,096 Total (rounded) 32,060 47,510ES4-3 W ATER U SE The California Water Plan Update B ULLETIN 160-98

0 - 20%

20 - 40%

40 - 60%

60 - 80%

80 - 100%

Over 100% 

## Legend Legend F IGURE ES4-1. Projected Growth Rates by County, 1995-2020ES4-4 W

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agencies ultimately have the responsibility for balancing desires to achieve demand reduction through water pricing with desires to provide affordable water rates to consumers. Urban water rates in California vary widely and are affected by factors such as geographic location, source of supply, and type of water treatmentprovided. Water rates are set by local agencies to recover costs of providing water service, and are highlysite-specific. According to several price elasticity studies for urban water use, residential water demand isusually inelastic, i.e., water users were relatively insensitive to changes in price for the price ranges evaluated. Water price currently plays a small role in relation to other factors affecting water use—public education, plumbing retrofit programs, etc.

Urban Water Use Forecasting The Department forecasted change in per capitawater use by 2020 in each hydrologic region to estimate 2020 urban applied water by hydrologic region. Variables included changes in population, income,economic activity, water price, and conservation measures (implementation of urban BMPs and changes to State and federal plumbing fixture standards). The general forecasting procedure was to determine 1995base per capita water use, estimate the effects of conservation measures and socioeconomic change on future use for 20 major representative water service areas in California, and calculate 2020 base per capitawater use by hydrologic region from the results of service area forecasts. (See Table ES4-2.)

Summary of Urban Water Use
Table ES4-3 summarizes Bulletin 160-98 urbanapplied water use by hydrologic region. Statewide urHigh efficiency horizontal axis washing machines (front loading washers) are being used in commercial applications, but are just becoming available for home use. A check of large appliance dealers in 1998 showed that two brands of horizontal axis washers are commonly in stock, at prices ranging from $700 to $1,100. Comparable standard washers cost from $100 to $600 less. Some utilities are offering their customers rebates on the order of $100 to $150 for purchasing the horizontal axis machines. T ABLE ES4-2 Effects of Conservation on Per Capita Water Use a by Hydrologic Region (gallons per capita per day)

Region 1995 2020
without conservation with conservation

North Coast 249 236 215 San Francisco Bay 192 188 166 Central Coast 179 188 166 South Coast 208 219 191 Sacramento River 286 286 264 San Joaquin River 310 307 274 Tulare Lake 298 302 268 North Lahontan 411 390 356 South Lahontan 282 294 268 Colorado River 564 626 535 Statewide 229 243 215

a Includes residential, commercial, industrial, and landscape use supplied by public water systems and self-produced surface and groundwater. Does not

include recreational use, energy production use, and losses from major conveyance facilities. These are normalized data.ES4-5 W ATER U SE The California Water Plan Update B ULLETIN 160-98

ban use at the 1995 base level is 8.8 maf in average water years and 9.0 maf in drought years. (Droughtyear demands are slightly higher because less precipitation is available to meet exterior urban water uses,such as landscape watering.) Projected 2020 use increases to 12.0 maf in average years and 12.4 maf in drought years. Full implementation of urban BMPs is estimated to result in demand reduction of 1.5 maf inaverage year water use by 2020. Without implementation of urban BMPs, average year use would have increased to 13.5 maf. As indicated in the Table ES4-3, the South Coast and San Francisco Bay Hydrologic Regions together amount to over half of the State’s total urban water use. The table also illustrates that precipitation plays asmall role in meeting urban outdoor water needs (landscape water needs) in arid regions such as the Tulare Lake, South Lahontan, and Colorado River Regions.

Agricultural Water UseThe Department’s estimates of agricultural water use are derived by multiplying water userequirements for different crop types by their corresponding statewide irrigated acreage, and summing the results to obtain a total for irrigated crops in the State. This section begins by covering crop water use requirements. A description of the process for estimating future irrigated acreage, and factors affecting acreage forecasts, follows. Forecasted 2020 agricultural water demands are summarized at the end of the section. Crop Water Use The water requirement of a crop is directly related to the water lost through evapotranspiration. The amount of water that can be consumed through ET depends in the short term on local weather and in the long term on climatic conditions. Energy from solar radiation is the primary factor that determines the rate of crop ET. Also important are humidity, temperature,wind, stage of crop growth, and the size and aerodynamic roughness of the crop canopy. Irrigation frequency affects ET after planting and during early growth, because evaporation increases when the soilsurface is wet and is exposed to sunlight. Growing season ET varies significantly among crop types, depending primarily on how long the crop actively

grows. Direct measurement of crop ET requires costly investments in time and in sophisticated equipment. There are more than 9 million acres of irrigated cropland in California, encompassing a wide range of climate, soils, and crops. Even where annual ET for two areas is similar, monthly totals may differ. For example, average annual ET for Central Coast interior valleys is similar to that in the Central Valley. Central Valley ET is lower than that in coastal valleys during the winter fog season, and higher during hot summer weather. Obtaining actual measurements for every combinationof environmental variables would be prohibitively difficult and expensive. A more practical approach is to estimate ET using methods based on correlation of measured ET with observed evaporation, temperature, and other climatologic conditions. Such methods can

T

ABLE ES4-3 Applied Urban Water Use by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 169 177 201 212 San Francisco Bay 1,255 1,358 1,317 1,428 Central Coast 286 294 379 391 South Coast 4,340 4,382 5,519 5,612 Sacramento River 766 830 1,139 1,236 San Joaquin River 574 583 954 970 Tulare Lake 690 690 1,099 1,099 North Lahontan 39 40 50 51 South Lahontan 238 238 619 619 Colorado River 418 418 740 740 Total (rounded) 8,770 9,010 12,020 12,360ES4-6 W

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be used to transfer the results of measured ET to other areas with similar climates.The Department uses the ET/evaporation correlation method to estimate growing season ET. Concurrent with field measurement of ET rates, theDepartment developed a network of agroclimate stations to determine the relationship between measured ET rates and pan evaporation. Data from agroclimatic studies show that water evaporation from a standard water surface (the Department uses the U.S. Weather Bureau Class A evaporation pan) closely correlates to crop evapotranspiration. The ET/evaporation method estimates crop water use to within ±10 percent of measured seasonal ET. Crop coefficients are applied to pan evaporation data to estimate evapotranspiration rates for specific crops. (Crop coefficients vary by crop, stage of cropgrowth, planting and harvest dates, and growing season duration.) The resulting data, combined withinformation on effective rainfall and water use efficiency, form the basis for calculating ETAW and applied water use. Crop applied water use includes theirrigation water required to meet crop ETAW and cultural water requirements. The amount of water applied to a given field for crop production is influenced by considerations such as crop water requirements, soil characteristics, theability of an irrigation system to distribute water uniformly on a given field, and irrigation managementpractices. In addition to ET, other crop water requirements can include water needed to leach soluble salts below the crop root zone, water that must be appliedfor frost protection or cooling, and water for seed germination. The amount required for these uses depends upon the crop, irrigation water quality, and weather conditions. Part of a crop’s water requirements can be met by rainfall. The amount of rainfall beneficially used for crop production is called effective rainfall. Effective rainfall is stored in the soil and is available to satisfy crop evapotranspiration or to offset water needed forspecial cultural practices such as leaching of salts. Irrigation provides the remainder of the crop water requirement. Irrigation efficiency influences the amount of applied water needed, since a portion ofeach irrigation goes to system leaks and deep percolation of irrigation water below the crop root zone.The Bulletin’s 1995 base applied agricultural water use values were computed from normalized data to account for variation in annual weather patterns and water supply. Normalizing entails applying crop coefficients to long-term average evaporative demand data. Actual applied crop water use during 1995 was less than the Bulletin 160-98 base in many areas due towet hydrologic conditions that increased effective rainfall, thus decreasing crop ETAW. Likewise, applied water use during a dry year (assuming no constraints on water supplies) would likely exceed the base due to less than average effective rainfall with an attendant increase in crop ETAW.Bulletin 160-98 quantifies agricultural water conservation based on assumed statewide implementation of the 1996 agricultural MOU. This conservation is expected to reduce agricultural applied water demands by about 800 taf annually by 2020.
Quantifying Base Year Irrigated Acreage Forecasts of agricultural acreage start with land usedata that characterize existing crop acreage. The Department has performed land use surveys since the1950s to quantify acreage of irrigated land and corresponding crop types, and currently maps irrigated acreage in six to seven counties per year. The base datafor land use surveys are obtained from aerial photography or satellite imagery, which is superimposed on a cartographic base. Site visits are used to identify orverify crop types growing in the fields. From this information, maps showing locations and acreage of crop types are developed.The Department’s land use surveys focus on quantifying irrigated agricultural acreage. Although fieldsof dry-farmed crops are mapped in the land use surveys, their acreage is not tabulated for calculating water use. In certain areas of the State, climate and market conditions are favorable for producing multiple cropsper year on the same field (for example, winter vegetables followed by a summer field crop). In these cases, annual irrigated acreage is counted as the sum of theacreage of the individual crop types. In the years between county land use surveys, the Department estimates crop types and acreage using data collected from county agricultural commissioners, local wateragencies, University of California Cooperative Extension Programs, and the California Department of Food and Agriculture. The starting point for determining Bulletin 160- 98 1995 base acreage was normalized 1990 irrigatedacreage from Bulletin 160-93. Changes in crop acreage between 1990 and 1995 were evaluated to determine if they were due to short-term causes (e.g.,ES4-7 W ATER U SE The California Water Plan Update B ULLETIN 160-98

drought or abnormal spring rainfall), or if there wasan actual change in cropping patterns. Base year acreage was normalized to represent the acreage that wouldmost likely occur in the absence of weather and market related abnormalities. Crop acreage by region for the normalized 1995base is presented in Table ES4-4. The 1995 base irrigated land acreage is about 9.1 million acres, which, when multiple cropped areas are tabulated, becomes a base irrigated cropped acreage of about 9.5 million

acres. Forecasting Future Irrigated Acreage The Department’s 2020 irrigated acreage forecast was derived from staff research, a crop market outlook study, and results from the Central Valley Production Model. As with any forecast of future conditions, thereare uncertainties associated with each of these approaches. The Department’s integration of the resultsfrom three independent approaches is intended to represent a best estimate of future acreage, absent major changes from present conditions. It is important to emphasize that many factors affecting future croppedacreage are based on national (federal Farm Bill programs) or international (world export markets)circumstances. California agricultural products compete with products from other regions in the globaleconomy, and are affected by trade policies and market conditions that reach far beyond the State’s boundaries. The Federal Agriculture Improvement and Reform Act of 1996, for example, affects agricultural markets nationwide, by changing federal price supports for specified agricultural commodities. Under the terms of that act, federal payments to growers will be reduced by 2002, and prior farm bill provisions that requiredgrowers to reduce planted acreage of regulated commodities are no longer in force. (Commodities with significant federal price support include wheat, feed grains, rice, cotton, dairy products, sugar, and peanuts.) The overall impact of the act to California, however, may be less than its impact to states whose agriculture is less diversified and who are less active in exportmarkets. In 1994, for example, federal farm bill production payments to California growers represented about one percent of California’s agricultural revenue.The potential impacts of FAIRA to California’s agricultural market are considered in Bulletin 160-98 by the crop market outlook study. Intrastate factors considered in making acreage forecasts included urban encroachment onto agricultural land and land retirement due to drainage problems. Urbanization on lands presently used for irrigated agriculture is a significant consideration inthe South Coast Region and in the San Joaquin Valley, based on projected patterns of population growth.DOF 2020 population forecasts, along with information gathered from local agency land use plans, wereused to identify irrigated lands most likely to be affected by urbanization. Local water agencies and countyfarm advisors were interviewed to assess their perspective on land use changes affecting agricultural acreage.For example, urbanization may eliminate irrigated acreage in one area, but shift agricultural development onto lands presently used as non-irrigated pasture. Soil typesand landforms are important constraints in agricultural land development. If urbanization occurs onprime Central Valley farmland, some agricultural production may be able to shift to poorer quality soils on hilly lands adjoining the valley floor. A consequent shiftin crop types and irrigation practices would likely result—for example, from furrow-irrigated row crops to vineyards on drip irrigation. The Department’s crop market outlook, a form of Delphi analysis, was developed using information and expert opinions gathered from interviews with more than 130 University of California farm advisors, agricultural bankers, commodity marketing specialists,

Factors that influence the conversion of irrigated lands to urban use include the lands’ proximity to existing urban areas and transportation corridors, and local agency land use planning and zoning policies.ES4-8 W

ATER U SE The California Water Plan Update B ULLETIN 160-98TABLEES4-4California Crop and Irrigated Acreage by Hydrologic Region, 1995 Level(thousands of acres)Irrigated Crop NC SF CC SC SR SJ TL NL SL CR TotalGrain722 26 11 270 180 26072 70 900Rice0 0 0 0494 22 0 1 0 0517Cotton0 0 0 0 91851,02600 24 1,244Sugar beets6 0 3 054 47 30 0 038 178Corn1 1 3 492 212 116 0 0 9438Other field31 164 155 120 9701 70 467Alfalfa530 21 10 149 231 296 44 34 256 1,094Pasture1225 18 20 352 199 49 107 18 43 933Tomatoes00 107 138 82 111 0 0 9357Other truck23 11 382 87 56 130 19423 172 1,060Almond/pistachios0 0 0 0106 251 177 0 0 0534Other deciduous76 183 219 154 191 0 3 1602Subtropical00 19 161 288 20200 37 455Grapes36 39 566 17 184 37800 20 736Total Crop Area 323 65 572 313 2,139 2,005 3,127 161 61 749 9,515Multiple Crop00 142 30 52 56 6300 104 447Irrigated Land Area 323 65 430 283 2,087 1,949 3,064 161 61 645 9,068ES4-9 W ATER U SE The California Water Plan Update B ULLETIN 160-98

managers of cooperatives, and others. Three basic factors guided the CMO: current and future demand for food and fiber by the world’s consumers; the shareCalifornia could produce to meet this worldwide demand; and technical factors, such as crop yields, pasturecarrying capacities, and livestock feed conversion ratios that affect demand for agricultural products. (Milk and dairy products are California’s largest agricultural product, in terms of gross value. The demand for these products is reflected in the markets for alfalfa, grains, and other fodder used by dairies.) The CMO forecastsa statewide crop mix and estimates corresponding irrigated acreage. The major findings of the CMO for year 2020 were that grain and field crop acreage would decrease, while acreage of truck crops and permanent crops would increase.The Central Valley Production Model is a mathematical programming model that simulates farmingdecisions by growers. Inputs include detailed information about production practices and costs as well as water availability and cost by source. The model alsouses information on the relationship between production levels of individual crops and crop market prices.The model’s geographic coverage is limited to the Central Valley, which represents about 80 percent of theState’s irrigated agricultural acreage. The CVPM results also indicated future crop shifting, from grains and field crops to vegetables, trees, and vines. TheCVPM forecast showed a small reduction in crop acreage from 1995 to 2020.One factor not included in Bulletin 160-98 irrigated acreage forecasts is the potential large-scale conversion of agricultural land to wildlife habitat for reasons other than westside San J oaquin Valley problems. The CALFED program represents the largest pending example of potential conversion of irrigated agricultural lands to habitat, as described in CALFED’s March 1998 first draft programmaticEIR/EIS and supporting documents. CALFED’s potential land conversion amounts have not been included in the Bulletin 160-98 irrigated acreage forecast because they are preliminary at this time (asite-specific environmental document with an implementation schedule for land conversion has not yet been prepared), and because CALFED’s preliminarynumbers are so large relative to the Bulletin’s market-based forecast of irrigated acreage that they would negate the results of the forecast. Overall, CALFED program activities as presently plannedcould convert up to 290,000 irrigated acres to habitat and other uses, an amount almost as great as the 325,000-acre reduction in irrigated acreage forecast in the Bulletin. Water use implications of large-scale land conversions are not included in the Bulletin 160-98 forecast. Impacts of such land conversions are expected to be addressed in the next water plan update, when CALFED’s program may be better defined. The difficulty in estimating impacts from large-scale land conversion programs stems from the domino effect that changes in acreage in one location have on acreageand crop types in other areas, and how crop markets determine which crop shifts are feasible. For example, CALFED’s preliminary reports suggest that up to 190,000 irrigated acres in the Delta could be converted to other land uses. This amount represents about 40 percent of Delta irrigated acreage, whose principal crops are corn, alfalfa, tomatoes, grain, orchard crops, and truck crops (e.g., asparagus). Some land conversion in the Delta might result in production on new agricultural lands—most likely, rolling hills on the edge of the valley floor whichare only suitable for limited crop types (orchards and vineyards). Some of the land conversion might result in increased demand in other areas for the affected crops,such as increased demand for asparagus from the Imperial and Salinas V alleys.Table ES4-5 shows the 2020 irrigated acreage foreThere is a perception that only drip irrigation is an efficient agricultural water use technology. High efficiencies are possible with a variety of irrigation techniques. Considerations such as soil type, field configuration, and crop type influence the choice of irrigation technique.ES4-10 W

ATER U SE The California Water Plan Update B ULLETIN 160-98TABLEES4-5California Crop and Irrigated Acreage by Hydrologic Region, 2020 Level(thousands of acres)Irrigated Crop NC SF CC SC SR SJ TL NL SL CR TotalGrain661 215 249 152 20180 97 800Rice0 0 0 0484 15 0 1 0 0500Cotton0 0 0 015 171 888 0 0461,120Sugar beets6 0 2 052 18 13 0 029 120Corn2 0 3 290 188 101 1 0 3390Other field31 141 154 139 11000 33 455Alfalfa620 206 147 181 238 50 24 217 945Pasture1235 166 316 165 26 103 18 32 810Tomatoes0 0 8 4141 93 130 0 014 390Other truck28 11 373 43 79 197 30021 231 1,265Almond/pistachios0 0 0 0127 270 198 0 0 0595Other deciduous76 203 234 153 199 0 2 1625Subtropical00 18 117 33 10 21500 32 425Grapes38 41 753 29 183 36600 15 750Total Crop Area 335 65 570 190 2,150 1,935 2,985 165 45 750 9,190Multiple Crop00 150 10 70 80 10000 145 555Irrigated Land Area 335 65 420 180 2,080 1,855 2,885 165 45 605 8,635ES4-11 W ATER U SE The California Water Plan Update B ULLETIN 160-98

cast. The total irrigated crop acreage is forecasted todecline by 325,000 acres from 1995 to 2020, primarily in the San Joaquin Valley and South Coast areas.Reductions in crop acreage are due to urban encroachment, drainage problems in the westside San Joaquin Valley, and a more competitive economic market for California agricultural products. Grain and field crops are forecasted to decline by about 631,000 acres. Truck crops and permanent crops are forecasted to increaseby about 238,000 and 68,000 acres, respectively. Acreage with multiple cropping is forecasted to increase by108,000 acres, reflecting the expected increased production of truck crops. These statewide findings areused in developing the base year and forecasted agricultural water demands.
Summary of Agricultural Water Use Crop water use information and irrigated acreage data are combined to generate the 2020 agricultural water use by hydrologic region shown in Table ES4-6. As previously noted, the 2020 forecasted values take into account EWMP implementation, which results in a 2020 applied water reduction of about 800 taf.

