Paradise Regained
SOLUTIONS FOR RESTORING YOSEMITE’S HETCH HETCHY VALLEY Paradise Regained
SOLUTIONS FOR RESTORING YOSEMITE’S HETCH HETCHY VALLEY
AUTHORS Spreck Rosekrans Nancy E. Ryan Ann H. Hayden Thomas J. Graff John M. Balbus Cover image: Composite created using digital panorama photography and 3D animation software. Photo and composite by Greg Richardson, Level Par.
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©2004 Environmental Defense
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The complete report is available online at www.environmentaldefense.org. Contents
Foreword iv CHAPTER 9 Impact of restoration on Acknowledgments v hydropower production and revenues 68 About the authors vi CHAPTER 10 Executive summary vii Water and power replacement costs 86
CHAPTER 11 CHAPTER 1 Introduction 1 Legal status and institutional considerations 94
CHAPTER 2 CHAPTER 12 Hetch Hetchy: past, present 5 Conclusion and recommendations 106 and future Glossary of technical terms 110 CHAPTER 3 California water summary 13 Acronyms 112
CHAPTER 4 Notes 113 California power summary 22 APPENDIX A CHAPTER 5 Summary of technial analyses The Tuolumne River and 30 Hetch Hetchy Reservoir alternatives Bay Area water system (Schlumberger Water Services)
CHAPTER 6 APPENDIX B Alternative water-system 42 Water quality evaluation for Hetch components Hetchy Reservoir alternatives (Eisenberg, Olivieri & Associates) CHAPTER 7 Equivalent water-supply reliability 49 APPENDIX C Memorandum: Hetch Hetchy water CHAPTER 8 and power issues Water-quality analysis 62 (Somach, Simmons & Dunn)
iii Foreword
Douglas P. Wheeler More than a decade ago, the renowned system. Whatever one’s opinion of the and Huey D. Johnson Harvard biologist, E.O. Wilson, spoke merits of the original decision or of of the need of repairing, where possible, federal and state water policies as they the environmental damage which is an evolved over the last century, however, unfortunate legacy of heedless devel- no plan for the restoration of the Hetch opment in sensitive areas. In his seminal Hetchy Valley, no matter how felicitous, book, The Diversity of Life, Wilson urges can be considered without addressing that we now “go beyond mere salvage to this dependency on the current system. begin the restoration of natural environ- Indeed, restoration advocates bear ments, in order to enlarge wild popula- the burden of proving that alternatives tions and stanch the hemorrhaging of can be made to work. In accepting this biological wealth.” challenge, Environmental Defense, with To a remarkable extent, 21st-century the help of three distinguished consult- Americans have taken Wilson’s updated ing firms, has produced an extraordi- definition of the public trust to heart, narily thorough and thought-provoking and are everywhere engaged in restora- assessment. As veterans of many an tion projects small and large. Some are environmental controversy, we know audacious indeed, striving to reweave that a lengthy dialog must precede any and restore entire habitats on a scale as decision as momentous as the proposal large as Florida’s Everglades, the Chesa- to restore Hetch Hetchy and that the peake Bay, and San Francisco’s Bay- legitimate concerns of all stakeholders Delta Estuary; others are as small as the must be addressed. We welcome the watersheds of local, but nonetheless publication of this report as an essential productive, creeks and tributaries. These element of that dialog, coming at a time projects result from the growing con- when the San Francisco Public Utilities viction that we have the capability, if not Commission must make costly long- the obligation, to make amends for past term decisions about upgrades to its mistakes, using newfound scientific Hetch Hetchy infrastructure. It is also knowledge and advanced technologies. time, as E.O. Wilson suggests, to begin We think of Wilson’s words as we “reweaving the wondrous diversity of life read this report on the development of that still survives around us.” feasible alternatives to the water supply and hydroelectricity, which are currently Douglas P.Wheeler and Huey D. Johnson provided by the O’Shaughnessy Dam on both served as Secretary for Resources, State the Tuolumne River in the Hetch Hetchy of California, in 1991–99 and 1978–82, Valley. Almost from the time of its con- respectively. Doug Wheeler presently chairs struction early in the last century, vision- the National Park System Advisory Board aries have argued for the restoration of and was formerly Executive Director of the Hetch Hetchy to its splendid natural Sierra Club and co-founder and President condition. Perhaps they can be excused of American Farmland Trust. Huey for having given short shrift to the Johnson was formerly the Western Regional social and economic consequences of so Director of The Nature Conservancy and bold a vision: millions of northern Cali- founder and President of the Trust for fornians have come to depend on the Public Land. He presently leads the water and power of the Hetch Hetchy Resource Renewal Institute.
iv Acknowledgments
Environmental Defense thanks the TREWSSIM model developed for the many individuals who have made study. In addition, we thank Dr. Richard financial contributions large and small Ferguson of the Center for Energy to the completion of this report. We also Efficiency and Renewable Technologies thank all individuals who have made and Dr. James Bushnell of the U.C. contributions to the report’s final text. Energy Institute for reviewing the study’s We particularly acknowledge the hydropower-replacement analysis. And significant contributions made by three we thank Dr. George Tchobanoglous and independent technical consultants— Dr. Bob Cooper for their review of EOA’s Schlumberger Water Services; Eisenberg, contributions on water quality. All state- Olivieri & Associates (EOA); and ments of fact and opinion found in the Somach, Simmons & Dunn. They text of this report, however, are ours alone report their detailed findings in and we bear full responsibility for them. Appendices A, B, and C, respectively. We are very thankful as well to All interpretations of their findings in Janice Caswell for her art direction, this report are our own. Bonnie Greenfield for her design and We owe special thanks to the San production efforts, and Steven J. Marcus Francisco Public Utilities Commission, for his editing of the manuscript. We the Bay Area Water Supply and Con- also thank the many others—particu- servation Agency, the Turlock Irrigation larly Marcia Aronoff, Melinda Taylor, District, and the Modesto Irrigation Pam Vivian, David Yardas, Johanna District, all of whom helped us prepare Thomas, Jennifer Witherspoon, a more complete and accurate study. Meredith Niess, Kate Larsen, Brandon While the SFPUC, MID, and TID Hunter, Elaine Capers, Terrel Hutton, provided helpful comments, their Allison Cobb, Tim Connor, Joel assistance in no way endorses the study’s Plagenz, and Peter Klebnikov—who findings and recommendations. were instrumental in the report’s proof- Many state- and federal-agency staff reading, editing, photo research, data provided data, information and photo- collection, and other elements of pro- graphs for use in this report, for which duction. We owe special thanks to we are very grateful. We also thank the Yolanda Cazessus for her exceptional Bancroft Library for providing access to commitment and patience throughout the O’Shaughnessy Collection, which the report preparation. Finally, we thank contained many of the photographs those who helped more broadly on this used in this report. project, including Fred Krupp, Tom We very much appreciate the helpful Belford, Steve Cochran, Colin Rowan, comments received from Dr. Jay Lund Victoria Markell, Joy Carrigan, and and Sarah Null of U.C. Davis, on the Lisa Domitrovich.
v About the authors
John Balbus is a physician and director Sacramento and San Joaquin Delta of the health program at Environmental estuary ecosystem and its Central Valley Defense. He has published on a range of and Sierra Nevada watershed. She is a topics including health consequences of committee member of the State Water global climate change, susceptibility to Plan update and the California Urban waterborne contaminants, microbial risk Water Conservation Council. She has a assessment and lead neurotoxicity. Balbus master’s degree in environmental science received his undergraduate degree in and management from the University of biochemistry from Harvard University, California, Santa Barbara. his M.D. from the University of Penn- Spreck Rosekrans specializes in hydro- sylvania, and a master’s in public health logic modeling and operations analysis degree from Johns Hopkins University. to improve the timing and volume of Tom Graff co-founded the California flows to ecosystems in California and the office of Environmental Defense in 1971. West. His work has improved fishery For over three decades, he has worked to and wetland habitat along the Colorado protect and restore California rivers, wet- River in the Grand Canyon, on the lands, lakes and estuaries. Graff played Trinity River in northern California and a central role in the passage in the U.S. in the Sacramento-San Joaquin Bay-Delta Congress of the Central Valley Project watershed. Rosekrans works closely with Improvement Act of 1992, in the sign- water agencies, Indian Tribes and con- ing of the San Francisco Bay-Delta servationists throughout California, and Accord of 1994 and in the formation was Convener of the multi-stakeholder of the federal Bay-Delta Act of 1996. A California Water and Environmental past member of the Bay-Delta Advisory Modeling Forum in 1999. He has a Council, the University of California’s B.A. in Mathematics from the Uni- Agriculture and Natural Resources versity of California, San Diego. Advisory Commission, the National Nancy Ryan is an economist with Research Council’s Commission on Geo- expertise in energy markets and the sciences, Environment and Resources, and health and ecological impacts of energy the Colorado River Board of California, production. Since joining Environmental Graff has also taught at the University Defense in 2001, Ryan has led policy of California’s Boalt Law School and at initiatives focusing on reducing green- Harvard Law School. He has an LL.M. house gas emissions from vehicles and from the London School of Economics power plants, curbing air pollution and a J.D. from Harvard Law School. from diesel engines and restoring rivers Ann Hayden researches and analyzes affected by hydropower operations. Previ- water operations and policies through- ously, Ryan worked as a consultant on a out the state and works to protect aquatic diverse array of energy-related projects. resources and habitats in the West. Since 1996, Ryan has also taught applied Hayden coordinates with conservation economics courses at U.C. Berkeley’s partners and other interests to achieve Richard and Rhoda Goldman School sustainable water management solutions of Public Policy. She has a Ph.D. in that restore ecological health and water economics from the University of quality throughout the San Francisco- California, Berkeley.
vi Executive summary
Paradise lost Hetch Hetchy Valley lies along the Imagine yourself in Hetch Hetchy on a western slope of the Sierra Nevada sunny day in June, standing waist-deep mountains, 160 miles east of San in grass and flowers, while the great pines Francisco and 3700 feet above sea level. sway dreamily . . . These are the words The same glacial forces that sculpted of the great naturalist John Muir, who Yosemite Valley created Hetch Hetchy. first visited Hetch Hetchy Valley in Glaciers gouged the Tuolumne River 1871. He praised it as a twin of nearby canyon, leaving towering granite domes Yosemite, with comparable soaring cliffs and cliffs jeweled by waterfalls that once and cascading waterfalls. plunged hundreds of feet to the grassy Today, we have to take Muir’s valley floor. word for it. Hetch Hetchy Valley lies Native Americans lived in Yosemite submerged under 300 feet of water, for millennia before the 1849 Gold a vast storage tank for the Bay Area. Rush lured prospectors to the area. Congress preserved Hetch Hetchy Soon, homesteaders began arriving. Valley in 1890 as part of Yosemite Alarmed by this onslaught, John Muir National Park. But just two decades and other naturalists lobbied Congress later, in a stunning political turn- to protect Yosemite. In 1864 President around, Congress allowed Hetch Hetchy’s Lincoln signed a bill to preserve the area Tuolumne River to be dammed, despite for “public use, resort, and recreation . . . a nationwide outcry. It was the only inalienable for all time.” In 1890, dam of its scale ever erected inside a Yosemite National Park was born, en- national park. compassing Hetch Hetchy Valley. TIM CONNOR John Muir called Hetch Hetchy the “wonderfully exact counterpart” of Yosemite, likening its waterfalls and sheer granite walls to those in its more famous twin.
vii The ink on the park bill had hardly Today, there is a chance to return dried, before San Francisco proposed Hetch Hetchy to the American people. damming Hetch Hetchy Valley as a San Francisco has begun a $3.6 billion water source. Teddy Roosevelt’s Capital Improvement Program to administration denied the City’s repair and modernize its water supply requests as “not in keeping with the system. The overhaul presents a once- public interest.” In 1906, a powerful in-a-lifetime opportunity to modify Yosemite Valley’s Half earthquake and devastating fire struck the system to restore Hetch Hetchy
Dome and John Muir, WWW.QUARTERDESIGNS.COM along with the California San Francisco. The City’s water sup- Valley while continuing to provide Condor, were chosen for plies were ample but useless against safe, reliable water and power. Nearly the California quarter, due to be released in 2005. the fire because quake-damaged pipes a century of innovation has brought failed. Nevertheless, the pro-dam new technologies and options for faction contended that too little meeting these needs. water had allowed the fires to burn out of control. The battle over the dam marked About this report a turning point in America’s attitude In this report Environmental Defense toward natural resources. Where once provides a planning-level analysis for Americans supported unfettered replacing the water and hydropower progress, now many felt some things benefits that the Hetch Hetchy were too precious to lose. The public Reservoir and O’Shaughnessy Dam rallied behind Roosevelt’s initiative to provide. We show how practical, proven preserve the nation’s unique features water storage, conveyance and treatment in a network of national parks, and the alternatives can provide San Francisco a conservation movement, including healthy, reliable and secure supply of John Muir’s Sierra Club, came to life. water that is adequate for current and LIBRARY OF CONGRESS John Muir campaigned to save Hetch Hetchy, arguing that better sites were available to store San Francisco’s water.
viii future needs. We also explain how Three expert consultants assisted hydropower lost as a result of restoring in our analysis: Schlumberger Water the valley can be replaced without Services provided engineering analyses contributing to air pollution or global and modeling assistance; Eisenberg, warming. The alternatives analyzed Olivieri and Associates analyzed water do not comprise all possible options, quality issues; and Somach, Simmons but they do demonstrate that workable &Dunn assessed the legal landscape. solutions for restoring Hetch Hetchy Academic experts provided peer review. Valley exist. The San Francisco Public Utilities We began this study with the Commission, the Bay Area Water premise that all solutions must be tech- Supply and Conservation Agency, and nologically feasible and affordable and the Turlock and Modesto Irrigation must assure a dependable supply of safe Districts also provided information to drinking water. In addition to address- help ensure an accurate report. ing the water and power needs of SanFrancisco and other Bay Area communities that rely on the Tuolumne Ensuring adequate water River, solutions must also protect all supplies for today and tomorrow affected California communities. Most Hetch Hetchy Reservoir is a key com- obviously, any restoration plan must ponent of a water supply system that protect the Turlock and Modesto serves 2.4 million people in the San Irrigation Districts, whose uses of the Francisco Bay Area (see Figure ES-1). Tuolumne River predate and are inter- Hetch Hetchy Reservoir holds 360,000 twined with those of the San Francisco acre-feet of water, slightly less than Public Utilities Commission (SFPUC) 25% of the SFPUC’s total storage and its customers. Of course, a restora- capacity. The reservoir is also the prin- tion plan must also consider the Grove- cipal diversion point for the Tuolumne land area, both as a user of the Tuolumne River water that provides approximately River water and as a gateway community 85% of the SFPUC’s supply. The to the Hetch Hetchy region of Yosemite SFPUC sells about one third of this National Park. water within San Francisco and the Our analysis focuses mainly on rest to other Bay Area communities, alternative ways to move and store which are represented by the Bay Area SanFrancisco’s existing supply of Water Supply and Conservation Agency Tuolumne River water. Environmental (BAWSCA). Defense developed the TREWSSIM The 1913 Raker Act authorized San (Tuolumne River Equivalent Water Francisco to construct a dam in Hetch Supply Simulation) model to evaluate Hetchy Valley and recognized its rights the SFPUC’s system performance under to a portion of the Tuolumne River’s a range of water supply alternatives, flow. The SFPUC shares the Tuolumne with and without Hetch Hetchy with the Turlock and Modesto Irriga- Reservoir. TREWSSIM incorporates tion Districts (TID and MID). The features of both the SFPUC’s plan- Districts do not use Hetch Hetchy ning model HHSM-LSM and the Reservoir, but do share storage with state-federal CALSIM model. The the SFPUC in Don Pedro, a reservoir TREWSSIM analysis addresses not downstream on the Tuolumne River only water supply issues, but also water that holds almost six times as much treatment and hydropower. water as Hetch Hetchy Reservoir.
ix FIGURE ES-1 Overview of SFPUC water system and other Tuolumne River facilities
19 Hetch Hetchy 18 20 15 Valley
17 San Francisco 16 14 7 Yosemite 10 Valley 8 11 13 6 r 5 Ive 1 9 Tuolumn e R 4 12 2 3 S iver an R J ed o erc
a M
q
u i n
Ri ver
1. Peninsula Reservoirs 11. Modesto T ID Canal 2. Tracy Treatment Plant 12. Turlock ID Canal 3. Calaveras Reservoir 13. Don Pedro Reservoir
4. Sunol Treatment Plant 14. Moccasin Powerhouse 5. San Antonio Reservoir 15. Holm Powerhouse Reservoir 6. Coast Range Tunnel 16. Kirkwood Powerhouse HH system pipelines 7. CA Aqueduct 17. Early Intake Reservoir r 8. San Joaquin Pipelines 18. Cherry Reservoir Major canals 9. Delta Mendota Canal 19. Eleanor Reservoir 10. Foothill Tunnel 20. Hetch Hetchy Reservoir Yosemite National Park
Hetch Hetchy Reservoir is part of an extensive system that includes several reservoirs, water treatment plants, hydropower facilities and a 160-mile series of pipelines and tunnels that carries Tuolumne River water from the Sierra Nevada to the Bay Area. Hetch Hetchy Reservoir holds less than 25% of the system's total storage capacity.
Under state law, TID and MID Figure ES-2a provides an overview of have water rights that are “senior” to the SFPUC’s delivery objectives, storage San Francisco’s and are entitled to most capacity and water rights. Figure ES-2b of the river’s flow. San Francisco’s rights provides the same information for the are limited to occasions when the natural TID and MID, and delineates their flow of the river is high and all of the obligation to release flows below Don Districts’ needs are being met. In most Pedro Reservoir to support the lower years, these rights are more than suffi- Tuolumne River and its fisheries. cient for the SFPUC and its customers. In dry years, however, and especially in droughts, the SFPUC’s share of What we propose Tuolumne River flow can’t meet demand. Under our proposal to restore Hetch Because the SFPUC depends on the Hetchy Valley, San Francisco would con- Tuolumne River for 85% of its supplies, tinue to rely on Tuolumne River water it must rely on storage in Hetch Hetchy, for the vast majority of its needs using Don Pedro and its other reservoirs mainly the existing infrastructure. In to ensure reliability for its customers. winter and spring, the river’s natural flow
x would be diverted as it is today. In sum- would allow the SFPUC to make full mer and fall, system reservoirs outside deliveries, with no loss of reliability from Hetch Hetchy would provide enough restoring Hetch Hetchy Valley, in most water for all users, while leaving ade- years. This report also includes a prelimi- quate “carryover” supplies as insurance. nary investigation of the feasibility of The most obvious means of assuring diverting San Francisco’s share of Tuo- reliable delivery of Tuolumne River lumne River water further downstream, water would be to tap the SFPUC’s from the Sacramento-San Joaquin Delta. storage in Don Pedro Reservoir, which San Francisco shared the cost of represents nearly double the volume of constructing Don Pedro Dam with the Hetch Hetchy. Presently, San Francisco Turlock and Modesto Irrigation Districts uses its storage at Don Pedro Reservoir and, as a result of a complex set of agree- only as a “water bank,” from which it ments with the Districts, has access to repays the Turlock and Modesto Irri- storage in Don Pedro that effectively gation Districts, with whom it shares provides it with the ability to divert the reservoir’s storage, when it diverts Tuolumne River water even when flows the Districts’ supplies upstream in Hetch are below the levels at which it has Hetchy Valley. Accessing SFPUC’s recognized water rights. Currently the water bank will require an intertie to be City has no infrastructure to convey its built connecting its San Joaquin pipe- Don Pedro supplies to the Bay Area, nor lines to the Don Pedro Reservoir. This has it established the legal right to build
FIGURE ES-2 Delivery objectives, storage capacity, and water rights
(a) San FranciscoŁ (b) Turlock and ModestoŁ Public Utilities Commission Irrigation Districts 2000 2000
■ Lower Tuolumne River flow requirements ■ Consumptive use 1500 1500 Hetch Hetchy
BayŁ 1000 Area 1000
Cherry- Eleanor Thousands of acre-feet Thousands of acre-feet 500 500 Don Pedro Water Bank
0 0 Demand TotalŁ Water rightsŁ Water rightsŁ Water rightsŁ Demand Don PedroŁ Water rights Water rights WaterŁ surfaceŁ annualŁ droughtŁ minimumŁ storage annualŁ droughtŁ rightsŁ storage averageŁ averageŁ year (1977) average average minimumŁ (1922-1994) (1987-1992) (1922-1994) (1987–1992) year (1977)
(a) In most years San Francisco’s water rights are enough to meet its customers’ needs. The SFPUC relies on storage in Hetch Hetchy, Don Pedro and other reservoirs to provide insurance against droughts, when its water rights are inadequate. (b) The Turlock and Modesto Irrigation Districts share the Tuolumne River with San Francisco, holding “senior” water rights that predate the City’s. The Districts store water in Don Pedro for irrigation and domestic use and release flows below the reservoir to support the lower Tuolumne River and its fisheries. Source: SFPUC
xi FIGURE ES-3 Sources of SFPUC (a) Current delivery objective water supply with WITHŁ WITHOUTŁ and without HETCH HETCHYŁ HETCH HETCHYŁ Hetch Hetchy RESERVOIR RESERVOIR Reservoir (a) Without Hetch Hetchy Reservoir, the SFPUC could meet customer demand in most years AdequateŁ using Tuolumne River precipitationŁ
water and runoff cap- (4 out of 5 years) tured in existing Bay Area reservoirs. In the driest 20% of years, a small amount of additional water would be needed. (b) The SFPUC can satisfy projected future demands without Hetch Hetchy Reservoir in all but the driest years if key
elements of the CIP are 18% built. In most years, local Critically dryŁ (1 out of 5 years) supplies and Tuolumne River water diverted directly from the river or stored in Don Pedro Reservoir would be adequate. During (b) Future delivery objective with CIP components critically dry years, the SFPUC would also draw WITHŁ WITHOUTŁ on Tuolumne River water HETCH HETCHYŁ HETCH HETCHYŁ stored off-stream in an RESERVOIR RESERVOIR expanded Calaveras Reservoir and a small reserve of additional supplies.
