Challenges of Managing California's Sacramento — San Joaquin Delta

The Sacramento-San Joaquin Delta is the hub of California's water supply system and the home of numerous native fish species, five of which already are listed as threatened or endangered. The recent rapid decline of populations of many of these fish species has been followed by court rulings restricting water exports from the Delta, focusing public and political attention on one of California's most important and iconic water controversies. In our previous report, Envisioning Futures for the Sacramento—San Joaquin Delta, we explored the alternatives available for the long-term management of this multifaceted resource. We concluded that change is inevitable for the Delta and that retaining the current policy of exporting large amounts of water through pumps in the southern Delta was both risky and unsustainable. We examined nine long-term strategies for managing the Delta from the perspectives of environmental, economic, and water supply performance. In this report, we continue the theme of analyzing how the Delta will change in the future and how California can respond to expected changes to meet state economic and environmental objectives. We focus on a central question for long-term Delta policy: Which water management strategies best meet the goals of environmental sustainability and water supply reliability? Many other decisions concerning California's water management, the Delta aquatic environment, and Delta land use depend on the answer to this question. We provide an integrated analysis of these issues in a series of technical appendices and summarize the results and their policy implications in this report. These analyses allow us to arrive at some firm conclusions regarding the desirability of various long-term alternatives for the Delta from a scientific and technical perspective.