Environmental Water Use
Bulletin 160-98 defines environmental water as the sum of: • Dedicated flows in State and federal wild and
scenic rivers • Instream flow requirements established by water right permits, DFG agreements, court actions, or other administrative documents • Bay-Delta outflows required by SWRCB • Applied water demands of managed freshwater wildlife areas This definition recognizes that certain quantities of water have been set aside or otherwise managedfor environmental purposes, and that these quantities cannot be put to use for other purposes in thelocations where the water has been reserved or otherwise managed. This definition also recognizes that these uses of environmental water can be quantified. Unlike urban and agricultural water use, much of thisenvironmental water use is brought about by legislative or regulatory processes. Certainly the environment uses more water than is encompassedin this definition—the rainfall that sustains the forests of the Sierra Nevada and the North Coast, thewinter runoff that supports flora and fauna in numerous small streams, the shallow groundwater that supports riparian vegetation in some ephemeral streams—but the Bulletin’s definition captures uses of water that are managed (in one fashion or another) and quantifiable. As described earlier, average annual statewide precipitation over California’s land surface amounts to about 200 maf. About 65 percent of this precipitation is consumed through evaporation and transpiration by the State’s forests, grasslands, and other vegetation. The remaining 35 percent comprises the State’s average annual runoff of about 71 maf. The environmental water demands discussed in this section are demands that would be met through a designated portion of that average annual runoff. Aswith urban and agricultural water use, environmental water use is shown on an applied water basis. T

ABLE ES4-6 Applied Agricultural Water Use by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 894 973 927 1,011 San Francisco Bay 98 108 98 108 Central Coast 1,192 1,279 1,127 1,223 South Coast 784 820 462 484 Sacramento River 8,065 9,054 7,939 8,822 San Joaquin River 7,027 7,244 6,450 6,719 Tulare Lake 10,736 10,026 10,123 9,532 North Lahontan 530 584 536 594 South Lahontan 332 332 257 257 Colorado River 4,118 4,118 3,583 3,583 Total (rounded) 33,780 34,540 31,500 32,330ES4-12 W

ATER U SE The California Water Plan Update B ULLETIN 160-98

Wild and Scenic River FlowsFlows in wild and scenic rivers constitute the largest environmental water use in the State. Figure ES4-2is a map of California’s State and federal wild and scenic rivers. The 1968 National Wild and Scenic Rivers Act, codified to preserve the free-flowing characteristics ofrivers having outstanding natural resources values, prohibited federal agencies from constructing, authorizing, or funding the construction of water resources projects having a direct or adverse effect on the values for which the river was designated. (This restriction also appliesto rivers designated for potential addition to the national wild and scenic rivers system.) There are twomethods for having a river segment added to the federal system—congressional legislation, or a state’spetition to the Secretary of the Interior for federal designation of a river already protected under state statutes. No new federal designations have been made since publication of Bulletin 160-93. A number of river systems within lands managed by federal agencies are being studied as candidates. For example, USFS draft environmental documentation in 1994 and 1996 recommended designation of five streams (129 river miles) in Tahoe National Forest and 160 river miles in Stanislaus National Forest. These waterways drain to the Central Valley where their flowsare used for other purposes, and wild and scenic designation would not affect the existing downstream uses. The California Wild and Scenic Rivers Act of 1972prohibited construction of any dam, reservoir, diversion, or other water impoundment on a designated river. As shown on Figure ES4-2, some rivers are included inboth federal and State systems. No new State designations have been made since Bulletin 160-93, althoughthe Mill and Deer Creeks Protection Act of 1995 (Section 5093.70 of the Public Resources Code) gave portions of these streams special status similar to wild and scenic designation by restricting construction ofdams, reservoirs, diversions, or other water impoundments. Table ES4-7 shows the wild and scenic river flows used in Bulletin 160-98 water budgets by hydrologicregion. The flows shown are based on the rivers’ unimpaired flow. (The unimpaired flow in a river is the flow measured or calculated at some specific locationthat would be unaffected by stream diversions, storage, imports or exports, and return flows.) For the average year condition, the long-term unimpaired flowfrom the Department’s Bulletin 1 was used. The estimated average unimpaired flow for the 1990-91 water years was used for the drought condition.

Instream Flows Instream flow is the water maintained in a stream or river for instream beneficial uses such as fisheries, wildlife, aesthetics, recreation, and navigation. Instream flow is a major factor influencing the productivity and diversity of California’s rivers and streams. Instream flows may be established in a variety of ways—by agreements executed between DFG and a water agency, by terms and conditions in a water right permit from SWRCB, by terms and conditions in a FERC hydropower license, by a court order, or by an agreement among interested parties. Required flows on most rivers vary by month and year type, with wet year requirements generally being higher than dry year requirements. Converting from net water use analyses performed for prior editions of Bulletin 160 to the T

ABLE ES4-7 Wild and Scenic River Flows by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 17,800 7,900 17,800 7,900 San Francisco Bay 0 0 0 0 Central Coast 98 28 98 28 South Coast 69 51 69 51 Sacramento River 1,733 736 1,733 736 San Joaquin River 1,974 939 1,974 939 Tulare Lake 1,614 751 1,614 751 North Lahontan 271 154 271 154 South Lahontan 0 0 0 0 Colorado River 0 0 0 0 Total (rounded) 23,560 10,560 23,560 10,560ES4-13 W ATER U SE The California Water Plan Update B ULLETIN 160-98

Redding Federal and State Designation

State Designation Only

Federal Designation Only

E. Fork Carson River

W. Walker River

Kings River Eel River S. Fork Van S. Fork

Trinity Smith River

K l a m a t h

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i v e r F IGURE ES4-2.
California Wild and Scenic RiversES4-14 W

ATER U SE The California Water Plan Update B ULLETIN 160-98

applied water budgets used in Bulletin 160-98 created a challenge in properly accounting for multiple instream flows within a river basin. Bulletin 160-98 used a simplified approach in which only the largest downstream flow requirement was included in the water budgets. This simplified approach undercounts applied instream flow requirements on streams havingmultiple requirements. The Department is developing a new modeling approach for the next water plan update that will more accurately quantify applied instream flows. Since the determination of 1990-level instream flow values used as base conditions in Bulletin 160- 93, subsequent agreements or decisions have increased or added instream flow requirements for the Trinity River, Mokelumne River, Stanislaus River, Tuolumne River, Owens River, Putah Creek, and Mono Lake tributaries. In addition, ten new waterways have beenadded to the Bulletin 160-98 instream flow water budgets—the Mad River, Eel River, Russian River, Truckee River, East Walker River, Nacimiento River, San Joaquin River (at Vernalis), Walker Creek, Lagunitas Creek, and Piru Creek.Table ES4-8 shows instream flows used in Bulletin 160-98 water budgets by hydrologic region. The drought year scenario shown in the tables representsthe minimum annual required flow volume. For average water years, the annual required flow volume is computed by combining the expected number of years in each year type (wet, above normal, normal, below normal, and/or dry, as specified in existing agreements or orders).
Bay-Delta Outflow Environmental water use for Bay-Delta outflow is computed by using operations studies to quantify SWRCB Order WR 95-6 requirements. Order WR 95-6 established numerical objectives for salinity, river flows, export limits, and Delta outflow. Operationsstudies were used to translate these numerical objectives into Delta outflow requirements for average and drought year scenarios. The studies computed outflow requirements of approximately 5.6 maf in average years and 4.0 maf in drought years.

Wetlands The wetlands component of environmental wateruse is based on water use at freshwater managed wetlands, such as federal national wildlife refuges and State wildlife management areas. In general, wetlands can be divided into saltwater and brackish water marshes(usually located in coastal areas) and freshwater wetlands (generally located in inland areas).Five areas of California contain the largest remaining wetlands acreage in the State—the Central Valley, Humboldt Bay, San Francisco Bay, Suisun Marsh, and Klamath Basin. The majority of the State’s wetland protection and restoration efforts are occurring in theseareas. Nontidal wetlands usually depend on a supplemental water supply, and protecting or restoring them may create demands for freshwater supplies. Bulletin 160-98 quantifies applied water needs only for managed wetlands, because other wetlands types such as vernal pools or coastal wetlands use naturally-occurring water supply (precipitation or tidal action). Managed wetlands are defined for the Bulletin as impounded freshwater and nontidal brackish water wetlands. Managed wetlands may be State and federal wildlife areas or refuges, private wetland preserves owned by nonprofit organizations, T

ABLE ES4-8 Instream Flow Requirements by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 1,410 1,285 1,410 1,285 San Francisco Bay 17 9 17 9 Central Coast 20 9 20 9 South Coast 4 4 4 4 Sacramento River 3,397 2,784 3,397 2,784 San Joaquin River 1,169 712 1,169 712 Tulare Lake 0 0 0 0 North Lahontan 85 84 85 84 South Lahontan 107 81 107 81 Colorado River 0 0 0 0 Total (rounded) 6,210 4,970 6,210 4,970ES4-15 W ATER U SE The California Water Plan Update B ULLETIN 160-98

private duck clubs, or privately owned agricultural lands flooded for cultural practices such as rice straw decomposition. Some of the largest concentrations of privately owned wetlands are the duck clubs in the Suisun Marsh and the flooded rice fields in the Sacramento Valley. (Acreage of rice fields floodedto enhance decomposition of stubble remaining after harvest and to provide habitat for overwintering waterfowl was identified by Department land usesurveys.) Table ES4-9 shows wetlands water demands by region.
Summary of Environmental Water Use
Table ES4-10 shows base 1995 and forecasted 2020 environmental water use by hydrologic region. The large values in the North Coast Region illustrate the magnitude of demands for wild and scenic rivers in comparison to other environmental water demands.

Water Use Summary by Hydrologic Region

Tables ES4-11 and ES4-12 summarize California’saverage and drought year applied water use by hydrologic region. The tables combine the urban, agricultural, and environmental water use described in this chapter.Also included are related minor uses such as conveyance losses and self-supplied industrial and powerplant cooling water. These demands, together with the water supply information presented in Chapter ES3, are usedto prepare the statewide water balance shown in Chapter ES5 and the regional water balances shown in Appendix ES5A. T

ABLE ES4-9 Wetlands Water Use by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 325 325 325 325 San Francisco Bay 160 160 160 160 Central Coast 0 0 0 0 South Coast 27 27 31 31 Sacramento River 632 632 632 632 San Joaquin River 230 230 240 240 Tulare Lake 50 50 53 53 North Lahontan 18 18 18 18 South Lahontan 0 0 0 0 Colorado River 39 38 44 43 Total (rounded) 1,480 1,480 1,500 1,500

T

ABLE ES4-10 Applied Environmental Water Use by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 19,544 9,518 19,545 9,518 San Francisco Bay 5,762 4,294 5,762 4,294 Central Coast 118 37 118 37 South Coast 100 82 104 86 Sacramento River 5,833 4,223 5,839 4,225 San Joaquin River 3,396 1,904 3,411 1,919 Tulare Lake 1,672 809 1,676 813 North Lahontan 374 256 374 256 South Lahontan 107 81 107 81 Colorado River 39 38 44 43 Total (rounded) 36,940 21,240 36,980 21,270ES4-16 W

ATER U SE The California Water Plan Update B ULLETIN 160-98TABLEES4-11California Average Year Water Use by Hydrologic Region (taf)1995 2020Region Urban Agricultural Environmental Total Urban Agricultural Environmental Total(rounded)(rounded)North Coast16989419,54420,61020192719,54420,670San Francisco Bay 1,255985,7627,1101,317985,7627,180Central Coast2861,1921181,6003791,1271181,620South Coast4,3407841005,2205,5194621046,080Sacramento River 7668,0655,83314,6601,1397,9395,83914,920San Joaquin River 5747,0273,39611,0009546,4503,41110,820Tulare Lake69010,7361,67213,1001,09910,1231,67612,900North Lahontan3953037494050536374960South Lahontan238332107680619257107980Colorado River4184,118394,5707403,583444,370Total (rounded) 8,77033,78036,94079,49012,02031,50036,98080,500TABLEES4-12California Drought Year Water Use by Hydrologic Region (taf)19952020Region Urban Agricultural Environmental Total Urban Agricultural Environmental Total(rounded)(rounded)North Coast1779739,51810,6702121,0119,51810,740San Francisco Bay 1,3581084,2945,7601,4281084,2945,830Central Coast2941,279371,6103911,223371,650South Coast4,382820825,2805,612484866,180Sacramento River 8309,0544,22314,1101,2368,8224,22514,280San Joaquin River 5837,2441,9049,7309706,7191,9199,610Tulare Lake69010,02680911,5301,0999,53281311,440North Lahontan4058425688051594256900South Lahontan2383328165061925781960Colorado River4184,118384,5707403,583434,370Total (rounded) 9,01034,54021,24064,79012,36032,33021,27065,960ES4-17 W ATER U SE The California Water Plan Update B ULLETIN 160-98ES5-1 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

The 1848 discovery of gold at

Sutter’s Mill on the

American River led to California’s
statehood in 1850. California celebrates

its sesquicentennial

in 2000.

Miners in the Sierra, Detail of painting by Charles Nahl

and Frederick Wenderoth, 1851.

Courtesy of Smithsonian Institution 

# T his chapter assesses California’s water future, based on today’s conditions
and on options being considered by California’s water purveyors. The
Department’s Bulletin 160 series does not forecast a particular vision for the
future, but instead attempts to forecast the future based on today’s data, economic conditions,
and public policies.
Although no forecast of the future can be perfect, several key trends appear inevitable.
California’s population will increase dramatically by 2020. How growth is accommodated
and the land use planning decisions made by cities and counties have important implications
for future urban and agricultural water use. California’s agricultural acreage is forecasted to
decline slightly by 2020 (reflecting the State’s increasing urbanization), as is its agricultural
water use. (California agriculture is still anticipated to lead the nation’s
agricultural production because of advantages such as climate and proximity
to domestic and export markets.) As the State’s population expands, greater
attention will be directed to preserving and restoring California ecosystems
and to maintaining the natural resources which have attracted so many people

to California. 

# Balancing Supply and Demand Executive SummaryES5-2 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

This chapter begins by reviewing water supply and demand information and the statewide applied water budget with existing facilities and programs. Watermanagement options identified as likely to be implemented are then tabulated and included in a statewide applied water budget with options. The chapter ends with an evaluation of how actions planned by water purveyors statewide would affect forecasted water shortages, and then summarizes key findings.

Future with Existing Facilities and Programs Table ES5-1 shows the California water budget with existing facilities and programs. Regional water budgets with existing facilities and programs are shown in Appendix ES5A.

Water Supply

As described in Chapter ES3, average annual statewide precipitation over California’s land surface is about200 maf. About 65 percent of this precipitation is consumed through evaporation and transpiration by California’s forests, grasslands, and vegetation. The remaining 35 percent comprises the State’s averageannual intrastate runoff of about 71 maf. Over 30 percent of this runoff is not explicitly designated for urban, agricultural, or environmental uses. The State’s 1995-level average water year applied water supply—from intrastate sources, interstatesources, and return flows—is about 78 maf. Even assuming a reduction in Colorado River supplies to California’s 4.4 maf basic apportionment, average year statewide supply is projected to increase 0.2 maf by 2020 without additional water supply options. This projected increase in water supply is due mainly to higher CVP and SWP deliveries in response to higher2020 level demands. Additional groundwater extraction and facilities now under construction will also provide new supplies. The State’s 1995-level drought year supply is about 60 maf. Drought year supply is projected to increase slightly by 2020 without futurewater supply options, for the same reasons that average year supplies are expected to increase. Bulletin 160-98 estimates statewide groundwateroverdraft of about 1.5 maf/yr at a 1995 level of development. Increasing overdraft in the 1990s reverses thetrend of basin recovery seen in the 1980s. Most increases are occurring in the San Joaquin and TulareLake regions, due primarily to Delta export restrictions associated with the SWRCB Order WR 95-6, ESA requirements, and reductions in CVP supplies. Water recycling is a small, yet growing, element ofCalifornia’s water supply. At a 1995 level of development, water recycling and desalting produce about 0.3maf/yr of new water (reclaiming water that would otherwise flow to the ocean or to a salt sink), upsignificantly from the 1990 annual supply of new water. The California Water Code urges wastewater treatment agencies located in coastal areas to recycle as much of their treated effluent as possible, recognizing that this water supply would otherwise be lost to theState’s hydrologic system. Greater recycled water production at existing treatment plants and additionalproduction at plants now under construction are exT

ABLE ES5-1 California Water Budget with Existing Facilities and Programs (maf)

1995 2020 Average Drought Average Drought

Water Use

Urban 8.8 9.0 12.0 12.4 Agricultural 33.8 34.5 31.5 32.3 Environmental 36.9 21.2 37.0 21.3 Total 79.5 64.7 80.5 66.0 Supplies

Surface Water 65.1 43.5 65.0 43.4 Groundwater 12.5 15.8 12.7 16.0 Recycled and Desalted 0.3 0.3 0.4 0.4 Total 77.9 59.6 78.1 59.8 Shortage 1.6 5.1 2.4 6.2ES5-3 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

pected to increase new recycled and desalted supplies by nearly 30 percent to 0.4 maf/yr by 2020.