AdequateŁ precipitationŁ
(4 out of 5 years)
14% Critically dryŁ (1 out of 5 years)
Tuolumne sources Other sources ■ Tuolumne River flow diversion ■ Existing Bay Area storage ■ Hetch Hetchy storage ■ Expanded local storage ■ Don Pedro storage Ł ■ Existing shortages
■ New supplies
xii any such infrastructure. To construct an directly from the river or stored in Don intertie between Don Pedro reservoir and Pedro Reservoir would be adequate to the SFPUC’s conveyance system would serve the SFPUC’s customers in most require the cooperation of the Turlock years. In critically dry years the SFPUC and Modesto Irrigation Districts. would also draw on Tuolumne River Under either of these alternatives, water stored off-stream in an expanded San Francisco could still take much of Calaveras Reservoir, but without storage its water supply directly from high up at Hetch Hetchy would need to tap a on the Tuolumne River. These “run-of- small reserve of additional supplies. river” diversions would take place just a An expanded Calaveras Reservoir few miles downstream from Hetch and a fourth San Joaquin pipeline are Hetchy Valley at the Early Intake elements in San Francisco’s CIP that Diversion Dam, where the SFPUC would help provide increased water diverted all water to the Bay Area until supplies to meet projected increases in 1967. The rest of the supply, as is now demand. Environmental Defense does the case, would be provided by diversions not assume that these elements will of stored water that would be sent to the be expanded or take any position at Bay Area during periods of low flows, this time on the expansion. This report typically the late summer and fall simply uses these elements of the CIP months. The main difference would be to project one possible future for the that water awaiting shipment to cus- SFPUC against which to compare alter- tomers would be held at Don Pedro natives for restoring Hetch Hetchy Valley. Reservoir instead of in Hetch Hetchy Several cost-effective and dependable Valley. Under a Delta Diversion alter- sources are available to augment existing native the stored water would move water supplies during critically dry through the natural river channel years. Although they would be more instead of San Francisco’s pipelines. costly on a per-unit basis than the bulk As illustrated in Figure ES-3a, of San Francisco’s water, the incremental TREWSSIM modeling shows that supplies would only be required in one without Hetch Hetchy Reservoir the in five years, and even within those years SFPUC could still provide full deliveries would constitute only 14–18% of total to its customers in most years using supply. So their overall contribution to Tuolumne River water and runoff the cost of water in the Bay Area over captured in its existing Bay Area the long term would be low. This report reservoirs. In the driest 20% of years, focuses on three supplemental water additional supply would be necessary to sources, all of which are being used by fully meet demands without reducing water agencies throughout California storage to an unacceptable level or and have been investigated by the San imposing “shortages,” as the SFPUC has Francisco Public Utilities Commission: done during recent droughts. The modeling also shows that if key • Increased local storage. San elements of the Capital Improvement Francisco is investigating expanding Program (CIP) are built, the SFPUC Calaveras Reservoir in its Capital can also fully satisfy projected future Improvement Program and has identi- demands without Hetch Hetchy fied other potential sites for local Reservoir in all but the driest years. reservoir expansion. In recent years, Figure ES-3b shows that local supplies the Metropolitan Water District and and Tuolumne River water diverted Contra Costa Water District have
xiii built Diamond Valley and Los could not be operated without the Vaqueros reservoirs, respectively, near Hetch Hetchy Reservoir” and made a their own service areas to enhance series of recommendations for further water supply reliability. water quality analyses that should be • Groundwater exchange programs pursued concurrently with the investi- with agricultural agencies. San gation of water supply alternatives. Francisco has identified groundwater The SFPUC has been granted a rare exchange as a potential source of exemption and is not presently required supply but has not yet successfully to filter its Tuolumne supplies. Flows that completed any agreements. Santa are diverted downstream of Yosemite Clara Valley Water District, Alameda National Park are likely to have higher County Water District, Zone 7 and concentrations of some constituents, Metropolitan Water District have necessitating additional treatment. contracted with Semitropic or Arvin- Based upon available data, EOA found Edison Water Storage Districts to that with the addition of existing water increase reliability in dry years. treatment technologies, the water qual- ity predicted to result from the Don • Dry-year purchases from irrigation Pedro or Sacramento-San Joaquin Delta districts. San Francisco identifies systems should be comparable or superior water transfers in its Water Supply to the quality of water from the current Master Plan as a source of supply but Hetch Hetchy system. In particular, has not yet successfully completed filtration should reduce the presence any agreements. Recent long-term of giardia and cryptosporidium to levels transfer agreements throughout lower than those present in the current California have helped to shore up system. The addition of a water filtra- supplies for a variety of urban agen- tion system also provides an extra layer cies. The most widely publicized of protection and, along with other is the historic agreement in 2003 precautions in the watershed, would between the Imperial Irrigation protect customers from contamination District and the San Diego County resulting from increased recreational use Water Authority. of the restored valley. While public safety is paramount, other water quality characteristics such Providing safe water for all as taste, odor and appearance also matter Safe,clean drinking water is essential to consumers. Adding filtration to the to life. Any plan to restore Hetch treatment process may reduce the amount Hetchy Valley must assure Bay Area of chemicals added in the disinfection residents who drink Tuolumne River stage. Augmenting filtration with addi- water that the quality of their water tional treatment steps, especially for will not be diminished if it is stored Delta supplies, will not only ensure the and diverted further downstream. effectiveness of filtration but could also Based on a review of raw water quality yield finished water that closely matches data from potential replacement other aspects of existing water quality. sources, our consultants Eisenberg, Currently San Francisco uses its Olivieri and Associates determined Tracy and Sunol water treatment plants that “there does not appear to be any to filter and disinfect supplies stored technical reason that the SFPUC in local reservoirs. As part of the CIP, Hetch Hetchy water supply system SanFrancisco is already planning an
xiv expansion of its Sunol plant. All of the Developing clean energy restoration alternatives considered in alternatives for Hetch Hetchy this study envision that San Francisco’s power entire water supply would be conven- When Congress authorized San tionally treated, including filtration. Francisco to dam Hetch Hetchy Valley, Our analysis focused on water treat- hydropower was the primary energy ment technologies in use today in the source for California’s rapidly growing United States. However, significant electricity system. As part of its grant advances are being made in this field, to San Francisco, Congress directed the and it is possible that new water filtra- city to develop hydroelectric facilities tion methods will soon cost-effectively “for the use of its people.” Energy not provide even cleaner water than is pro- used by the City was to be sold to TID jected using existing technology. It is and MID at cost. Since it first began also possible that even if San Francisco generating electricity in 1918, San continues to store its water in Hetch Francisco has steadily expanded its Hetchy Valley, the Environmental Pro- hydroelectric facilities in the Tuolumne tection Agency may eventually require watershed. Today it operates three power- the City to filter its entire supply. Such houses that generate electricity from the adevelopment would lower the total Tuolumne River and its tributaries. cost of restoring the valley by reducing Hetch Hetchy hydropower accounts incremental treatment costs for water for a tiny share of California’s electricity stored and diverted lower in the supply, just 0.6% of total statewide gen- Tuolumne River watershed. eration in 2002, but it is an important and TIM CONNOR Without storage at Hetch Hetchy, the SFPUC would still derive most of its water supply from the Tuolumne River. Constructing a new intertie at or below Don Pedro Reservoir (shown above), would allow the City to have access to its supplies in the reservoir. To protect against contamination, the SFPUC would need to filter all of its water, as virtually all U.S. communities already do. The available data indicate that conventional treatment methods would yield water comparable or superior to the current quality of water from the current SFPUC water system.
xv inexpensive energy source for those who Don Pedro powerhouse could also use it. In recent years, the City has used decrease slightly (1.4%) or increase by as about one third of the Hetch Hetchy much as 10%, depending on how much hydropower to serve public facilities such water San Francisco withdraws from the as the airport, San Francisco General Tuolumne River and whether the Hospital and city offices. Most of the rest diversions take place above or below has been sold to TID and MID. Don Pedro Dam. Restoring Hetch Hetchy Valley If the valley is restored, the SFPUC’s would reduce generation from two of the Tuolumne River hydroelectric plants SFPUC’s three Tuolumne River power- would still provide enough energy to houses. On an annual basis, the forgone meet current municipal needs on an energy could average up to 690 million annual basis in all but the driest years kWh per year, about 40% of average (see Figure ES-4). In the latter half of annual generation. With modifications the year, San Francisco would need to to the SFPUC’s facilities, the average increase the amount of energy that it annual loss could be as low as 339 mil- already purchases to augment hydro- lion kWh per year, just 20% of average electric output in order to meet its own annual generation. The SFPUC would needs. In dry years, the City might need lose relatively little valuable on-peak to buy additional power at other times energy: most of the lost hydroelectric as well. Less surplus energy would be output would be base-load energy, which available to sell to TID, MID and others. is relatively inexpensive to replace. Hydro- Several options are available to electric production at TID and MID’s replace—or eliminate the need for—
FIGURE ES-4 Projected annual generation vs. 2002 uses of Hetch Hetchy hydropower
2500 ■ Power sales (others) Average annual energy production ■ Power sales (TID) ■ Base ■ Restored-maximum ■ Restored-minimum ■ Power sales (MID) 2000
1500
1000 Millions of KWh
500 San Francisco City/County use
0 Wet Above normal Below normal Dry Critical Uses of energy (2002) Water year type
Hetch Hetchy hydropower accounts for a tiny share of California’s electricity supply, but is a valuable energy source for San Francisco and the Turlock and Modesto Irrigation Districts. If the valley is restored, the SFPUC’s powerhouses would still provide enough energy to supply the City’s current needs in all but the driest years. The City would have to buy additional power at times, and less energy would be available to sell to the Districts and others. Renewable energy and investments in energy efficiency can cost-effectively fill the gap without increasing air pollution. Source: US DOE Form EIA-861 and EIA-412
xvi the lost energy. Demand-side measures, The amount of hydropower that would such as increased investments in energy be lost as a result of restoring the valley is efficiency and expansion of dynamic dwarfed by the potential to save energy pricing programs, offer cost-effective by improving efficiency. The power loss means of displacing both the energy also appears negligible when one con- and capacity needs currently met by siders the potential to develop new sources the SFPUC’s hydropower facilities. of renewable energy, and the recent New supplies could be obtained by additions to California’s fleet of power purchasing power from or constructing plants. More than a dozen new gas-fired new generating facilities. Renewable power plants with a typical capacity of energy, especially solar and wind 500 MW have entered service in Cali- power, are the greenest new supply-side fornia since 2001, and less than 20% resources. New highly efficient gas-fired of the annual output of just one of them plants are the best available fossil-fueled could replace all of the foregone energy. alternative. In most parts of California, new gas-fired plants must install state- of-the-art pollution controls and offset Costs of replacing water all of their emissions of smog-forming and power chemicals and other criteria pollutants The cost of replacing the water and power by finding ways to cut an equivalent services provided by O’Shaughnessy amount of pollution from other sources. Dam ranges from $500 million to While not currently required by law, $1.65 billion. Figure ES-5 shows the inexpensive approaches are available to range of estimated water and power offset greenhouse gas emissions as well. replacement costs developed for each
FIGURE ES-5 Estimated range of water and power replacement costs
Water supplyŁ replacement alternatives
Surface storage
Groundwater exchangeŁ (Tuolumne source)
TransferŁ (Tuolumne source)
Groundwater and transferŁ (Tuolumne source)
Transfer or groundwaterŁ (Delta source)
0 500 1,000 1,500 2,000 Millions of 2004 dollars
Our study focuses on the most challenging and expensive components of restoration—the costs of replacing the water and power services Hetch Hetchy Reservoir provides. Cost estimates vary depending on where replacement water supplies are diverted and stored. Costs also depend on key uncertainties, including the future level of demand, whether the SFPUC can continue to avoid filtering its entire water supply, the capital costs of restoration components, and how much restoration reduces hydropower generation. Devising an equitable approach to sharing these costs will be an essential element in developing a plan to finance the valley’s restoration.
xvii restoration alternative under a set •Whether the SFPUC’s delivery objective of scenarios that account for critical will increase as currently forecast from uncertainties. Estimates of the annual 260 to 303 million gallons per day. and capital costs of water and power replacement alternatives follow usual While this study does not fully conventions regarding discounting, in account for all costs, it does encompass which future costs are included in the the most challenging and costly com- overall estimate at lower costs depend- ponents of restoration. We did not ing on how far in the future they will attempt to estimate the cost of removing occur. A discount rate of 5% was used to O’Shaughnessy Dam, restoring Hetch convert cash flows to present values. Hetchy Valley or building facilities to Each alternative considered in this accommodate the visitors from across study includes two key components— the United States and around the world an expanded water treatment plant and who would flock to see the valley and its construction of an intertie connecting unprecedented restoration. the San Joaquin Pipeline with the lower We also did not try to place a mone- Tuolumne River. The alternatives differ tary value on the many benefits of a in the components they include for restored valley. These would accrue to replacing existing water supply in dry generations of future visitors who would years, since multiple workable solutions come to Hetch Hetchy to hike, climb, are available. picnic and revel in the scenery. Tuolumne Many factors will influence the cost county businesses along Highway 120 of implementing the water supply alter- would profit from increased visitation. natives considered in this report, so it Also sharing the benefits would be people is difficult to predict which alternative who never set foot in the valley but take will be the most cost-effective or how pleasure simply in knowing that it has much its various elements will cost. been restored. Indeed, in government For the purposes of this initial analysis, sponsored cost-benefit analyses of recent we identified some critical uncertain- proposals to restore rare landscape ties that are most likely to have the features such as Olympic National largest impact on total costs. The esti- Park’s Elwah River and California’s mated cost of each alternative was then Mono Lake, estimates of “existence computed under a variety of scenarios value” have significantly exceeded the that take these key uncertainties into projected value to direct users. account:
•Whether the loss in hydroelectric Financing restoration power from the SFPUC’s Tuolumne Our analysis focuses on estimating costs River powerhouses is at the high or low to society at large and does not address end of the range of estimated values; who should pay these costs. Clearly, •Whether the capital costs for new determining who should pay these costs infrastructure are in the high or low will be a major factor in developing a range of estimated values; plan to finance the valley’s restoration. The benefits of recovering a vital part of •Whether the SFPUC will continue one of America’s most revered national to use only chloramine to treat water parks will be shared by millions of diverted from the Tuolumne or begin people nationwide and around the to filter all of its supplies; globe. The valuable water and power
xviii tution’s injunctions against the un- reasonable use, diversion or waste of water, seem to require an ongoing con- sideration of alternatives that might lead to the valley’s restoration. With public support, the opportunity to restore Hetch Hetchy Valley can be pursued in a variety of ways, including through the Corps of Engineers’ review of San Francisco’s Capital Improve- ment Program. Legal challenges that must be overcome include the following: •Congress must amend and modern- ize the Raker Act and authorize an altered set of purposes for using national park land. BANCROFT LIBRARY The Tuolumne River once meandered through wildflower-dotted meadows and • The State of California likely will need groves of oaks, pines, and firs. A 1988 study by the National Park Service found that if the valley is drained Hetch Hetchy’s plant and animal life would come to affirm San Francisco’s water use, back with some human assistance. This hand-tinted photograph suggests how diversion and storage rights in a new a restored Hetch Hetchy Valley might appear. configuration and otherwise assure San Francisco, Turlock and Modesto Irriga- services now provided by Hetch Hetchy tion Districts, BAWSCA, and others Reservoir are shared by a much smaller that a fair resolution of the myriad number of Bay Area and Central Valley issues raised by such major changes in residents, and they stand to lose the San Francisco’s water delivery and most from restoration if they are not power generation system will be legally compensated for those losses. required prior to restoration. As restoration alternatives are further • The affected entities—San Francisco, explored and refined in the public its customers, the Districts and others process, a variety of funding sources that have long shared the Tuolumne should be examined to find an equitable River’s bounty—will need to negotiate way to pay for restoration. Sources could new arrangements that respond to the include federal and state governments, legitimate water and power demands current users of Tuolumne River water of all. and hydropower, user fees from park visitors and philanthropic donations. • Those who will benefit from the valley’s restoration will need to share the cost of making it possible. The state legisla- Legal and institutional ture (or the state’s voting public) and challenges and opportunities the U.S. Congress will be asked not Substantial legal and institutional only to promulgate the changes in law hurdles must be overcome for restora- and to provide the necessary assurances tion to be successful. On the other that should accompany restoration, but hand, a variety of authorities, including also to share significantly in the fund- the Raker Act itself, the public-trust ing of the arrangements required to doctrine, and the California consti- provide those assurances.
xix ADSWORTH ATHENEUM ADSWORTH W Albert Bierstadt’s grand paintings of western landscapes, including this 1870s view of Hetch Hetchy Valley, allowed a generation of Americans to envision the region’s natural wonders at a time when travel was arduous and prohibitively expensive. Today millions of visitors flock to Yosemite National Park each year and many would stop to see the restored valley.
Paradise regained? Conclusions 50 years, the valley would begin to The idea of restoring Hetch Hetchy appear as it once did. Over the next Valley is not new. In 1987, President century, trees would mature, the bath- Reagan’s Interior Secretary, Donald tub ring on the valley’s walls would Hodel, proposed dismantling gradually fade away and Hetch Hetchy O’Shaughnessy Dam. The following would recover its natural glory. year the National Park Service Nonetheless, returning Hetch Hetchy produced a report investigating a Valley to the American people will require range of alternatives for restoring the a broad public effort. This study serves valley. The report concludes that a as a starting point. We call on local, restored valley would eventually state and federal officials to develop our rebound. Within five years, mammals, findings and involve the public in a plan amphibians and reptiles endemic to the to restore the valley. With support from area would return to the valley. After a dedicated public, imagination and a 10 years, meadows, willow thickets willingness on the part of officials to and conifer groves would begin to work together, perhaps an American resume their original pattern. After paradise can be regained.
xx CHAPTER 1 Introduction
Imagine an earthly paradise where Hetch Hetchy Valley in 1890 as part of waterfalls cascade off soaring granite Yosemite National Park. But in 1913, cliffs into flowering mountain meadows, after a bitter public debate, Congress where groves of pine, fir and oak shade sacrificed Hetch Hetchy: it allowed the the banks of a meandering river and Tuolumne River to be dammed at the where life all around is in harmony. valley’s narrow western end, and the val- Such a scene greeted naturalist John Muir ley to then be inundated with 117 billion upon his first visit to Hetch Hetchy gallons of water. The proceedings that Valley, which he called “one of nature’s culminated in the creation of this reservoir rarest and most precious mountain marked a turning point in the nation’s temples.” Today this glory is long gone. attitude toward natural resources. In Hetch Hetchy now serves as a giant Wilderness and the American Mind, storage tank for the San Francisco Bay Roderick Nash notes, “For three area, and lies entombed under 300 feet centuries, [Americans] had chosen of water. civilization without any hesitation. By In one of its first official acts to pro- 1913 they were no longer so sure.” tect nature, the U.S. Congress preserved While Hetch Hetchy’s O’Shaughnessy Dam—the only major dam ever built FIGURE 1-1 within a national park—has long been Hetch Hetchy Valley location within Yosemite National Park justified as an irreplaceable component of San Francisco’s water-supply system, the controversy surrounding its existence has never disappeared. And now an his- toric opportunity has arisen to revisit that nearly century-old decision. As SanFrancisco embarks on a $3.6 billion program to upgrade its water system, the time is right for a rigorous exploration of alternative water-supply options. The
Hetch Hetchy Valley alternatives outlined in this report, we assert, could cost-effectively replace the San Francisco water and power provided by the Hetch Hetchy Reservoir and allow the valley to Yosemite Valley be restored, bringing one of America’s most splendid places back to life.
Paradise regained, step by step In 1987, Donald P.Hodel, Secretary of the Interior under President Reagan, proposed dismantling O’Shaughnessy Dam, and in a report published a year later, the National Park Service examined ■ Yosemite National Park a range of alternatives for restoring the valley. The report concluded that after
1 draining the reservoir over a five-year vegetative cover would be complete period, relatively few sediments would and recolonization of animals and re- remain. Before long, the Tuolumne River establishment of habitat would con- would reoccupy its original channel, and tinue. Within a century, the conifer native vegetation could be planted along- forest would closely resemble that of the side. Five years later, small mammals, Yosemite Valley; ponderosa pines and amphibians and reptiles once prevalent incense cedars, for example, would be in the area would have returned to the 125 to 150 feet high (see Restoring Hetch valley, and within 10 years its meadows Hetchy: a timeline). would be restored with native plant At present, however, the Hetch communities. Over a 50-year period, Hetchy Reservoir is a major component
Restoring Hetch Hetchy Valley: a timeline
Five years: As areas become exposed and are planted annually, vegetation will rapidly cover the valley floor. Within the first few years, grasses, sedges and rushes will appear. In those areas planted during the first year, conifers and black oaks will reach heights of 15 feet and 6 feet, respectively. Streamside habitat consisting of willow thickets and alders will begin to return, both naturally and through planting efforts. As the water level goes down, small mammals, amphibians and reptiles will explore the valley. As herbaceous forage becomes available and the dry valley floor provides travel paths, black bear and deer will begin to use the valley; meanwhile, populations of bald eagles will increase. 10 years: Plant communities will resume their original patterns; for example, meadows will again appear as meadows. In the higher elevations of the valley, the thin layer of sediments will be eroded, resulting in coarser soils and therefore restoration of more natural habitats. Streamside habitats will feature willow thickets and alder clumps. Small mammals, amphibians and reptiles will reoccupy the valley, with those species faced with physical barriers receiving assistance. As foraging and breeding habitats for mammals become available, populations of predators and birds will increase. 50 years: Boundaries for most plant communities will stabilize, in close resemblance to those originally present in Hetch Hetchy Valley. Prescribed burning, initiated after 20 years, will prevent excessive conifer encroachment on oak woodlands and meadows, thereby maintaining a more natural composition of species. Suitable habitat for peregrine-falcon prey, which decreased with the loss of the reservoir, will completely recover, and deer fawning will begin in the valley. 100 years: The conifer forest will closely resemble that of the Yosemite floodplain. Ponderosa pines and incense cedars will be 125 to 150 feet high, and maturing oak woodlands will be present. In general, animal population and distribution will closely approximate the historical setting. 150 years: The entire valley will very much resemble the pre-flooded valley, and forest and woodland communities will be nearly mature. Note: This information summarizes the moderate-management scenario of the National Park Service’s 1988 report Alternatives for Restoration of Hetch Hetchy Valley Following Removal of the Dam and Reservoir.
