Restoring the Delta ecosystem and creating a more reliable water supply for California

About the Delta

About the Delta
Threats to the Delta
Facts and Figures

ABOUT THE DELTA Man fishing in delta waters

The Sacramento-San Joaquin Delta is the West Coast’s largest estuary. It is a unique resource of local, state and national significance.
The Delta:

  • Is home to more than 500,000 people.
  • Contains 500,000 acres of agriculture.
  • Provides habitat for 700 native plant and animal species.
  • Provides water for more than 25 million Californians and 3 million acres of agriculture.
  • Is traversed by energy, communications and transportation facilities vital to the economic health of California.
  • Supports a $400 billion economy.

But this heartland – our state’s economic engine, chief water source and a natural treasure – is in trouble. Current uses and environmental conditions are not sustainable. We must act now to secure the future of this vital resource.


There is a growing consensus among scientists, supported by recent legislation and other information, indicating that:

  • Environmental conditions and the current Delta “architecture” are not sustainable.
  • Current land and water uses and related services dependent on the Delta are not sustainable based on current management practices and regulatory requirements.
  • Current environmental conditions and current and ongoing services (e.g., utility, transportation and water conveyance services) are reliant on an aging and deteriorating levee system.
  • Major “drivers of change” that are largely outside of our control will impact the Delta during the coming decades, including seismic events, land subsidence, sea level rise, regional climate change and urbanization.
  • The current fragmented and complex governance systems within the Delta are not conducive to effective management of the fragile Delta environment in the face of the cumulative threats identified above.
  • Failure to act to address identified Delta challenges and threats will result in potentially devastating environmental and economic consequences of statewide and national significance.


Click here to download a fact sheet (PDF).
Population: 515,264 (2000 Census)
Counties: Contra Costa, Sacramento, San Joaquin, Solano, and Yolo
Major Cities Partly within the Delta: Sacramento, Stockton, West Sacramento, Oakley and Rio Vista
Levees: 1,300 including the Delta and Suisun Marsh (total mileage, 1987)
Rivers Flowing into the Delta: Sacramento, San Joaquin, Mokelumne, Cosumnes, and Calaveras
Diversions Directly from the Delta: State Water Project, Federal Central Valley Project, Contra Costa Canal, North Bay Aqueduct, City of Vallejo, Western Delta Industry and 1,800+ Agricultural Users
Water Supply: Drinking water for 25 million people; supports California’s $1 trillion economy (eighth largest in the world) and $27 billion agricultural industry (nation’s number one)
Agriculture: Average Annual Gross Value totals more than $2 billion. Crops include corn, grain, hay, alfalfa, tomatoes, asparagus, pears and wine grapes.(2001)
Wildlife: 52 mammals, 22 reptiles and amphibian species, 225 birds, and 54 species of fish. The Delta is also home to approximately 260 invasive species of plants and animals.
Recreation: More than 12 million visitors annually. There are 290 shoreline recreational areas, 300 marinas, and about 500,000 boaters. The Delta has 57,000 acres of navigable waterways. (Figures from the Department of Boating and Waterways)
Major Sport Fish:*

American Shad
Bass (Striped, Smallmouth, Largemouth, Spotted)
Black Crappie
Catfish (Channel, Blue, White, Black Bullhead, Brown Bullhead)
Chinook Salmon
Starry Flounder
Sunfish (Bluegill, Pumpkinseed, Redear, Green)
Tule Perch
White Sturgeon
* Before fishing in the Delta, always check with the California Department of Fish & Game for regulations regarding particular fish species and specific license requirements for the region.


Click here to view the California Department of Fish & Game’s map of the Delta Region.
Click here to download more maps of the Delta Region.