Water Demand

California’s estimated demand for water at a 1995 level of development is about 80 maf in average yearsand 65 maf in drought years. California’s water demand in 2020 is forecasted to reach 81 maf in averageyears and 66 maf in drought years. California’s increasing population is a driving force behind increasing water demands. California’s population is forecasted to increase to 47.5 million people by 2020 (about 15 million people more than the 1995 base). Forty-six percent of the State’s population increase is expected to occur in theSouth Coast Region. Even with extensive water conservation, urban water demand will increase by about 3.2 maf in average years. (Bulletin 160-98 assumes thatall urban and agricultural water agencies will implement BMPs and EWMPs by 2020, regardless ofwhether they are cost-effective for water supply purposes.) Irrigated crop acreage is expected to decline by 325,000 acres—from the 1995 level of 9.5 million acresto a 2020 level of 9.2 million acres. Reductions in forecasted irrigated acreage are due primarily to urban encroachment and to impaired drainage on lands in the western San Joaquin Valley. Increases in water useefficiency combined with reductions in irrigated acreage are expected to reduce average year agricultural water demand by about 2.3 maf by 2020. Shifts from lower to higher value crops are expected to continue,with an increase in permanent plantings such as orchards and vineyards. This trend would tend to harden agricultural demands associated with permanent plantings, making it less likely that this acreage would be temporarily fallowed during droughts.Average and drought year water needs for environmental use are forecasted to increase by about 0.1 maf by 2020. Drought year environmental water needsare considerably lower than average year environmental water needs, reflecting the variability of unimpaired flows in wild and scenic rivers. North Coast wild andscenic rivers constitute the greatest component of environmental water demands. CVPIA implementation, Bay-Delta requirements, new ESA restrictions, andFERC relicensing could significantly modify environmental demands within the Bulletin 160-98 planning period. Water ShortagesThe shortage shown in Table ES5-1 for 1995 average water year conditions reflects the Bulletin’sassumption that groundwater overdraft is not available as a supply. Forecasted water shortages vary widely from region to region, as presented in Figure ES5-1. For example, the North Coast and San Francisco BayRegions are not expected to experience future shortages during average water years but are expected to seeshortages in drought years. Most of the State’s remaining regions experience average year and drought yearshortages now, and are forecasted to experience increased shortages in 2020. The largest future shortages are forecasted for the Tulare Lake and South CoastRegions, areas that rely heavily on imported water supplies. These regions of the State are also where some of the greatest increases in population are expected to

occur. The shortages shown in Figure ES5-1 highlightthe need for future water management actions to reduce the gap between forecasted supplies and demands. As Californians experienced during the most recent drought (especially in 1991 and 1992), drought year shortages are large. Urban residents faced cutbacks insupply and mandatory rationing, some small rural communities saw their wells go dry, agricultural lands werefallowed, and environmental water supplies were reduced. By 2020, without additional facilities and programs, these conditions will worsen. Future water shortages have direct and indirect economic consequences. Direct consequences include costs to residential water users to replace landscapinglost during droughts, costs to businesses that experience water supply cutbacks, or costs to growers who fallow land because supplies are not available. Indirectconsequences include decisions by businesses and growers not to locate or to expand their operations in California, and reductions in the value of agricultural lands. Other consequences of shortages are less easilymeasured in economic terms—loss of recreational activities or impacts to environmental resources, for example.

The Bulletin 160-98 Planning Process At an appraisal level of detail, the Bulletin draws upon integrated resources planning techniques to evaluate alternatives for meeting California’s futurewater needs. IRP evaluates water management options—both demand reduction options and supplyES5-4 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

AVERAGE YEAR

DROUGHT YEAR North Coast

South Coast North Lahontan

South Lahontan Sacramento River

San Francisco Bay San Joaquin River

Central Coast Tulare Lake

Colorado River 0 194

85 989

63 711

10 128

270 308 720 1,851 172 270 0 287

147 158 944 1,317 F IGURE ES5-1. 2020 Shortages by Hydrologic Region with Existing Facilities and ProgramsES5-5 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

augmentation options—against a fixed set of criteriaand ranks the options based on costs and other factors. Although the IRP process includes economicevaluations, it also incorporates environmental, institutional, and social considerations which cannot be expressed easily in monetary terms.The development of likely regional water management options uses information prepared by local agencies. The regional water management options evaluations are not intended to replace local planningefforts, but to complement them by showing the relationships among regional water supplies and waterneeds and the statewide perspective. Local water management options form the basis of the regional summaries which are combined into the statewide options evaluation.

Major Steps in Planning Process The major steps involved in the Bulletin 160-98water management options evaluation process included: • Identify water demands and existing water supplies on a regional basis. • Compile comprehensive lists of regional and statewide water management options. • Use initial evaluation criteria to either retain or defer options from further evaluation. For options retained for further evaluation, some were grouped by categories and others were evaluated individually. • Identify characteristics of options or option categories, including costs, potential demand reduction or supply augmentation, environmental considerations, and significant institutional issues. • Evaluate each regional option or category of options in light of identified regional characteristics using criteria established for this Bulletin. If local agencies have performed their own evaluation, review and compare their evaluation criteria with those used for the Bulletin. • Evaluate statewide water management options. • Develop tabulation of likely regional water management options. • Develop a statewide options evaluation by integrating the regional results. The first step in evaluating the regional water management options was to prepare applied water budgets for the study areas to identify the magnitude of potential water shortages for average and drought year conditions. In addition to identifying shortages, other water supply reliability issues in the region were identified. Once the shortages were identified, a list of local water management options was prepared. Where possible, basic characteristics of these options (e.g.,yields, cost data, significant environmental or institutional concerns) were identified.After the options were identified, they were compared with the initial screening criteria shown in the sidebar. For options deferred from further evaluation,the major reasons for deferral were given. Options retained for further evaluation were categorized (some options within each category were further combined into groups based upon their estimated costs) and were evaluated and scored against the set of fixed criteria shown in the options category evaluation sidebar. The Bulletin 160-98 options evaluation process relied heavily upon locally developed information.

Initial Screening Criteria The criteria used for initial screening of water management options were: • Engineering—an option was deferred from further evaluation if it was heavily dependent on the development of technologies not currently in use, it used inappropriate technologies given the regional characteristics (e.g., desalting in the North Lahontan Region), or it did not provide new water (e.g., water recycling in the Central Valley). • Economic—an option was deferred from further evaluation if its cost estimates (including environmental mitigation costs) were extraordinarily high given the region’s characteristics. • Environmental—an option was deferred from further evaluation if it had potentially significant unmitigable environmental impacts or involved use of waterways designated as wild and scenic. • Institutional/Legal—an option was deferred from further evaluation if it had potentially unresolvable water rights conflicts or conflicts with existing statutes. • Social/Third Party—an option was deferred from further evaluation if it had extraordinary socioeconomic impacts, either in the water source or water use areas. • Health—an option was deferred from further evaluation if it would violate current health regulations or would pose significant health threats.ES5-6 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

Options Category Evaluation

Evaluation What is Measured? How is it Measured? Score

Criteria
Engineering Engineering feasibility Increase score for greater reliance upon current technologies Operational flexibility Increase score for operational flexibility with existing facilities and/or other options Drought year supply Increase score for greater drought year yield/ reliability Implementation date Increase score for earlier implementation date Water quality limitations Increase score for fewer water quality constraints Engineering Score 0 - 4

Economics Project financial feasibility Increase score for lower overall costs and the ability to finance Project unit cost Increase score for lower overall unit cost (including mitigation costs) Economics Score 0 - 4

Environmental Environmental risk Increase score for least amount of environmental risk Irreversible commitment of resources Increase score for least amount of irreversible commitment of resources Collective impacts Increase score for least amount of collective impacts Proximity to environmentally Increase score for little or no proximity to sensitive resources sensitive resources Environmental Score 0 - 4

Institutional/Legal Permitting requirements Increase score for least amount of permitting requirements Adverse institutional/legal effects upon Increase score for least amount of adverse water source areas institutional/legal effects Adverse institutional/legal effects upon Increase score for least amount of adverse water use areas institutional/legal effects Stakeholder consensus Increase score for greater amount of stakeholder

consensus Institutional/Legal Score 0 - 4

Social/Third Party Adverse third party effects upon Increase score for least amount of adverse third water source areas party effects Adverse third party effects upon Increase score for least amount of adverse third water use areas party effects Adverse social and community effects Increase score for least amount of adverse social and community effects Social/Third Party Score 0 - 4

Other Benefits Ability to provide benefits in addition Increase score for environmental benefits to water supply Increase score for flood control benefits
Increase score for recreation benefits Increase score for energy benefits Increase score for additional benefits Increase score for improved compliance with health and safety regulations Other Benefits Score 0 - 4

Total Score 0 - 24ES5-7 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

Methods used to develop this information vary fromone local agency to the next, thus making direct comparisons between cost estimates difficult. To make costinformation comparable, a common approach for estimating unit cost (cost per acre-foot) was developed for this Bulletin. Where project information was readily available, costs were normalized using this approach. However, due to time constraints and lack of detailed information, not all option costs were normalized. Option unit cost estimates took into account capitalcosts associated with construction and implementation, including any needed conveyance facilities, and annual operations, maintenance, and replacement

costs. Water management options can serve purposes other than water supply; they can also provide floodcontrol, hydroelectric power generation, environmental enhancement, water quality enhancement, andrecreation. In recognition of the multipurpose benefits provided by some water management options, the options evaluation scoring process assigned a high value to multipurpose options, as shown in the sidebar. However, since the focus of the Bulletin 160 series is water supply, cost estimates were based solely on the costs associated with water supply. Once options had been evaluated and scored, they were ranked according to their scores. This rankingwas used to prepare a tabulation of likely regional water management options, taking into account options that might be mutually exclusive or could be optimizedif implemented in conjunction with other options. Depending on a region’s characteristics, its potentialoptions, and its ability to pay for new options, the tabulation of likely options might not meet all of a region’s water shortages (especially in drought years). In regions where options do not meet all shortages, the economic costs of accepting shortages would be less than the costs of acquiring additional water supplies through the options identified in this Bulletin.This appraisal-level evaluation of options at a statewide level of detail is based on the information presently available. The ultimate implementability of any water management option is dependent on factors such asthe sponsoring entity’s ability to complete the appropriate environmental documentation, obtain the necessary permits, and finance the proposed action.
Shortage Management Water agencies may choose to accept less than 100 percent water supply reliability, especially under drought conditions, depending on the characteristics of their service areas. Shortage contingency measures, such as restrictions on residential outdoor watering or deficit irrigation for agricultural crops, can be used tohelp respond to temporary shortages. However, demand hardening is an important consideration inevaluating shortage contingency measures. Implementing water conservation measures such as plumbingretrofits and low water use landscaping reduces the ability of water users to achieve future drought year water savings through shortage contingency measures.The impacts of allowing planned shortages to occur in water agency service areas are necessarily site-specific, and must be evaluated by each agency on an individual basis. In urban areas where conservation measures have already been put into place to reducelandscape water use, imposing rationing or other restrictions on landscape water use can create significant impacts to homeowners, landscaping businesses, and entities that manage large turf areas such as parks and golf courses. Drought year cutbacks in the agricultural sector create economic impacts not only to individualgrowers and their employees, but also to local businesses that provide goods and services to the growers.
Using Applied Water Budgets to Calculate New Water NeedsSome municipal wastewater discharges, agricultural return flows, and required environmental instream flows are reapplied several times before finally beingdepleted from the State’s hydrologic system. An applied water budget explicitly accounts for this unplanned reuse of water. Because reapplication has the potential to account for a substantial portion of aregion’s water supply, applied water budgets may overstate the supply of water actually needed to meet future water demands. Therefore, shortages calculated froman applied water budget must be interpreted with caution to determine new water needs for a region. The amount of new water required to meet aregion’s future needs depends on several factors, including the region’s applied water shortage, opportunities to reapply water in the region, and thetypes of water management options that are implemented in the region. If no water reapplication opportunities exist, then the region’s new water needis equivalent to its applied water shortage. In this extreme case, the new water need would be independent of the types of water management options that are implemented. However, if opportunities are availableES5-8 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

to reapply water in a region, then the region’s new water need is less than its applied water shortage. In this case,the new water need depends on the types of water management options that are implemented. Not all water management options are createdequal in their ability to meet new water needs. Because supply augmentation options provide new waterto a region, the opportunity exists for the options’ effectiveness to be multiplied through reapplication. For example, a supply augmentation option may provide100 taf of new water to a region. But through reapplication within the region, the option effectively meets applied water demands in excess of 100 taf. Demand reduction options, on the other hand, do not provide new water to a region. Hence, the opportunity does not exist to multiply the options’ effectiveness through reapplication. To satisfy an applied water shortage of 100 taf, a demand reduction option must conserve 100 taf of water.Based on the above discussion, calculation of regional and statewide new water needs is more complex than computing regional and statewide applied watershortages—new water needs also depend on reapplication and implemented water management options. An applied water shortage provides an upper bound on the new water need. A lower bound on the newwater need can be estimated for each region by assuming that new water supplies are reapplied in the same proportion that existing supplies are reapplied.The tabulations of likely regional water management options utilize minimum new water needs (ratherthan applied water shortages) as target values for selecting the appropriate number of regional options. If a region is unable to meet minimum new water needs as a result of regional characteristics, lack of potentialoptions, or inability to pay for potential options, specifying minimum new water needs rather than applied water shortages as regional target values has no impact on options selection. On the other hand, if a region is able to meet its minimum new water needs, this doesnot necessarily guarantee that all applied water shortages would be met. The remaining applied water shortages would depend on the selected option mix— the more water conservation selected, the greater the remaining applied water shortages would be (as water conservation options do not provide reapplicationopportunities.) This approach is consistent with Bulletin 160-93, which used net water shortages as target values for selecting regional options. Because data innet water budgets factor out reapplied water, net water shortages are essentially the same as minimum new water needs.

Summary of Options Likely to be Implemented The options summarized in this section represent water purveyors’ strategies for meeting future needs. This information relies heavily on actions identified by local water agencies, which collectively provideabout 70 percent of the State’s developed water supply. As described earlier, water management optionslikely to be implemented were selected based on a ranking process that evaluated factors such as technical feasibility, cost, and environmental considerations. This process is most effective in hydrologic regions where local agencies have prepared plans for meeting futureneeds in their service areas. Affordability is a key factor for local agencies in deciding the extent to which they wish to invest in alternatives to improve their water service reliability. Water agencies must balance costsand quantity of supply (and sometimes quality of supply) based on their service area needs. The Bulletin 160 series focuses on water supply. The statewide compilation of likely options has not been tailored to meet other water-related objectivessuch as flood control, hydropower generation, recreation, or nonpoint source pollution control. The evaluation process used to select likely options rated the options based on their ability to provide multiple benefits, as described in the previous section. Options shown in Table ES5-2 include demand reduction beyond BMP and EWMP implementation included in Table ES5-1. Future demand reduction options are options that would produce new watersupply through reduction of depletions. For these optional water conservation measures to have been identified as likely, they must be competitive in cost with water supply augmentation options. Local supply augmentation options comprise the largest potential new source of drought year water for California. (Local options include implementation of the draft CRB 4.4 Plan to reduce California’s use ofColorado River water.) In Table ES5-2 and in the water budgets, only water marketing options that resultin a change of place of use of the water (from one hydrologic region to another), or a change in type of use(e.g., agricultural to urban) have been included. Considerably more marketing options are described in theBulletin than are shown in the water budgets, reflecting local agencies’ plans to purchase future suppliesES5-9 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

from sources yet to be identified. Where the participants in a proposed transfer are known, the selling region’s average year or drought year supply has beenreduced in the water budgets. Presently, the only transfers with identified participants that are large enough to be visible in the water budgets are those associated with the draft CRB 4.4 Plan. Water agencies’ plans to acquire water through marketing arrangements will depend on their ability to find sellers and on the levelof competition for water purchases among water agencies and environmental restoration programs (such as CVPIA’s AFRP or CALFED’s ERP). Possible statewide options include actions thatcould be taken by CALFED to develop new water supplies. The timing and extent of new water supplies that CALFED might provide are uncertain at the time ofthe Bulletin’s printing, since CALFED has not identified a draft preferred alternative and a firm schedule for its implementation. CALFED’s current schedulecalls for a first phase of program implementation spanning seven to ten years, at the end of which time a final decision would be made about the extent of anystorage and conveyance facilities that might be constructed. Given the long lead time required forimplementing large storage projects, no CALFED facilities may be in service within the Bulletin’s 2020 planning horizon. Bulletin 160-98 uses a placeholder analysis for new CALFED water supply development to illustrate the potential magnitude of new water supply the programmight provide. The placeholder does not address specifics of which surface storage facilities might be selected, since this level of detail is not available. Other statewide options include specific projects to improve SWP water supply reliability, the State’s drought water bank, and two multipurpose reservoirs. A third potential multipurpose reservoir option, an enlarged Shasta Lake, was recommended for further study because additional work is needed to quantify benefits and costs associated with different reservoir
sizes. The two multipurpose reservoir projects included as statewide options—Auburn Reservoir and enlargedMillerton Lake—were included to emphasize the interrelationship between water supply needs and the Central Valley’s flood protection needs. Each reservoir would offer significant flood protection benefits. Both projects have controversial aspects, and neither of themis inexpensive. However, they merit serious consideration. The potential future water management options summarized in this section are still being planned. Theirimplementation is subject to completion of environmental documents, permit acquisition, and compliance with regulatory requirements such as those of ESA.These processes will address mitigating environmental impacts and resolving third-party impacts. If watermanagement options are delayed or rendered infeasible as a result of these processes, or if their costs are increased to the point that the options are no longer affordable for the local sponsors, statewide shortages will be correspondingly affected. T

ABLE ES5-2 Summary of Options Likely to be Implemented by 2020, by Option Type (taf)

Option Type Average Drought Local Demand Reduction Options 507 582 Local Supply Augmentation Options

Surface Water 110 297 Groundwater 24 539 Water Marketing 67 304 Recycled and Desalted 423 456 Statewide Supply Options

CALFED Bay-Delta Program 100 175 SWP Improvements 117 155 Water Marketing (Drought Water Bank)

— 250 Multipurpose Reservoir Projects 710 370 Expected Reapplication 141 433 Total Options 2,199 3,561ES5-10 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

Implementing Future Water Management OptionsTable ES5-3 was developed by combining the regional and statewide analyses of water management options with the water budget with existing facilities and programs (Table ES5-1). Table ES5-3 illustratesthe effect these options would have on forecasted future shortages. (Appendix ES5B shows regional waterbudgets with option implementation.) The table indicates that water management options now under consideration by water purveyors throughout the Statewill not reduce shortages to zero in 2020. The difference between average water year and drought year watershortages is significant. Water purveyors generally consider shortages in average years as basic deficiencies that should be corrected through long-term demand reduction or supply augmentation measures. Shortages in drought years may be managed by such long-term measures in combination with short-term actions usedonly during droughts. Short-term measures could include purchases from the State’s drought water bank, urban water rationing, or agricultural land fallowing.Agencies may evaluate the marginal costs of developing new supplies and conclude that the cost of their development exceeds that of shortages to their service areas, or exceeds the cost of implementing contingencymeasures such as transfers or rationing. As water agencies implement increasing amounts of waterconservation in the future (especially plumbing fixture changes), there will be a correspondingly lessened ability to implement short-term drought response actions such as rationing. Demand hardening will influence agencies’ decisions about their future mix of water management actions.Ability to pay is another consideration. Large urban water agencies frequently set high water servicereliability goals and are able to finance actions necessary to meet the goals. Agencies supplying small rural communities may not be able to afford expensive projects. Small communities have limited populationsover which to spread capital costs and may have difficulty obtaining financing. If local groundwater resources are inadequate to support expected growth, these communities may not be able to afford projectssuch as pipelines to bring in new surface water supplies. Small rural communities that are geographicallyisolated from population centers cannot readily interconnect with other water systems. Agricultural water agencies may be less able to pay for capital improvements than urban water agencies.Much of the State’s earliest large-scale water development was for agriculture, and irrigation works were constructed at a time when water development was inexpensive by present standards. Agricultural users today may not be able to compete with urban users for development of new supplies. Some agricultural water users have historically been willing to acceptlower water supply reliability in return for less expensive water supplies. It may be less expensive for some agricultural users to idle land in drought years rather Floodflows on the
American River in 1986 breached the cofferdam that USBR had constructed when it began its initial work at the

Auburn damsite.