2 of a water system that supplies 2.4 water-supply and hydropower opera- million people. This water, renowned for tions of the San Francisco Public Utili- its high quality, receives only minor ties Commission (SFPUC); and the treatment and is one of the very few recreational and ecosystem-restoration unfiltered systems still permitted to activities related to the river. operate in the United States. Releases The remainder of the report presents from the reservoir also generate valuable and analyzes ways of restoring Hetch hydropower. Thus the first step to Hetchy Valley. Chapter 6 provides cost restoring Hetch Hetchy Valley is the estimates of alternative components of development of a plan to replace the water-supply systems. Chapter 7 presents reservoir’s significant water-supply, results from computer-based simulations water-quality and hydropower benefits. of the SFPUC’s operations that show This report documents a systematic how incorporating these alternatives can exploration of that challenge and offers obviate the need for the Hetch Hetchy a set of explicit recommendations for Reservoir while maintaining, even meeting it. improving, the reliability and safety of This report shows how a few key the water supply. Chapter 8 then offers projects within San Francisco’s $3.6 bil- abrief overview of water-quality and lion Capital Improvement Program treatment issues, together with estimates could not only improve the City’s ability of the unit costs of treating water from to deliver water but also allow for the alternative sources. Chapter 9 explains ultimate restoration of Hetch Hetchy how restoring Hetch Hetchy Valley Valley. These projects include the would affect power generation and expansion of the Calaveras Reservoir revenues, considers available substitutes near Fremont to more than four times for the forgone energy resources, and its present size, an increase in the capacity provides estimates of replacement costs. to move water across the San Joaquin Chapter 10 integrates the cost estimates Valley, and the enlargement of the Sunol developed in the preceding chapters, and Water Treatment Plant. presents a range of discounted present values for the total cost of replacing present water and power services. Chap- Organization of the report ter 11 discusses this project’s legal and Following this introduction’s brief dis- institutional ramifications. Finally, cussion of the purpose and scope of Chapter 12 summarizes our findings our study, several chapters provide back- and recommendations, and proposes a ground information on Hetch Hetchy public process that the SFPUC and Valley and the water and power services other stakeholders, with the support of that it now provides. Chapter 2 presents state and federal governments, should an overview of the natural history of follow in developing a restoration plan. the valley, the events that led to its dam- ming and flooding, and the emerging discussion on restoring it. Chapters 3 Scope of the report and 4 outline California’s current water This report is intended to lay the ground- and power systems, respectively, and work for further investigation into re- describe options for meeting projected storing Hetch Hetchy Valley. While it increases in demand. Chapter 5 surveys does not claim to analyze all possible the Tuolumne River and its uses through alternatives, the report concentrates two sets of discussions: the current on what we consider to be the most
3 viable—those that maintain the use O’Shaughnessy Dam within Yosemite of Tuolumne River water but divert it National Park. Each consulting group farther downstream, outside the boun- prepared a full account of its findings, daries of Yosemite National Park. which are included as appendices to Our analysis considers both current this document; Environmental Defense delivery objectives and the SFPUC’s summarizes those findings within the initially projected increased delivery main text. objectives for 2030. The City of San Francisco and its customers are presently engaged in comprehensive analyses of An opportune time for the potential for increased implementa- collaboration tion of proven water-use efficiency This report shows that there are a measures to decrease future demand. number of feasible and cost-effective The results of these analyses should alternatives to storing water in Hetch guide the development of a cost-effective Hetchy Valley. Moreover, Environ- and environmentally-protective water mental Defense believes that the supply system. present—as San Francisco embarks on a Beyond referring to the 1988 report fundamental upgrade of its water of the National Park Service, this study system—is an opportune time to does not address the actual physical consider these alternatives. restoration of Hetch Hetchy Valley or Any effort to bring back Hetch how to manage it afterward. Similarly, Hetchy Valley must respect the rights analysis of the restored valley’s signifi- and concerns of people who use the cant economic impacts in general, or of Tuolumne River, as well as of those who its value to surrounding communities in would revere a restored valley. Crafting particular, is outside the study’s scope. a solution acceptable to all will require Rather, this report examines the com- a cooperative effort among local, state plex—but surmountable—water and and federal agencies and the public. All power issues that present the most parties must work to fairly allocate obvious political obstacles to restoring costs, not only for replacing the water Hetch Hetchy Valley. and power benefits currently provided While the main body of the report by O’Shaughnessy Dam but for is the work of Environmental Defense restoring and managing the valley itself. staff, three independent consultants Restoring Hetch Hetchy Valley helped with key elements. Schlumberger after nearly 100 years would recover Water Services analyzed the basic one of our planet’s geological wonders— engineering components of conveyance a unique natural habitat for wildlife and and storage alternatives, and assisted an oasis for people in the midst of the with hydrologic modeling of alternative rugged Sierra Nevada. A restored valley water-supply options. Eisenberg Olivieri would also relieve the pressure on & Associates assessed how the SFPUC the much loved but highly congested might handle water if it were diverted Yosemite Valley 15 miles to the south. at locations farther downstream. Finally, With support from a dedicated public, Somach, Simmons & Dunn provided some imagination, and a willingness an initial overview of the complex legal by government officials at all levels to issues surrounding water rights, includ- work together, we believe that Yosemite’s ing aspects of the 1913 Raker Act long-lost twin can be brought back to that authorized the construction of its natural glory.
4 CHAPTER 2 Hetch Hetchy: past, present and future
Millions of years ago, a series of upheavals River to be dammed in 1913, and today deep inside the earth thrust up Cali- the valley—serving as a storage tank for fornia’s Sierra Nevada Mountains. Over the San Francisco Bay Area—lies sub- time, rivers then carved narrow canyons merged beneath 300 feet of water. into the rock. Glaciers widened and deep- ened some of these canyons, leaving the tributaries’ less-deeply-incised valleys Yosemite’s residents suspended above vertical cliffs. Today, Elevations in Yosemite National Park those “hanging” valleys harbor lakes, range from 2,000 to more than 13,000 and streams cascade from the cliffs. feet, providing habitat for a vast array The most spectacular legacies of of plants and animals. Vegetation varies the Sierra’s glacial past lie in Yosemite dramatically, from rugged chaparral in National Park. Particularly revered is the lower elevations to high-country Yosemite Valley, world-famous for its alpine meadows, and the park harbors mountain meadows nestled below sheer more than 160 rare plants. Yosemite rock faces and thundering waterfalls. also hosts more than 300 species of Yosemite Valley draws more than 3 mil- mammals, such as black bears, bighorn lion visitors each year, but few of them sheep and bobcats, and a wide variety know that two magnificent valleys once of bird species that includes the white- graced the park. Hetch Hetchy Valley, headed woodpecker, northern goshawk Yosemite’s nearby twin, provided a simi- and spotted owl. larly spectacular setting. But Congress Yosemite attracted its first human allowed Hetch Hetchy’s Tuolumne residents some 7,000 to 10,000 years BANCROFT LIBRARY Tueeulala and Wapama Falls descend from cliffs on the north side of Hetch Hetchy Valley. John Muir described Tueeulala Falls as excelling even Yosemite’s Bridalveil Falls “in height and airy-fairy beauty and behavior.”
5 BANCROFT LIBRARY Hetch Hetchy Valley as its original Native American residents saw it for thousands of years before Europeans came to the Americas. ago. By the time European colonists farmers created fields and orchards, and landed in the New World, the Ahwah- livestock grazed in the meadows. neechee Indians thrived in Yosemite Naturalists, artists and other respect- Valley and surrounding areas. They ful visitors began to advocate for pro- named the area Hetch Hetchy after the tections. In fact, the national debate native grass that grew in the valley. about preserving land in national parks The 1849 gold rush brought large began with Yosemite. Israel Ward numbers of prospectors to the Sierra Raymond, a representative of the Central Nevada, and they quickly came into American Steamship Line, rallied a conflict with the native people. In 1851, one year after statehood, California formed the Mariposa Battalion to bring an end to the “Mariposa Indian War.” Soon afterward, the Indians left Yosemite and dispersed into the Mono Basin and other areas beyond the mountains.
The campaign to preserve Yosemite Through the images produced by artists, photographers and writers, awareness of Yosemite’s wonders spread. Increasing numbers of people made their way to the area on foot and horseback,1 and the growing population began to develop LIBRARY OF CONGRESS Less than a year after delivering the Gettysburg the region and compromise its natural Address, Abraham Lincoln signed an historic bill beauty. Homes and hotels sprang up, to protect parts of Yosemite.
6 ADSWORTH ATHENEUM ADSWORTH W Before Hetch Hetchy was the center of controversy, and even before it was made accessible to the public, the valley was appreciated by some of the nation’s most renowned landscape artists, including painters Albert Bierstadt and William Keith and photographer Carleton Watkins. They traveled miles through the wilderness and often spent weeks camped in Hetch Hetchy in order to capture the valley’s splendor. Their works, including the above Bierstadt painting “The Hetch Hetchy Valley”, are still treasured today. small but persistent group to lobby the October 1, 1890, thereby creating U.S. Congress to shelter Yosemite from Yosemite National Park. unrestrained development. Persistence paid off. In the midst of the Civil War, with Confederate troops The plan to dam Hetch Hetchy advancing on Washington, President Valley Abraham Lincoln took time to consider President Harrison’s signature was barely the future of faraway Yosemite. On dry, however, when a proposal to exploit June 30, 1864, inspired by glowing the young national park emerged. The reports of the area’s beauty, Lincoln booming City of San Francisco had been signed the Yosemite Act to preserve the eyeing the Sierra Nevada Mountains, valley for “public use, resort, and recrea- and especially Hetch Hetchy Valley, as a tion . . . inalienable for all time.”2 potential source of fresh water since the But many soon recognized that in 1880s. The City petitioned the federal order to preserve the character of the government twice, in 1903 and 1905, to region, additional land would have to dam the Hetch Hetchy gorge, but Presi- be set aside. Writer-naturalist John dent Theodore Roosevelt’s administra- Muir and others tirelessly lobbied tion denied both proposals as “not in Congress over the issue. In March of keeping with the public interest.” 1890, a bill was introduced that called A bitter dispute followed, with Muir for land surrounding the Yosemite leading the fight against the dam. “Dam Valley, including Hetch Hetchy Valley, the Hetch Hetchy?” he famously declared. to be designated a protected national “As well dam for water tanks the people’s park. The bill passed easily, and Presi- cathedrals and churches, for no holier dent Benjamin Harrison signed it on temple has ever been consecrated by the
7 LIBRARY OF CONGRESS John Muir consistently and vigorously opposed damming Hetch Hetchy. Teddy Roosevelt strug- gled between his commitments to preserving wild places and supporting development, but
NATIONAL INFORMATION SERVICE FOR EARTHQUAKE ENGINEERING, U.C. BERKELEY SERVICE FOR INFORMATION NATIONAL eventually declared that Hetch Hetchy Valley The 1906 earthquake’s damage to San Francisco’s pipes-not any inadequacies should be protected and “the scenery kept in its reservoirs-resulted in a lack of water to fight the devastating fire. wholly unmarred.”8
heart of man.” The battle over Hetch sider San Francisco’s request for rights- Hetchy marked the beginning of a new of-way to develop the Hetch Hetchy era: as the forces behind unfettered devel- project in Yosemite National Park. opment clashed with conservationists, Preservationists were outraged at the the environmental movement was born.3 prospect of such large-scale destruction The turning point came on April 18, within a national park. Muir vowed to 1906, when a powerful earthquake struck keep the protest letters flying to Wash- San Francisco, followed by a devastating ington “as thick as snowflakes,”5 and fire. As firefighters struggled to contain opposition to damming Hetch Hetchy the blazes, hydrants went dry. In actuality, gained momentum nationwide. More the City’s reservoirs held ample supplies, than 100 newspapers (see The Hetch but the Spring Valley Water Company’s Hetchy Grab, page 9) decried the project. water pipes had failed because of quake In 1913, the New York Times printed six damage.4 Even though water supply anti-dam editorials, lambasting “San wasn’t the problem, the pro-dam faction Francisco Philistines who know how to saw an opportunity to exploit the nation’s ‘improve’ the handiwork of the Creator.” sympathy for the young metropolis. In 6 Unmoved, supporters of the dam 1908 the Department of Interior reversed dismissed the preservationists as “short- its earlier position and elected to recon- haired women and long-haired men.”7
8 Despite the public outcry, the A natural wonder succumbs to a efforts of John Muir and others, and feat of engineering the existence of feasible water-supply Damming Hetch Hetchy Valley and alternatives, Congress upheld the 1908 building a system to carry water 160 miles permit and passed the Raker Act in from the Sierra Nevada to San Francisco 1913, authorizing San Francisco to was a vast undertaking. Not only were begin building the dam. The Times the challenges of the engineering struc- railed: “The battle was lost by supine tures daunting in and of themselves, but indifference, weakness and lack of also the project required transporting funds.” Legend holds that Muir died supplies through rugged mountainous of a broken heart over the loss of areas where few roads existed. the valley. San Francisco mayor Jim Rolph tapped Michael O’Shaughnessy-an abrasive but accomplished engineer whose work on the Southern Pacific Railroad, Marin County’s Alpine Dam, and other large projects had established his skills and reputation-to lead the effort (see Michael “The Chief ” OShaughnessy: a man of action, page 10). It took O’Shaughnessy and his workers 10 arduous years to complete the 312-foot-high dam; the first stage of the project, a 68-mile supply railroad, went into operation in 1918, carrying 400 tons of cement a day to the dam site. During his decade of work there, O’Shaughnessy developed an appreciation for Hetch Hetchy Valley, even using a photo of it in his 1919 Christmas card. However, sentimentality seems not to have impeded him moving ahead with the project. In 1923, the City held an opening ceremony for the dam, which it named after its chief engineer.
The debate re-emerges The controversy provoked by the dam never truly disappeared. In 1921, Con- gress passed a law prohibiting the issu- ance of licenses for hydroelectric projects within national parks, unless authorized by Congress. Later, in 1992, the law was amended to further restrict new projects within the National Park system. In 1987 Donald P.Hodel, President Reagan’s BANCROFT LIBRARY More than 100 newspapers nationwide decried the plan to build a dam in Secretary of the Interior, proposed re- Yosemite National Park. moving the dam and restoring the valley.
9 Michael “The Chief” O’Shaughnessy: a man of action The brains behind the massive engineering project to The dam posed several engineering challenges dam Hetch Hetchy Valley, Michael O’Shaughnessy, because of Hetch Hetchy Valley’s remote location was a combative, colorful character and a skilled in the Sierra Nevada. Not only did O’Shaughnessy engineer. To his workers he was known simply as have to build a massive dam and power plant, he “The Chief.” To others he was “a man of action” also had to oversee the construction of miles of who would stop at nothing to achieve his ends. In roads, railroads, tunnels and aqueducts to move addition to conceiving the Hetch Hetchy project, the needed water and supplies. O’Shaughnessy lobbied Congress tirelessly on its Despite his commitment to its success, O’Shaugh- behalf. During one particular week, the Senate nessy appeared ambivalent at times about the questioned him continuously from Monday morning project. Even before the Raker Act authorizing the until late Saturday night. Many who sat through the dam had passed, O’Shaughnessy acknowledged the debates came just to see The Chief in action. binding nature of the investment in a letter to Mayor Born and raised in Ireland, O’Shaughnessy trained Rolph dated June 14, 1912. “The City has spent as a civil engineer in his home country and departed, so much money under government rights,” said shortly after graduating, for San Francisco. There he O’Shaughnessy, “that they cannot now abandon the built an impressive engineering reputation with Tuolumne for another and even more economical projects such as the Mill Valley street system and the Sierra Project.”11 In 1919, as construction of the Marin County Alpine Dam, and with his work on the dam began in earnest, he used a dramatic image of Southern Pacific, Sierra Valley and Mohawk railroads.9 the valley as a Christmas card. San Francisco Mayor Jim Rolph appointed Nonetheless, O’Shaughnessy, the “man of action,” O’Shaughnessy the City’s chief engineer in 1912. He completed the dam—and its complex delivery system held this office until 1932, completing projects such of aqueducts, pipes and tunnels—with the focus and as the Twin Peaks tunnel, the San Francisco Munici- skill for which he was renowned.12 He died in 1934 pal Railway, the Great Highway from the Cliff House at the age of 70, only days before the first Hetch to Sloat Boulevard, and, his largest project, the Hetchy water from behind the O’Shaughnessy Dam O’Shaughnessy dam.10 arrived in San Francisco. BANCROFT LIBRARY Even hard-bitten chief engineer Michael O’Shaughnessy, for whom the dam is named, found Hetch Hetchy Valley enchanting. This 1919 Christmas card, sent to his friends and acquaintances, features its unique beauty.
10 BANCROFT LIBRARY After the passage of the Raker Act, it took 10 years to build O’Shaughnessy Dam. Shown above: pre-dam panorama of Hetch Hetchy Valley; Hetch Hetchy Railroad, built to bring necessary materials to the remote dam site; the valley floor cleared of trees; construction in progress; dedication of O’Shaughnessy Dam in 1923; the completed reservoir (where public boating has never been allowed).
11 A year later, the Bureau of Reclamation of San Francisco receive a comparable released its report, Hetch Hetchy Water water and power supply from other and Power Replacement Concepts, and the sources? Could the Hetch Hetchy National Park Service issued a study Valley be restored as part of the living evaluating the possibilities for restoring heritage of our national park system? the valley’s ecosystem. In a world of diminishing natural Now the debate over using a national resources, what is the highest use of park for municipal water supply has re- the valley? These are questions worth emerged. As San Francisco launches a asking.” Environmental Defense major renovation of its water system, agrees, and we believe that their there is a once-in-a-lifetime opportunity answers, and the ultimate results of to return Hetch Hetchy to the public the sound and inspired programs poten- trust, and to its natural splendor. tially engendered, would very much In its 1988 study, the Bureau of delight John Muir and his kindred Reclamation wrote: “Could the City spirits past, present and future.
12 CHAPTER 3 California water summary
California is the most populous and agri- culturally productive state in the nation, Water volumes are often measured largely due to vast irrigated basins span- in acre-feet. One acre-foot (326,000 gallons) is enough water to satisfy ning the interior of the state. Californians the average annual needs of two to value their natural environment and four families. are increasingly selective in approving projects that might degrade it. Residents are especially sensitive about the twentieth largest in the state, holds further depleting the state’s water re- only 360,000 acre-feet (Figure 3-2)— sources. But because California is semi- although it was once the largest reservoir arid, like much of the American West, its in the entire Central Valley watershed. communities and economy depend on Lying downstream of Hetch Hetchy and secure, safe, and reliable water supplies. holding almost six times as much water, For most of the past century, ensuring this Don Pedro Reservoir is one of California’s reliability meant building a vast network of largest. The Turlock Irrigation District, dams and canals to move water from rivers the Modesto Irrigation District and the to distant farms and cities (Figure 3-1). San Francisco Public Utilities Commis- California now has more than 1,000 sion all store water in Don Pedro. San dams, with a combined water-storage Francisco alone can store up to 740,000 capacity of over 40,000,000 acre-feet. acre-feet there, more than twice the maxi- Hetch Hetchy Reservoir, which today is mum storage of Hetch Hetchy Reservoir.
FIGURE 3-1 Surface water development in California, 1900–2000
50 Surface storage capacity (acre-feet) Population Eastside New Melones 40
Don Pedro 30 Oroville
Trinity Millions 20
Shasta 10
0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
This graph traces the course of surface-water development over the 20th century, including the dam- building boom in the decades that followed World War II. With few locations left for which dams are practical, many water agencies have found the development and management of groundwater basins to be an effective alternative. Source: California Department of Water Resources
13 FIGURE 3-2 Comparative surface storage volumes
50,000 43,158
40,000
30,000 Millions 20,000
10,000
1,530 360 0 Statewide total SFPUC total Hetch Hetchy
While the Hetch Hetchy Reservoir provides significant benefits, it is a small part of the statewide water-storage picture. Hetch Hetchy accounts for less than 25 percent of SFPUC’s total storage. Source: California Department of Water Resources and Bureau of Reclamation
Today there are few practical oppor- exchanges with other agencies that have tunities to build new dams that would different sources and needs. impound the natural flow of a large This chapter provides an overview river. Most of California’s major rivers of current trends among California’s are already dammed, protected by law, municipalities and farming communities or too remote to be economically in how they meet their customers’ water developed. But innovative water needs, including the recent approaches managers are finding that they can taken by urban water agencies. Context extend supplies in a variety of other is thus established for the water-supply ways, including increased efficiency, components, presented in Chapter 6, recycling, local storage, groundwater offered as possible alternatives to the management, and transfers and Hetch Hetchy Reservoir.
Moving water to cities and farms in California In California, precipitation occurs disproportionately in the north, while most cities and farms are located in the southern two-thirds of the state. The State Water Project and the federal Central Valley Project store winter storm runoff and spring snowmelt in a series of large dams in northern California on the Sacramento, Feather, Trinity, and American Rivers. Releases from these reservoirs pass through the Sacramento-San Joaquin Delta, where as much as 6,000,000 acre-feet per year of water are diverted to cities and farms in central and southern California via an intricate system of pumps, pipes and canals. Southern California also receives significant supplies from the Colorado River through the All-American and Coachella Canals and the Colorado River Aqueduct, though their supplies have recently been cut.
14 FIGURE 3-3 Projected changes in statewide water use (1995–2020)
40 ■ 1995 survey ■ 2020 estimate ■ Projected change 35
30
25
20
15 Millions
10
5
0
-5 Urban Agricultural
California’s State Water Plan projects increases in urban water use that are partially offset by slight decreases in agricultural use. Source: California Department of Water Resources
Agricultural water-use trends be taking a greater share of State Water Statewide, approximately 80 percent Project (SWP) supplies, leaving less avail- of developed water in California is used able for the SWP’s agricultural con- by irrigated agriculture. Over the next tractors. In addition, agricultural districts 30 years, as cities, suburbs and rural are finding that they can improve water- communities continue to grow, a slight use efficiency or switch to crops that use reduction in the agricultural proportion less water. Some of them have profited is expected.1 Some of this reduction is from this strategy by selling or leasing un- attributable to the Metropolitan Water needed water for urban use or to provide District of Southern California, which will environmental benefits. ALIFORNIA DEPARTMENT OF WATER RESOURCES OF WATER DEPARTMENT ALIFORNIA STUART WOOLF C Left: Farms throughout California are increasingly adopting water efficient technologies, such as above ground drip irrigation, as used on the Central Valley farm pictured above. Right: California is the top agricultural producer in the nation contributing over half of the nation’s nut, fruit, and vegetable production.
