Comparing Futures for the Sacramento, San Joaquin Delta

An ecosystem in freefall, a shrinking water supply for cities and agriculture, an antiquated network of failure-prone levees—this is the Sacramento-San Joaquin Delta, the major hub of California's water system. Written by a team of independent water experts, this analysis of the latest data evaluates proposed solutions to the Delta's myriad problems. Through in-depth economic and ecological analysis, the authors find that the current policy of channeling water exports through the Delta is not sustainable for any interest. Employing a peripheral canal-conveying water around the Delta instead of through it—as part of a larger habitat and water management plan appears to be the best strategy to maintain both a high-quality water supply and at the same time improve conditions for native fish and wildlife. This important assessment includes integrated analysis of long term ecosystem and water management options and demonstrates how issues such as climate change and sustainability will shape the future.

Published in cooperation with the Public Policy Institute of California

Jay R. Lund is Professor of Environmental Engineering and Director of the Center for Watershed Sciences. William E. Fleenor is a Research Engineer in the Environmental Dynamics Laboratory. William A. Bennett is a Research Scientist with the John Muir Institute of the Environment. Richard E. Howitt is Professor and Chair of Agricultural and Resource Economics. Jeffrey F. Mount is Professor of Applied Geosciences. Peter B. Moyle is Professor in the Department of Wildlife, Fish, and Conservation Biology. They are all affiliated with the Center for Watershed Sciences, University of California, Davis. Ellen Hanak is Director of Research and Thomas C. Sutton is Chair in Policy Research at the Public Policy Institute of California.

Contributors ix
Preface xi
Acknowledgments xv
Sacramento–San Joaquin Delta and Delta Islands Maps xix

1. Introduction 1
What Is the Delta? 3
Why the Delta Matters to Californians 6
The Delta in Crisis 8
Responding to the Crisis 10
Four Central Issues 11
Searching for a Soft Landing 14

2. The Legacies of Delta History 17
Pre-European Delta: Fluctuating Salinity and Lands 17
Reclamation: Foundations of the Modern
Delta Economy 19
Big Water Projects Transform the Delta to a
Freshwater Body 28
Environmental Concerns Change the Course
of Delta Policy Debates 33
The CALFED Era: Testing the Limits
of Consensus 35
New Initiatives and New Troubles in the Delta 38
The Lessons of Delta History 40

3. Managing the Inevitable 43
Introduction 43
Drivers of Change 44
Managing or Resisting Change 49
A Future Different from the Past 56

4. Delta Water Exports and Strategies 57
State and Regional Use of Delta Water Supplies 57
Four Water Export Strategies 61
Exporting Through the Delta 62
Exporting Around the Delta 64
Dual Conveyance 66
Ending Delta Exports 67
Water Exports and the Delta’s Economy 68

5. Hydrodynamics and the Salinity of Delta Waters 69
Modeling Tools and Approach 70
Comparing Scenarios 71
No Exports and Unimpaired Flows 72
Consequences of Sea-Level Rise 76
Consequences of Island Flooding 78
Consequences of Peripheral Canal Exports 82
The Limits of Current Knowledge 88
Conclusions 91

6. What a Changing Delta Means for the Ecosystem
and Its Fishes 93
Basic Premises for Rebuilding the Delta Ecosystem 94
The Role of Habitat Diversity 95
Fish Species Responses to Water Export Strategies 96
Attributes of an Ecosystem Solution 105
Conclusions 108

7. Economics of Changing Water Supply and Quality 111
Statewide Adaptations to Delta Water Management 111
Costs of Providing More Water for
the Environment 115
Urban and Agricultural Water Quality 120
Implications for Export Management Alternatives 123
Costs from Unrepaired Delta Islands 124

8. Policy and Regulatory Challenges 127
Funding Principles for a Soft Landing 128
Softening the Costs of Adjustment 133
Bringing Delta Land Use into the Fold 136
Regulating Water Quality in a Changing Delta 139
Anticipating Levee Failures 142
Including Upstream Diverters in a Delta Solution 143
Protecting Endangered Species in the Face
of Uncertainty 145
Governance Safeguards for a Peripheral Canal 147
Governance and Decision-making for a New Delta 149
Conclusion 150

9. Decision Analysis for Delta Exports 153
Decision Analysis Applied to the Delta
Export Alternatives 153
Information Needed for Decision Analysis 156
Comparing Water Export Alternatives 158
Implementation Issues 162
The Timing of Delta Decisions and Consequences 165
Conclusion 166

10. Charting the Future for a Changing Delta 169
The Changing Delta Landscape 169
Fish and the Delta Ecosystem 171
Long-Term Water Export Alternatives 173
Governance, Regulation, and Finance 175
Navigating Change 177

Appendix: Estimation of Probabilities, Costs,
and Reductions for Delta Outcomes and Strategies 179
Acronyms and Abbreviations 191
Notes 193
Glossary 203
References 207
Index 219