This flood event produced record flows in the American River through metropolitan Sacramento.ES5-11 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

than to incur capital costs of new water supply development. This can be particularly true for regions facedwith production constraints such as short growing seasons or lower quality lands—areas where the dominant water use may be irrigated pasture. In areas such as the North Lahontan Region, for example, local agenciesgenerally do not have plans for new programs or facilities to reduce agricultural water shortages in droughtyears. Figure ES5-2 shows forecasted shortages by hydrologic region to illustrate the effects of option implementation on a regional basis.Local agencies that expect to have increased future demands generally do more water supply planning than do agencies whose demands remain relatively level. Most agricultural water agencies are not planning for greater future demands, although some agencies are examining ways to improve reliability of their existing supplies. Cost considerations limit the types of options available to many agricultural users. The agricultural sector has thus developed fewer options that could be evaluated in statewide water supply planning. Many options have been generated from planning performedby urban agencies, reflecting Urban Water Management Planning Act requirements that urban watersuppliers with 3,000 or more connections, or that deliver over 3 taf/yr, prepare plans showing how they will meet service area needs.Geography plays a role in the feasibility of implementing different types of options, and not solely withrespect to the availability of surface water and groundwater supplies. Water users in the Central Valley, Bay Area, and Southern California having access to majorregional conveyance facilities have greater opportunities to rely on water marketing arrangements and conjunctive use options than do water users isolated from the State’s main water infrastructure.

Bulletin 160-98 FindingsBulletin 160-98 forecasts water shortages in California by 2020, as did the previous water plan update.The water management options identified in the Bulletin as likely to be implemented by 2020 would reduce, but not completely eliminate future shortages. Wateragencies faced with meeting future needs must determine how those needs can be met within the statutory and regulatory framework affecting water use decisions,including how the needs can be met in a manner equitable to existing water users. Land use planning decisions made by cities and counties—locations where T

ABLE ES5-3 California Water Budget with Options Likely to be Implemented (maf)

1995 2020 Average Drought Average Drought

Water Use

Urban 8.8 9.0 11.8 12.1 Agricultural 33.8 34.5 31.3 32.1 Environmental 36.9 21.2 37.0 21.3 Total 79.5 64.7 80.1 65.5 Supplies

Surface Water 65.1 43.5 66.4 45.4 Groundwater 12.5 15.8 12.7 16.5 Recycled and Desalted 0.3 0.3 0.8 0.9 Total 77.9 59.6 79.9 62.8 Shortage 1.6 5.1 0.2 2.7

Options identified as likely are still in the planning stages. Agencies implementing the options must complete environmental documentation and obtain the necessary permits. The permitting and environmental documentation process must consider impacts to listed species such as this San Joaquin Valley kit fox.ES5-12 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

AVERAGE YEAR

DROUGHT YEAR North Coast

South Coast North Lahontan

South Lahontan Sacramento River

San Francisco Bay San Joaquin River

Central Coast Tulare Lake

Colorado River 0 176

0 722

0 658

10 128

0 0 202 868 0 100 0 0

0 0 0 0 F IGURE ES5-2. 2020 Shortages by Hydrologic Region with Likely OptionsES5-13 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

future growth will or will not be allowed, housing densities, preservation goals for open space or agricultural reserves—will have a significant influence on California’s future water demands. Good coordinationamong local land use planning agencies and water agencies, as well as among water agencies themselves at aregional level, will facilitate finding solutions to meeting future needs.Bulletin 160-98 makes no specific recommendations regarding how California water purveyors should meet the needs of their service areas, because it is the water purveyors who are responsible for meeting those needs. The purpose of Bulletin 160-98 is to predict future water needs based on today’s conditions. Clearly,different agencies and individuals have different perspectives about how the future should be shaped. TheCALFED discussions, for example, illustrate conflicting values among individuals and agencies. There is not one magic bullet for meeting California’s future water needs—not new reservoirs, not new conveyance facilities, not more groundwater extraction, not more water conservation, not more water recycling. Each of these options has its place. The most frequently used methods of providing new water supplies have changed with the times, reflecting changing circumstances. Much of California’s earlywater development was achieved by constructing reservoirs and diverting surface water. Advances in technology, in the form of deep well turbine pumps,subsequently allowed substantial groundwater development. More recent improvements in water treatment technology have made water recycling and desalting feasible options. Today, water purveyors have an array of water management options available to meet futurewater supply reliability needs. The magnitude of potential shortages, especially drought year shortages,demonstrates the urgency of taking action. The donothing alternative is not an alternative that will meet the needs of 47.5 million Californians in 2020. California water agencies have made great stridesin water conservation since the 1976-77 drought. Bulletin 160-98 forecasts substantial demand reduction from implementing presently identified urban BMPsand agricultural EWMPs, and assumes a more rigorous level of implementation than water agencies are now obligated to perform. Presently, about half of California’s urban population is served by retailers thathave signed the urban memorandum of understanding for water conservation measures. Less than one-third of California’s agricultural lands are served by agencies that have signed the corresponding agricultural MOU. Bulletin 160-98 assumes that all water purveyors statewide will implement BMPs andEWMPs by 2020, even if the actions are not cost-effective from a water supply perspective. Waterconservation offers multipurpose benefits such as reduced urban water treatment costs and potential reduction of fish entrainment at diversion structures. The Bulletin also identifies as likely additional demand reduction measures that would create new water and would be cost-competitive with supply augmentation options. These optional demand reductions are almost as large as the average year water supply augmentation options planned by local agencies. California water agencies have also made great strides in water recycling. As discussed earlier, the new water supply produced from recycling has almost doubled between 1990 and 1995. By 2020, recycling could potentially contribute almost 1.4 maf of total water to the State’s supplies, which would exceed the goal expressed in Section 13577 of the Water Code that total recycling statewide be 1 maf by 2010. (The potential 2020 recycling of 1.4 maf would represent about 2 percent of the State’s 2020 water supply.) Waterrecycling offers multipurpose benefits, such as reduction of treatment plant discharges to waterbodies. Cost is a limiting factor in implementing recycling projects. Bulletin 160-98 forecasts that projects implemented by local agencies by 2020 will increase the State’s new water supply from recycling to about 0.8 maf. Clearly, conservation and recycling alone are not sufficient to meet California’s future needs. Bulletin160-98 has included all of the conservation and recycling measures likely to be implemented by 2020. Adding supply augmentation options identified by California’s water purveyors still leaves a shortfall in meeting forecasted future demands. Review of local agencies’ likely supply augmentation options shows that relatively few larger-scale or regional programs are in active planning, especially among small and mid-size water agencies. This outcome reflects local agencies’ concerns about perceived implementability constraints associated with larger-scale options, and their affordability. In the interests of maintaining California’s vibrant economy, it is important that the State take an active role in assisting water agencies in meeting their future needs. New storage facilities are an important part of the mix of options needed to meet California’s futureneeds. Just as water conservation and recycling proES5-14 B ALANCING S UPPLY AND D EMAND The California Water Plan Update B ULLETIN 160-98

vide multiple benefits, storage facilities offer flood control, power generation, and recreation in addition to water supply benefits. The devastating January 1997 floods in the Central Valley emphasized the need for increased attention to flood control. It is important for small and mid-size water agencies who could not develop such facilities on their own to have access toparticipation in regional projects. The more diversified water agencies’ sources of supply are, the better their odds of improved water supply reliability.An appropriate State role would be for the Department to take the lead in performing feasibility studies of potential storage projects—not on behalf of the SWP, but on behalf of all potentially interestedwater agencies. State funding support is needed to identify likely projects, so that local agencies may determine how those projects might benefit their service areas. In concept, the Department could use State funding to complete project feasibility studies, permitting, and environmental documentation for likely new storage facilities, removing uncertainties that would prevent smaller water agencies from funding planning studies themselves. Agencies wishing to participate in projects shown to be feasible would repay their share of the State planning costs as a condition of participation in a project. Feasible projects would likely be constructed by a consortium of local agencies acting through a joint powers agreement or other contractual mechanism.Meeting California’s future needs will require cooperation among all levels of government—federal,State, and local. Likewise, all three of California’s water-using sectors—agricultural, environmental, and urban—must work together to recognize each others’ legitimate needs and to seek solutions to meeting the State’s future water shortages. When the Bay-Delta Accord was signed in 1994, it was hailed as a truce in, if not an end to, one of the State’s longstanding waterwars. The Accord, and the efforts by California agencies to negotiate a resolution to interstate and intrastate Colorado River water issues, represent a new spirit offostering cooperation and consensus rather than competition and conflict. Such an approach will be increasingly necessary, given the magnitude of the water shortages facing California. Mutual accommodation of each others’ needs is especially important in drought years, when water purveyors face the greatest water supply challenges. With continued efforts to prepare for the future, California can have safe and reliable water supplies for urban areas, adequate long-term water supplies to maintain the State’s agricultural economy, and restoration and protection of fish and wildlife habitat.ES5A-1 A PPENDIX ES5A Appendix ES5A The California Water Plan Update B ULLETIN 160-98 Appendix 5A Executive Summary 

# 5A

Regional Water Budgets with Existing Facilities and Programs

The following tables show the water budgets for each of the State’s ten hydrologic regions with existing facilities and programs. Water use/supply totals and shortages may not sum due to rounding.ES5A-2 A

PPENDIX ES5A The California Water Plan Update B ULLETIN 160-98 Appendix 5A Executive Summary

T ABLE ES5A-2 San Francisco Bay Region Water Budget with Existing Facilities and Programs (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 1,255 1,358 1,317 1,428 Agricultural 98 108 98 108 Environmental 5,762 4,294 5,762 4,294 Total 7,115 5,760 7,176 5,830 Supplies

Surface Water 7,011 5,285 7,067 5,417 Groundwater 68 92 72 89 Recycled and Desalted 35 35 37 37 Total 7,115 5,412 7,176 5,543 Shortage 0 349 0 287 T

ABLE ES5A-1 North Coast Region Water Budget with Existing Facilities and Programs (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 169 177 201 212 Agricultural 894 973 927 1,011 Environmental 19,544 9,518 19,545 9,518 Total 20,607 10,668 20,672 10,740 Supplies

Surface Water 20,331 10,183 20,371 10,212 Groundwater 263 294 288 321 Recycled and Desalted 13 14 13 14 Total 20,607 10,491 20,672 10,546 Shortage 0 177 0 194

T

ABLE ES5A-3 Central Coast Region Water Budget with Existing Facilities and Programs (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 286 294 379 391 Agricultural 1,192 1,279 1,127 1,223 Environmental 118 37 118 37 Total 1,595 1,610 1,624 1,652 Supplies

Surface Water 318 160 368 180 Groundwater 1,045 1,142 1,041 1,159 Recycled and Desalted 18 26 42 42 Total 1,381 1,328 1,452 1,381 Shortage 214 282 172 270ES5A-3 A PPENDIX ES5A Appendix ES5A The California Water Plan Update B ULLETIN 160-98 Appendix 5A Executive Summary

T

ABLE ES5A-4 South Coast Region Water Budget with Existing Facilities and Programs (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 4,340 4,382 5,519 5,612 Agricultural 784 820 462 484 Environmental 100 82 104 86 Total 5,224 5,283 6,084 6,181 Supplies

Surface Water 3,839 3,196 3,625 3,130 Groundwater 1,177 1,371 1,243 1,462 Recycled and Desalted 207 207 273 273 Total 5,224 4,775 5,141 4,865 Shortage 0 508 944 1,317

T

ABLE ES5A-5 Sacramento River Region Water Budget with Existing Facilities and Programs (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 766 830 1,139 1,236 Agricultural 8,065 9,054 7,939 8,822 Environmental 5,833 4,223 5,839 4,225 Total 14,664 14,106 14,917 14,282 Supplies

Surface Water 11,881 10,022 12,196 10,012 Groundwater 2,672 3,218 2,636 3,281 Recycled and Desalted 0 0 0 0 Total 14,553 13,239 14,832 13,293 Shortage 111 867 85 989

T

ABLE ES5A-6 San Joaquin River Region Water Budget with Existing Facilities and Programs (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 574 583 954 970 Agricultural 7,027 7,244 6,450 6,719 Environmental 3,396 1,904 3,411 1,919 Total 10,996 9,731 10,815 9,609 Supplies

Surface Water 8,562 6,043 8,458 5,986 Groundwater 2,195 2,900 2,295 2,912 Recycled and Desalted 0 0 0 0 Total 10,757 8,943 10,753 8,898 Shortage 239 788 63 711ES5A-4 A

PPENDIX ES5A The California Water Plan Update B ULLETIN 160-98 Appendix 5A Executive Summary

T ABLE ES5A-7 Tulare Lake Region Water Budget with Existing Facilities and Programs (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 690 690 1,099 1,099 Agricultural 10,736 10,026 10,123 9,532 Environmental 1,672 809 1,676 813 Total 13,098 11,525 12,897 11,443 Supplies

Surface Water 7,888 3,693 7,791 3,593 Groundwater 4,340 5,970 4,386 5,999 Recycled and Desalted 0 0 0 0 Total 12,228 9,663 12,177 9,592 Shortage 870 1,862 720 1,851

T

ABLE ES5A-8 North Lahontan Region Water Budget with Existing Facilities and Programs (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 39 40 50 51 Agricultural 530 584 536 594 Environmental 374 256 374 256 Total 942 880 960 901 Supplies

Surface Water 777 557 759 557 Groundwater 157 187 183 208 Recycled and Desalted 8 8 8 8 Total 942 752 950 773 Shortage 0 128 10 128

T

ABLE ES5A-9 South Lahontan Region Water Budget with Existing Facilities and Programs (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 238 238 619 619 Agricultural 332 332 257 257 Environmental 107 81 107 81 Total 676 651 983 957 Supplies

Surface Water 322 259 437 326 Groundwater 239 273 248 296 Recycled and Desalted 27 27 27 27 Total 587 559 712 649 Shortage 89 92 270 308ES5A-5 A PPENDIX ES5A Appendix ES5A The California Water Plan Update B ULLETIN 160-98 Appendix 5A Executive Summary

T

ABLE ES5A-10 Colorado River Region Water Budget with Existing Facilities and Programs (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 418 418 740 740 Agricultural 4,118 4,118 3,583 3,583 Environmental 39 38 44 43 Total 4,575 4,574 4,367 4,366 Supplies

Surface Water 4,154 4,128 3,920 3,909 Groundwater 337 337 285 284 Recycled and Desalted 15 15 15 15 Total 4,506 4,479 4,221 4,208 Shortage 69 95 147 158ES5A-6 A

PPENDIX ES5A The California Water Plan Update B ULLETIN 160-98 Appendix 5A Executive SummaryES5B-1 A PPENDIX ES5B Appendix ES5A The California Water Plan Update B ULLETIN 160-98 Appendix 5B Executive Summary 

# 5B

Regional Water Budgets with Options Likely to be Implemented

The following tables show the water budgets for each of the State’s ten hydrologic regions with options likely to be implemented. Water use/supply totals and shortages may not sum due to rounding.ES5B-2 A

PPENDIX ES5B The California Water Plan Update B ULLETIN 160-98 Appendix 5B Executive Summary

T ABLE ES5B-2 San Francisco Bay Region Water Budget with Options (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 1,255 1,358 1,317 1,371 Agricultural 98 108 98 108 Environmental 5,762 4,294 5,762 4,294 Total 7,115 5,760 7,176 5,773 Supplies

Surface Water 7,011 5,285 7,067 5,607 Groundwater 68 92 72 96 Recycled and Desalted 35 35 37 70 Total 7,115 5,412 7,176 5,773 Shortage 0 349 0 0 T

ABLE ES5B-1 North Coast Region Water Budget with Options (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 169 177 201 194 Agricultural 894 973 927 1,011 Environmental 19,544 9,518 19,545 9,518 Total 20,607 10,668 20,672 10,722 Supplies

Surface Water 20,331 10,183 20,371 10,212 Groundwater 263 294 288 321 Recycled and Desalted 13 14 13 14 Total 20,607 10,491 20,672 10,546 Shortage 0 177 0 176

T

ABLE ES5B-3 Central Coast Region Water Budget with Options (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 286 294 347 359 Agricultural 1,192 1,279 1,127 1,223 Environmental 118 37 118 37 Total 1,595 1,610 1,592 1,620 Supplies

Surface Water 318 160 477 287 Groundwater 1,045 1,142 1,043 1,161 Recycled and Desalted 18 26 71 71 Total 1,381 1,328 1,592 1,519 Shortage 214 282 0 100ES5B-3 A PPENDIX ES5B Appendix ES5A The California Water Plan Update B ULLETIN 160-98 Appendix 5B Executive Summary