15 FIGURE 3-4 Projected change in crop acreage (1995–2000)
1400 ■ 1995 survey ■ 2020 estimate ■ Projected change 1200
1000
800
600
400
Thousands of acres 200
0
–200
–400 Grain Rice Cotton SugarŁ Corn OtherŁ Alfalfa Pasture Tomatoes OtherŁ Almonds/Ł OtherŁ Subtropical Grapes beets field truck pistachios deciduous
The California State Water Plan projects adjustments in various crop acreages between 1995 and 2020. The largest projected decrease is for alfalfa, a crop that uses up to 7 acre-feet of water per acre annually, depending on location. The largest increase is for “other truck” crops (such as vegetables and melons) that typically use less than one-half of the water per-acre required by alfalfa, even as they result in greater revenue and employment.2 Source: California Department of Water Resources
To compete in today’s global economy, exception of multi-year droughts, ade- farmers have needed to become increas- quate supplies have been available to ingly sophisticated. They must carefully meet demands despite a rapidly growing determine which crops to grow each year, population. In fact, since the late 1970s, based on factors ranging from water avail- urban water use has increased only mod- ability and soil quality to international erately as urban agencies throughout the market trends. California’s State Water state have found new ways to provide Plan thus predicts overall shifts within safe, clean and reliable water supplies agriculture over the next few decades, in for their constituents. Increasingly, these response both to anticipated competition agencies are turning from remote dams from other regions and the future costs of and reservoirs to a host of other alterna- production (Figure 3-4). In many areas, tives that are more cost-effective, more farmers have already gone “high-tech”— reliable, and usually far less environ- they are using Global Positioning Sys- mentally damaging. They include: tems, for example, to better manage their • Building local reservoirs to store sup- fields. This technology complements other plies, whether local and imported efficiency investments, such as drip irri- •Transfers, either in all years or in dry gation, which help farmers grow more years, from agricultural districts for the same or lesser amounts of water. •Surface and groundwater exchanges with agricultural districts Urban water use • Increased water-use efficiency (also In 2000, California’s cities used about known as conservation or demand-side 8.7 million acre-feet of water.3 With the management)
16 • Recycling and wastewater reclamation mation related to water resources, iden- • Desalination tified 30 separate transactions, including 7 permanent acquisitions, that took place in California during 2003. In most cases, LOCAL STORAGE the buyers were municipal agencies rep- In the last 10 years, two new reservoirs resenting large and small cities. The have been built by California water agen- state and federal governments also cies to better serve local customers. In bought supplies, on behalf of the public, 1998, the Contra Costa Water District to protect and restore fisheries in the completed Los Vaqueros Reservoir Sacramento-San Joaquin Delta estuary.7 (100,000 acre-foot capacity). In 2003, the Southern California agencies in par- Metropolitan Water District of Southern ticular, including the Metropolitan Water California completed the Eastside Res- District (MWD), have in recent years ervoir (800,000 acre-feet). Both are “off- been actively purchasing both Central stream” reservoirs that do not dam major Valley and Colorado River water supplies rivers but are filled primarily in wet years through a variety of means, including: with imported supplies, thereby provid- •A 1988 agreement between MWD and ing increased reliability in dry years. the Imperial Irrigation District (IID) San Francisco’s proposal to expand the for 90,000-110,000 acre-feet per year capacity of its Calaveras Reservoir from in exchange for funding a conservation 97,000 acre-feet to 420,000 acre-feet is investment program within IID. in a similar spirit. If Calaveras Reservoir were to grow to that size, it would need to •A 2002 agreement with Sacramento include infrastructure for pumping sur- Valley parties that would provide plus (wet-year) Tuolumne River supplies MWD and other agencies that receive into the reservoir for use in dry years.4 supplies from the Delta with at least 92,500 acre-feet (and up to 185,000 TRANSFERS acre-feet) at costs ranging from $50 Water transfers, put simply, are one water per acre-foot in above-normal years user’s sales to another. Historically, muni- to $125 in critically dry years. cipal agencies and agricultural districts •A 2003 agreement between the San developed water supplies independently, Diego County Water Authority with few market-based dealings between (SDCWA) and IID for a long-term them. But water managers from the dif- agreement to purchase 200,000 acre- ferent sectors have learned to implement feet per year from IID at a starting mutually beneficial transactions. Given price of about $260 per acre-foot. the great difference in scale between established agricultural and urban water •A 2004 agreement between the Palo demands, moreover, transfers to meet Verde Irrigation District (PVID) and moderate growth in the urban sector can MWD to purchase up to 111,000 be accomplished without major disrup- acre-feet per year from PVID farmers tion in overall agricultural uses statewide.5 for approximately $100 per acre-foot. Thus short- and long-term water The deal also includes a one-time transfers, totaling hundreds of thousands initial payment of approximately $500 of acre-feet, have annually been occurring per acre-foot. between water users.6 Water Strategist, a publication that reports on marketing, Transfers have the potential to reduce legislation, litigation and financial infor- water scarcity. However, like every other
17 ALIFORNIA DEPARTMENT OF WATER RESOURCES OF WATER DEPARTMENT ALIFORNIA C After years of negotiations, a long-term agreement between San Diego and the Imperial Irrigation District was reached in 2003.
source of water in California, voluntary GROUNDWATER BANKING AND transfers are frequently accompanied by EXCHANGE PROGRAMS controversy. Local communities often Urban agencies and agricultural districts assert that while water sales may benefit are beginning to work together to man- a few local agencies or farmers, the age groundwater efficiently. Under a broader community can be harmed typical groundwater banking and ex- through a variety of effects, including change program, in wet years a portion depressed agricultural production or of an urban agency’s surface water is depleted groundwater. Both the IID- diverted to an agricultural district, SDCWA and PVID-MWD agree- where it can be stored underground ments noted above include advance (Figure 3-5). In a dry year, some of the commitments to mitigate at least some agricultural district’s surface water is of these potentially adverse socio- diverted to the urban area to augment economic impacts. the urban area’s limited supply, and the FIGURE 3-5 How a groundwater exchange program works
WET YEAR DRY YEAR RIVER RIVER
City Farm Groundwater City $ Farm Groundwater Bank Bank In wet years, the river flows are diverted to cities In dry years, some of the farms' supplies are diverted to and farms, as well as to groundwater storage. cities and are replaced with stored groundwater.
18 TABLE 3-1 Current groundwater exchange programs Urban agency Maximum extraction capacity Maximum storage capacity Thousand acre-feet/year Thousand acre-feet Metropolitan Water District 153 700 Santa Clara Valley 78 350 Water District Alameda County 33 150 Water District Zone 7 (Livermore- 14 65 Amador Valley)
These programs are currently in place with Semitropic and Arvin-Edison Water Districts. MWD’s agreements involve costs of about $300 per acre-foot.8 agricultural district can then extract the these agencies to stimulate efficient stored groundwater to supplement its water use among their customers. Local own supply. The frequency of physical crises also play a role. In large part as a exchange under these agreements varies, result of the 1976-1977 and 1987–1992 but additional groundwater is normally droughts, many agencies—including the pumped in dry years only. Los Angeles Department of Water and Several Bay Area districts have Power and MWD—were driven to banked water in the Semitropic Water increase their investments in water- District in Kern County, and Southern conserving devices in homes and California’s Metropolitan Water District businesses as well as in educational has banked water with Semitropic and programs to encourage behavioral with the nearby Arvin-Edison Water changes among urban water users. District as well (Table 3-1). For most agencies, however, there is San Francisco has investigated room for improvement. Some Central groundwater-banking alternatives for Valley cities do not even measure a more than a decade, though has yet to customer’s water use. In Waste Not, implement any such programs. A 1993 Want Not: The Potential for Urban Water study evaluated 15 separate alternatives, Conservation in California (November ranking 7 of them as “good” 2003), the Pacific Institute estimates opportunities9.San Francisco’s Water that one-third of California’s current Supply Master Plan (2000) identifies urban water use—more than 2.3 million groundwater-banking opportunities in acre-feet—can be conserved with exist- the Bay Area, the lower Tuolumne ing technology. Though some might watershed and other Central Valley believe that an inevitable consequence locations as well. of improved water-use efficiency is increased urban growth, it should be URBAN WATER CONSERVATION noted that conservation can provide Water agencies throughout California many environmental benefits. Con- now recognize that assuring a reliable served water may be used to enhance supply includes the management of in-stream flows, for example, or play a demand. The combination of new role in restoring Hetch Hetchy Valley. technology, educational opportunities In a cooperative effort to increase and public sentiment are prompting efficiency, urban water agencies and
19 public-interest organizations created the with recycled water for uses such as California Urban Water Conservation industrial processes or irrigation. The Council (CUWCC) in 1991. The San Diego County Water Authority, for council has since identified 14 “Best example, currently reuses 13,000 acre- Management Practices,” including toilet feet of recycled water, or 3 percent of retrofits, horizontal-axis washing total supply, each year; and by 2020 it is machines, metering, and public educa- projected to reuse over 53,000 acre-feet tion, to help ensure reliability by per year, or 6 percent of total supply.11 reducing demand. The Southern California Water The San Francisco Public Utilities Recycling Initiative, a partnership of Commission has implemented a num- 10 urban water agencies (including ber of the Council’s recommendations SDCWA and MWD), plans to launch and is providing water-conservation 34 new projects by 2010 with a total incentives to its residential, commercial, potential yield of 451,500 acre-feet per GETTY IMAGES The campaign to save Mono Lake included a and large-landscape customers; more year of additional recycled water. grassroots effort, led by generally, the SFPUC is engaging in The San Francisco Bay Area is begin- The Mothers of East L.A. with funding from MWD public outreach. The Commission esti- ning to catch up with the southern part and Los Angeles Depart- mates that water-conservation measures of the state. The Contra Costa Water ment of Water & Power, will help reduce its retail demand in District currently recycles some 10,000 to retrofit older water- wasting toilets. 2020 by over 30,000 acre-feet. acre-feet per year—about 8 percent of Other urban water agencies, includ- its total use. The SFPUC is currently ing some members of the Bay Area developing a cost-effective system to Water Supply and Conservation deliver recycled water to parks, open Agency, are either not members of the spaces, golf courses, street medians and CUWCC or have only begun to imple- commercial buildings, as well as to other ment its recommendations. This suggests customers for non-drinking purposes. that considerable untapped possibilities Once it is implemented in 2006, San remain for water conservation in the Francisco’s Recycled Water Program Bay Area and likely in other parts of the should be producing almost 17,000 state as well. acre-feet per year12 or 6 percent of total supplies. Meanwhile, the Bay Area water RECYCLED MUNICIPAL WATER and wastewater agencies, assisted by state Water recycling, which involves treating and federal agencies, have formed a municipal wastewater sufficiently to partnership—the Bay Area Regional protect public health and then making Water Recycling Program—and have it available to customers—normally, for collectively identified a recycled water non-potable uses—has been used in market of at least 125,000 acre-feet per California since the 1800s. But it has year in the Bay Area. become a significant supplemental water source only in the past few decades. DESALINATION Currently, California’s urban areas New technologies have created recycle about 500,000 acre-feet of increased optimism that desalination, a wastewater annually, and the statewide water-treatment process that removes potential is estimated to be some salt from brackish water and seawater, 1.5 million acre-feet per year statewide might play a significant role in assuring by 2030.10 future water supplies. Since the mid- Public policy in California has placed 1960s, urban water agencies throughout a high priority on replacing freshwater the state had found desalination to be
20 infeasible because of its associated high Bay Area water interconnections energy and environmental costs. Over The Bay Area’s largest water agencies the past decade, however, improvements developed independently, with separate in technology combined with the in- infrastructure and their own sources of creased cost of conventional supplies supply. In many cases, these agencies have made desalination competitive, have pipelines that cross but do not in some cases, with importing water or interconnect, making it difficult for recycling water.13 them to help each other in times of In a joint effort, the four largest need. In 2000, the Association of Bay Bay Area urban agencies (SFPUC, Area Governments and the CALFED East Bay Municipal Utility District, Bay-Delta program (a collaboration of Contra Costa Water District, and state and federal agencies) acted to Santa Clara Water District) are cur- address this oversight. The two entities rently exploring the development of established a task force of local urban regional desalination facilities. Through water agencies to help coordinate and this Bay Area Regional Desalination connect these independent systems and Project, it is estimated that almost to encourage their mutual pursuit of 135,000 acre-feet per year could be avail- conservation and water transfers. As the able for potable use by 2020 at an eco- many water agencies are finally starting nomically viable cost of $377–429 million to work together, some interconnections (2002 dollars). have already been completed.
21 CHAPTER 4 California power summary
Californians, whose economic prosperity past century by utilities in order to link and quality of life are largely dependent sources of electrical energy (both in- on a reliable electric-power system, have state and out-of-state) to end users. become increasingly aware of the need California’s grid is extensively inter- for energy resources that are both efficient connected with a much larger regional and environmentally friendly. The grid that encompasses parts of all 14 shortages and price spikes of 2000–2001 Western U.S. states, the Canadian also brought home the value of locally province of British Columbia, and the controlled generation, renewable energy, Mexican state of Baja California. The and conservation. This chapter pro- routine exchange of energy with pro- vides an overview of California’s power ducers throughout western North system, including the electricity oper- America ensures a reliable supply of ations of Hetch Hetchy Water and electricity for California’s expanding Power and the Turlock and Modesto population and growing business sector. Irrigation Districts. Figure 4-1 shows how the state’s port- folio of generating resources has evolved since the early days of electrification. Overall system During the early and middle part of the California’s electric-power system is 20th century, rivers were the main source comprised of an intricate grid of power of Californians’ electricity. But in the last plants, transmission lines, and distribu- few decades, hydroelectric development tion lines that were developed over the has dropped significantly: few cost-
FIGURE 4-1 Cumulative generating capacity in California by decade and energy
70,000
■ Solar ■ 60,000 Wind ■ Waste to energy ■ Geothermal ■ 50,000 Nuclear ■ Cogen (coal) ■ Cogen (gas) ■ 40,000 Oil/gas ■ Hydro
Megawatts 30,000
20,000
10,000
0 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s
Hydrogen provided most of California’s energy supply in the early days of electrifiction. More recently, fossil-fired plants and nuclear energy have met most of the state’s ever-growing demand for elec- tricity, as the number of cost-effective hydroelectric sites has dwindled and public opposition to new dams has mounted. Source: California Energy Commission
22 FIGURE 4-2 California electricity sources, 2002
Energy imports 24% Geothermal 5% Gas 34% Renewable 9%
Hydroelectric Organic waste 11% 2% Coal Nuclear 10% 13% Wind 1%
Solar 0.3%
California relies on a diverse portfolio of resources to meet its energy needs. Renewable energy sources such as geothermal, wind and solar power will increase as the state’s investor-owned utilities comply with a new law that requires them to obtain 20 percent of their supply from renewable sources by 2017. Source: California Energy Commission effective hydroelectric sites remain, while including irrigation districts, are exempt public opposition to new dams has grown. from the RPS, some have undertaken Fossil-fuel-fired plants have met much voluntary efforts to increase their reli- of the state’s ever-growing demand since ance on renewable energy. the 1950s, with newly built fossil-fuel Imported electricity accounts for facilities now using natural gas. Several a significant part of the resources for large nuclear reactors came on line in meeting the state’s electricity needs. the 1980s, but none have been devel- Hydropower from the Northwest and oped (or proposed) since then. In the coal-fired generation in the Southwest last quarter-century, over 5000 mega- provide much of California’s imported watts of renewable generation have been energy, but interconnection with other added to the state’s resource mix. Western states means that power from Today, California’s electricity portfolio all types of sources can flow here from includes a combination of natural gas, throughout the region. Ongoing con- coal, hydropower, nuclear, and renewable- struction of new gas-fired plants in the energy sources, as shown in Figure 4-2. Mexican state of Baja California may Annual mixes vary dramatically from year add a new source of imports. In 2002, to year, depending on factors such as pre- California imported approximately cipitation and natural-gas prices. A sig- 62,859 million KWh, while power nificant recent development, which will plants within the state generated shape the evolution of the state’s power approximately 209,650 million KWh. supply, was the Legislature’s adoption Conservation and energy efficiency of a renewable portfolio standard (RPS). are playing an increasingly important Passed in 2002, SB1078 (Sher) requires role in balancing California’s electricity that California’s investor-owned utili- supply and demand. Since the 1970s, ties, including Pacific Gas and Electric residents have invested in upgrading Company, purchase 20 percent of their buildings and equipment so that elec- electricity from renewable sources by tricity may be used more sparingly, and 2017. Although municipal utilities, these investments have paid off. The
23 California Energy Commission (CEC) management systems, and even coating estimates that since 1977 Californians rooftops with reflective materials. have shaved 6000 MW from peak An especially important development demand, the equivalent of a dozen new is the installation of sophisticated new natural-gas power plants.1 Meanwhile, electricity meters for most of the state’s technological innovation continues to large energy users. These devices will yield new efficiency-enhancing—and permit such customers to participate in relatively low-cost—technologies. “dynamic pricing” programs that provide Beyond the last three decades’ im- incentives for them to cut power use pressive progress, the shortages and during peak periods. Adding this price spikes of 2000–2002 taught Cali- demand-side flexibility means that fornians that they could save even more fewer new power plants will be needed energy. About 70 percent of the signifi- to accommodate the relatively few hours cant peak-load reduction that California each year when energy demand is at its realized during the summer of 2001 maximum level. According to CEC came from conservation— behavioral forecasts of the resources required to changes such as darkening empty meet California’s future energy needs, rooms, shutting off idle equipment and dynamic pricing could pare more than turning down the air conditioning.2 The 2500 MW from system peak demand, rest of the savings came from new avoiding the need for at least five new investments in energy-efficiency natural-gas powerplants.3 measures such as replacing incandescent Although these advances are slowing light bulbs with compact fluorescent the growth in demand for electricity, lamps, discarding old air conditioners in California still needs to develop new homes and offices in favor of newer and generating capacity to maintain ade- more efficient models, installing energy- quate energy supplies. Power-plant construction in the state has recently followed a boom-bust pattern, partly in Electricity units response to changing policies toward Watt (W): Basic measurement for the rate of power output cost recovery and industry structure. or use The Legislature’s enactment in 1996 of a law that radically restructured the Watt-hour(Wh): Basic measurement for energy output or use. For example, a 100-W light bulb that is on for 10 hours electricity industry, AB1890, ended a has used 1000 Wh of energy. 10-year lull in new construction and launched a rush to build new power Kilowatt (KW)—1000 watts: Kilowatt-hours (KWh) is the usual plants. Although the new plants were basic unit on consumers’ electric bills. not finished fast enough to prevent Megawatt (MW)—1,000,000 watts: is usually the unit used to shortages and price spikes in 2000– measure power-plant capacity. Yearly output is sometimes 2001, their steady arrival since then has measured in megawatt-hours. brought supply and demand back into The U.S. average residential monthly energy usage in 2002, balance. Since 2001 over 8000 MW of according to the U.S. Department of Energy (DOE), was new generating capacity has come on 907 KWh. line in California, and the state currently Net energy production in the United States in 2002, according enjoys an energy surplus. But the rate of to the DOE, was 3,858,452 million KWh. new construction has once again slowed, Net energy production in California in 2002, according to the and shortages may return in just a few CEC, was 272,509 million KWh. years if the pace of development does not pick up.
24 The current construction slowdown Hydropower and California’s is happening mainly because private- rivers sector power-plant developers cannot Almost all of California’s major river get financing for new projects. Skittish systems, including the Tuolumne, have lenders are withholding funds, citing been developed not only to supply water their uncertainty about the industry’s but also to produce hydropower. Over the future structure and regulatory environ- past 20 years the proportion of California’s ment as California legislators and regu- energy provided by in-state hydroelectric lators develop new policies to reconfigure facilities has varied from 9 percent to the industry once again. nearly 30 percent, depending on precipi- Policymakers have gone back to the tation, the timing of spring snowmelt, and drawing board because AB1890 is widely other factors. Hydropower produces no perceived as a failure, even though the emissions of harmful air pollutants or bill’s passage did help stimulate the global-warming gases, and production recent wave of new construction. In costs at existing facilities are typically low. particular, flaws in AB1890’s market Some hydroelectric plants also play an redesign have been blamed for creating important role in maintaining a robust conditions that allowed the Enron electric system by varying their energy Corp. and other power marketers to output rapidly, in response to grid oper- exploit the tight market conditions of ators’ signals, to assure the grid’s stability. 2000-01, thereby driving electricity It should be noted, however, that Cali- prices to astronomical levels and fornia’s new gas-fired plants share this imperiling the financial health of the operating flexibility, thereby reducing state’s three big investor-owned utilities. the need for hydroelectric facilities. Consequently, policymakers are revisit- Although hydropower is clean, it is ing critical questions, including who will not always green: hydropower facilities be responsible for building new projects throughout California have had signifi- (utilities or independent merchant gen- cant adverse impacts on aquatic eco- erators?) and how to assure developers’ systems. Dams block fishes’ access to recovery of construction costs even as spawning and rearing habitat (causing they are held accountable for unreason- declines in many native fish populations), able delays and excessive expenses. while diversions of water from natural California’s many municipal utilities riverbeds cause environmental degrada- have not experienced the credit crunch, tion. Sudden changes in river flows can however, and have continued to build occur downstream of hydropower facilities new plants even as private-sector con- when production is ramped up (i.e., to struction has lagged. Although they provide power during peak demand), must secure approval from state envi- further harming streamside and river eco- ronmental regulators for new projects systems.4 A 1996 report by the University larger than 50 MW, municipal utilities of California, Davis—the most ambitious such as the Turlock and Modesto Irri- compilation of research on the Sierra gation Districts are mostly unaffected by Nevada to date—deemed rivers and the regulatory changes now being con- riparian ecosystems the “most endan- sidered. These changes will mainly gered” habitats in the Sierra, and it identi- affect investor-owned utilities, such as fied dams and other hydropower facilities Pacific Gas and Electric Company, which as their number-one threat.5 serve over 80 percent of California’s In many cases federal law provides an electricity demand. avenue to address these problems. The
25 Federal Energy Regulatory Commission However, the Federal Power Act (sec- (FERC) regulates private, state and local tion 29) stipulates that “nothing herein hydropower projects that are larger than shall be held or constructed to modify or 5MW. In California there are 119 appeal any of the provisions of the Act FERC-licensed dams, with 11,930 MW of Congress approved December 19, of generating capacity (85 percent of 1913 [the Raker Act],” granting certain California’s total hydropower portfolio). rights of way to the City and County of Environmentally important operating San Francisco in the State of California. parameters, such as provisions for fish Consequently, FERC does not oversee passage and required flows in bypassed San Francisco’s hydroelectric plants on reaches, are specified in 30- to 50-year the Tuolumne River. licenses granted by FERC. Most of California’s FERC-licensed plants came on-line more than 30 years Hetch Hetchy hydropower and ago, before the emergence of the modern its users environmental movement and the passage San Francisco operates three hydroelectric of today’s environmental laws. As these plants—the Kirkwood, Moccasin and projects’ FERC licenses come up for Holm powerhouses—on the Tuolumne renewal over the next two decades, Cali- River (see Chapter 5). While they fornians will have the opportunity not provide a significant amount of energy only to bring them into compliance with to the City of San Francisco and to current regulations but to weigh their Central Valley communities, these electricity benefits against their environ- facilities account for only a tiny fraction mental costs in light of contemporary of the electricity produced statewide. public policies and community values. As illustrated in Figure 4-3, in 2002
FIGURE 4-3 Hetch Hetchy hydropower in perspective, 2002
300,000 272,509
250,000
200,000
150,000 Million KWh
100,000
50,000 31,221
1,703 0 CaliforniaŁ CaliforniaŁ Hetch HetchyŁ electricity generation hydropower production system
The SFPUC’s hydroelectric plants play a minor role in meeting California’s energy needs. In 2002 they provided just 5.5 percent of statewide hydropower production and 0.6 percent of the state’s overall electricity supply. Source: California Energy Commission and United States Department of Energy, Energy Information Administration
26 the three plants provided 0.6 percent of retail customers in San Francisco with California’s electricity supply and repre- its own blend of purchased and self- sented 5.5 percent of statewide hydro- generated energy. power production. Also, only the Total electricity consumption in the Moccasin and Kirkwood plants actually City of San Francisco was 5,374 million generate power using water stored KWh in 2002 and has been slowly rising behind O’Shaughnessy Dam. in recent years (except for a dip during Chapter 9 presents an analysis of the energy shortages of 2000–2001).6 how restoring Hetch Hetchy Valley According to data reported annually would affect hydropower generation by the San Francisco Public Utilities on the Tuolumne River. Commission (SFPUC) to state agen- Meanwhile, although the Hetch cies, Hetch Hetchy energy supplied to Hetchy Reservoir accounts for only a public facilities has been approximately small part of California’s overall elec- 900 million KWh per year in recent tricity supply, it is an important and valu- years.7 Although average generation able resource to the people who use it. from the SFPUC’s Tuolumne power- The remainder of this section discusses houses significantly exceeds the City’s the role of Hetch Hetchy power in meet- public-sector needs—as discussed in ing the needs of electricity customers in Chapter 5, the balance is sold to the San Francisco and in those parts of the Turlock Irrigation District, the Modesto Central Valley served by the Turlock Irrigation District, and other utilities and Modesto Irrigation Districts. and power marketers—it is less than a third of overall consumption in San SAN FRANCISCO Francisco. Even if all Hetch Hetchy Most homes and businesses located in energy were made available for all users San Francisco receive their electricity in the City, considerable additional from Pacific Gas and Electric Com- resources would be required. pany (PG&E). However, the electrical San Francisco has developed an energy delivered to the airport, the Electricity Resource Plan that sets Port of San Francisco and San Francisco ambitious environmental, economic General Hospital, and other City-owned and equity goals for meeting the facilities, are provided by the Hetch City’s electricity needs through 2012. Hetchy Water and Power system; In the short term, closing the highly PG&E provides the transmission and polluting Hunters Point and Potrero distribution services that deliver power plants will yield significant advances to these customers. on all of these fronts (see Clearing the As a practical matter, electrons origi- Air in San Francisco, page 28). For the nating from San Francisco’s Tuolumne longer term, the Plan calls for max- River hydroelectric generators are com- imizing energy efficiency in City build- mingled with those from the diverse ings and investing in renewable energy array of resources that feed into the technologies such as wind and solar. In Western grid. However, for cost account- 2002, San Francisco joined other cities ing and other purposes, power-market in setting the 2012 goal of greenhouse- participants keep track of what they gas emissions that are 20 percent “pour into” the grid and what they draw below the 1990 levels; to meet this out of it. Thus, PG&E delivers a mix of goal will require significantly increasing Hetch Hetchy and purchased power to the share of renewable energy in the City facilities while serving its own City’s portfolio.
