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The European settlement in the Sacramento-San Joaquin Delta resulted in the transformation of forested areas and vegetation into agricultural sites and urban communities. Vast areas of tidal wetlands were converted into farmlands surrounded by levees. This chapter presents the history and foundations of the modern delta economy. It describes the geologic and institutional factors that brought the Delta to its current state. The chapter also discusses the reclamation of Delta lands and efforts to provide solutions to the Delta's problems, such as levee construction, flood control, expansion of shipping channels, upstream mining activities, and salinity intrusion. It also highlights the first major public works project in the Delta—the Central Valley flood control system. The chapter concludes with several policy initiatives for developing sustainable solutions to Delta problems.

The Sacramento-San Joaquin Delta is part of the largest estuary on the West Coast of the Americas. It is the largest single source of California's water supply and supports many ecological, economic, and cultural functions. The Delta is now widely perceived to be in crisis, with dramatic population declines among several fish species, salinity intrusions, and levee failures. This book is about finding long-term solutions to the problems facing the Sacramento-San Joaquin Delta. It addresses four central issues: the salinity and quality of Delta waters, in-Delta land use and water supply, water supply exports, and the Delta ecosystem.

The Sacramento-San Joaquin Delta moves water from Northern California watersheds to farmlands and cities south and west of the Delta. Recent water exports from the Delta have ranged from 5 to 6 million acre-feet per year, supplying much of the water used in the Bay Area, the southern Central Valley, and Southern California. This chapter discusses the state and regional use of Delta water supplies, strategies to manage water exports from the Delta, and some key economic and environmental considerations. It also describes four water export approaches: continue pumping exports through the Delta; divert water upstream and convey it around the Delta through a peripheral canal; combine the current through-Delta pumping strategy with a peripheral canal (so-called “dual conveyance” or “dual facility”); and end exports altogether.

This chapter examines the effects of physical changes in the Delta and different water management alternatives on Delta salinity. It uses hydrodynamic modeling tools to explore the effects of sea-level rise, island flooding, and changes in water management. The water analysis module (WAM) is used to examine the effects of sea-level rise and of Delta water management alternatives. Results from a more complete model for the Delta Risk Management Strategy (DRMS) flooded-island modeling work are also used to explore the effects of permanent island flooding.

Over the last decade, fish populations in the Sacramento-San Joaquin Delta ecosystem has substantially declined. In the Delta, the water allocation strategy has resulted in a diminishing proportion of the water being made available for fish or ecosystem needs. This chapter addresses whether alternatives to the present through-Delta pumping strategy can transform the Delta ecosystem into a favorable habitat for desirable fish species and other organisms. It begins by discussing the basic concepts and premises that must underlie any rebuilding of the Delta ecosystem and then assesses the likely responses of key species to general export strategies. It concludes with a brief discussion of initiatives to manage the Delta as a resilient ecosystem that maintains desirable characteristics, as it adjusts to natural and human-induced climatic variability.

Before the European settlement, Sacramento-San Joaquin Delta was one of California's most dynamic landscapes. Today's Delta is unstable and has significantly changed from its historic condition. It faces inevitable changes in landscape, economy, and ecology, driven by land subsidence, changing inflows, sea-level rise, earthquakes, and biological invasions. All these changes increase future risks of Delta island flooding. This chapter focuses on the state's investments to resist or manage these changes through levee improvements and repairs. The Delta Levee Subventions Program, in particular, has significantly reduced levee failures and is the most important state investments in Delta levees today.