T

ABLE ES5B-4 South Coast Region Water Budget with Options (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 4,340 4,382 5,435 5,528 Agricultural 784 820 455 477 Environmental 100 82 104 86 Total 5,224 5,283 5,993 6,090 Supplies

Surface Water 3,839 3,196 4,084 3,832 Groundwater 1,177 1,371 1,243 1,592 Recycled and Desalted 207 207 667 667 Total 5,224 4,775 5,994 6,090 Shortage 0 508 0 0

T

ABLE ES5B-5 Sacramento River Region Water Budget with Options (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 766 830 1,139 1,236 Agricultural 8,065 9,054 7,939 8,822 Environmental 5,833 4,223 5,839 4,225 Total 14,664 14,106 14,917 14,282 Supplies

Surface Water 11,881 10,022 12,282 10,279 Groundwater 2,672 3,218 2,636 3,281 Recycled and Desalted 0 0 0 0 Total 14,553 13,239 14,918 13,560 Shortage 111 867 0 722

T

ABLE ES5B-6 San Joaquin River Region Water Budget with Options (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 574 583 954 970 Agricultural 7,027 7,244 6,448 6,717 Environmental 3,396 1,904 3,411 1,919 Total 10,996 9,731 10,813 9,607 Supplies

Surface Water 8,562 6,043 8,497 6,029 Groundwater 2,195 2,900 2,317 2,920 Recycled and Desalted 0 0 0 0 Total 10,757 8,943 10,814 8,949 Shortage 239 788 0 658ES5B-4 A

PPENDIX ES5B The California Water Plan Update B ULLETIN 160-98 Appendix 5B Executive Summary

T ABLE ES5B-7 Tulare Lake Region Water Budget with Options (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 690 690 1,099 1,099 Agricultural 10,736 10,026 10,106 9,515 Environmental 1,672 809 1,676 813 Total 13,098 11,525 12,880 11,426 Supplies

Surface Water 7,888 3,693 8,292 4,167 Groundwater 4,340 5,970 4,386 6,391 Recycled and Desalted 0 0 0 0 Total 12,228 9,663 12,678 10,558 Shortage 870 1,862 202 868

T

ABLE ES5B-8 North Lahontan Region Water Budget with Options (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 39 40 50 51 Agricultural 530 584 536 594 Environmental 374 256 374 256 Total 942 880 960 901 Supplies

Surface Water 777 557 759 557 Groundwater 157 187 183 208 Recycled and Desalted 8 8 8 8 Total 942 752 950 773 Shortage 0 128 10 128

T

ABLE ES5B-9 South Lahontan Region Water Budget with Options (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 238 238 568 568 Agricultural 332 332 252 252 Environmental 107 81 107 81 Total 676 651 927 901 Supplies

Surface Water 322 259 651 578 Groundwater 239 273 248 296 Recycled and Desalted 27 27 27 27 Total 587 559 926 901 Shortage 89 92 0 0ES5B-5 A PPENDIX ES5B Appendix ES5A The California Water Plan Update B ULLETIN 160-98 Appendix 5B Executive Summary

T

ABLE ES5B-10 Colorado River Region Water Budget with Options (taf)

1995 2020 Average Drought Average Drought

Water Use

Urban 418 418 715 715 Agricultural 4,118 4,118 3,393 3,393 Environmental 39 38 44 43 Total 4,575 4,574 4,152 4,151 Supplies

Surface Water 4,154 4,128 3,852 3,852 Groundwater 337 337 285 284 Recycled and Desalted 15 15 15 15 Total 4,506 4,479 4,152 4,151 Shortage 69 95 0 0ES5B-6 A

PPENDIX ES5B The California Water Plan Update B ULLETIN 160-98 Appendix 5B Executive Summaryi The California Water Plan Update B ULLETIN 160-98

D E P A R T M E N T O

F W A

T E R R E S O U R C E S

S T A T E O

F C A

L I F O R N I A 

# C ALIFORNIA 

# W ATER 

# P LAN 

# U PDATE 

# B ULLETIN 

# 160-98

Volume 1
November 1998

Pete Wilson

Governor

Douglas P. Wheeler Secretary for Resources The Resources Agency

David N. Kennedy
Director Department of Water Resourcesii The California Water Plan Update B ULLETIN 160-98

Department of Water Resources, Sacramento, 1998

Copies of Bulletin 160-98 may be purchased for $25 from: California Department of Water Resources P. O. Box 942836 Sacramento, CA 94236-0001

Make checks payable to: Department of Water Resources California residents add current sales tax Ciii The California Water Plan Update B ULLETIN 160-98



# I n 1957, the Department published Bulletin 3, the California Water Plan . Bulletin 3 was followed by the Bulletin 160 series, published six times between 1966 and 1993, updating the California Water Plan . A 1991 amendment to the California Water Code directed the Department to update the plan every five years. Bulletin 160-98 is the latest in the series. The Bulletin 160 series assesses California’s water needs and evaluates water supplies, to quantify the gap between future water demands and water supplies. The series presents a statewide overview of current water management activities and provides water managers with a framework for making decisions. In response to public comments on the last update, Bulletin 160-93, this 1998 update evaluates water management options that could improve California’s water supply reliability.Water management options being planned by local agencies form the building blocks for evaluations performed for each of the State’s ten major hydrologic regions. Local options are integrated into a statewide overview that illustrates potential progress in reducing the State’s expected future water shortages.When the previous water plan update was released, California was just emerging from a sixyear drought. This update follows the largest and most extensive flood disaster in California’s history, the January 1997 floods. These two hydrologic events fittingly illustrate the complexity of water management in the State.The Department appreciates the assistance provided by the Bulletin 160-98 public advisory committee, which met with the Department over a three-year period as the Bulletin was being prepared. The Department also appreciates the assistance provided by the many local water agencies who furnished information about their planned water management activities.

David N. Kennedy
Director 

# Foreword

. . .iv The California Water Plan Update B ULLETIN 160-98v The California Water Plan Update B ULLETIN 160-98

Chapter 1. Introduction California—An Overview..................................................................................................................... 1-2 Bulletin 160-98 Hydrologic Regions .................................................................................................... 1-8 Some Trends in California Water Management Activities ................................................................... 1-10 Changes Since the Last California Water Plan Update ........................................................................ 1-12 Changes in Response to Bulletin 160-93 Public Comments......................................................... 1-13 Changes in Future Demand/Shortage Forecasts ........................................................................... 1-13 Preparation of Bulletin 160-98 ........................................................................................................... 1-14
Public Comments on Draft....................................................................................................... ... 1-14 Works in Progress and Uncertainties ............................................................................................ 1-16
Presentation of Data in Bulletin 160-98....................................................................................... 1 -16 Organization of Bulletin 160-98 ........................................................................................................ 1-16

Appendix 1A. Comparison of 2020 Average Year Forecasts Between Bulletin 160-93 and Bulletin 160-98 ..................................................................................................................................1A-1

Appendix 1B. Summary of Public Comments on Draft Bulletin 160-98 ...................................................1B-1

Chapter 2. Recent Events in California Water Infrastructure Update ........................................................................................................................... 2-1 Legislative Update ................................................................................................................................ 2-3

State Statutes ................................................................................................................................. 2-3
Federal Statutes .............................................................................................................................. 2-5 State and Federal Programmatic Actions ............................................................................................... 2-7 SWP Monterey Agreement Contract Amendments ........................................................................ 2-7 CVPIA Implementation................................................................................................................. 2-8 Title Transfer of Reclamation Projects ......................................................................................... . 2-11 FERC Relicensing ........................................................................................................................ 2-12 Recent ESA Listings ..................................................................................................................... 2-12 San Francisco Bay and Sacramento-San Joaquin River Delta .............................................................. 2-14 Bay-Delta Accord and CALFED .................................................................................................. 2- 14
Suisun Marsh ............................................................................................................................... 2-16
Delta Protection Commission .................................................................................................... .. 2-16 San Francisco Estuary Project....................................................................................................... 2-17 Coordinated Operation Agreement Renegotiation ....................................................................... 2-17

Interstate Issues .................................................................................................................................. 2-18 Truckee-Carson River System .................................................................................................... .. 2-18
Walker River ................................................................................................................................ 2-18
Klamath River ............................................................................................................................. 2-19 

# Contents

. . .vi The California Water Plan Update B ULLETIN 160-98

Colorado River ............................................................................................................................ 2-19 Regional and Local Programs ............................................................................................................. 2-20 Local Agency Groundwater Management Programs ..................................................................... 2-20 Watershed-Based Planning ....................................................................................................... .... 2-20 Implementation of Urban Water Conservation MOU ................................................................. 2-24 Implementation of Agricultural Efficient Water Management Practices MOU............................. 2-24

Appendix 2A. Institutional Framework for Allocating and Managing Water Resources in California .............................................................................................................................................2A-1

Chapter 3. Water Supplies Climate and Hydrology ........................................................................................................................ 3-1 Geographic Variability ................................................................................................................... 3-2 Seasonal Variability ........................................................................................................................ 3-5 Climatic Variability ........................................................................................................................ 3-6 Water Supply Calculation ................................................................................................................... 3-12 Definition of Bulletin 160 Water Supplies ................................................................................... 3-12 Water Supply Scenarios ................................................................................................................ 3-18 California Water Supplies with Existing Facilities and Programs .................................................. 3-23 Surface Water Supplies ....................................................................................................................... 3-24 Surface Water Development Projects............................................................................................ 3 -24 Reservoir and River Operations ................................................................................................. .. 3-42 Impacts of Recent Events on Surface Water Supplies .................................................................... 3-45 Impacts of Reservoir Reoperation on Surface Water Supplies ....................................................... 3-47 Groundwater Supplies ........................................................................................................................ 3-48 Base Year Supplies ........................................................................................................................ 3-48
Groundwater Basin Yield ............................................................................................................. 3-49 Groundwater Management Programs .......................................................................................... 3-51 Water Marketing ................................................................................................................................ 3-53 Definition of Water Marketing .................................................................................................. .. 3-53 Short-Term Agreements ............................................................................................................... 3-56 Long-Term Agreements ........................................................................................................... .... 3-57 Water Recycling and Desalting Supplies ......................................................................................... .... 3-59 Water Recycling Status................................................................................................................. 3-59 Water Recycling Potential ............................................................................................................ 3-60 Seawater Desalting ....................................................................................................................... 3-60 Water Quality..................................................................................................................................... 3-60 Overview of Pollutants and Stressors Causing Water Quality Impairment .................................... 3-61 Establishing and Meeting Water Quality Standards ...................................................................... 3-66 Drinking Water Standards ....................................................................................................... .... 3-66 Source Water Protection/Watershed Management Activities ........................................................ 3-67vii The California Water Plan Update B ULLETIN 160-98

Groundwater Quality................................................................................................................... 3-71 Water Supply Summary by Hydrologic Region................................................................................... 3-72

Appendix 3A. Survey of Planned Water Recycling................................................................................. ....3A-1

Chapter 4. Urban, Agricultural, and Environmental Water Use Water Use Calculation .......................................................................................................................... 4-2
Land Use Considerations...................................................................................................................... 4-2
Urban Water Use .................................................................................................................................. 4-4 Population Growth ........................................................................................................................ 4-4 Factors Affecting Urban Per Capita Water Use ............................................................................... 4-7 Urban Water Use Planning Activities ........................................................................................... 4 -12 Urban Water Use Forecasting .................................................................................................... ... 4-13 Summary of Urban Water Use ..................................................................................................... 4-16 Agricultural Water Use ....................................................................................................................... 4-17 Crop Water Use ........................................................................................................................... 4-17 Factors Influencing Agricultural Water Use .................................................................................. 4-19 Agricultural Acreage Forecasting ............................................................................................... ... 4-22 Summary of Agricultural Water Use............................................................................................. 4 -33
Environmental Water Use................................................................................................................... 4-34
Flows in Wild and Scenic Rivers ................................................................................................ .. 4-34
Instream Flows............................................................................................................................. 4-36 Bay-Delta Outflow ...................................................................................................................... 4-39
Wetlands ...................................................................................................................................... 4-46 Summary of Environmental Water Use ........................................................................................ 4-51 Water Use Summary by Hydrologic Region ....................................................................................... 4- 51

Appendix 4A. Urban and Agricultural Water Pricing .............................................................................. ..4A-1

Appendix 4B. BMP Revisions and Water Savings Assumptions ................................................................. 4B-1

Appendix 4C. Normalizing Urban Water Use Data.................................................................................. 4C-1

Chapter 5. Technology in Water Management Demand Reduction Technologies ......................................................................................................... 5-1 Landscape Irrigation Technology.................................................................................................... 5-2 Residential Indoor Water Use Technology ...................................................................................... 5-2 Interior CII Water Use Technology .............................................................................................. .. 5-3 Agricultural Water Use Technology .............................................................................................. .. 5-4 Water Treatment Technologies ............................................................................................................ 5-10 Description of Water Treatment Technologies .............................................................................. 5-10 Application of Water Treatment Technologies .............................................................................. 5-13
Treatment of Contaminated Groundwater ................................................................................... 5-18viii The California Water Plan Update B ULLETIN 160-98

Water Supply/Flood Control Technologies ........................................................................................ . 5-19
Inflatable Dams ........................................................................................................................... 5-19
Weather Modification .................................................................................................................. 5-21 Long-Term Weather Forecasting .................................................................................................. 5-22 Environmental Water Use Technologies........................................................................................... ... 5-23 Wetlands Management ............................................................................................................ .... 5-23 Real-Time Water Quality Management ....................................................................................... 5-23 Fish Screen Technologies .............................................................................................................. 5-23 Temperature Control Technology ................................................................................................ 5 -27

Chapter 6. Evaluating Options From a Statewide Perspective Statewide Water Budget .............................................................................................................................. 6-2 The Bulletin 160-98 Planning Process ........................................................................................................ 6-2 Major Steps in Planning Process ........................................................................................................... 6-4 Shortage Management .......................................................................................................................... 6-6 Using Applied Water Budgets to Calculate New Water Needs .............................................................. 6-6 Demand Reduction Options ....................................................................................................................... 6-8 Urban Water Conservation Options ..................................................................................................... 6-9
Outdoor Water Use ....................................................................................................................... 6-9
Residential Indoor Water Use ................................................................................................... ... 6-10

Interior CII Water Use ................................................................................................................. 6-10 Distribution System Losses .......................................................................................................... 6-11 Agricultural Water Conservation Options ........................................................................................ .. 6-11 Irrigation Management (Options 1, 2, and 3) .............................................................................. 6-12 Water Delivery Flexibility (Option 4) .......................................................................................... 6-13 Canal Lining and Piping (Option 5) ............................................................................................ 6 -13 Tailwater and Spill Recovery Systems (Option 6) ......................................................................... 6-13 Environmental Water Conservation Options ...................................................................................... 6 -13 Water Supply Augmentation Options ....................................................................................................... 6-14 Conveyance Facilities ......................................................................................................................... 6-14 SWP Interim South Delta Program ............................................................................................. 6-14 CALFED Delta Conveyance ........................................................................................................ 6-14 Mid-Valley Canal ......................................................................................................................... 6-16 Surface Storage Facilities ..................................................................................................................... 6-16 Area of Origin Protections ........................................................................................................... 6-16 CALFED Surface Storage ......................................................................................................... ... 6-16 Multipurpose Storage Facilities ................................................................................................ .... 6-20 Groundwater and Conjunctive Use ................................................................................................ .... 6-22 Potential for Conjunctive Use in the Central Valley ..................................................................... 6-22 Recent Groundwater Studies with Statewide Scope ...................................................................... 6-23ix The California Water Plan Update B ULLETIN 160-98

Water Marketing ............................................................................................................................... 6-25 Sources of Water for Marketing ................................................................................................. .. 6-26 Prospects for Water Marketing .................................................................................................. ... 6-27 Drought Year Marketing .............................................................................................................. 6-29 Every Year Marketing ................................................................................................................... 6-31 Water Recycling and Desalting ........................................................................................................... 6-32 Water Recycling ........................................................................................................................... 6-32 Desalting ..................................................................................................................................... 6-33
Weather Modification ........................................................................................................................ 6-35 Other Supply Augmentation Options.............................................................................................. ... 6-36 Importing Water from Out of State ............................................................................................. 6 -36 Gray Water .................................................................................................................................. 6-36 Watershed Management on National Forest Lands ...................................................................... 6-36 Long-Range Weather Forecasting ................................................................................................. 6-37 Summary of Statewide Supply Augmentation Options ....................................................................... 6-37
CALFED ..................................................................................................................................... 6-37 Other Statewide Options ............................................................................................................. 6-38 Allocating Options Yield Among Hydrologic Regions ................................................................. 6-38 Uncertainties in the Bulletin Planning Process ............................................................................. 6-38 Options for Future Environmental Habitat Enhancement ........................................................................ 6-41 Central Valley Project Improvement Act ......................................................................................... .... 6-41 Category III Program ......................................................................................................................... 6-45 CALFED Bay-Delta Ecosystem Restoration Program ......................................................................... 6-46 Other Environmental Enhancement Options ..................................................................................... 6-47 SWP’s Sherman and Twitchell Islands Wildlife Management Plans .............................................. 6-47 Fish Protection Agreements.......................................................................................................... 6-47 Upper Sacramento River Fisheries and Riparian Habitat Restoration Program ............................. 6-47 Financing Local Water Management Options ....................................................................................... .... 6-47
Sources of Revenues ........................................................................................................................... 6-48 Financing Methods............................................................................................................................. 6-48 Self-Financing .............................................................................................................................. 6-49 Short-Term Debt Financing ...................................................................................................... ... 6-49 Conventional Long-Term Debt Financing ................................................................................... 6-49 Innovative Long-Term Debt Financing ........................................................................................ 6-49
Credit Substitution and Enhancement ......................................................................................... 6-50 State and Federal Financial Assistance Programs........................................................................... 6-51 Relationship Between Financing and Water Agency Ownership and Size ........................................... 6-51 Public Water Agencies .................................................................................................................. 6-51
Investor-Owned Water Utilities ................................................................................................. .. 6-51 Mutual Water Companies ......................................................................................................... ... 6-52x The California Water Plan Update B ULLETIN 160-98

Appendix 6A. Regional Water Budgets with Existing Facilities and Programs............................................6A-1