27 Clearing the air in San Francisco Air pollution from aging power plants in low-income, predominantly non-white communities is a major environmental-justice issue in San Francisco. PG&E’s Hunters Point power plant and the Potrero Unit 3 (operated by the Mirant Corporation) are among the oldest and dirtiest plants in the state; Hunters Point is the City’s most significant stationary source of air pollution. Plans to close these plants have been developed, but they are currently on hold. Standing in the way is the California Independent System Operator (CAISO), which controls the state’s electricity grid and is responsible for assuring reliable service. The delay derives not from any shortage of replacement power but from a trans- mission bottleneck that limits the flow of power into San Francisco. Because almost all of the City’s electricity supply is imported via a few transmission lines that run up the peninsula, the CAISO requires a City-based backup source of power should the peninsula suffer a transmission outage. Therefore the CAISO will not allow Hunters Point and Potrero to close until new transmission lines are built or enough new local generation is added to guarantee reliable service in the City. In any case, efforts to restore Hetch Hetchy Valley would not be adversely affected by the closure of Hunters Point and Potrero. As discussed in Chapter 9, there are several options for developing new resources to replace the hydro- power that would be lost, and these supplies would most likely be imported into San Francisco, just as Hetch Hetchy energy is now. New generation or con- servation resources developed locally to enable the closing of Hunters Point and Potrero might even hasten the valley’s restoration.
TURLOCK IRRIGATION DISTRICT whose capacity totals 152 MW. With Organized in 1887, the Turlock Irriga- atwo-thirds ownership share in the tion District (TID) is the oldest irriga- Don Pedro Dam, TID takes the lead tion district in California and was the in managing that facility’s hydropower first in the state to sell electricity on a operations, as well as its flood-control, retail basis.8 TID provides water to recreation, and water-supply operations. 5,800 growers in Stanislaus and Merced A new 250-MW gas-fired plant, Counties and electricity service to over expected to enter service in 2006, is 77,500 retail accounts. In addition, TID currently under construction in the City currently sells surplus energy at a profit of Turlock. TID also has holdings in when opportunities arise: from 1998 to transmission capacity and generation 2002, the district’s annual wholesale resources elsewhere in California and power sales ranged from 148 to 1,002 the Northwest through its membership million KWh. Major objectives for in public-power consortiums and long- TID’s power supply operations are term power-purchase contracts. minimizing power procurement costs, Hetch Hetchy energy has generally maximizing the extent of local decision- accounted for about 10-15 percent of making, and maintaining independence TID’s supply. Until recently, TID from outside control. bought power from San Francisco under While most of TID’s energy needs a 1987 contract that provided for are met with purchased power, the purchases of firm power, as well as the district also owns two 49-MW natural- surplus, to which the Raker Act entitles gas-fired power plants and it has the District. San Francisco terminated financial interests in hydroelectric plants the contract early in February 2004, but
28 TID continues to dispute whether the its resource base by acquiring additional termination was valid. interests in hydroelectric and coal facil- ities, entering new long-term power MODESTO IRRIGATION DISTRICT purchase contracts, and investing in The Modesto Irrigation District (MID) conservation and renewable energy. provides electricity to over 100,000 MID and its customers recognize the retail accounts in rapidly growing parts value of investing in energy efficiency. of Stanislaus County. From 1998 to MID already operates several programs, 2002, MID also sold between 385 and including an air-conditioner cycling 1,047 Million KWh annually to whole- project, to shave summer peak loads. sale customers. MID seeks to maintain a In a 2002 survey of 800 MID residential balanced portfolio of energy sources, in- and commercial customers, 75 percent cluding hydropower, natural gas, geo- ranked energy conservation as “important” thermal energy and coal. In 2002, nearly or “very important.”9 90 percent of the energy that MID dis- tributed to its customers was purchased, mostly through long-term contracts. Moving water MID’s principal sources of purchased In the present study (on which this power are the Hetch Hetchy system and report is based), a number of alternatives the M-S-R Public Power Agency, to storing water in Hetch Hetchy through which it owns a portion of the Reservoir are being considered that may energy produced by the San Juan coal- require transporting water to another fired plant in New Mexico. MID also storage site. But water is heavy. buys energy from the federal Central Excepting cases where it can be moved Valley Project and others, under various via gravity, significant energy is required agreements, and it purchases a limited to move and pump water. California’s amount of energy on the short-term rugged landscape, moreover, makes the “spot market.” MID’s own generating transport of water from sources to resources include the 49-MW Wood- population centers especially energy- land Avenue and 112-MW McClure intensive, using an average of 1,955 natural-gas-fired plants and an approx- KWh per acre-foot—almost twice the imately one-third interest in the Don average power needed for this purpose Pedro Dam’s hydroelectric generation. in most other states.10 In 2002, purchases of Hetch Hetchy Pumping is the single largest cost energy accounted for about one-fifth category for the State Water Project, of MID’s supply. which transports water from the According to its 2002 Annual Report, Sacramento-San Joaquin Delta more MID intends to reduce its dependence on than 300 miles south over the Tehachapi the state grid through more investments Mountains to the L.A. Basin.11 Approx- in local generation sources. Current imately 3,200 KWh per acre-foot are projects include additions and upgrades required to deliver water from the to MID’s existing facilities, and plans to Edmonston pumping plant to the Devil build a new 90-MW gas-fired plant. Canyon Power Plant Afterbay, a net lift MID is also exploring options to expand of 1,924 feet.
29 CHAPTER 5 The Tuolumne River and Bay Area water system
The Tuolumne River has been extensively waters lying above the 10,000-foot level developed so that its water and hydro- in Yosemite National Park. The main power may be delivered to multiple users. river begins in Tuolumne Meadows at In addition to meeting these demands, the confluence of streams descending the Tuolumne River watershed supports from the slopes of Mt. Lyell (13,100 feet) a wide variety of wildlife and provides and Mt. Dana (13,155 feet). Tuolumne excellent recreational opportunities. Meadows (8,600 feet), easily accessed This chapter provides an overview of from Highway 120, is a popular high- the Tuolumne River watershed, includ- country destination for summer visitors. ing descriptions of its annual hydrology, From there the river descends through related water rights, and dams. Also the steep Yosemite wilderness, including discussed are water-supply operations, the Tuolumne’s own “Grand Canyon,” hydropower operations, and recreation before its flow is impounded by the and ecosystem protections. O’Shaughnessy Dam in Hetch Hetchy Valley (3,500 feet). In addition to its tributaries within Watershed overview Yosemite National Park, several other The Tuolumne River is one of the streams add to the Tuolumne’s flows at largest rivers in California’s Sierra lower elevations in the Sierra Nevada. Nevada mountain range, with head- Just below the park, Cherry Creek
FIGURE 5-1 The Upper Tuolumne River system
ne um l Eleanor Reservoir o
u Cherry Reservoir T k Hetch Hetchy Reservoir r o F
h t r o N Hetch Hetchy umne R ol ive Valley u r T Tuolumne S Meadows ou ork th F Tuolu e mn Yosemite Valley
Don Pedro Reservoir
d erc e Rive M r
Reservoir HH system pipelines Yosemite National Park
30 enters the river. Further downstream, particular during the period of hydrologic the Tuolumne’s South and North Forks, record (1922–1994) have caused water as well as the Clavey River, join the main planners in California to pay special atten- stem (Figure 5-1). Like all other rivers tion. Depending on a district’s location in that descend the Sierra’s western slope, the state and its water-supply options, any the Tuolumne is a “hard-working” river, one of the three might be considered the largely controlled by a plumbing network most severe. The bone-dry two-year that provides water to farms and cities drought in 1976–1977 hit some dis- while generating valuable electricity. tricts—especially those with limited alternatives—the hardest. The Marin HYDROLOGY Municipal Water District, for example, With an average annual flow of about was forced in 1977 to build an emergency 1.8 million acre-feet, the Tuolumne is pipeline across the Richmond-San Rafael the largest river flowing into California’s Bridge. For most of the California, San Joaquin Valley. About 60 percent which relies heavily on supplies from of the river’s flow occurs between April the Sacramento Valley, a repeat of the and June, when warm weather melts the seven-year drought from 1928-1934 Sierra snowpack. As shown in Figure 5-2, would cause the most difficulty. For the the Tuolumne’s flows, like those of most Bay Area communities that are served California rivers, vary widely with annual by the Tuolumne River, however, a precipitation. In about one out of every repeat of the more recent drought from four years, the annual flow is less than 1987–1992 would be most severe.1 1.1 million acre-feet. For agencies responsible for delivering WATER RIGHTS water to urban or agricultural customers, Under state law, the Turlock and Modesto drought periods (i.e., successive dry years) Irrigation Districts control far more of are of great concern. Three droughts in the Tuolumne River than does the San
FIGURE 5-2 Historic Tuolumne River flows (1922–1994)
5000
■ Historic annual flow Average
4000
3000
2000 Thousands of acre-feet
1000
0 1922 1927 1932 1937 1942 1947 1952 1957 1962 1967 1972 1977 1982 1987 1992
The Tuolumne’s flows, like those of most California rivers, vary widely with annual precipitation. Source: California Department of Water Resources
31 Francisco Public Utilities Commission (SFPUC). These “senior” water-rights The rate of the flow in streams and holders are entitled to the river’s base rivers is typically measured in cubic feet per second (cfs). One cubic foot flow, with water accruing to the “junior” is about 7.5 gallons; one cfs is SFPUC only during periods of high flow. equivalent to 724 acre-feet per year. The exact distribution is determined daily by a calculated estimate of what the flow would be at La Grange (located just below the City. With very limited alternative Don Pedro Reservoir), absent any dams sources, it is more dependent on storage on the river. Most of the year, all of the than most other urban districts. river’s flows below 2,416 cubic feet per Figures 5-3a and b show two examples second (cfs) belong to the two Districts. of how water rights are divided between Unless the flow is higher than this the Turlock and Modesto Irrigation threshold, San Francisco and the rest Districts and the SFPUC, in accordance of the Bay Area get absolutely no water. with the daily criteria specified by their Over the 60-day period from mid-April respective water rights. 1992 was not to mid-June, typically the period of only a dry year, it marked the sixth- highest river flow due to melting snow, straight year of a drought. Less than that threshold is raised to 4,066 cfs. 25 percent of San Francisco’s delivery Given its limited water rights, objective, only 68,000 acre-feet (mostly therefore, in many years very little of in April) accrued to the City that year. the Tuolumne’s flow belongs to the Because storage in its dams was low due SFPUC. In 1977, the driest year on to the extended drought, the City and record, only 3,000 acre-feet accrued to other retail agencies asked customers to FIGURE 5-3 Tuolumne River water rights distribution
(a) Water year 1992 (b) Water year 1993 10000 10000 ■ SFPUC ■ SFPUC ■ TID/MID ■ TID/MID 8000 8000
6000 6000
4000 4000 Cubic feet per second Cubic feet per second Cubic feet
2000 2000
0 0 3/1/93 4/1/93 5/1/93 6/1/93 7/1/93 8/1/93 9/1/93 2/1/93 1/1/93 5/1/92 1/1/92 2/1/92 3/1/92 4/1/92 6/1/92 7/1/92 8/1/92 9/1/92 12/1/92 11/1/91 10/1/91 12/1/91 11/1/92 10/1/92
For Bay Area water users, the extremes of the Tuolumne’s natural hydrology are exacerbated by the SFPUC’s “junior” water rights. 1992 was not only a dry year, it marked the sixth straight year of drought. Fortunately, in 1993, heavy rains and snowfall returned to the Tuolumne River watershed. Source: California Department of Water Resources
32 1987 and 1992, the SFPUC’s average The hydrologic water year is the annual water-rights accrual was 151,000 12-month period lasting from Octo- acre-feet, about half of its current water- ber to September. For instance, the delivery objective. Assuring enough year ending September 30, 2002 is referred to as the “2002 water year.” supply under existing water rights to allow the Bay Area to make it through such a drought with sufficient water conserve. The City also bought addi- both for homes and businesses is one of tional supplies from the California’s the SFPUC’s biggest challenges. emergency drought water bank. Fortu- Water agencies throughout the West nately, 1992 was the last year of the normally rely on historic hydrologic drought. In 1993, rain and snow returned records for their planning studies. But to the Sierra Nevada, allowing full water many planners are beginning to grapple deliveries and replenishing diminished with potential changes, both in the mag- surface storage in the Tuolumne River nitudes and timing of future precipitation watershed and the Bay Area. that may occur because of global warming. Figure 5-4 shows how the annual As events unfold, particular users may be flow of the Tuolumne River is divided better or worse off; under the water-rights between the San Francisco Public criteria regarding the Tuolumne River, Utilities Commission and the Turlock peak snowmelt occurring earlier could and Modesto Irrigation Districts on actually increase the SFPUC’s supplies at average (1922–1994) and during the certain times. If the peak snowmelt from droughts of 1928–1934 and 1987–1992. mid-April through mid-May in 1992 The total volumes were similar during (Figure 5-3a) had occurred a month the two droughts, though the earlier earlier, for example, the SFPUC would period was slightly wetter. Between have been entitled to all flows above
FIGURE 5-4 Historic Tuolumne River water rights distribution average and drought periods
2000
■ SFPUC ■ TID/MID
1500
1000 Thousands of acre-feet 500
0 1928–1934 1987–1992 1922–1994
Between 1987 and 1992, the SFPUC’s average annual water-rights accrual was 151,000 acre-feet, about half of its current water-delivery objective.
33 TABLE 5-1 Reservoir (273,000 acre-feet) lies just Principle Tuolumne River and outside (see Figure 5-5). SFPUC reservoirs The largest reservoir on the Tuolumne Region reservoir Storage capacity River is Don Pedro, which holds just over (thousand acre-feet) 2 million acre-feet of water. Most of Don Bay Area Pedro’s storage capacity is dedicated to Pilarcitos 3 meeting summertime and dry-year needs San Andreas 19 of the Turlock and Modesto Irrigation San Antonio 51 Districts. The SFPUC does not divert Crystal Springs 69 Calaveras 97 water directly from Don Pedro, but owns the right to store up to 740,000 acre-feet Upper Tuolumne in the reservoir (more than twice the total Eleanor 27 Cherry 273 volume of Hetch Hetchy Reservoir). Hetch Hetchy 360 San Francisco therefore uses its storage Lower Tuolumne in Don Pedro as a water “bank.” When Don Pedro2 634 Tuolumne River flows are low (and by (SF Water Bank) law belong to the Turlock and Modesto Don Pedro 1395 Irrigation Districts), the SFPUC is still (MID/TID able to divert river flows upstream by Portion) using its bank. In accordance with its SFPUC Total 1533 agreement with Turlock and Modesto, it simply gives some of that water to the Districts as it impounds the upstream flow 2416 cfs (as opposed to only those flows in Hetch Hetchy Reservoir or diverts it to over 4066 cfs). Under these hypothetical the Bay Area. circumstances, the SFPUC would have Water storage in Don Pedro Reservoir received more water, while the Turlock is also managed to prevent the Tuolumne and Modesto Irrigation Districts received from flooding Modesto and surrounding less. In any case, the prospect of global areas. Consequently, neither San Francisco warming has added one more factor that nor the irrigation districts are allowed water agencies must take into account to fill their portions of the reservoir until as they develop plans to ensure the relia- the end of the spring snowmelt. Despite bility of their systems. these precautions, however, Don Pedro overflowed during the New Year’s DAMS flood of 1997, causing severe damage Like all major rivers in the Sierra Nevada, downstream. As on many rivers, in Cali- the Tuolumne River watershed is dammed fornia and elsewhere, efficient operation in several places, principally to provide of a reservoir involves striking a delicate reliable water supplies for California’s balance between two conflicting goals: farms and cities. Table 5-1 lists the filling the reservoir to ensure a plentiful reservoirs on the Tuolumne, along with water supply and keeping its storage their storage capacities. Hetch Hetchy, low to prevent floods. On the Tuolumne, with 360,000 acre-feet of storage capacity, the most effective long-term control is the largest in the upper watershed. The solution is likely to involve expansion SFPUC owns and operates two other “up- of the tightly-constrained river channel country” reservoirs: Lake Eleanor (27,000 below Don Pedro Reservoir. acre-feet) also lies within Yosemite The SFPUC owns several water- National Park, while Cherry Valley storage facilities in the Bay Area as
34 FIGURE 5-5 Overview of SFPUC water system and other Tuolumne River facilities
19 Hetch Hetchy 18 20 15 Valley
17 San Francisco 16 14 7 Yosemite 10 Valley 8 11 13 6 r 5 Ive 1 9 Tuolumn e R 4 12 2 3 S iver an R J ed o erc
a M
q
u i n
Ri ver
1. Peninsula Reservoirs 11. Modesto T ID Canal 2. Tracy Treatment Plant 12. Turlock ID Canal 3. Calaveras Reservoir 13. Don Pedro Reservoir
4. Sunol Treatment Plant 14. Moccasin Powerhouse 5. San Antonio Reservoir 15. Holm Powerhouse Reservoir 6. Coast Range Tunnel 16. Kirkwood Powerhouse HH system pipelines 7. CA Aqueduct 17. Early Intake Reservoir r 8. San Joaquin Pipelines 18. Cherry Reservoir Major canals 9. Delta Mendota Canal 19. Eleanor Reservoir 10. Foothill Tunnel 20. Hetch Hetchy Reservoir Yosemite National Park
Hetch Hetchy Reservoir is part of an extensive system that includes several reservoirs, water treatment plants, hydropower facilities and a 160-mile series of pipelines and tunnels that carries Tuolumne River water from the Sierra Nevada to the Bay Area. Hetch Hetchy Reservoir holds less than 25% of the system's total storage capacity.
