A Scientific Assessment of Alternatives for Reducing Water Management Effects on Threatened and Endangered Fishes in California’s Bay–Delta
NATIONAL RESEARCH COUNCIL
OF THE NATIONAL ACADEMIES
THE NATIONAL ACADEMIES PRESS
THE NATIONAL ACADEMIES PRESS
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NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the panel responsible for the report were chosen for their special competences and with regard for appropriate balance.
Support for this study was provided by the Department of the Interior under contract no. 80221-A-G100. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.
International Standard Book Number-13: 978-0-309-12802-5
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Photo of the California Bay-Delta on the cover is courtesy of David Policansky.
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THE NATIONAL ACADEMIES
Advisers to the Nation on Science, Engineering, and Medicine
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COMMITTEE ON SUSTAINABLE WATER AND ENVIRONMENTAL MANAGEMENT IN THE CALIFORNIA BAY-DELTA*
ROBERT J. HUGGETT, Chair, Professor Emeritus,
College of William and Mary, Seaford, Virginia
JAMES J. ANDERSON,
University of Washington, Seattle
MICHAEL E. CAMPANA,
Oregon State University, Corvallis
University of California, Santa Barbara
ALBERT E. GIORGI,
BioAnalysts, Inc., Redmond, Washington
PATRICIA M. GLIBERT,
University of Maryland Center for Environmental Science, Horn Point Laboratory, Cambridge
CHRISTINE A. KLEIN,
University of Florida College of Law, Gainesville
SAMUEL N. LUOMA,
John Muir Institute of the Environment, University of California, Davis
MICHAEL J. MCGUIRE,
Michael J. McGuire, Inc., Santa Monica, California
University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, Solomons, Maryland
South Florida Water Management District, West Palm Beach
MAX J. PFEFFER,
Cornell University, Ithaca, New York
DENISE J. REED,
University of New Orleans, New Orleans, Louisiana
KENNETH A. ROSE,
Louisiana State University, Baton Rouge
DESIREE D. TULLOS,
Oregon State University, Corvallis
DAVID POLICANSKY, NRC Study Director, Scholar
LAURA J. HELSABECK, Deputy Study Director
STEPHEN D. PARKER, WSTB Director, Scholar
SUSAN ROBERTS, OSB Director
ELLEN A. DE GUZMAN, Research Associate
HEATHER CHIARELLO, Senior Program Assistant
California, like many states, faces challenges related to water. Much of the state is too dry to support many human activities, such as municipal and industrial water use and irrigated agriculture, without supplementing the natural water supply. It has done this through an extensive series of engineering projects that include reservoirs, canals, levees, and pumps, largely to move water from the more humid north to the more arid and densely populated south. Much of California’s natural surface-water supply flows into and through the Sacramento and San Joaquin watersheds into California’s Bay-Delta, and from there through San Francisco Bay into the ocean. The delta itself is a biologically diverse estuarine ecosystem, and is the main point of diversion for water that is transported to the south.
As California’s population and economic activity have increased, along with water diversions from the delta, conflicts over various water uses have increased as well, especially surrounding the bay-delta. Those conflicts have been brought to a head by restrictions on water diversions that have been required by two biological opinions, one by the U.S. Fish and Wildlife Service, covering delta smelt, and one by the National Marine Fisheries Service, covering salmon, steelhead, and sturgeon, to protect those fishes, which are listed as threatened or endangered under the federal Endangered Species Act. In addition, several recent dry years have exacerbated the situation. Conflicts over water are not new in California, but the current conflicts over the bay-delta appear to be unprecedented in their scale. Few parts of the state are unaffected by what happens to delta water.
Protecting all the listed species and preserving existing and projected uses of the region’s water is a serious challenge. The complexity of the problem and the difficulty of identifying solutions have been highlighted by a plethora of scientific publications and arguments, in which many qualified and distinguished experts have reached differing conclusions. Nobody disagrees that engineering changes; the introduction of many exotic species, the addition of contaminants to the system, and the general effects of an increasing human population have contributed to the fishes’ declines. There are, however, disagreements
about the relative contributions of those factors and the appropriate remedies for them. This is the context in which the National Research Council was asked by Congress and the Department of the Interior to help resolve the issue by evaluating the scientific bases of the biological opinions. In response, the NRC appointed a special committee of experts to carry out a complex and challenging study in two phases.