Appendix 6B. Applied Water Shortages by Hydrologic Region with Existing Facilities and Programs ....... 6B-1

Appendix 6C. Estimating a Water Management Option’s Unit Cost ........................................................ 6C-1

Appendix 6D. Calculation of Minimum New Water Needs ..................................................................... 6D-1

Appendix 6E. Net Water Budgets ............................................................................................................. 6E-1

Appendix 6F. Land Retirement Analysis in Drainage-Impaired Areas ........................................................ 6F-1

Appendix 6G. Review and Evaluation of Statewide-Level Storage Facilities That Could Be Included in CALFED Alternatives .............................................................................................................................. 6G-1

Chapter 7. Options for Meeting Future Water Needs in Coastal Regions of California North Coast Hydrologic Region ................................................................................................................. 7-3 Description of the Area ........................................................................................................................ 7-3 Water Demands and Supplies ............................................................................................................... 7-3 Local Water Resources Management Issues ........................................................................................ ... 7-5 Klamath River Fishery Issues.......................................................................................................... 7-5 Trinity River Fish and Wildlife Management Program ................................................................... 7-5 Water Supplies of Small Coastal Communities .............................................................................. 7-6
Russian River Environmental Restoration Actions ......................................................................... 7-7 City of Santa Rosa Long-Term Wastewater Project ........................................................................ 7-8 SCWA Water Supply and Transmission Project .............................................................................. 7-8 Potter Valley Project ....................................................................................................................... 7-8 Water Management Options for the North Coast Region .................................................................... 7-8

Water Conservation ....................................................................................................................... 7-8 Modifying Existing Reservoirs or Operations ............................................................................... 7-10 New Reservoirs and Conveyance Facilities ................................................................................... 7-10 Groundwater Development or Conjunctive Use .......................................................................... 7-11 Water Recycling ........................................................................................................................... 7-11 Desalting ..................................................................................................................................... 7-11 Other Local Options.................................................................................................................... 7-11 Options Likely to be Implemented in North Coast Region ................................................................ 7-11 San Francisco Bay Hydrologic Region ....................................................................................................... 7-15 Description of the Area ...................................................................................................................... 7-15 Water Demands and Supplies ............................................................................................................. 7-15 North Bay .................................................................................................................................... 7-15 South Bay .................................................................................................................................... 7-17 Local Water Resources Management Issues ........................................................................................ . 7-20 Bay-Delta Estuary ........................................................................................................................ 7-20xi The California Water Plan Update B ULLETIN 160-98

Suisun Marsh ............................................................................................................................... 7-20 Local Water Agency Issues ........................................................................................................... 7-20 Bay Area Regional Water Recycling Program ............................................................................... 7-24 Water Management Options for the San Francisco Bay Region .......................................................... 7-24
Conservation ............................................................................................................................... 7-24 Modify Existing Reservoirs/Operations ........................................................................................ 7- 24 New Reservoirs and Conveyance Facilities ................................................................................... 7-27 Groundwater Development or Conjunctive Use .......................................................................... 7-28 Water Marketing .......................................................................................................................... 7-28 Water Recycling ........................................................................................................................... 7-28 Desalting ..................................................................................................................................... 7-29 Other Local Options.................................................................................................................... 7-29 Statewide Options ....................................................................................................................... 7-29 Options Likely to be Implemented in San Francisco Bay Region ........................................................ 7-29 Central Coast Hydrologic Region ............................................................................................................. 7-33 Description of the Area ...................................................................................................................... 7-33 Water Demands and Supplies ............................................................................................................. 7-34
Northern PSA .............................................................................................................................. 7-34
Southern PSA .............................................................................................................................. 7-34 Local Water Resources Management Issues ........................................................................................ . 7-35
Seawater Intrusion ....................................................................................................................... 7-35 Local Water Agency Issues ........................................................................................................... 7-36 Seawater Desalting ....................................................................................................................... 7-37 Water Management Options for the Central Coast Region ................................................................ 7-37
Water Conservation ..................................................................................................................... 7-40 Modify Existing Reservoirs or Operations .................................................................................... 7-40 New Reservoirs and Conveyance Facilities ................................................................................... 7-40 Groundwater Development and Conjunctive Use ........................................................................ 7-41 Water Marketing .......................................................................................................................... 7-41 Water Recycling ........................................................................................................................... 7-42 Desalting ..................................................................................................................................... 7-42 Other Local Options.................................................................................................................... 7-42 Statewide Options ....................................................................................................................... 7-42 Options Likely to be Implemented in Central Coast Region .............................................................. 7-42 South Coast Hydrologic Region ................................................................................................................ 7-47 Description of the Area ...................................................................................................................... 7-47 Water Demands and Supplies ............................................................................................................. 7-47 Los Angeles Aqueduct .................................................................................................................. 7-48 Colorado River Aqueduct ........................................................................................................ .... 7-48xii The California Water Plan Update B ULLETIN 160-98

State Water Project....................................................................................................................... 7-49 Local Surface Water Supplies ................................................................................................... .... 7-50 Groundwater Supplies ................................................................................................................. 7-52 Local Water Resources Management Issues ........................................................................................ . 7-54 Water Supply Reliability .............................................................................................................. 7-54 Management of California’s Colorado River Water ...................................................................... 7-56

Mono Basin ................................................................................................................................. 7-57
Restoration of Coastal Wetlands and Estuaries ............................................................................. 7-57
Flood Control .............................................................................................................................. 7-58 Salinity Management Actions .................................................................................................... .. 7-59
Groundwater Issues...................................................................................................................... 7-60 Southern California Comprehensive Water Reclamation and Reuse Study ................................... 7-61 Water Marketing .......................................................................................................................... 7-61 New Conveyance Facilities from Colorado River Region to South Coast Region ......................... 7-62 Mexican Border Environmental Quality Issues ............................................................................ 7-62 Water Management Options for South Coast Region ......................................................................... 7-62
Water Conservation ..................................................................................................................... 7-63 Modify Existing Reservoirs or Operations .................................................................................... 7-63
New Reservoirs ............................................................................................................................ 7-63 Groundwater Development and Conjunctive Use ........................................................................ 7-67 Water Marketing .......................................................................................................................... 7-67 Implementing the CRB’s Draft 4.4 Plan ...................................................................................... 7-68 Water Recycling ........................................................................................................................... 7-68 Desalting ..................................................................................................................................... 7-70 Other Local Options.................................................................................................................... 7-71 Statewide Options ....................................................................................................................... 7-71 Options Likely to be Implemented in South Coast Region ................................................................. 7-71

Appendix 7A. Options Evaluations for Coastal Regions ........................................................................... .7A-1

Chapter 8. Options for Meeting Future Water Needs in Interior Regions of California Sacramento River Hydrologic Region ......................................................................................................... 8-3 Description of the Area ........................................................................................................................ 8-3 Water Demands and Supplies ............................................................................................................... 8-3 CVP Water Supply ........................................................................................................................ 8-4 Supply from Other Federal Water Projects ..................................................................................... 8-5 SWP Water Supply ........................................................................................................................ 8-5 Local Surface Water Supply............................................................................................................ 8-5 Groundwater Supply...................................................................................................................... 8-6xiii The California Water Plan Update B ULLETIN 160-98

Local Water Resources Management Issues ........................................................................................ ... 8-6 Sierra Nevada Foothills Water Supply ........................................................................................... . 8-6 Foothill Area Water Supply from American River Basin ................................................................. 8-7

Sacramento Area Water Forum .................................................................................................... .. 8-8 Colusa Basin Drainage District ...................................................................................................... 8-9 Groundwater Management Actions ............................................................................................... 8-9
American River Flood Protection ................................................................................................ . 8-10
Yuba River Flood Protection .................................................................................................... .... 8-11 Sacramento River Mainstem Flood Protection and Water Supply................................................. 8-12 Putah Creek Adjudication ............................................................................................................ 8-12 Fish Passage at Red Bluff Diversion Dam ..................................................................................... 8-12 Glenn-Colusa Irrigation District Fish Screen ............................................................................... 8-13 Fish and Wildlife Restoration Activities in the Sacramento Valley ................................................ 8-13 Water Needs for Rice Field Flooding............................................................................................ 8-15 Water Management Options for the Sacramento River Region ........................................................... 8-15
Water Conservation ..................................................................................................................... 8-15 Modify Existing Reservoirs/Operations ........................................................................................ 8- 15
New Reservoirs ............................................................................................................................ 8-17 New Conveyance Facilities ........................................................................................................... 8-19 Groundwater Development or Conjunctive Use .......................................................................... 8-19 Water Marketing .......................................................................................................................... 8-19 Water Recycling ........................................................................................................................... 8-19 Other Local Options.................................................................................................................... 8-19 Statewide Options ....................................................................................................................... 8-20 Options Likely to be Implemented in the Sacramento River Region................................................... 8-20 San Joaquin River Hydrologic Region ....................................................................................................... 8-23 Description of the Area ...................................................................................................................... 8-23 Water Demands and Supplies ............................................................................................................. 8-24
Surface Water............................................................................................................................... 8-24
Groundwater ............................................................................................................................... 8-26 Local Water Resources Management Issues ........................................................................................ . 8-27 Cosumnes River Flood Management ........................................................................................... 8-27 Integrity of Delta Levees .............................................................................................................. 8-27 Interim South Delta Program and Temporary Barriers Project ..................................................... 8-28 San Joaquin County Groundwater Overdraft ............................................................................... 8-29
Penn Mine Remediation ......................................................................................................... .... 8-29 Conservation Storage in Farmington Reservoir ............................................................................ 8-29 New Melones Reservoir Water Supply and Operations ................................................................ 8-30 Urban Growth Pressures from San Francisco Bay Area ................................................................. 8-30xiv The California Water Plan Update B ULLETIN 160-98

East County Water Supply Study ................................................................................................. 8-31
Los Banos Grandes Reservoir Studies ........................................................................................... 8 -31 Merced Area Conjunctive Use Study............................................................................................ 8- 32 Agricultural Drainage .................................................................................................................. 8-32 Enlargement of Friant Dam ...................................................................................................... ... 8-33 Instream Flow Requirements Below Friant Dam .......................................................................... 8-33 Environmental Restoration Activities in the San Joaquin River Basin ........................................... 8-33 San Joaquin River Parkway Development .................................................................................... 8-34 January 1997 San Joaquin River Region Flood Event ................................................................... 8-34 Water Management Options for the San Joaquin River Region .......................................................... 8-35
Water Conservation ..................................................................................................................... 8-35 Modify Existing Reservoirs .......................................................................................................... 8-35

New Reservoirs ............................................................................................................................ 8-35 New Conveyance Facilities ........................................................................................................... 8-37 Groundwater Development or Conjunctive Use .......................................................................... 8-38 Water Recycling ........................................................................................................................... 8-38 Desalting ..................................................................................................................................... 8-38 Statewide Options ....................................................................................................................... 8-38 Options Likely to be Implemented in the San Joaquin River Region .................................................. 8-38 Tulare Lake Hydrologic Region ................................................................................................................. 8-43 Description of the Area ...................................................................................................................... 8-43 Water Demands and Supplies ............................................................................................................. 8-44 Local Water Resources Management Issues ........................................................................................ . 8-45
Groundwater Overdraft ............................................................................................................... 8-45 Groundwater Banking Programs .................................................................................................. 8 -46 Agricultural Drainage .................................................................................................................. 8-46 Arroyo Pasajero and Other Westside Cross-Drainages .................................................................. 8-47 Kings River Fishery Restoration Actions ...................................................................................... 8- 47 Water Management Options for the Tulare Lake Region .................................................................... 8-47
Water Conservation ..................................................................................................................... 8-47 Modifying Existing Reservoirs and New Reservoirs ...................................................................... 8-49 New Conveyance Facilities ........................................................................................................... 8-50 Groundwater Development or Conjunctive Use .......................................................................... 8-50 Water Marketing .......................................................................................................................... 8-51 Water Recycling and Desalting .................................................................................................. .. 8-52 Statewide Options ....................................................................................................................... 8-52 Options Likely to be Implemented in the Tulare Lake Region ............................................................ 8-52

Appendix 8A. Options Evaluations for Interior Regions.......................................................................... ..8A-1xv The California Water Plan Update B ULLETIN 160-98

Chapter 9. Options for Meeting Future Water Needs in Eastern Sierra and Colorado River Regions of California North Lahontan Hydrologic Region ........................................................................................................... 9-3 Description of the Area ........................................................................................................................ 9-3 Water Demands and Supplies ............................................................................................................... 9-3 Local Water Resources Management Issues ........................................................................................ ... 9-7 Truckee River Operating Agreement .............................................................................................. 9-7
Walker River .................................................................................................................................. 9-8
Lake Tahoe .................................................................................................................................... 9-8
Leviathan Mine.............................................................................................................................. 9-9 Sierra Nevada Ecosystem Project .................................................................................................... 9-9 January 1997 Flood Event ............................................................................................................. 9-9 Water Management Options for the North Lahontan Region .............................................................. 9-9

Water Conservation ..................................................................................................................... 9-11 New Reservoirs or Conveyance Facilities ...................................................................................... 9- 11 Groundwater Development or Conjunctive Use .......................................................................... 9-11 Options Likely to be Implemented in the North Lahontan Region .................................................... 9-12 South Lahontan Hydrologic Region.......................................................................................................... 9-15 Description of the Area ...................................................................................................................... 9-15 Water Demands and Supplies ............................................................................................................. 9-16 Los Angeles Aqueduct .................................................................................................................. 9-16 State Water Project....................................................................................................................... 9-17 Local Surface Water Supplies ................................................................................................... .... 9-18 Groundwater Supplies ................................................................................................................. 9-18 Local Water Resources Management Issues ........................................................................................ . 9-19 Owens Valley Area ....................................................................................................................... 9-19

Mono Basin ................................................................................................................................. 9-20 Mojave River Adjudication ...................................................................................................... .... 9-21 Antelope Valley Water Management ............................................................................................ 9-21
Interstate Groundwater Basins .................................................................................................. ... 9-22 Water Management Options for South Lahontan Region ................................................................... 9-22

Water Conservation ..................................................................................................................... 9-22 Modify Existing Reservoirs or Operations .................................................................................... 9-23 New Reservoirs or Conveyance Facilities ...................................................................................... 9- 24 Water Marketing .......................................................................................................................... 9-24 Water Recycling ........................................................................................................................... 9-24 Other Local Options.................................................................................................................... 9-24 Statewide Options ....................................................................................................................... 9-24 Options Likely to be Implemented in the South Lahontan Region ..................................................... 9-24xvi The California Water Plan Update B ULLETIN 160-98

Colorado River Hydrologic Region ........................................................................................................... 9-27 Description of the Area ...................................................................................................................... 9-27 Water Demands and Supplies ............................................................................................................. 9-28 Supplies from the Colorado River ............................................................................................... . 9-28 Supplies from Other Sources.................................................................................................... .... 9-32 Local Water Resources Management Issues ........................................................................................ . 9-33 Management of California’s Colorado River Water ...................................................................... 9-33 Tribal Water Rights ...................................................................................................................... 9-35 Water Conservation Programs.................................................................................................... .. 9-35
Salton Sea .................................................................................................................................... 9-35 Coachella Valley Groundwater Overdraft ..................................................................................... 9-38
Lower Colorado River Environmental Water Issues ..................................................................... 9-39 Lower Colorado River Multi-Species Conservation Program........................................................ 9-40 Water Management Options for the Colorado River Region .............................................................. 9-40
Water Conservation ..................................................................................................................... 9-40 Potential Sources of Water for Intrastate Marketing ..................................................................... 9-42 Intrastate Groundwater Recharge or Banking............................................................................... 9-44 Interstate Banking/Conservation................................................................................................ .. 9-45 Reoperating Colorado River System Reservoirs ............................................................................ 9-45
Weather Modification .................................................................................................................. 9-45 Options for Coachella Valley ................................................................................................... .... 9-46 Statewide Options ....................................................................................................................... 9-46 Options Likely to be Implemented in the Colorado River Region ...................................................... 9-46

Appendix 9A. Options Evaluations for Eastern Sierra and Colorado River Regions...................................9A-1

Chapter 10. Conclusions Future with Existing Facilities and Programs ................................................................................... ... 10-2 Water Supply ............................................................................................................................... 10-2
Water Demand ............................................................................................................................ 10-3 Water Shortages ........................................................................................................................... 10-4 Summary of Options Likely to be Implemented ................................................................................. 10-6 Implementing Future Water Management Options ............................................................................ 10-8 Bulletin 160-98 Findings.................................................................................................................. 10-11

Appendix 10A. Regional Water Budgets with Likely Options .................................................................10A-1

Abbreviations and Acronyms ....................................................................... A-1

Glossary ................................................................................................... G-1

Tables Table 1A-1. 2020 Average Year Forecasts ...................................................................................................1A-1xvii The California Water Plan Update B ULLETIN 160-98