well, including the San Andreas, Crystal River’s water. Less than one-fifth of Springs, and Pilarcitos Reservoirs in it is diverted to the San Francisco Bay the Peninsula region, and Calaveras Area, to be consumed by San Francisco’s and San Antonio Reservoirs in the hills residents and its customers in the Bay above Fremont near the Sunol Valley. Area Water Supply and Conservation The Division of Safety of Dams within Agency (BAWSCA) districts. California’s Department of Water BAWSCA consists of a total of 29 Resources has declared Calaveras— wholesale districts in San Mateo, at 97,000 acre-feet, the largest of the Santa Clara, and Alameda Counties SFPUC’s local reservoirs—to be unsafe, (see Figure 5-6). The SFPUC also and presently allows it to be kept no diverts a small amount of water to more than one-third full. Groveland, a community in the foothills of the Sierra on the south side of the Tuolumne River. Water-supply operations Because water from the river’s flow is The Turlock and Modesto Irrigation available to the City mostly in the winter Districts use most of the Tuolumne and spring, stored water is released from
35 reservoirs to meet delivery objectives has diverted water from the Sacramento- during much of the year. Currently, most San Joaquin Delta directly into the water consumed by San Francisco and SanAntonio Reservoir and finally into its customers comes directly from the San Francisco’s distribution system. Hetch Hetchy Valley via releases from The water diverted from Hetch O’Shaughnessy Dam. A small fraction Hetchy typically passes through the of the supply comes from watersheds in Kirkwood and Moccasin power plants Alameda County and on the Peninsula before entering the conveyance system (San Mateo and Santa Clara Counties). to San Francisco. That transport occurs At times, specifically during the drought entirely by gravity, starting at Moccasin years of 1991 and 1992, San Francisco then continuing through the Foothill
FIGURE 5-6 Location of BAWSCA member agencies
San Francisco
Daly City 2 9 Lawrence 6 Livermore San Francisco Bay National Laboratory 28 10 22 SFO Hayward San Antonio 18 15 Reservoir 3 4b San Andreas Reservoir 11 San 8 1 Pilarcitos Mateo Reservoir 4b 5 Crystal 14 Springs Calaveras Reservoir Reservoir 4b 21 13 4b 7 Half Moon Palo Bay 4a Alto 23 16 26 25 14 19 17 San Jose 24 20 27 Pacific Ocean 12
19 Source: Bay Area Water Supply and Conservation Agency
1 Alameda County Water District 14 Mid-Peninsula Water District 2 City of Brisbane 15 City of Millbrae 3 City of Burlingame 16 City of Milpitas 4a Cal Water Service Co.-Bear Gulch 17 City of Mountain View 4b Cal Water Service Co.-Bayshore 18 North Coast County Water District 5 Coastside County Water District 19 City of Palo Alto 6 City of Daly City 20 Purissima Hills Water District 7 East Palo Alto 21 City of Redwood City 8 Estero Municipal Improvement District 22 City of San Bruno 9 Guadalupe Valley Municipal Improvement 23 City of San Jose District 24 City of Santa Clara 10 City of Hayward 25 Skyline County Water District 11 Town of Hillsborough 26 Stanford University 12 Los Trancos County Water District 27 City of Sunnyvale 13 City of Menlo Park 28 Westborough Water District
36 Tunnel and San Joaquin pipelines into Releases from Crystal Springs, Pilarcitos, the Coast Range Tunnel. The water and San Andreas Reservoirs on the then crosses the Sunol Valley, passes Peninsula are treated at the Harry Tracy through the Irvington Tunnel and enters plant in San Bruno. Presently, these the distribution system in the Bay Area. plants are not large enough to filter and Most of San Francisco’s water is not treat all releases from Hetch Hetchy. filtered. It is only disinfected with chlora- Typically, releases from the Cherry and mine, a combination of chlorine and Eleanor Reservoirs do not directly enter ammonia. The chlorine is injected into San Francisco’s water-supply system. They the water at Tesla Portal, just east of the flow instead into Don Pedro Reservoir, Coast Range Tunnel; and ammonia is meeting San Francisco’s water rights’ obli- added to the water in the Sunol Valley. gations to the Turlock and Modesto The water not released directly from Irrigation Districts and thereby allowing Hetch Hetchy—emanating instead diversions from Hetch Hetchy Reservoir. from Calaveras Reservoir, San Antonio Releases from Cherry also generate hydro- Reservoir, or the various reservoirs on power at Holm Powerhouse, often on a the Peninsula—passes through conven- schedule that allows whitewater boating tional water-treatment plants, where it on the Tuolumne River in the summer. is filtered and then disinfected. San There is a small canal connecting Cherry Antonio and Calaveras releases are Reservoir and Early Intake Reservoir, treated at the nearby Sunol plant. which, under rare circumstances, has been FIGURE 5-7 used to convey water to the Bay Area. The SFPUC’s Tuolumne River hydropower facilities
Hydropower operations San Francisco has been generating—and selling—hydropower from the Tuolumne River since the completion in 1918 of Early Intake Powerhouse and the Lower Cherry Creek Aqueduct, which delivered water from Cherry and Eleanor Creeks. Constructed to supply reliable power to the dam-construction efforts, Early Intake also yielded revenues from commercial sale of electricity. A series of progressively larger and more modern hydropower facilities were added over the succeeding decades. The current system was com- pleted in 1988 with the addition of a third generator at Kirkwood powerhouse. Today San Francisco operates three powerhouses—Moccasin, Holm and Kirkwood—along the Tuolumne River (see Figure 5-7). Their seven turbines are capable of collectively generating at a rate of up to 401 MW.3 Kirkwood powerhouse is operated as a “base-load” facility, nor- Source: Bureau of Reclamation mally producing power at a constant rate,
37 24 hours per day. Moccasin and Holm rather than to take advantage of daily and powerhouses, by contrast, provide “peak- seasonal variations in electricity prices. In ing” power, concentrating energy pro- this regard, the City’s hydropower opera- duction during those hours of the day tions differ from those of comparable when electricity is most valuable. Accord- facilities elsewhere in California, which ing to the San Francisco Electricity are owned by electric utilities and operated Resource Plan, this system produces 1,700 to maximize power-sales revenues. In million KWh in years of average rainfall.4 most years, the demand for electricity is Hydropower production is highly greatest and power is most valuable in variable, however, fluctuating from year August and September; thus hydropower to year with the amount of precipitation operators generally try to conserve stored and the rate at which the winter snow- water for generation during hot summer pack melts. This variability is illustrated afternoons. San Francisco’s power produc- in Figure 5-8, which shows annual pro- tion tends to decline during those months, duction by powerhouse for water years however, as illustrated in Figure 5-9. 1971–2002. Over the last three decades, About a third of this electricity is used annual energy produced at San Francisco’s by public facilities, including the San Hetch Hetchy powerhouses has ranged Francisco International Airport, the San from 544 million KWh in the drought Francisco Municipal Railway (Muni), the year of 1977 to 2,391 million KWh in Port of San Francisco, San Francisco 1983. But one consistent feature across county hospitals, the Recreation and all water-year types is that average gen- Parks Department, street lighting, the eration is highest in May or June, when Moscone Convention Center, and the the spring runoff typically peaks. City’s water and sewer utilities. Until The hydropower of San Francisco’s recently, much of the remainder was sold system is essentially a byproduct of its to the Turlock Irrigation District (TID) water-supply operations, with flows and Modesto Irrigation District (MID) scheduled to meet water users’ needs under long-term contracts at rates below FIGURE 5-8 Annual production by powerhouse: SFPUC Tuolumne River system
3,000,000 ■ Holm ■ Moccasin ■ Kirkwood
2,500,000
2,000,000
1,500,000 MWh
1,000,000
500,000
0 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
The SFPUC’s Tuolumne River hydroelectric plants can produce 1,700 million KWh in years with average rainfall, but output varies widely from year to year. Source: United States Department of Energy, Energy Information Administration
38 market prices, as mandated by the Raker pany, but the City sells surplus power to Act. The Act also prohibits San Fran- other public entities as well.5 cisco from selling the Tuolumne’s In most years, the SFPUC is a net hydropower to investor-owned utilities seller of electricity, as illustrated in such as Pacific Gas and Electric Com- Figure 5-10. Although the Tuolumne’s
FIGURE 5-9 Average monthly energy production by water year type, 1974–2002, SFPUC Tuolumne River powerhouses
250
200
150
100 Million KWh
50 Critically dry Dry Below normal Above normal Wet
0 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept
Hydroelectric production at the SFPUC’s powerhouses typically peaks during the spring runoff, tapering off in late summer. This seasonal pattern reflects the SFPUC’s focus on water supply operations. In hydropower systems that are operated to maximize power sales revenues, water is typically conserved to generate electricity in July–September, when it is most valuable. Source: United States Department of Energy, Energy Information Administration
FIGURE 5-10 Sources and uses of SFPUC energy, 2002
2500
2000 Line losses Power purchases Others
1500 TID
1000 MID Million KWh
Own generation RESALE SALES FOR
500 City/county use
0 Sources Uses
In most years, the SFPUC is a net seller of electricity. Power that is not used in San Francico’s public facilities is sold to the Turlock and Modesto Irrigation Districts and other power market participants. The SFPUC also purchases energy when the output from its Hetch Hetchy System is insufficient to meet its own needs and satisfy contractual obligations. Source: United States Department of Energy, Energy Information Administration
39 CORBIS High Sierra streams converge in Tuolumne Meadows, the headwaters of the Tuolumne River and a popular trailhead for backpackers exploring Yosemite’s backcountry. annual hydropower production exceeds traverse the high Sierra lakes or some- the City’s municipal energy needs, at times explore the “Grand Canyon of the times San Francisco must purchase Tuolumne” above Hetch Hetchy Valley. energy to satisfy its own total demand Downstream of Hetch Hetchy Valley, and meet its contractual obligations to beginning just below the confluence of MID and TID. These purchases usually Cherry Creek and the Tuolumne River, occur during the summer and fall months, lie two world-class stretches of white- when power production is reduced so that drinking water can be stored.6 Cur- rently the City has a long-term contract with the Calpine Corporation in order to achieve those ends.
Recreation and ecosystem protection In addition to supplying water for urban, agricultural and power-genera- tion uses, the Tuolumne River also provides recreational opportunities and environmental benefits. Tuolumne Meadows, high in the Yosemite National Park, is a popular destination for visitors, many of whom return home with tales of encounters with Yosemite’s hungry, but normally harmless, black
bears. Tuolumne Meadows also serves as LANCE LOUGEE a trailhead for hardy backpackers who A paddle crew frolics on the Tuolumne River.
40 water. In spring and summer, experi- provided spawning habitat for chinook enced kayakers and rafters come to “run salmon and steelhead trout. But habitat the T,” floating the river’s exciting and degradation, drought, water diversions well known rapids by day and camping and other factors combined to drastic- on the its banks by night. ally reduce spawning there; the low The “Class 5” upper stretch, known point was in 1991, when only 77 fall- as the Cherry Creek run, is for veteran run salmon returned to the lower river runners only, even when in the Tuolumne. Since then, the efforts of company of professional guides. The government agencies, local communi- lower “Lumsden” run is a wet, fast and ties, environmentalists and water dis- sometimes scary ride in May and June, tricts, as well as protective minimum when Sierra snowmelt often spills from flows mandated by the Federal Energy the upstream reservoirs and provides Regulatory Commission, have im- high flows. As flows recede, the Lums- proved the fishery’s status significantly. den run is less intimidating, but it is still Restoration projects in the 52-mile a popular and exciting challenge; inex- stretch between La Grange and the perienced river runners should not Tuolumne’s confluence with the San attempt to run the Tuolumne alone. On Joaquin River continue, not only to weekdays throughout the summer, the improve fishery populations but also SFPUC makes hydropower releases to expand the river channel’s capacity from Holm Powerhouse that accommo- to control flooding. Responsibility for date boating on both of these stretches. providing instream flows below La The lower Tuolumne River, like other Grange Reservoir is borne by the Turlock Central Valley streams, historically and Modesto Irrigation Districts.
41 CHAPTER 6 Alternative water-system components
This chapter describes a variety of local surface storage, groundwater ex- components, for possible use in place changes, or transfers, but acknowledges of the Hetch Hetchy Reservoir, that that other options are available as well. would maintain or even improve the • Treatment. The existing SFPUC reliability and safety of San Francisco’s system applies conventional water treat- water-supply system. Most of these com- ment methods only to its releases from ponents are already being considered— its Bay Area reservoirs; it is not required either in the SFPUC’s Water Supply to filter its Tuolumne River supplies and Master Plan, its Capital Improvement therefore does not have the physical 1 Program (CIP), or both —as they could capacity to do so. Under the restoration enhance system performance even if alternatives considered in this report, Hetch Hetchy Valley were not restored. significant supplies would be diverted Such improvements are evaluated with- from locations downstream of Hetch out expansion of local conservation and Hetchy Valley and the SFPUC would recycling programs, and with significant expand its conventional treatment increases in Bay Area water use over capacity to cover all of its supplies. the next 25 years—though a final plan should include serious examination of these issues. The components fall into three basic Conveyance options categories: While Hetch Hetchy is the best-known component of San Francisco’s present • Conveyance. Establishing reliable system, it holds less than 25 percent conveyance from all potential sources (360,000 out of a total of 1,533,000 of supply is the best way of ensuring acre-feet) of total system storage. But uninterrupted delivery of water to the given its limited conveyance and treat- SFPUC’s Bay Area customers. But ment capabilities, it is often difficult at present, SFPUC does not have for the SFPUC to make full use of its direct access to most of its water water storage in the other reservoirs— storage in Sierra Reservoirs. Also, Cherry, Eleanor and Don Pedro—in as addressed in detail by the CIP, the Tuolumne watershed. Getting full in many places the system’s reliance access to these supplies is critical to on a very limited set of tunnels and maximizing the reliability of SFPUC’s pipelines makes it too vulnerable to water supply, with or without Hetch earthquakes, droughts, and other Hetchy Reservoir. adverse events. Under all restoration alternatives, • Supply. Even without Hetch Hetchy SanFrancisco would continue to divert Reservoir, the total storage capacity in Tuolumne River flows during winter SFPUC reservoirs would be more than and spring months, and diversions three times its annual delivery objectives. might even be increased under some In dry years, however, the SFPUC’s circumstances and stored in local water rights are very limited, and alter- reservoirs closer to Bay Area customers. native supplies would be needed. This Diversions from the Tuolumne River in report examines alternatives for provid- the summer and fall would have to be ing those supplies through increased made farther downstream, drawn from
42 the SFPUC’s supplies stored in other higher-quality water already under San Tuolumne watershed reservoirs. Francisco’s control, an intertie to the The simplest approach would be California Aqueduct would establish a to build a new intertie between the link to most water systems in the state Tuolumne River and San Francisco’s and allow the SFPUC much greater aqueduct. If the intertie were at or flexibility in purchasing water from below Don Pedro Reservoir, the City other water agencies or exchanging would have access to its supplies stored supplies. Constructing both interties in Don Pedro itself, as well as upstream would offer additional alternatives to in Cherry and Eleanor Reservoirs. San Francisco, and would help ensure Alternatively, water could be released reliable supplies in the future. from Don Pedro Reservoir, flow down the Tuolumne and San Joaquin Rivers INTERTIE TO LOWER TUOLUMNE to the Sacramento-San Joaquin Delta, RIVER and be diverted to the SFPUC via the Don Pedro Reservoir, completed in state or federal export pumps. While the 1970, holds over 2 million acre-feet, intertie to Don Pedro would provide almost six times the storage of the FIGURE 6-1 Potential locations for lower Tuolumne or Delta intertie
Delta Mendota 5 Canal San Francisco San Joaquin Pipelines 6 South Bay Aqueduct 4 3 1 California Aqueduct e R Don Pedro 2 mn iver Reservoir Tuolu South Bay Aqueduct r ced Riv e er S M a n Don Pedro J o a Reservoir qu in R iv e Lower Tuolumne Intertie options r 4. Canal from La Grange Reservoir (below Don Pedro) to San Joaquin Pipeline Delta Intertie options 5. Direct connection4. Canal between Intertie 1. Expanded South Bay Aqueduct Don Pedro and Foothill Tunnel to San Joaquin Pipeline Intertie junction 2. California Aqueduct Intertie 6. Pipeline from Don Pedro to 3. Delta Mendota Canal Intertie Moccasin Reservoir HH system pipelines
An intertie on the lower Tuolumne River could provide the SFPUC access to more than 1,000,000 acre-feet of water supply stored in Cherry and Eleanor Reservoirs and its water bank in Don Pedro Reservoir. An intertie to the State-federal Delta system could provide access to additional supplies, particularly in critically dry years or under emergency conditions, but would require negotiation with a variety of agencies which rely on supplies from the Delta.
43 TIM CONNOR San Francisco’s water bank in Don Pedro holds more than twice as much water as Hetch Hetchy Reservoir.
Hetch Hetchy Reservoir. While San Without storage in the Hetch Hetchy Francisco owns up to 740,000 acre-feet Reservoir, the SFPUC might divert of “water bank” storage in Don Pedro, the directly from its bank in Don Pedro SFPUC does not currently draw this Reservoir (assuming that the afore- water directly. Rather, when the SFPUC mentioned legal and infrastructural issues diverts water upstream that belongs, were resolved). There are in fact several under the water-rights criteria, to the ways that the SFPUC’s supplies in Don Turlock and Modesto Irrigation Districts, Pedro Reservoir could be moved into the it repays these districts from its bank. Hetch Hetchy Aqueduct for transport to San Francisco shared the cost of the Bay Area, either for immediate use or constructing Don Pedro Dam with storage in local reservoirs. Water could be: the Turlock and Modesto Irrigation • pumped directly from Don Pedro into Districts through a complex set of the Foothill Tunnel, which runs directly agreements. As a result, SFPUC has beneath the reservoir; access to storage in Don Pedro even when Tuolumne flows are below the •released through the Don Pedro Power- levels at which it possesses recognized house and diverted farther down- water rights. The City has no infra- stream, perhaps via a new pipeline or structure for conveying its Don Pedro canal from La Grange Reservoir to the supplies to the Bay Area, however, Hetch Hetchy Aqueduct; nor has it established the legal right to • pumped to Moccasin Reservoir (the build any such infrastructure. Thus con- entrance to the SFPUC’s Foothill struction of an intertie between Don Tunnel), where present-day releases from Pedro reservoir and the SFPUC’s con- Hetch Hetchy enter the aqueduct. veyance system would require the active cooperation of the Turlock and Modesto Schlumberger Water Services has Irrigation Districts. estimated that constructing such an
44 TIM CONNOR The California Aqueduct carries water from the Sacramento-San Joaquin Delta to a number of Bay Area communities and much of urban Southern California. intertie directly to Don Pedro Reservoir, able.2 Delta pumping constraints are most with the capacity to pump up to 407 cfs, restrictive in the spring, when the SFPUC would cost $29.7 million. Incorporating would normally be able to divert the estimates for engineering, legal and Tuolumne’s flows. During wet years, when administrative costs, and a standard these plants are often at full capacity as range for the uncertainty of construction they move water supplies from northern factors indicates that the cost of the California to urban southern California intertie could range from $25 million and irrigated agriculture in the Tulare to $53.5 million (see Appendix A). Basin, San Francisco’s needs for diversion would be smallest. Of course, INTERTIE TO THE STATE WATER SFPUC could also pump Delta supplies, PROJECT when available, into its local storage Most of California diverts at least some reservoirs for delivery at a later time. of its water supply from the Sacramento- With improved access to its Tuolumne San Joaquin Delta, but the SFPUC has River supplies, an intertie to the State rarely done so, even though its San Water Project’s California Aqueduct Antonio Reservoir is physically con- would not be used in most years. In nected to the Delta via the State Water critically dry years, however, such an Project’s South Bay Aqueduct. In the future, however, releases from San Francisco’s water bank in Don Pedro The San Francisco Public Utilities Reservoir could be timed to coincide Commission diverted 71,000 acre- feet from the Delta in 1991 and with diversions from the Delta. 1992, when its storage at Hetch Delta pumping plants are often oper- Hetchy as well as its water bank in ated at full capacity, but San Francisco’s Don Pedro Reservoir reached low most critical needs might coincide with levels. periods when some spare capacity is avail-
45 intertie would allow the SFPUC access from willing sellers—are options that to purchase supplies from a wide vari- urban water districts throughout Cali- ety of agencies throughout the state. fornia have been adopting in recent Without improved access to its years as they have diversified their port- Tuolumne River supplies, the SFPUC folios to assure reliable water supplies would need to use an intertie to the for their customers. Other options State Water Project much more fre- should be considered as well; for exam- quently, requiring significant negotia- ple, the SFPUC and its customers are in tions with SWP contractors. the midst of a comprehensive effort to identify and implement cost-effective conservation measures. Supply alternatives The supply alternatives discussed LOCAL SURFACE STORAGE below—increased local surface storage, The SFPUC owns five principal groundwater exchange and transfers storage reservoirs in the Bay Area, with a total capacity of about 239,000 acre-feet, which could be expanded to offset the storage capacity lost if Hetch Hetchy Valley were restored. The most obvious opportunity is the expansion of the Calaveras Reservoir—at 97,000 acre-feet, the largest of the SFPUC’s Bay Area reservoirs—which must be rebuilt anyway because it has been declared unsafe by the state’s Division of Safety of Dams (a unit of California’s Department of Water Resources). The SFPUC has proposed that the dam be increased to hold as much as 420,000 acre-feet, an increase that is nearly equivalent to the storage capacity of Hetch Hetchy Reservoir. For the analysis in this report, Schlumberger Water Services has reviewed the SFPUC’s investigation of an expanded Calaveras Reservoir and has estimated that the cost of recon- struction would be $23 million (to rebuild Calaveras at its current size of 97,000 acre-feet) or $90 million (to enlarge it to 420,000 acre-feet). The inclusion of additional expenses—for engineering, legal and administrative costs, and a standard range for the un-
MIKE MULLEN SFPUC certainty of construction factors—indi- Calaveras Reservoir (top) lies on a tributary of Alameda Creek (bottom). cates that rebuilding the reservoir at its Expansion of the reservoir would create challenges for protecting sensitive species in the watershed, but also opportunities to provide enhanced flows for current size would cost from $19.3 mil- native steelhead restoration in nearby Alameda Creek. lion to $41.4 million and that enlarging
46 the reservoir to 420,000 acre-feet would aries for deals with other districts in the cost between $75.6 million and $162 eastern San Joaquin Valley—together million (see Appendix A). with incentives for the area’s agencies In addition, Schlumberger has esti- and landowners to participate. mated that the cost of building facilities Schlumberger Water Services has to pump up to 204 cfs of Tuolumne evaluated the physical potential of supplies into Calaveras would be groundwater-management opportunities $43.4 million. Incorporating estimates in or near the lower Tuolumne water- for engineering, legal and administrative shed. Schlumberger estimated total costs costs, and a standard range for the of $119.2 million to install infrastructure uncertainty of construction factors for a 400,000 acre-foot groundwater bank, indicates that the pumping station and with extraction capability of 200 cfs and pipeline would cost from $36.5 million recharge capability of between 283 and to $78.2 million (see Appendix A). 386 cfs. Incorporating estimates for The SFPUC, in its Water Supply engineering, legal and administrative Master Plan and supporting documents, costs, and a standard range for the has also considered a long list of other uncertainty of construction factors new or expanded storage sites. For indicates developing the lower- example, it has investigated a partner- Tuolumne groundwater bank would incur ship role in the proposed expansion a total cost between $100.1 million and of Los Vaqueros Reservoir in Contra $214.5 million (see Appendix A). Costa County. Alternatively, the SFPUC could bank groundwater in a number of locations GROUNDWATER EXCHANGE throughout the Central Valley. Under Many agricultural and urban water such an agreement, dry-year supplies agencies throughout California rely would likely be provided through a State on groundwater as part of their long- Water Project intertie. term water supply for the simple reason In any case, while significant new that groundwater storage increases a groundwater-storage capacity might be system’s reliability and flexibility. San developed as one way of replacing the Francisco’s Water Supply Master Plan storage in Hetch Hetchy Valley, it has also identified groundwater oppor- would probably not be accessed during tunities—in the Westside Basin in most years. This supply could, however, SanFrancisco, Daly City and San provide important additional capacity Bruno, as well as in exchange programs during dry years and extended droughts. throughout the Central Valley and in the Tuolumne watershed. TRANSFERS In the latter case, diversions from Don With or without the storage provided by Pedro would be made during wet years O’Shaughnessy Dam in Hetch Hetchy to replenish groundwater storage. In dry Valley, the biggest challenges generally years, surface-water diversions from Don facing water managers in California, and Pedro would decrease and groundwater the SFPUC in particular, arise in dry years pumping would increase. Such changes in when the perennial conflicts between Don Pedro operations for the manage- users of water for beneficial agricultural, ment of groundwater resources would urban and environmental purposes are require agreements with the Turlock and exacerbated. But in some parts of the Modesto Irrigation Districts—whose state, these conflicts have been resolved, officials might in turn act as intermedi- and agreements between water-rights
47 holders and buyers have helped to im- filter all of its supplies. But to do so, the prove water-supply reliability while SFPUC would need to increase respecting legal ownership rights. treatment capacities beyond the levels Such transfers are not easy to negotiate, identified in its CIP. and for a variety of reasons—including While a variety of locations, either alack of clarity over who “owns” the in the Bay Area or the Central Valley, water, a perceived weakening of rights might be suitable for the expanded when they are leased or sold, and treatment facilities, this report assumes potential impacts on third parties and that the increase would occur at the the environment. Nevertheless, the SFPUC’s existing Sunol Treatment potential benefits of agreements Plant. Schlumberger Water Services between willing sellers and buyers have has estimated that expanding the made transfers a significant part of capacity of the plant by 160 million water portfolios for many districts. gallons per day (beyond the SFPUC’s Analysis for this report considers planned 80 million gallons per day potential transfers from agricultural expansion) would incur a total cost of districts to the SFPUC during dry years. between $134 million and $288 million As in the case of groundwater, the (see Appendix A). simplest water transfers would involve agreements with water rights holders in the Tuolumne River area. With an intertie Integrating water-system to the California Aqueduct, however, components the SFPUC could purchase water from Combining many of the components a wide variety of sellers statewide. described above could not only preserve It is not known what the costs of these the level of reliability currently provided transfer agreements would be. The price by O’Shaughnessy Dam and Hetch per acre-foot of water purchased only in Hetchy Reservoir, but meet projected dry years would likely be significantly increases in water-delivery objectives as higher than if transfers were executed well. They could also provide the every year or in wetter years. For the pur- SFPUC with additional options in case pose of this report’s analysis, we assume its San Joaquin pipelines were rendered transfer costs of $500 per acre-foot—a inoperable. conservative estimate that is significantly Chapter 7 examines several possible higher than the transfer and groundwater- alternatives, using computer-based sim- banking costs identified in Chapter 3. ulation modeling, for these components’ integration into the SFPUC water- supply system. The total costs of imple- Expanded water-treatment menting these scenarios, including the facilities costs of forgone hydropower and addi- Whatever the restoration alternatives tional water treatment, are provided in pursued, San Francisco would have to Chapter 10.