In its first phase, the committee was tasked to focus on the scientific bases of the reasonable and prudent alternatives (RPAs) in the two biological opinions. The committee also assessed whether the RPAs might be in conflict with one another, as well as whether other options might be available that would protect the fishes with lesser impacts on other water uses. Finally, we were asked to consider the effects of “other stressors” on the fishes if sufficient time were available. The results of this first-phase analysis are the subject of this report. The committee did consider other stressors, but it did not evaluate them in depth. They will be more thoroughly addressed in a second report, scheduled to be published late in 2011, which will focus on broader issues surrounding attempts to provide more sustainable water supplies and to improve the ecological sustainability of the delta, including consideration of what ecological goals might be attainable.
The committee met in Davis, California for five days in January 2010. The committee heard presentations from representatives of federal and state agencies and a variety of other experts, and from members of several stakeholder groups and the public (see Appendix D). The information gathering sessions of this meeting were open to the public and widely advertised. The committee sought to hear from as many groups and individuals as possible within the time constraints. All speakers, guests, and members of the public were encouraged to provide written comments during and after the meeting. All presentations and written materials submitted were considered by the committee as time allowed. The committee thanks all the individuals who provided information.
This report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise in accordance with the procedures approved by the NRC’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the NRC in making its published report as sound as possible, and to ensure that the report meets NRC institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.
We thank the following for their reviews of this report: Joan G. Ehrenfeld, Rutgers University; Mary C. Fabrizio, Virginia Institute of Marine Science; Peter Gleick, Pacific Institute; William P. Horn, Birch, Horton, Bittner & Cherot;
D. Peter Loucks, Cornell University; Jay Lund, University of California, Davis; Tammy Newcomb, Michigan Department of Natural Resources; and Andrew A. Rosenberg, Conservation International.
Although these reviewers provided constructive comments and suggestions, they were not asked to endorse the report’s conclusions and recommendations, nor did they see the final draft of the report before its release. The review of this report was overseen by Michael Kavanaugh, Malcolm Pirnie, Inc., who was appointed by the NRC’s Report Review Committee and by Leo Eisel, Brown and Caldwell, who was appointed by the NRC’s Division on Earth and Life Studies. They were responsible for ensuring that an independent examination of this report was conducted in accordance with NRC institutional procedures and that all review comments received full consideration. Responsibility for this report’s final contents rests entirely with the authoring committee and the NRC.
I am enormously grateful to my committee colleagues for their diligence, enthusiasm, persistence, and hard work. The schedule for the preparation of this report was short, and without everyone’s engagement, it could not have been completed. I also am grateful to David Policansky, Stephen Parker, Laura Helsabeck, Heather Chiarello, Ellen de Guzman, and Susan Roberts of the NRC staff for their efforts in facilitating the committee’s meeting and for their work in helping to get this report completed on schedule in the face of historic snowstorms.
California will continue to face great challenges in managing, allocating, and using water, including managing California’s Bay-Delta. We hope the committee’s reports can help in that difficult process.
Robert J. Huggett
Acronyms and Abbreviations
BA Biological Assessment
BO Biological Opinion
(C)DFG California Department of Fish and Game
(C)DWR California Department of Water Resources
C.F.R. Code of Federal Regulations
Cir Circuit Court (federal system)
CVP Central Valley Project
CVPIA Central Valley Project Improvement Act
DCC Delta Cross Channel
DOI (U.S.) Department of the Interior
DSM2 Delta Simulation Model II
EDT Ecosystem Diagnosis and Treatment
ESA Endangered Species Act
EWA Environmental Water Account
FMT Fall Midwater Trawl (survey)
FWS (U.S.) Fish and Wildlife Service
HORB Head of Old River Barrier
MAF Million acre-feet
M&I Municipal and Industrial
NAS National Academy of Sciences
NMFS National Marine Fisheries Service
NOAA National Oceanic and Atmospheric Administration
NRC National Research Council
OCAP Operations Criteria And Plan
OMR Old and Middle River
OSB Ocean Studies Board of the NRC
PTM Particle-Tracking Model
RBDD Red Bluff Diversion Dam
RPA Reasonable and Prudent Alternative
SWP State Water Project
TAF Thousand acre-feet
USBR United States Bureau of Reclamation
U.S.C. United States Code
USGS United States Geological Survey
VAMP Vernalis Adaptive Management Plan
WSTB Water Science and Technology Board of the NRC
X2 Contour line of salinity 2