Table 2-1. Large Dams Under Construction or Recently Completed .......................................................... 2-2 Table 2-2. Major Water Conveyance Facilities Since 1992 ........................................................................ .. 2-2 Table 2-3. Large Structural Fishery Restoration Projects .............................................................................. 2-2 Table 2-4. Sample Restoration Projects Funded in Part by the SWP’s 4-Pumps Program............................. 2-3 Table 2-5. Proposition 204 Funding Breakdown ......................................................................................... 2-4 Table 2-6 California Hydropower Projects—License Years 2000-2010 ...................................................... 2-13 Table 2-7. Partial List of Targeted Watersheds and Watershed Activities Identified for the Watershed Management Initiative ............................................................................................................. 2-21 Table 3-1. Severity of Extreme Droughts in the Sacramento and San Joaquin Valleys .................................. 3-7 Table 3-2. Major Floods Since the 1950s .................................................................................................. 3-10 Table 3-3. California Water Supplies with Existing Facilities and Programs ............................................... 3-23 Table 3-4. Major Central Valley Project Reservoirs .................................................................................... 3-25 Table 3-5. Major State Water Project Reservoirs ........................................................................................ 3-30 Table 3-6. Major Reservoirs of USBR’s Klamath Project .......................................................................... . 3-38 Table 3-7. Other USBR Projects in California .......................................................................................... 3-38 Table 3-8. Major Reservoirs in the Los Angeles Aqueduct System ............................................................. 3-39 Table 3-9. Major Reservoirs in the Tuolumne River Basin ........................................................................ . 3-39 Table 3-10. Mokelumne Aqueduct System Reservoirs ............................................................................... 3-40 Table 3-11. Major Reservoirs on the Yuba and Bear River Systems ............................................................ 3-42 Table 3-12. Federal Flood Control Storage in Major Central Valley Reservoirs.......................................... 3-43 Table 3-13. Major Changes in Delta Criteria from D-1485 to WR 95-6 .................................................. 3-47 Table 3-14. Estimated 1995 Level Groundwater Supplies by Hydrologic Region ...................................... 3-48 Table 3-15. 1995 and 2020 Level Overdraft by Hydrologic Region .......................................................... 3-50 Table 3-16. California Adjudicated Groundwater Basins and Watermasters .............................................. 3-55 Table 3-17. Drought Water Bank Purchases and Allocations ..................................................................... 3- 57 Table 3-18. CVP Interim Water Acquisition Program Purchases ............................................................... 3-58 Table 3-19. Recently Completed Long-Term Water Marketing Agreements .............................................. 3-58 Table 3-20. 1995 and 2020 Level Water Recycling by Hydrologic Region with Existing Facilities and Programs ............................................................................................................................................ 3-60 Table 3-21. 1995 Level Total Water Recycling by Category ....................................................................... 3-61 Table 3-22. 2020 Level Total Water Recycling and New Water Supply...................................................... 3-61 Table 3-23. Significant Cryptosporidium Outbreaks ................................................................................... 3-63
Table 3-24. Some Waterborne Diseases of Concern in the United States ................................................... 3-63 Table 3-25. Disinfectants and Disinfection By-Products ......................................................................... .. 3-64
Table 3-26. A Partial List of Potential Beneficial Uses of Water ............................................................... .. 3-66 Table 3-27. A Partial List of Existing Water Quality Limits .................................................................... ... 3-66 Table 3-28. A Partial List of Water Quality Constituents or Characteristics for Which Water Quality Objectives May Be Established .............................................................................. . 3-66 Table 3-29. Constituents Regulated Under the Federal Safe Drinking Water Act ...................................... 3-67 Table 3-30. Potential Sources and Causes of Water Quality Impairment ................................................... 3-69xviii The California Water Plan Update B ULLETIN 160-98

Table 3-31. SWP Sanitary Survey Update Recommendations ................................................................... 3-70

Table 3-32. Waterborne-Disease Outbreaks Associated with Groundwater Used as a Drinking Water Source, 1993-94............................................................................................... 3-71 Table 3-33. California Average Year Water Supplies by Hydrologic Region ............................................... 3-73 Table 3-34. California Drought Year Water Supplies by Hydrologic Region .............................................. 3-73 Table 3A-1. Planned Water Recycling for North Coast Region .................................................................3A-2 Table 3A-2. Planned Water Recycling for San Francisco Bay Region .........................................................3A-3 Table 3A-3. Planned Water Recycling for Central Coast Region ...............................................................3A-5 Table 3A-4. Planned Water Recycling for South Coast Region ..................................................................3A-6 Table 3A-5. Planned Water Recycling for Sacramento River Region........................................................3A-11 Table 3A-6. Planned Water Recycling for San Joaquin River Region .......................................................3A-12 Table 3A-7. Planned Water Recycling for Tulare Lake Region .................................................................3A-13 Table 3A-8. Planned Water Recycling for North Lahontan Region .........................................................3A-13 Table 3A-9. Planned Water Recycling for South Lahontan Region ..........................................................3A-14 Table 3A-10. Planned Water Recycling for Colorado River Region .........................................................3A-14 Table 4-1. California Population by Hydrologic Region .............................................................................. 4-7 Table 4-2. Comparison Between Department of Finance and Councils of Governments Population Projections ................................................................................................................................ 4-7 Table 4-3. Summary of California and Federal Plumbing Fixture Requirements ......................................... 4-9 Table 4-4. Annual Reductions in Applied Water and Depletions Due to BMP Implementation by 2020 .......................................................................................................................... 4-12 Table 4-5. 1995 Urban Water Management Plans by Hydrologic Region .................................................. 4-13 Table 4-6. Urban Water Use Study Input Variables ............................................................................... .... 4-14 Table 4-7. Urban Water Use Study Data Sources....................................................................................... 4-15 Table 4-8. Model Study Results—Per Capita Water Use With Economic Growth and Conservation Measures ............................................................................................................................. 4-15 Table 4-9. 2020 Change in Per Capita Use by Hydrologic Region-Application of Model Results .............. 4-16 Table 4-10. Effects of Conservation on Per Capita Water Use by Hydrologic Region ................................ 4-16 Table 4-11. Applied Urban Water Use by Hydrologic Region ................................................................... 4-17 Table 4-12. Relationship Among Agricultural Water Use Efficiency Measures........................................... 4-20 Table 4-13. 2020 Agricultural Water Use Reductions Due to Conservation .............................................. 4-21 Table 4-14. California Crop and Irrigated Acreage by Hydrologic Region, 1995 Level .............................. 4-25 Table 4-15. California Crop and Irrigated Acreage by Hydrologic Region, 2020 Level .............................. 4-32 Table 4-16. Applied Agricultural Water Use by Hydrologic Region ........................................................... 4-33 Table 4-17. Wild and Scenic River Flows by Waterway ............................................................................ . 4-36 Table 4-18. Wild and Scenic River Flows by Hydrologic Region ............................................................... 4-36 Table 4-19. Proposed Instream Flows, CVPIA PEIS Alternative 4 ............................................................. 4-39 Table 4-20. Instream Flow Requirements by Waterway ............................................................................. 4-41 Table 4-21. Instream Flow Requirements by Hydrologic Region ............................................................... 4-41 Table 4-22. CVPIA Refuge Water Supplies ............................................................................................... 4-48xix The California Water Plan Update B ULLETIN 160-98

Table 4-23 . Ranges of Applied Water on Central Valley Managed Wetlands............................................. 4-51 Table 4-24. Wetlands Water Use by Hydrologic Region ............................................................................ 4-51 Table 4-25. Applied Environmental Water Use by Hydrologic Region ...................................................... 4-51 Table 4-26. California Average Year Water Use by Hydrologic Region ...................................................... 4-52 Table 4-27. California Drought Year Water Use by Hydrologic Region ..................................................... 4-52 Table 4A-1. Types of Local Supply Water Agencies in California ...............................................................4A -1 Table 4A-2. Urban Water Demand Price Elasticity Studies........................................................................ 4A-4 Table 4A-3. DWR Survey of 1996 Agricultural Surface Water Costs .........................................................4A-5 Table 4A-4. Average Water Costs as a Percent of Total Production Costs for Selected Crops in the Tulare Lake Region .........................................................................................................................4A-6 Table 4A-5. Price Elasticities for Surface Water Irrigation Demand ...........................................................4A -6
Table 4B-1. BMP Revisions ...................................................................................................................... 4B-2 Table 4B-2. BMP Water Savings Assumptions ...................................................................................... .... 4B-8
Table 5-1. Distribution of Residential Indoor Water Use ............................................................................ 5-2 Table 5-2. Water Recycling Plants with a Capacity of at Least 10 mgd ...................................................... 5-14 Table 5-3. Sample Desalting Plants ........................................................................................................... 5-17 Table 5-4. Examples of Contaminated Groundwater Treatment Sites ........................................................ 5-19 Table 6-1. California Water Budget with Existing Facilities and Programs................................................... 6-2 Table 6-2. 1991 Urban Water Shortage Management................................................................................ .. 6-7 Table 6-3. Urban Depletion Reduction Potential Due to Water Conservation Options Beyond BMPs ....... 6-9 Table 6-4. Agricultural Depletion Reduction Potential Due to Water Conservation Options Beyond EWMPs ....................................................................................................................................... 6-12 Table 6-5. CVP Yield Increase Plan Conjunctive Use Options .................................................................. 6-24 Table 6-6. Sample of Potential Water Purchases ........................................................................................ 6-29 Table 6-7. Drought Water Bank Summary ................................................................................................ 6-30 Table 6-8. 2020 Level Water Recycling Options and Resulting New Water Supply ................................... 6-32 Table 6-9. Potential 2020 Water Recycling Options by Hydrologic Region ............................................... 6-33 Table 6-10. Statewide Supply Augmentation Options Likely to be Implemented by 2020 ........................ 6-38 Table 6-11. Likely Statewide Supply Augmentation Options by Hydrologic Region, 2020 Average Year ... 6-39 Table 6-12. Likely Statewide Supply Augmentation Options by Hydrologic Region, 2020 Drought Year . 6-39 Table 6-13. Effects of Alternative Assumptions on 2020 Applied Water Shortages .................................... 6-40 Table 6-14. Environmental Restoration Funding .................................................................................. .... 6-42 Table 6-15. Sample Projects Funded by Category III Program .................................................................. 6-45 Table 6-16. Significant Sources of Revenue to Water Agencies by Type of Ownership ............................... 6-48 Table 6-17. Significant Sources of Revenue to Water Agencies by Water Agency Size ................................ 6-48 Table 6-18. Major State and Federal Financial Assistance Programs .......................................................... 6-50 Table 6-19. Financing Methods Available to Water Agencies by Type of Ownership ................................. 6-51 Table 6-20. Financing Methods Typically Available to Water Agencies by Water Agency Size .................... 6-52 Table 6-21. Financial Assistance Programs Available to Water Agencies by Type of Ownership ................. 6-52 Table 6A-1. North Coast Region Water Budget with Existing Facilities and Programs ..............................6A-2xx The California Water Plan Update B ULLETIN 160-98

Table 6A-2. San Francisco Bay Region Water Budget with Existing Facilities and Programs ......................6A-2 Table 6A-3. Central Coast Region Water Budget with Existing Facilities and Programs ............................6A-2 Table 6A-4. South Coast Region Water Budget with Existing Facilities and Programs ...............................6A-3 Table 6A-5. Sacramento River Region Water Budget with Existing Facilities and Programs ......................6A-3 Table 6A-6. San Joaquin River Region Water Budget with Existing Facilities and Programs ......................6A-3 Table 6A-7. Tulare Lake Region Water Budget with Existing Facilities and Programs ................................6A-4 Table 6A-8. North Lahontan Region Water Budget with Existing Facilities and Programs ........................6A-4 Table 6A-9. South Lahontan Region Water Budget with Existing Facilities and Programs .........................6A-4 Table 6A-10. Colorado River Region Water Budget with Existing Facilities and Programs ........................6A-5 Table 6B-1. Applied Water Shortages by Hydrologic Region, 1995-Level Average Year ............................. 6B-2 Table 6B-2. Applied Water Shortages by Hydrologic Region, 1995-Level Drought Year............................6B-2 Table 6B-3. Applied Water Shortages by Hydrologic Region, 2020-Level Average Year ............................. 6B-3 Table 6B-4. Applied Water Shortages by Hydrologic Region, 2020-Level Drought Year............................6B-3 Table 6C-1. Sample Cost Computation ................................................................................................... 6C-2 Table 6D-1. Minimum New Water Needs by Hydrologic Region, 2020 Average Year .............................. 6D-2 Table 6D-2. Minimum New Water Needs by Hydrologic Region, 2020 Drought Year ............................ 6D-2 Table 6E-1. North Coast Region Net Water Budget with Existing Facilities and Programs........................ 6E-2 Table 6E-2. San Francisco Region Net Water Budget with Existing Facilities and Programs ...................... 6E-2 Table 6E-3. Central Coast Region Net Water Budget with Existing Facilities and Programs...................... 6E-2 Table 6E-4. South Coast Region Net Water Budget with Existing Facilities and Programs ........................ 6E-3 Table 6E-5. Sacramento River Region Net Water Budget with Existing Facilities and Programs ................ 6E-3 Table 6E-6. San Joaquin River Region Net Water Budget with Existing Facilities and Programs ............... 6E-3 Table 6E-7. Tulare Lake Region Net Water Budget with Existing Facilities and Programs ......................... 6E-4 Table 6E-8. North Lahontan Region Net Water Budget with Existing Facilities and Programs.................. 6E-4 Table 6E-9. South Lahontan Region Net Water Budget with Existing Facilities and Programs .................. 6E-4 Table 6E-10. Colorado River Region Net Water Budget with Existing Facilities and Programs ................. 6E-5 Table 6E-11. California Net Water Budget with Existing Facilities and Programs ..................................... 6E-5 Table 6F-1. Agricultural Depletion Reductions Due to Land Retirement .................................................. 6F-2
Table 6F-2. Costs of Land Retirement ...................................................................................................... 6F-2 Table 6F-3. Land Retirement Analysis—Scenario 1 Economic Impacts .................................................... 6F-3 Table 6F-4. Land Retirement Analysis—Scenario 2 Economic Impacts .................................................... 6F-3 Table 6G-1. Onstream Storage Options Upstream of the Delta ............................................................... 6G-2 Table 6G-2. Retained Onstream Storage Options and Environmental Issues............................................ 6G-4 Table 6G-3. Offstream Storage Options Upstream of the Delta ............................................................... 6G-5 Table 6G-4. Retained Offstream Storage Options and Environmental Issues ........................................... 6G-6 Table 6G-5. Watersheds Identified for South of the Delta Storage Options ............................................ 6G-10 Table 6G-6. South of the Delta Off-Aqueduct Storage Size Categories................................................... 6G-10 Table 6G-7. Ranking of Off-Aqueduct Storage Options South of the Delta ........................................... 6G-11 Table 6G-8. Retained Off-Aqueduct Storage Option South of the Delta................................................ 6G-12xxi The California Water Plan Update B ULLETIN 160-98

Table 7-1. Population and Crop Acreage ..................................................................................................... 7-3 Table 7-2. North Coast Region Water Budget ............................................................................................. 7-4 Table 7-3. North Coast Region List of Water Management Options ........................................................... 7-9 Table 7-4. Options Ranking for North Coast Region .............................................................................. .. 7-12 Table 7-5. Options Likely to be Implemented by 2020, North Coast Region............................................ 7-12 Table 7-6. Population and Crop Acreage ................................................................................................... 7-15 Table 7-7. San Francisco Bay Region Water Budget ............................................................................... ... 7-16 Table 7-8. Major North Bay Water Suppliers ............................................................................................ 7-17 Table 7-9 . Local Agency Reservoirs Serving the North Bay ...................................................................... 7-17 Table 7-10. Major South Bay Water Suppliers ........................................................................................... 7-18 Table 7-11. Local Surface Reservoirs Serving the South Bay ..................................................................... . 7-18 Table 7-12. San Francisco Bay Region List of Water Management Options .............................................. 7-25 Table 7-13. Options Ranking for San Francisco Bay Region ..................................................................... 7- 30 Table 7-14. Options Likely to be Implemented by 2020, San Francisco Bay Region ................................. 7-31 Table 7-15. Population and Crop Acreage ................................................................................................. 7-34 Table 7-16. Central Coast Region Water Budget ....................................................................................... 7-34 Table 7-17. Central Coast Region List of Water Management Options ..................................................... 7-38 Table 7-18. Options Ranking for Central Coast Region ........................................................................... . 7-43 Table 7-19. Options Likely to be Implemented by 2020, Central Coast Region........................................ 7-44 Table 7-20. Population and Crop Acreage ................................................................................................. 7-47 Table 7-21. South Coast Region Water Budget ......................................................................................... 7-48 Table 7-22. Metropolitan Water District of Southern California Member Agencies .................................. 7-49 Table 7-23. State Water Project Contractors in the South Coast Region .................................................... 7-50 Table 7-24. Major Reservoirs in the South Coast Region ......................................................................... . 7-51 Table 7-25. Reservoirs Owned by Water Retailers in MWDSC’s Service Area ........................................... 7-51 Table 7-26. San Diego County Water Authority Member Agencies ........................................................... 7-52 Table 7-27. Adjudicated Groundwater Basins in the South Coast Region ................................................. 7-55 Table 7-28. Salinity of South Coast Region Groundwater Supplies ........................................................... 7-59 Table 7-29. South Coast Region List of Water Management Options ....................................................... 7-64 Table 7-30. Options Ranking for South Coast Region ............................................................................. . 7-72 Table 7-31. Options Likely to be Implemented by 2020, South Coast Region .......................................... 7-73 Table 7A-1. Options Evaluation North Coast Region .............................................................................. .7A-2 Table 7A-2. Options Evaluation San Francisco Bay Region .......................................................................7 A-3 Table 7A-3. Options Evaluation Central Coast Region ............................................................................ .7A-5 Table 7A-4. Options Evaluation South Coast Region .............................................................................. ..7A-7 Table 8-1. Population and Crop Acreage ..................................................................................................... 8-3 Table 8-2. Sacramento River Region Water Budget ..................................................................................... 8-4 Table 8-3. Major Sacramento River CVP Water Users .............................................................................. .. 8-5 Table 8-4. Sacramento River Region List of Water Management Options ................................................. 8-16xxii The California Water Plan Update B ULLETIN 160-98