48 CHAPTER 7 Equivalent water-supply reliability
This chapter analyzes potential alterna- Overview of simulation modeling tives for operating the San Francisco It is standard practice to use computer- Public Utilities Commission (SFPUC) based simulation models to evaluate system using computer-based simulation shifts in water-system performance that models. First we compare simulated may result from infrastructural, demand, operations with actual operations; that or operating-requirement changes. is, the analysis considers the system in The state-federal CALSIM is the most its present incarnation, with Hetch commonly used model in California’s Hetchy Reservoir in place and currently Central Valley, but it is designed to focus available water-delivery capability un- on the operations of the State Water changed. A second simulation, with Project and the federal Central Valley Hetch Hetchy Reservoir still in place, Project.1 Also, while CALSIM includes assumes a potential future system with Don Pedro Reservoir, operations of the increased water deliveries made possible Turlock Irrigation District (TID) and by implementation of some of the Modesto Irrigation District (MID), and expansion-oriented elements of the lower Tuolumne River flows, it does not SFPUC’s Capital Improvement Pro- include Hetch Hetchy Reservoir, other gram (CIP). Both of these “base” simu- SFPUC upstream reservoirs, or the lations include not only the delivery delivery of Tuolumne supplies to the Bay of water to customers but assume that Area. Thus it could not be used as the additional supplies are in storage, at all principal model in this study. times, as insurance against drought. An alternative option was the The two base cases are then com- HHSM-LSM model, which the SFPUC pared to a variety of “restoration” alter- generously provided to Environmental natives that simulate system operations Defense (under a proprietary agree- without Hetch Hetchy Reservoir. These ment). But while HHSM-LSM was simulations first calculate, on a monthly useful for understanding the capabilities basis, how much of the Tuolumne River of the SFPUC’s existing system, it flow could be diverted at the SFPUC’s proved difficult to modify for evaluating Early Intake Dam (between Hetch restoration alternatives. Hetchy and Don Pedro Reservoirs); To efficiently assess system reliability and the amount of water that could be under a range of possible alternatives, withdrawn at a downstream diversion Environmental Defense developed its own point at or below Don Pedro Reservoir. model—TREWSSIM (Tuolumne River These downstream diversions are con- Equivalent Water Supply Simulation). strained, in all model runs for the TREWSSIM includes data and meth- alternative cases, so that total system odologies found both in CALSIM and minimum-storage levels are consistent HHSM-LSM, and it accommodates the with base-case conditions. Alternative alternative components developed for this supplies would be needed to meet any study. Also, TREWSSIM can simulate remaining demands. The analysis operations not only of the SFPUC but presented below shows how often and also of TID and MID, with and without to what extent such supplies would be O’Shaughnessy Dam.2 needed, as well as how they might be Like CALSIM, TREWSSIM simu- integrated into system operations. lates operations using a monthly time
49 step and the natural flows that occurred objectives and storage capacity both for between 1922 and 1994. This “historical the SFPUC and the Districts. hydrology” approach is standard practice TREWSSIM’s principal outputs for water supply planning in California. include: TREWSSIM incorporates existing •Water deliveries to the SFPUC, TID infrastructure (such as reservoirs, canals, and MID. and pipelines), delivery objectives, and in-stream flow requirements. For this •Water storage for the SFPUC, TID study, the model evaluates both the cur- and MID. rent water-delivery objective of the •Hydropower generation at the SFPUC’s SFPUC (290,000 acre-feet per year) Kirkwood, Moccasin and Holm Power- and its projection for 2030 (339,000 houses and the Districts’ Don Pedro 3 acre-feet per year). Powerhouse. Modeling the performance of the • The proportions of SFPUC water SFPUC water system also requires model- supplies derived from each source. ing TID and MID operations, as all three rely on supplies from the Tuolumne •Flow levels downstream of Don Pedro River (see Figure 5-5 for a schematic of Reservoir, which affect the down- the SFPUC and Tuolumne River water- stream fishery and, under some condi- supply system). Figures 7-1a and 7-1b tions, the potential for flooding in summarize the inflows, current delivery Modesto and surrounding areas.
FIGURE 7-1 Water supply, storage capacity and delivery overview
(a) San FranciscoŁ (b) Turlock and ModestoŁ Public Utilities Commission Irrigation Districts 2000 2000
■ Lower Tuolumne River flow requirements ■ Consumptive use 1500 1500 Hetch Hetchy
BayŁ 1000 Area 1000
Cherry- Eleanor Thousands of acre-feet Thousands of acre-feet 500 500 Don Pedro Water Bank
0 0 Demand TotalŁ Water rightsŁ Water rightsŁ Water rightsŁ Demand Don PedroŁ Water rights Water rights WaterŁ surfaceŁ annualŁ droughtŁ minimumŁ storage annualŁ droughtŁ rightsŁ storage averageŁ averageŁ year (1977) average average minimumŁ (1922-1994) (1987-1992) (1922-1994) (1987–1992) year (1977)
(a) In most years San Francisco’s water rights are enough to meet its customers’ needs. The SFPUC relies on storage in Hetch Hetchy, Don Pedro and other reservoirs to provide insurance against droughts, when its water rights are inadequate. (b) The Turlock and Modesto Irrigation Districts share the Tuolumne River with San Francisco, holding “senior” water rights that predate the City’s. The Districts store water in Don Pedro for irrigation and domestic use and release flows below the reservoir to support the lower Tuolumne River and its fisheries. Source: SFPUC and Bureau of Reclamation
50 Water deliveries under the “Existing must be released from storage). Model- Conditions” simulation are specified to ing indicates that an average of 149,000 be identical to those reported in the San acre-feet (51 percent) of the SFPUC’s Francisco Water Supply Master Plan total water supply could be diverted (for the SFPUC) and in the Central directly from the river’s flow and 104,000 Valley Project’s Operations Criteria and acre-feet (36 percent) from storage. Plan (for TID and MID). For the Finally, Figure 7-4a shows years in which SFPUC, full objectives are generally the system cannot reliably meet full met, though 10- to 15-percent shortages delivery objectives. These “shortages,” are imposed in some critically dry years.4 consistent with the SFPUC’s Water Sup- TID and MID normally deliver supplies ply Master Plan (April 2000), require the very close to their full objectives, though SFPUC to reduce deliveries by about sometimes with the aid of groundwater 11 percent in one out of every nine years.6 pumping, especially in dry years. For the SFPUC, a repeat of condi- For operating Don Pedro Reservoir— tions similar to the six-year drought by far the largest reservoir in the com- from 1987–1992—when its share of bined system—TREWSSIM uses the Tuolumne water rights was barely one- evaporation, flood-control and minimum- half of its delivery objective—is of great downstream-flow parameters found in concern. Despite delivery reductions in CALSIM. For operating Hetch Hetchy, five out of six of these years, storage Cherry and Eleanor Reservoirs, levels dropped steadily throughout the TREWSSIM uses the corresponding period. Figure 7-3a shows this gradual parameters provided by the SFPUC. In but steady storage reduction, and com- assessing alternatives that include the pares the modeled values to actual restoration of Hetch Hetchy Valley, historical values. TREWSSIM accounts for the SFPUC’s Consistent with actual experience, flood-control criteria for operating TREWSSIM projects the lowest storage Hetch Hetchy Reservoir by moving it value for the SFPUC system would occur downstream to Don Pedro Reservoir.5 in late 1992, shortly before California welcomed back large winter storms for the first time in seven years. While the Existing conditions: Meeting water utility was indeed fortunate to current needs with today’s have almost twice its average annual system delivery objective at the end of a worst- Figure 7-4a provides an overview of case drought, generally the reduced TREWSSIM’s characterization of the storage would pose many problems for SFPUC water deliveries under Existing the current SFPUC system. Conditions. Over the course of an Most obviously, SFPUC’s Tuolumne average year, about 34,000 acre-feet River water rights are almost nonexistent (12 percent) of the SFPUC’s water in some dry years, and the system is ill supply comes from rainfall in Bay Area suited to make use of the Tuolumne sup- watersheds. The remainder is diverted plies that it does have in storage. There from Hetch Hetchy Reservoir. These is no physical connection between the diversions are of two types: “flow” SFPUC’s customers and its water bank in diversions (i.e., those that derive from Don Pedro; the ability to move water from the natural flow of the river) and “storage” Cherry and Eleanor Reservoirs to the Bay diversions (i.e., when the Tuolumne Area is very limited. Moreover, the River’s flow is insufficient and water SFPUC has limited ability to treat water
51 from some of its own storage or alterna- 2030. As the purpose of this report is to tive sources, largely because of its tradi- address what steps might be taken to tional reliance on diversions from Hetch restore Hetch Hetchy Valley, it is Hetchy, which have been granted a rare appropriate that both current and exemption from filtration requirements potential future levels of demand are by both the U.S. Environmental Pro- considered. This increased level of tection Agency and the California demand is therefore incorporated in the Department of Health Services. TREWSSIM analysis presented below. It should be noted, however, that the SFPUC and its wholesale customers are Potential future conditions: currently reviewing these initial Meeting tomorrow’s needs in projections, with particular attention to the Bay Area possibilities for implementing water-use The SFPUC’s Water Supply Master efficiency measures. Environmental Plan (WSMP) projects that its Defense strongly supports aggressive customers’ demand for water, resulting water-use efficiency and looks forward from population growth in San Mateo, to reviewing the agencies’ findings. Santa Clara and Alameda counties, will In any case, the SFPUC has not clearly increase to 339,000 acre-feet per year by stated how it plans to meet future in-
FIGURE 7-2 Elements of the SFPUC’s Capital Improvement Program that might overlap with a restoration plan for Hetch Hetchy Valley
Reservoir HH system pipelines Major pipelines
Additional San Francisco San Joaquin Pipeline J
Expanded Sunol Water Treatment Plant
Calaveras Reservoir Replacement (with proposed expansion) )
52 creased demand, should the projections in its WSMP change little under the current review process. With the presence of expanded conveyance across the San Joaquin Valley and expanded storage in the Bay Area, however, it does appear that the SFPUC anticipates a Tuolumne River management regime that would sharply increase the diversions of Tuolumne River water to the San Fran- cisco Bay Area. To evaluate alternatives for meeting increased water deliveries, we include in our Potential Future Con- ditions simulation the following three components of the SFPUC’s $3.6 billion Capital Improvement Plan (CIP): • Expansion of the Calaveras Reservoir to 420,000 acre-feet. •Construction of a fourth pipeline to increase conveyance capacity of Tuolumne supplies across the San
Joaquin Valley to 542 cubic feet per BANCROFT LIBRARY second.7 The Oakdale Portal, pictured in this 1931 photo- graph, connects the SFPUC’s Foothill tunnel and • Expansion of the capacity of the Sunol its San Joaquin pipelines. Adding a new fourth pipeline would improve reliability both by expand- Water Treatment Plant from 160 to ing conveyance capacity and providing a redundant 240 million gallons per day. pipeline (to facilitate repairs on the others). Environmental Defense does not assume, for example, that Calaveras need to be tapped in order to meet Reservoir will be expanded, nor do we anticipated demand. Yet even the take any position at this time on such 323,000 acre-feet of additional storage expansion. This report simply uses the provided by expanding Calaveras above three elements of the CIP to Reservoir from 97,000 acre-feet to project one possible future for the 420,000 acre-feet would not be sufficient SFPUC against which to compare to allow the SFPUC to fully meet its alternatives that would accommodate projected water-delivery objective of restoration of Hetch Hetchy Valley. 339,000 acre-feet per year while retain- Figure 7-4c provides an overview of ing the high level of carryover storage in how the SFPUC’s 2030 objective would the Existing Conditions alternative in be met with the expansion of Calaveras all years. Fully meeting this objective Reservoir. In most years, under current for the drought between 1987 and 1992 demand levels, existing local supplies would require an additional total supply and diversions of Tuolumne supplies of 77,000 acre-feet per year—462,000 would together be sufficient to meet an acre-feet for the six year period—to expanded delivery level of 339,000 acre- alleviate the shortages under the current feet. In critically dry years, however, system and to accommodate the storage at Calaveras Reservoir would projected increase in demand.
53 The Potential Future Conditions this report, but the restoration alternative does assume, however, that alternatives under this future demand the full delivery objective of 339,000 projection are constrained by acre-feet is accomplished in all years. TREWSSIM to retain a similar amount As a result, the system’s simulated mini- of storage under all conditions. The mum end-of-drought storage falls from SFPUC’s overall storage under this 559,000 acre-feet (under the Existing alternative during the 1987– Conditions alternative) to 331,000 acre- 1992 drought is shown in Figure 7-3b. feet—just under one year’s supply— While all water moved from the under the Potential Future Conditions Tuolumne system to the Bay Area alternative (see Figures 7-3a and 7-3b). under this alternative would be in strict For many systems, this amount of accordance with the SFPUC’s water carryover storage would be deemed rights, the modeling suggests that sufficient. The SFPUC, however, has adverse impacts to the TID and MID little supply under its water rights in dry could occur under these future condi- years, almost nonexistent alternative tions. Currently, the Districts rely on supplies, limited treatment facilities and receiving water that accrues to the limited conveyance-all of which leads it SFPUC under its water rights but that to rely heavily on significant carryover it is unable to use. Thus, when the storage. The efficacy of relying on lower SFPUC’s water in Don Pedro Reservoir storage levels is not discussed further in exceeds its maximum water-bank
FIGURE 7-3 Simulated drought-period storage values
(a) Existing system (b) Potential future system (c) Potential future system projected storage projected storageŁ projected storageŁ (1987–1992 drought) (1987–1992 drought) (1928–1936) 4000 4000 4000 ■ SFPUC ■ SFPUC ■ SFPUC ■ TID/MID ■ TID/MID ■ TID/MID Actual historic total storage 3000 3000 3000
2000 2000 2000
1000 1000 Thousands of acre-feet Thousands of acre-feet Thousands of acre-feet 1000 Turlock and Modesto's combined The SFPUC's total storage The SFPUC's total storage storage in Don Pedro Reservoir reaches a low point of 559,000 reaches a low point of 331,000 is entirely emptied under this acre-feet under this alternative. acre-feet under this alternative. alternative. 0 0 0 June June June June June June June June June June June June June June June June June June June June June June June June 1986 1987 1988 1989 1990 1991 1992 1986 1987 1988 1989 1990 1991 1992 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936
(a) Compares simulated storage values for the SFPUC, TID and MID, under the Existing Conditions alternative, during a hypothetical repeat of the 1987–1992 drought. Because of the dry hydrology, exacerbated by limited Tuolumne River water rights, SFPUC’s storage decreases steadily throughout the period, with only brief and minor occasional increases. (b) Shows simulated storage values for the SFPUC, TID and MID, under the Potential Future Conditions alternative, during a repeat of the 1987–1992 drought. Given the assumed expansion of Calaveras Reservoir, the SFPUC begins the drought period with more water in storage than under the Existing Condi- tions alternative. But because of the assumed increases in demand, the SFPUC ends the period with less water in storage. (c) Shows simulated storage values for the SFPUC, TID and MID, under the Potential Future Conditions alternative, during a repeat of the 1928–1936 period. The modeling suggests that, given certain hydrological conditions, increased diversions of Tuolumne water by the SFPUC under its water rights would leave less available to the Turlock and Modesto Irrigation Districts.
54 storage, it “spills” to the Districts. If the the TID and MID would probably SFPUC diverts more water directly to conserve water by reducing allocations its customers or stores water for later use and asking farmers to switch to ground- in an expanded Calaveras reservoir, its water. More generally, the analysis indi- water bank in Don Pedro Reservoir is cates that increased diversions by the less likely to spill. SFPUC do have the potential to Whether such spills occur is most diminish the Districts’ water supply. likely to be relevant to the Districts in years when near-average precipitation follows a dry period. (In wet years, all Simulation analysis of parties have plenty of water. In dry restoration alternatives years, the SFPUC’s water bank does not Operating the SFPUC water system spill.) Comparing the Potential Future without Hetch Hetchy Reservoir Conditions simulation to the Existing would require significant changes. Conditions simulation, average annual Still, San Francisco’s rights to Tuolumne spills of SFPUC’s water bank decrease River flows, as formalized under the by 57,000 acre-feet (from 466,000 acre- Raker Act, would remain, as would feet to 409,000 acre-feet) and the more than 75 percent of the system’s Districts’ average storage in Don Pedro existing storage. It would be necessary decreases by 66,000 acre-feet (from to move water differently, however, as 869,000 to 803,000 acre-feet). summer and fall releases from Hetch During some periods, the Districts’ Hetchy Reservoir storage would no storage would be reduced by 200,000 longer be possible. In most years, acre-feet or more. Under a repeat of storage in other Tuolumne River water- the conditions of December 1935, for shed and Bay Area reservoirs would example, TREWSSIM modeling shows provide sufficient supplies. In dry that the Districts would have no water years, additional supplies would be in storage in Don Pedro Reservoir (See needed to maintain reliability for Bay Figure 7-3c). Under such conditions, Area customers. TIM CONNOR Run-of-river flows could be diverted from Early Intake Dam, where the SFPUC diverted its Tuolumne supplies prior to the completion of the Canyon Tunnel in 1967.
55 RUN-OF-RIVER DIVERSIONS SFPUC conveyance system, as well as Without storing water in the Hetch the cooperation of TID and MID. Hetchy Valley, the SFPUC would still be With an intertie in place, diversions able to use most of its Tuolumne River of water released from the SFPUC’s supplies by diverting the river’s natural water-storage bank in Don Pedro would flow, mostly in the winter and spring, be sufficient to meet either current or either directly to customers or to storage potential future system demands in facilities in the Bay Area. These diversions most years. Figure 7-4b provides an would take place either at the current site overview of the simulated mix of local of O’Shaughnessy Dam or downstream water supplies, upper Tuolumne (run- at Early Intake Dam, where the SFPUC of-river) diversions, and Don Pedro diverted its supply prior to the completion diversions that would together meet the of the Canyon Tunnel in 1967. current delivery objective of 290,000 The single greatest factor in determin- acre-feet in all but critically dry years. ing the feasibility of these diversions, of Analysis indicates that these deliveries course, is sufficient natural flow through- could be accomplished while maintain- out the year. (Other factors include the ing a minimum carryover storage value SFPUC’s maximum conveyance capacity, that is similar to the Existing Condi- storage capacity in Bay Area reservoirs, tions alternative value of 559,000acre- and customer demand in the Bay Area.) feet (see Figure 7-3a).9 TREWSSIM analysis of the hydrologic Under the Potential Future Alter- record indicates run-of-river diversions native (with an expanded Calaveras could provide an average of 149,000 Reservoir), adding an intertie to Don acre-feet annually, or about 59 percent Pedro would also allow the SFPUC to of the SFPUC’s total Tuolumne supply, meet increased demand in most years. under current conditions. Under Poten- Figure 7-4d provides an overview of the tial Future Conditions described, the anticipated supply mix that would be additional conveyance, local storage and sufficient to meet the future delivery demand would accommodate a slight objective of 339,000 acre-feet in all but increase in run-of-river diversions to an critically dry years, while maintaining average of 167,000 acre-feet. a minimum carryover storage value that is similar to the Potential Future Condi- USING AN INTERTIE TO DON tions alternative value of 331,000 acre- PEDRO RESERVOIR feet (see Figure 7-3b.10 The remainder of the SFPUC’s water Under either the Existing Conditions supply would need to be diverted farther or Potential Future Conditions alterna- downstream. Don Pedro Reservoir, or tives, no additional supply is necessary immediately downstream of it, would to meet delivery objectives in most be a logical location because it could years. For either alternative, additional provide the SFPUC with access not supplies would be necessary in critically only to its stored water in Don Pedro dry years, or about 22 percent of the but also to its supplies upstream in time. Under the Existing Conditions Cherry Lake and Lake Eleanor.8 In alternative, an average additional supply addition, the SFPUC’s Foothill Tunnel of 69,000 acre-feet would be necessary already runs directly under Don Pedro in years classified as “critically dry” to Reservoir. Diverting from Don Pedro, fully meet demands in every year. Under however, would require construction of the Potential Future Conditions alter- an intertie between the reservoir and the native, an average additional supply of
56 FIGURE 7-4 Simulated water supply sources for the SFPUC
(a) Existing SFPUC system at 2004 level of demand 300
200
100
0
Thousands of acre-feet 1922 1926 1930 1934 1938 1942 1946 1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994
(b) SFPUC without Hetch Hetchy Reservoir at 2004 level of demand 300
200
100
0
Thousands of acre-feet 1922 1926 1930 1934 1938 1942 1946 1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994
(c) Potential SFPUC system with Hetch Hetchy and expanded Calaveras Reservoirs in 2030 400
300
200
100
0
Thousands of acre-feet 1922 1926 1930 1934 1938 1942 1946 1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994
(d) Potential SFPUC system without Hetch Hetchy in 2030 400
300
200
100
0
Thousands of acre-feet 1922 1926 1930 1934 1938 1942 1946 1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994
■ Don Pedro Reservoir diversions ■ Hetch Hetchy Reservoir storage diversions ■ Run-of-river diversions ■ Existing shortages ■ Existing local supply ■ New dry-year supplies ■ Expanded Calaveras Reservoir
(a) Under current operations, local supplies from runoff in Bay well as increased demand, the existing storage facilities would Area watersheds account for an average of 12 percent of total sup- be sufficient to meet demand in most years. During critically dry ply. The rest of the supply is diverted at Hetch Hetchy Reservoir, years, however, expanded local storage would be needed in order either from the Tuolumne River’s flow or from storage. Without to meet demand for Bay Area customers. As shown in Figure 7-3b, Hetch Hetchy Reservoir, the diversions from storage would not be this alternative would result in lower carryover storage compared possible. This figure also shows the existing shortages as pro- to Existing Conditions. (d) Under projected future alternatives jected by the SFPUC. (b) Without Hetch Hetchy Reservoir, diver- that include both increased local storage as well as increased sions from a point lower on the Tuolumne River provide sufficient demand, Tuolumne River diversions (even without Hetch Hetchy supply to the SFPUC in most years while maintaining carryover Reservoir) and existing local facilities would be sufficient to meet storage objectives. In critically dry years, additional supplies would increased demand in most years. In critically dry years, however, be necessary in order to meet delivery objectives. (c) Under a pro- both expanded local storage and new supplies would be necessary jected future alternative that includes increased local storage as to meet demand for Bay Area customers.
57 48,000 acre-feet would be needed. (This directly or exchange it with agricultural water-supply replacement value for districts for surface water. As discussed critical years is slightly lower under the in Chapter 3, urban and agricultural Potential Future Conditions alternative agencies have negotiated in recent years because it is modeled with a relaxed a series of such groundwater-exchange carryover storage constraint.) agreements, which provide water-supply reliability for urban areas and generate EXPANDED LOCAL STORAGE important revenue for agricultural areas. Expanding Calaveras Reservoir, as From a physical perspective, a envisioned in the CIP, could replace groundwater-exchange project with most of the storage lost if Hetch Hetchy Tuolumne-watershed parties—includ- Valley were restored. The projected in- ing TID, MID, or other adjacent dis- crease at Calaveras of 323,000 acre-feet tricts—would be straightforward and (from 97,000 acre-feet to 420,000 acre- could allow additional surface-water feet) is slightly less than the capacity of diversions to the SFPUC from Don Pedro Hetch Hetchy Reservoir. Consequently, Reservoir. Alternatively, the SFPUC using the proposed increase at Calaveras could enter into an exchange agreement alone as an offset to Hetch Hetchy with agencies throughout the Central Reservoir would result in slightly dimin- Valley (though their supplies, diverted ished overall system storage. from the Sacramento-San Joaquin Delta, Figure 7-5a provides a summary of would probably require increased con- the simulated operations of Calaveras veyance capacity between the SFPUC’s reservoir under this alternative. Releases aqueduct and the State Water Project or from Calaveras for consumptive use are the Central Valley Project). made under a variety of conditions. For TREWSSIM modeling of a ground- example, some of these releases are water-exchange program to replace the made when natural inflow occurs and supply currently provided by Hetch the reservoir is already full. The Hetchy Reservoir suggests that an reservoir is most valuable in dry years, annual average of 9,000 acre-feet, with however, when its supplies can either be a maximum annual value of 96,000 acre- provided directly to customers or its feet, would be pumped. Under future storage can be used as insurance while conditions, modeling suggests that use allowing other reservoirs to be used of groundwater would increase slightly, more aggressively. averaging 15,000 acre-feet annually with Model results project that an annual a maximum use of 119,000 acre-feet. average of 36,000 acre-feet would be The modeling assumes that agricultural pumped into an expanded Calaveras, agencies would use the additional ground- with a maximum annual value of water in some dry years, thus making 136,000 acre-feet. In addition to the additional surface water available to the cost of pumping water into Calaveras, SFPUC and its customers. it is anticipated that supplies released Figure 7-5b provides a summary of from the reservoir would be more costly the simulated operations of new ground- to treat than supplies diverted directly water that would replace the storage lost from the Tuolumne watershed. with the restoration of Hetch Hetchy Valley. In most years, this additional GROUNDWATER groundwater would not be used. It In dry years, urban agencies throughout would simply remain in storage as a California either pump groundwater backup supply and allow water agencies to
58 operate other facilities more aggressively. supply reliability to the SFPUC and Groundwater would be pumped during its customers. Given that the SFPUC some dry years, but it would be replaced has ample supply in most years, a long- as quickly as possible. term agreement with a purchase option The total costs of groundwater oper- would probably best serve its needs. ations, combining the capital and oper- Under such an agreement, the SFPUC ating costs provided by Schlumberger would pay a flat up-front fee or an Water Services and the frequency of annual fee for the right to purchase operation simulated by TREWSSIM, certain quantities at specific times, are provided in Chapter 10. should the need arise, during the course of a dry year. In most years, no water TRANSFERS would be sold. In dry years, the SFPUC With an intertie to Don Pedro, transfers would know in advance that it could could play essentially the same role as purchase additional supplies. Under groundwater exchanges in providing such agreements, a decision to exercise
FIGURE 7-5 Simulated operations
(a) Calaveras ReservoirŁ increased local storage replaces Hetch Hetchy storage at existing level of demand 500 400 300 Reservoir storage 200 ■ Evaporation ■ Releases for consumptive use ■ Natural inflow ■ Tuolumne supply diverted to storage 100 0
-100 -200 Thousands of acre-feet -300 1922 1926 1930 1934 1938 1942 1946 1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994
(b) New groundwaterŁ potential future conditions 500 400 300
200 ■ Pumping ■ Recharge Storage 100 0
-100 -200 Thousands of acre-feet -300 1922 1926 1930 1934 1938 1942 1946 1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994
(a) Provides an annual summary of the simulated operations of Calaveras Reservoir. The reservoir would be kept full in most years to ensure its availability in case of drought. Also in most years, some part of the supply would be released to make space for natural inflow. (b) Provides an annual summary of the simulated operations of a new groundwater bank. The bank would be kept full under most conditions and seldom accessed. Its availability to provide replacement supplies, however, would allow water agencies to operate surface reservoirs more aggressively.
59 the option must normally be made by The results of simulations that include a certain date, so the sellers have ample multiple elements show that this diversity opportunity to plan their own water use makes for a more robust system. The com- for the year. bined use of transfers and groundwater TREWSSIM modeling of transfers exchanges, for example, puts less pressure to replace supply currently provided by on system storage during dry years. Hetch Hetchy Reservoir suggests that SFPUC would purchase an annual aver- DELTA CONVEYANCE age of 9,000 acre-feet, with a maximum Alone or in conjunction with an intertie annual value of 56,000 acre-feet. Under to Don Pedro Reservoir, the SFPUC future conditions, modeling suggests that could divert its Tuolumne supplies use of transfers would increase slightly, (together with supplies from other averaging 11,000 acre-feet annually, with sources as well) farther downstream in amaximum annual use of 84,000 acre- the Sacramento-San Joaquin Delta. feet. In a transfer program with an agri- While SFPUC did divert Delta supplies cultural district, the seller could choose in 1991–1992 through its connection whether to switch to a less water-intensive to the State Water Project’s South Bay crop, implement alternative irrigation Aqueduct, this option is not reliable technology, or permit fields to go fallow with current infrastructure. The South during years in which transfers take place. Bay Aqueduct would need to be ex- In many parts of California, mistrust panded, or an interconnection between between urban agencies and the agricul- the San Joaquin pipelines and either tural districts that hold senior water rights the California Aqueduct or the Delta- has prevented transactions, whether Mendota Canal would have to be built. groundwater exchanges or transfers, that Such a link would give the SFPUC increase the efficient use of water for the broad access to the statewide water mar- benefit of both parties. As noted in ket and a greater opportunity to ensure Chapter 3, however, this mistrust has reliable supplies, should Tuolumne sup- been fading in recent years as agricul- plies not be sufficient in certain years. tural districts have found ways to assure Diverting from the Delta on a regular themselves that they can retain local basis could result in conflicts with other control of their water supplies while agencies that already do so, and it would simultaneously providing needed reve- require significant negotiation with the nue to their communities and assuring California Department of Water reliability for California’s cities. Resources, the U.S. Bureau of Reclama- tion, and their contractors. During dry COMBINING ELEMENTS years, however, conveyance capacity is Of course, a plan to restore the Hetch generally available and could more easily Hetchy Valley by replacing Hetch Hetchy be used to transport supplies obtained by Reservoir’s storage is not limited to a the SFPUC under exchange or purchase single element, such as local storage, agreements. Delta diversions might best groundwater exchange or transfers be accomplished if used to supplement alone. The plan might feature those diversions using a Don Pedro intertie. elements in various combinations and Transfers or groundwater exchanges degrees, and it might also include to meet supply needs in critically dry others—such as water conservation, years could be implemented via a Don reclamation, or enlargement of existing Pedro intertie alone, as long as the reservoirs—to replace the lost storage. agreement involved agencies within, or
60 possibly adjacent to, the Tuolumne drought period is a key indicator of a River watershed. If these additional system’s supply reliability. However, the supplies were obtained from other needed storage capacity diminishes as parties, however, a Delta intertie would access to additional supplies becomes be necessary. The costs for these two available. For example, if a water agency options are derived in Chapter 10. has an option to purchase additional Schlumberger Water Services has water during dry years, it has less need conducted preliminary modeling studies to retain a large supply of its own. Dry- that evaluate using a Delta intertie to year purchase agreements, in other provide supplies to the SFPUC on a words, could provide the same reliability regular basis (i.e., without a Don Pedro as additional storage. intertie). These studies do not rely on Thus while the SFPUC may prefer scheduled releases of Tuolumne River its own Tuolumne supply, it should very water and thus result in impacts to other carefully consider how to access addi- water supply agencies that would need tional supplies in times of need. To to be resolved. A summary of these guarantee access to water, either during analyses is provided in Appendix A. a drought or after a catastrophic event such as an earthquake, the SFPUC should continue to pursue physical Reliability benefits of a interconnections and purchase agree- diversified water supply ments with other sources of supply. The amount of water remaining in Bottom line: Reliability can be achieved storage at the end of a simulated in a variety of ways.
61 CHAPTER 8 Water-quality analysis
Any viable plan to restore Hetch Hetchy cause more severe illnesses and on rare Valley must assure that the quality occasions be fatal. of Bay Area residents’ drinking water Two types of protozoa—giardia and will not be diminished. As part of this cryptosporidia—are commonly associ- investigation of water-supply alterna- ated with untreated or poorly treated tives, Environmental Defense retained water supplies. These parasites cause Eisenberg, Olivieri and Associates persistent diarrhea, and cryptosporidi- (EOA) to assess the existing and future osis in particular can be fatal to children, quality of water delivered by the San the elderly, or patients with compromised Francisco Public Utilities Commission immune systems.1 Both pathogens are (SFPUC), both with and without Hetch resistant to chlorine disinfection.2 The Hetchy Reservoir. Based on a review of U.S. Environmental Protection Agency raw (untreated) water-quality data from (EPA) has in the past several years potential replacement sources, EOA promulgated new treatment rules for determined “there does not appear to be protecting water supplies from giardia any technical reason [why] the SFPUC and cryptosporidia. Compliance with Hetch Hetchy water-supply system these rules may involve one or more could not be operated without the Hetch of a variety of technologies, including Hetchy Reservoir,” though did enhanced filtration and sedimentation recommend that further water-quality to reduce turbidity and application of analysis be pursued concurrently with ozone and ultra-violet light. the examination of specific alternatives. Bacteria, which are smaller than This chapter provides a brief over- protozoa and thus more difficult to filter view of water-quality and treatment thoroughly, cause typhoid and cholera— issues, a summary of EOA’s findings, historically, among the greatest threats and the estimated costs for treating to human health through drinking water from alternative sources. For a water. These diseases, though still a more detailed summary of EOA’s find- serious threat in some parts of the ings, see Appendix B. world, have largely been eliminated in the United States. Other bacteria, including E. Coli, salmonella and Overview of major contaminants shigella, can cause major health prob- and treatment lems in untreated water or if a break- Contaminants that enter water-supply down occurs in the treatment process. systems can pose both immediate and Normally, however, such bacteria are chronic threats to human health. adequately treated with chlorine, chlora- Chronic risks are caused by a long list mine or other forms of disinfection. of chemicals, including lead, radon, More than 140 viruses, including arsenic and MTBE (methyl tertiary- those responsible for hepatitis and butyl ether), while the most immediate meningitis, are known to infect people risks tend to come from a range of through their digestive tracts. While microbiological contaminants, or path- most of these viral infections are trans- ogens. These protozoa, bacteria, or mitted through food or direct contact, viruses generally cause mild or moderate rotavirus and others are known to be gastroenteritis, but they can sometimes transmitted through water supplies.
62 Many viruses are effectively eliminated FIGURE 8-1 by chlorine or chloramine disinfection. Water treatment process Some are resistant to these processes, though new treatment approaches using The treatment process removes or neutral- izes micro-organisms, sediment, and ozone or ultraviolet light may be effective disease-causing pathogens in order to leave against them. water clear and safe for consumption. The water treatment process varies dependent In California, water quality is regu- both on the nature of the water source and lated by the EPA and the state Depart- the preferences and finances of the water ment of Health Services. The EPA has agency controlling the treatment process. set National Primary Drinking Water Regulations (NPDWRs) for 16 inorganic and 54 organic chemicals.3 The Cali- fornia Department of Health Services identifies seven chemicals as “of current Raw water interest, including arsenic and MTBE”.4 Screening. To begin the treatment While high concentrations of arsenic process, water is pumped from found in wells in Bangladesh have caused areservoir through screens to remove particulate matter and lower turbidity. a critical health problem there, arsenic is found in water systems only in certain Coagulation/rapid mixing. This is areas of the United States, and usually a chemical process with rapid mix- ing in which charged metals are in low concentrations. Disputes about added to the water to “attract” and “trap” acceptable levels of arsenic have most micro-organisms and other impurities. recently led to a new U.S. standard of Flocculation. This physical 10 micrograms per liter, which will be process assisting coagulation implemented in 2006. slowly agitates allowing the chemicals to interact with the impurities and MTBE is a colorless liquid hydro- form larger solids called “floc.” carbon that has been used to enhance gasoline. Its presence both in surface- Sedimentation. The floc then settles to the bottom of the basin water and groundwater supplies was a and is removed. major factor in its incorporation into water-quality standards. Because MTBE Filtration. The water is strained through a layer of activated car- is being phased out of gasoline produc- bon and sand to remove the small tion, it is not likely to be significant in particles missed by screening, coagulation and flocculation. future surface-water supplies, although it will likely persist in groundwater in Disinfection. The only impurities some areas. Most water agencies have remaining should be the very small, potentially disease-carry- taken steps, such as prohibiting 2-stroke ing pathogens, which must be removed or engines, to reduce or eliminate MTBE inactivated by chemical disinfectants such as chlorine, ozone, and chlorine dioxide. contamination in their reservoirs. Chemical disinfection of water sup- plies can sometimes create unwanted side effects through the treatment processes’ byproducts. For example, because water in the Sacramento- SanJoaquin Delta contains both bromide To distribution system and organic matter, treating these sup- Source: Report of the Walkerton Inquiry, Part Two, plies with chlorine can cause formation Chapter 6: Drinking Water Treatment Technologies. of trihalomethanes (THMs), which are pp. 189–208
63 suspected human carcinogens. As a result, unless water quality is assured. The some Delta users have switched from analysis conducted by EOA is intended chlorine to other disinfection technolo- to be merely the initial step in deter- gies, such as chloramine and ozone, mining whatever additional treatments though ozone reacts with bromide to may be necessary for ensuring that water form bromate—another carcinogen. The quality would not be diminished. EPA may promulgate more protective standards for THMs and bromate, which could cause Delta users to modify or Summary of water-quality abandon chlorine and ozone as major findings means of disinfection. Agencies have This section summarizes EOA’s analy- found that by injecting chemicals to lower sis, highlighting findings of particular the pH of water supplies, less chlorine or relevance to the question of how today’s ozone is needed for disinfection, result- high level of water quality can be main- ing in lower levels of these byproducts. tained if Hetch Hetchy Valley is restored. Ultimately some municipalities may The discussion below represents Environ- switch to pressure-driven membranes mental Defense’s characterization of to meet more stringent drinking water EOA’s findings. EOA’s complete report quality standards. is included as Appendix B. Given that no one process is likely to be a panacea, or even adequate for CURRENT SFPUC WATER QUALITY treating all contaminants, water systems Under its current system, the SFPUC normally use a multiple-barrier approach provides water—both to San Francisco to ensuring delivery of safe and healthy residents and those of other Bay Area water. The first step is at-the-source communities—that is obtained from protection of the watersheds themselves. several different sources. Most of the The second step is water treatment: water (85 percent) in the overall methods for treating water vary, though SFPUC water-distribution system most agencies’ processes include filtra- comes directly from Tuolumne River tion followed by chemical disinfection. supplies held in Hetch Hetchy Reservoir. Once a water supply is treated, providers The other 15 percent comes from local must ensure that its quality is protected reservoirs in Alameda County (across as it traverses the distribution system. the bay) and in San Mateo County Finally, they must monitor the quality (along the San Francisco peninsula). of their delivered product to detect any Water from Hetch Hetchy Reservoir breakdowns in the process, and they must comes from rain and snowmelt in the be prepared to respond immediately. Sierra Nevada. Because there is little For this report, the combination of human development in the vicinity, the source protection and treatment is par- water from Hetch Hetchy is very clean. ticularly germane. Under a rare regula- Monitoring results over the past decade tory exemption, the SFPUC is not show scant contamination of the water presently required to filter its Tuolumne by minerals and chemicals, with alumi- River supplies. Flows that are diverted num being the only mineral found above downstream of Yosemite National Park, monitoring equipment’s detection limits. however, are likely to have higher con- Water from Hetch Hetchy is also rela- centrations of some contaminants, thus tively low in bacteria, viruses, and proto- warranting filtration. In any case, Hetch zoa that can cause human infections. Hetchy Valley will not be restored Thus the SFPUC, like New York City,
64 has obtained a rare exemption from the barium, were higher in the Delta and EPA that allows it to distribute water Don Pedro Reservoir. The Delta water without sending it through a filtration in particular was higher in arsenic and plant; Hetch Hetchy water requires only had a greater capacity to form the addition of disinfectants prior to trihalomethanes than either the Don distribution. It is possible, however, Pedro or Hetch Hetchy raw waters, that the EPA will withdraw the current though it is known that agencies using exemption, thus requiring the SFPUC Delta water are able to remove arsenic to filter all of its supplies, even if Hetch through filtration, as it is largely present Hetchy Valley is not restored. as suspended particles.6 It should be noted that in all samples, WATER QUALITY UNDER VARIOUS the concentrations of chemical contami- RESTORATION ALTERNATIVES nants in the raw water were below state Restoration of Hetch Hetchy Valley and federal drinking-water standards. means that snowmelt waters of the Nonetheless, given the difficulty of Tuolumne River would no longer be removing many chemical contaminants captured and stored within Yosemite with standard water filtration, and National Park. With sufficient flow, a because few actual measurements were portion of the river could be diverted made of many of these contaminants— directly to the Bay Area. At other times, for example, only three measurements water supplies would be diverted down- of MTBE were available from the Don stream. In effect, the loss of storage Pedro system—the degree of contamina- capacity within Hetch Hetchy Valley tion with specific chemical contaminants would result in a smaller proportion will need to be more fully characterized of San Francisco’s water being diverted in the future. from the upper watershed, and more To get a preliminary estimate, how- coming from downstream locations— ever, of how water quality would be not only along the Tuolumne (via affected by restoration of Hetch Hetchy Don Pedro Reservoir) but possibly Valley,EOA evaluated three alternatives from the Sacramento-San Joaquin Delta based on the storage and conveyance as well. options considered in Chapters 6 and 7.7 The question is: How would these These alternatives are characterized by changes alter the quality of the water varying amounts of water diverted from that San Franciscans drink? To answer four principal locations, though in all it, data from the different potential water cases the primary source is direct sources was collected and analyzed. A diversion from high in the Tuolumne comparison of water samples from these River watershed (i.e., at Early Intake). sources—Don Pedro, the Sacramento- Under the first alternative, additional San Joaquin Delta, and Hetch Hetchy water is captured downstream, primarily Valley—indicated that they had minor through diversion at or just downstream differences in overall quality, although from Don Pedro Reservoir. Under the Hetch Hetchy samples did have lower second, additional water is obtained levels of several contaminants. Most from the Sacramento-San Joaquin important, the Hetch Hetchy water was Delta, while under the third, the addi- lower in bacterial contamination and tional water comes from Don Pedro slightly lower in levels of giardia and Reservoir and additional storage cryptosporidia.5 Several chemical capacity is available in an expanded contaminants, including MTBE and Calaveras Reservoir. In each alternative,
65 the Tuolumne River still provides the basic filtration and disinfection processes majority of San Francisco’s water on are effective at removing harmful bac- an annual-average basis. teria. The higher levels of MTBE in the Using current monitoring results from Don Pedro water may be more difficult each facility to predict the future quality to remove by filtration techniques, though of water blended from these sources, the the predicted levels of 1–2 micrograms/ first alternative reflects water-quality liter (mcg/L) are well below the Cali- differences between the Hetch Hetchy fornia state standard of 13 mcg/L. It and Don Pedro supplies—mainly, higher should also be noted that MTBE levels bacterial counts, slightly higher turbidity in water sources are expected to decline, (a reflection of dissolved solids), higher as this chemical is no longer added to total organic carbon (a predictor of gasoline in California. elevated trihalomethanes and other With the addition of existing filtra- disinfection byproducts) and MTBE. tion technologies, and based on available The second alternative, reflecting dif- data, the water quality predicted to ferences between Hetch Hetchy and result from use of the Don Pedro or Delta supplies, results again in higher Sacramento-San Joaquin Delta source bacterial counts, even higher turbidity, should be comparable, or even superior, higher total organic carbon, and a slight to the quality of water from the current increase in MTBE. In the last alterna- Hetch Hetchy source. In particular, tive, results are very similar to the first, filtration should reduce the presence as the increased Calaveras capacity only of giardia and cryptosporidia to levels marginally influences the total mixture. lower than those present in the current From a health standpoint, it is scheme. Further, filtration provides an assumed that the anticipated increase in additional layer of protection from water- bacterial counts or turbidity will necessi- contamination events. Table 8-1 provides tate filtering water from the Don Pedro a summary of anticipated water-treatment Reservoir and the Sacramento-San technologies that would be employed Joaquin Delta prior to consumption. for each of the sources. The higher turbidity of the Delta water While it is difficult to predict the may require some extra steps (i.e., addi- future capabilities of water-treatment tional coagulation and sedimentation) technologies, significant advances are to remove suspended solids so that the being made in this field. It is likely that TABLE 8-1 Summary of treatment requirements and recommendations
POINT OF DIVERSION
Treatment process Hetch Hetchy Early intake Don Pedro Calaveras Peninsula Sacramento- San Joaquin Delta
Screening, coagulation, flocculation, sedimentation Basic filtration Enhanced treatment Disinfection Additional treatment