Table 8-5. Options Ranking for Sacramento River Region ........................................................................ 8 -20 Table 8-6. Options Likely to be Implemented by 2020, Sacramento River Region .................................... 8-21 Table 8-7. Population and Crop Acreage ................................................................................................... 8-23 Table 8-8. San Joaquin River Region Water Budget ............................................................................... ... 8-23 Table 8-9. New Melones Releases for CVPIA Environmental Purposes ..................................................... 8-31 Table 8-10. San Joaquin River Region List of Water Management Options............................................... 8-36 Table 8-11. Comparison of Salinity of Water Sources............................................................................ .... 8-39 Table 8-12. Options Ranking for San Joaquin River Region ..................................................................... 8- 40 Table 8-13. Options Likely to be Implemented by 2020, San Joaquin River Region ................................. 8-41 Table 8-14. Population and Crop Acreage ................................................................................................. 8-43 Table 8-15. Tulare Lake Region Water Budget .......................................................................................... 8-45 Table 8-16. Tulare Lake Region List of Water Management Options......................................................... 8-48 Table 8-17. Options Ranking for Tulare Lake Region ............................................................................. .. 8-53 Table 8-18. Options Likely to be Implemented by 2020, Tulare Lake Region ........................................... 8-53 Table 8A-1. Options Evaluation Sacramento River Region .......................................................................8A -2 Table 8A-2. Options Evaluation San Joaquin River Region .......................................................................8 A-3 Table 8A-3. Options Evaluation Tulare Lake Region .............................................................................. ...8A-4 Table 9-1. Population and Crop Acreage ..................................................................................................... 9-3 Table 9-2. North Lahontan Region Water Budget ....................................................................................... 9-4 Table 9-3. Major Reservoirs in the Truckee River Basin in California .......................................................... 9 -5 Table 9-4. North Lahontan Region List of Water Management Options ................................................... 9-10 Table 9-5. Options Ranking for North Lahontan Region .......................................................................... 9 -12 Table 9-6. Options Likely to be Implemented by 2020, North Lahontan Region...................................... 9-12 Table 9-7. Population and Crop Acreage ................................................................................................... 9-16 Table 9-8. South Lahontan Region Water Budget .................................................................................. ... 9-17 Table 9-9. Los Angeles Aqueduct System Reservoirs.............................................................................. .... 9-17 Table 9-10. SWP Contractors in the South Lahontan Region ................................................................... 9-17 Table 9-11. South Lahontan Region List of Water Management Options ................................................. 9-23 Table 9-12. Options Ranking for South Lahontan Region ........................................................................ 9- 25 Table 9-13. Options Likely to be Implemented by 2020, South Lahontan Region .................................... 9-25 Table 9-14. Population and Crop Acreage ................................................................................................. 9-27 Table 9-15. Colorado River Region Water Budget ................................................................................. ... 9-28 Table 9-16. Key Elements of the Law of the River..................................................................................... 9-29 Table 9-17. Annual Apportionment of Use of Colorado River Water ........................................................ 9-30
Table 9-18. Estimated Colorado River Flow and Uses ............................................................................. .. 9-31 Table 9-19. SWP Contractors in the Colorado River Region .................................................................... 9-32 Table 9-20. Existing Colorado River Region Water Conservation Actions ................................................. 9-36 Table 9-21. Colorado River Region List of Water Management Options................................................... 9-41 Table 9-22. Potential Colorado River Water Conservation Programs......................................................... 9-42xxiii The California Water Plan Update B ULLETIN 160-98

Table 9-23. Options Ranking for Colorado River Region ......................................................................... 9 -48 Table 9-24. Options Likely to be Implemented by 2020, Colorado River Region ..................................... 9-48
Table 9-25. Future Actions Described in Bulletin 160-98 That Could be Part of Draft CRB 4.4 Plan Implementation ........................................................................................................ 9-48 Table 9A-1. Options Evaluation North Lahontan Region .........................................................................9A -2 Table 9A-2. Options Evaluation South Lahontan Region ..........................................................................9 A-3 Table 9A-3. Options Evaluation Colorado River Region ........................................................................... 9A-4 Table 10-1. California Water Budget with Existing Facilities and Programs............................................... 10-2 Table 10-2. Applied Water Shortages by Hydrologic Region With Existing Facilities and Programs ....................................................................................................... 10-4 Table 10-3. Summary of Options Likely to be Implemented by 2020, by Option Type ............................ 10-7 Table 10-4. California Water Budget with Options Likely to be Implemented .......................................... 10-8 Table 10-5. Water Shortages by Hydrologic Region With Likely Options ................................................. 10-9 Table 10A-1. North Coast Region Water Budget with Options...............................................................10A-2 Table 10A-2. San Francisco Bay Region Water Budget with Options ......................................................10A-2 Table 10A-3. Central Coast Region Water Budget with Options.............................................................10A-2 Table 10A-4. South Coast Region Water Budget with Options ...............................................................10A-3 Table 10A-5. Sacramento River Region Water Budget with Options .......................................................10A-3 Table 10A-6. San Joaquin River Region Water Budget with Options ......................................................10A-3 Table 10A-7. Tulare Lake Region Water Budget with Options ................................................................10A-4 Table 10A-8. North Lahontan Region Water Budget with Options.........................................................10A-4 Table 10A-9. South Lahontan Region Water Budget with Options .........................................................10A-4 Table 10A-10. Colorado River Region Water Budget with Options ........................................................10A-5

Figures Figure 1-1. California in Relation to the United States ................................................................................ 1-3 Figure 1-2. California’s Expected Population Growth Versus Neighboring States’ Populations ..................... 1-4 Figure 1-3. Relief Map of California ........................................................................................................... 1-5 Figure 1-4. California’s Major Water Projects .............................................................................................. 1-7 Figure 1-5. California’s Hydrologic Regions ................................................................................................ 1-9 Figure 3-1. Distribution of Average Annual Precipitation and Runoff ......................................................... 3-3 Figure 3-2. Regional Imports and Exports, 1995 Level of Development ..................................................... 3-4 Figure 3-3. Northern Sierra Eight Station Precipitation Index .................................................................. ... 3-5 Figure 3-4. Sacramento Four Rivers Unimpaired Runoff........................................................................... .. 3-6 Figure 3-5. San Joaquin Four Rivers Unimpaired Runoff .......................................................................... .. 3-7 Figure 3-6. Eight River Index Computed for January 1906-96 ................................................................... 3-8 Figure 3-7. Disposition of California’s Average Annual Precipitation ......................................................... 3- 13 Figure 3-8. Illustration of Applied and Net Water Methodologies: Inland Area ......................................... 3-15 Figure 3-9. Illustration of Applied and Net Water Methodologies: Coastal Area........................................ 3-16 Figure 3-10. Illustration of Applied and Net Water Methodologies: Inland Area with High Efficiency ................................................................................................................................. 3-17xxiv The California Water Plan Update B ULLETIN 160-98

Figure 3-11. Statewide Distribution of Precipitation for Water Years 1990 and 1992 ................................ 3-20 Figure 3-12. Colorado River Unimpaired Runoff at Lee Ferry Compact Point .......................................... 3-21 Figure 3-13. CVP and SWP Deliveries During 1987-92 Drought ............................................................ 3-21 Figure 3-14. Selected Reservoir Storage During 1987-92 Drought ............................................................ 3-22 Figure 3-15. Major Central Valley Project Facilities ................................................................................... 3-26 Figure 3-16. Central Valley Project Service Areas ...................................................................................... 3-28 Figure 3-17. Central Valley Project Deliveries ........................................................................................... 3-29 Figure 3-18. 1995 and 2020 Central Valley Project Delivery Capability South of Delta with Existing Facilities .............................................................................................................................. 3-29 Figure 3-19. Major State Water Project Facilities ....................................................................................... 3-31 Figure 3-20. State Water Project Service Areas........................................................................................... 3-32 Figure 3-21. State Water Project Deliveries ............................................................................................... 3-33 Figure 3-22. 1995 and 2020 State Water Project Delivery Capability with Existing Facilities .................... 3-33 Figure 3-23. Colorado River Watershed in United States ......................................................................... . 3-34 Figure 3-24. Colorado River Service Areas ................................................................................................ 3-36 Figure 3-25. Lake Oroville Flood Control Operating Diagram ................................................................. 3-44 Figure 3-26. 1995 Level Central Valley Project Delivery Capability South of Delta Under D-1485 and WR 95-6 .............................................................................................................................. 3-45 Figure 3-27. 1995 Level State Water Project Delivery Capability Under D-1485 and WR 95-6 ................ 3-45 Figure 3-28. Adjudicated Groundwater Basins .......................................................................................... 3-54 Figure 4-1. California Applied Water Use and Depletion ......................................................................... ... 4-3 Figure 4-2. Projected Growth Rates by County, 1995-2020 ........................................................................ 4-5 Figure 4-3. Components of Population Growth, 1940-95 ........................................................................... 4-6 Figure 4-4. Statewide Average Per Capita Urban Water Production Over Time ......................................... 4-12 Figure 4-5. Ranges of Applied Water and Evapotranspiration of Applied Water ........................................ 4-19 Figure 4-6. Typical Land Use Survey Map ................................................................................................. 4-23 Figure 4-7. General Trends in Cropping Patterns Over Time .................................................................... 4- 24 Figure 4-8. Changes in Land Use Over Time, DAU 233 ........................................................................... 4- 27 Figure 4-9. Areas of Shallow Groundwater in the San Joaquin Valley ........................................................ 4-29 Figure 4-10. California Wild and Scenic Rivers......................................................................................... 4-35 Figure 4-11. Annual Delta Inflow and Outflow 1980-96 .......................................................................... 4 -43 Figure 4-12. Bay-Delta Estuary ................................................................................................................. 4-44 Figure 4-13. Publicly-Owned Fresh Water Wetlands ............................................................................... .. 4-50 Figure 4C-1. Sample Urban Water Production Data ................................................................................ 4C-1 Figure 4C-2. Actual and Normalized Production Data ............................................................................. 4C-3 Figure 5-1. Recent Structural Fishery Improvements ............................................................................. .... 5-25 Figure 6-1. Index to Regional Chapters ....................................................................................................... 6-3 Figure 6G-1. Likely Reservoir Sites Upstream of the Delta ....................................................................... 6G-8 Figure 6G-2. Off-Aqueduct South of the Delta Watershed Sites............................................................. 6G-13 Figure 7-1. Coastal Hydrologic Regions ...................................................................................................... 7-1xxv The California Water Plan Update B ULLETIN 160-98

Figure 7-2. North Coast Hydrologic Region ............................................................................................... 7-2 Figure 7-3. San Francisco Bay Hydrologic Region ..................................................................................... 7-14 Figure 7-4. Central Coast Hydrologic Region. .......................................................................................... 7-32 Figure 7-5. South Coast Hydrologic Region.............................................................................................. 7-46 Figure 7-6. South Coast Groundwater Basins............................................................................................ 7-53 Figure 8-1. Interior Hydrologic Regions...................................................................................................... 8-1 Figure 8-2. Sacramento River Hydrologic Region ....................................................................................... 8-2 Figure 8-3. San Joaquin River Hydrologic Region ..................................................................................... 8-22 Figure 8-4. Tulare Lake Hydrologic Region ............................................................................................... 8-42 Figure 9-1. Eastern Sierra and Colorado River Hydrologic Regions............................................................. 9-1 Figure 9-2. North Lahontan Hydrologic Region ......................................................................................... 9-2 Figure 9-3. South Lahontan Hydrologic Region........................................................................................ 9-14 Figure 9-4. Colorado River Hydrologic Region ......................................................................................... 9-26 Figure 9-5. Basic Apportionment and Consumptive Use of Mainstem Colorado River in Lower Basin ..... 9-31 Figure 9-6. U.S.-Mexican Border Region .................................................................................................. 9-43 Figure 10-1. 2020 Shortages by Hydrologic Region with Existing Facilities and Programs ................................................................................................................ 10-5 Figure 10-2. 2020 Shortages by Hydrologic Region with Likely Options ................................................ 10-10

Sidebars Summary of Key Statistics ........................................................................................................................... 1-2 California’s Largest Water Retailers.............................................................................................................. 1-6

California Water Statistics ........................................................................................................................... 1-8 California’s Hydrologic Regions ................................................................................................................ 1-10 A California Water Chronology ................................................................................................................ 1-11
CVPIA’s Dedicated Water ........................................................................................................................... 2-9
CVPIA Waterfowl Habitat Provisions ....................................................................................................... 2-10 An Example of Water Year Classifications ................................................................................................... 3-8 Key Water Supply and Water Use Definitions ........................................................................................... 3-12 Operations Studies .................................................................................................................................... 3-19
Auburn Dam—Planned, But Not Constructed ........................................................................................ . 3-24 Colorado River Reservoir Operations ........................................................................................................ 3-37 Federal Flood Control Operating Criteria ................................................................................................. 3-44 Typical Groundwater Production Conditions ........................................................................................... 3-49 Land Subsidence in the San Joaquin Valley ............................................................................................... 3-52 Seawater Intrusion in Orange County ....................................................................................................... 3-53 Summary of Key Statistics ........................................................................................................................... 4-2 Landscape Water Use .................................................................................................................................. 4-8 Urban Best Management Practices (1997 Revision) ................................................................................ .. 4-10 Highlights of the Urban MOU ................................................................................................................. 4-11xxvi The California Water Plan Update B ULLETIN 160-98

Efficient Water Management Practices for Agricultural Water Suppliers in California ............................... 4-20 California’s Nursery Industry .................................................................................................................... 4-24 Water Use Impacts from Urbanization of Agricultural Lands, a San Joaquin Valley Example .................... 4-26 Agroforestry Research ............................................................................................................................... 4-30
Alfalfa and Market Conditions.................................................................................................................. 4-31 Environmental Water Use—An American River Example ......................................................................... 4-38 CVPIA Anadromous Fish Restoration Program ...................................................................................... .. 4-40 Recovery Efforts for Winter-Run Chinook Salmon ................................................................................. .. 4-42 California Wetlands Conservation Policy .................................................................................................. 4-47 Definition of Irrigation Terms ..................................................................................................................... 5-5 Gravity (Surface) Irrigation Systems ............................................................................................................ 5-6 Pressurized (Piped) Irrigation Systems ......................................................................................................... 5-8 San Diego Water Repurification Program ................................................................................................. 5-16 Seawater Desalting—Marina Coast Water District ................................................................................. ... 5-18 Remediation of Nitrate Contamination—City of McFarland.................................................................... 5-19 Remediation of Volatile Organics Contamination—McClellan Air Force Base.......................................... 5-20 Remediation of Pesticide and Fertilizer Contamination—Occidental Chemical Manufacturing Facility ... 5-20 Behavioral Barrier Demonstration Projects ................................................................................................ 5-27 Initial Screening Criteria ............................................................................................................................. 6-4 Options Category Evaluation ...................................................................................................................... 6-5 Data on Urban Landscaping ....................................................................................................................... 6-8 CALFED Water Conservation Planning ................................................................................................... 6-11 Land Retirement in Drainage-Impaired Areas ........................................................................................... 6-13 CALFED Bay-Delta Program Common Programs .................................................................................... 6-15 Prospects for Onstream Surface Storage Upstream of the Delta ................................................................. 6- 18 Feasibility Study for American Basin Conjunctive Use Project .................................................................. 6 -25
Is That Real Water? ................................................................................................................................... 6-26
Water Code Section 1810 et seq. ............................................................................................................... 6-28 Seawater Desalting as a Future Water Management Option ...................................................................... 6-34 Mission Basin Brackish Groundwater Desalting Research and Development Project ................................. 6-34 Monterey County Water Resources Agency’s Cloud Seeding Program ....................................................... 6-35 San Diego Area Water Reclamation Programs ........................................................................................... 7-69 Brackish Water Reclamation Demonstration Facility.............................................................................. ... 7-70 Sacramento River Flood Control Project ................................................................................................... 8-10 Grasslands Bypass Project Drainage Fee System ........................................................................................ 8-32 Westlands Water District Distribution System .......................................................................................... 8-50 Water Marketing—WaterLink Program .................................................................................................... 8-52
Searles Lake............................................................................................................................................... 9-19
Colorado River Board of California .......................................................................................................... 9-35 Reservoir Reoperation for Flood Control .................................................................................................. 10-6xxvii The California Water Plan Update B ULLETIN 160-98



### STATE OF CALIFORNIA

Pete Wilson, Governor

THE RESOURCES AGENCY Douglas P. Wheeler, Secretary for Resources

DEPARTMENT OF WATER RESOURCES David N. Kennedy, Director

Raymond D. Hart Robert G. Potter Stephen L. Kashiwada

Deputy Director Chief Deputy Director Deputy Director

L. Lucinda Chipponeri Susan N. Weber Assistant Director for Legislation Chief Counsel

DIVISION OF PLANNING AND LOCAL ASSISTANCE William J. Bennett, Chief

This Bulletin was prepared under the direction of Jeanine Jones . .......................................................................................................... Chief, Statewide Planning

by Naser Bateni ...................................................................................Former Chief, Water Resources Evaluation Paul Hutton ................................................................................................ Chief, Water Resources Evaluation Waiman Yip ..................................................................................................................... ........ Senior Engineer Bob Zettlemoyer ......................................................................................................................Senior Engineer

assisted by
Barbara Cross Tom Hawkins Dick Neal Steve Cowdin Ray Hoagland Virginia Sajac Dan Fua Scott Matyac Clara Silva

with assistance on special topics or studies by
Manucher Alemi Farhad Farnam Richard Le
Linton Brown Marla Hambright Claire LeFlore Randy Brown Darryl Hayes Jim Rich Ed Craddock Dale Hoffman-Floerke Maurice Roos Baryohay Davidoff Steve Kasower Ray Tom John Kramerxxviii The California Water Plan Update B ULLETIN 160-98

Data collection and regional information provided by Department District offices

Northern District Naser Bateni, Chief
assisted by
X. Tito Cervantes Douglas Denton Glen Pearson Andrew Corry Todd Hillaire Eugene Pixley

Central District Karl Winkler, Chief
assisted by Alan Aguilar Al Lind Doug Osugi Emil Calzascia Ed Morris James Wieking Toccoy Dudley

San Joaquin District Lou Beck, Chief
assisted by Jack Erickson Brian Smith Ernie Taylor Robert Polgar Arvey Swanson Iris Yamagata David Scruggs

Southern District Charles White, Chief
assisted by Glenn Berquist Vern Knoop Mark Stuart Sergio Fierro Kelly Lawler Garret Tam Sing David Inouye Michael Maisner

Editorial, design, and production services were provided by Nikki Blomquist Teresa Chaney Joanne Pierce John Carter Mike Miller Therese Tynan

Photography provided by Department of Water Resources, Photography Unit Peter Stoiber, Supervising Photographer

Paul Hames Dale Kolke Stephen Payer Norm Hughesxxix The California Water Plan Update B ULLETIN 160-98



### State of California The Resources Agency Department of Water Resources



### CALIFORNIA WATER COMMISSION

Daniel F. Kriege Stanley M. Barnes Chair, Capitola Vice Chair, Visalia

Donald C. Cecil ................................................................................................................................... Willows

George Gowgani, Ph.D........................................................................................................... San Luis Obispo

Homer F. Lundberg ............................................................................................................................ Richvale

Michael D. Madigan ............................................................................................................. ........... San Diego

Martin A. Matich............................................................................................................... ...... San Bernardino

Sayre M. Miller ....................................................................................................................................... Clovis



### Raymond E. Barsch, Executive Officer

The California Water Commission serves as a policy advisory body to the Director of the Department of Water Resources on all California water resources matters. The nine-member citizen commission provides a water resources forum for the people of the State, acts as a liaison between the legislative and executive branches of State government, and coordinates federal, State, and local water resources efforts.