The Big Water Projects in California

California has two gigantic water development systems: the California State Water Project and the Federal Central Valley Project.

 Both use multiple dammed reservoirs to capture and store water, which is then redistributed  via rivers and canals, generally from Northern California sources to San Joaquin Valley farms and southern California cities.

The operation of these enormous water projects is a primary factor in the collapse of  Delta fish populations in the San Francisco Bay-Delta estuary.   The idea that millions of acre feet of water can be exported  without massive impacts, and that such a system is sustainable, is premised on magical thinking by state water industry officials and regulators.

Further, these water projects have low priority water rights. They were acquired starting in the 1920s and 1930s, and are thus considered "junior" to more "senior" rights held by many irrigation and water districts in the Central Valley, the City and County of San Francisco, Pacific Gas & Electric Company, Southern California Edison Corporation, and the East Bay Municipal Utilities District (which supplies Mokelumne River water to Alameda and Contra Costa counties).



The Central Valley Project


Originally conceived by state engineers, the U.S. Bureau of Reclamation later took over construction of the Central Valley Project. The Bureau maintains the following  profile of the CVP:

·       Reaches from the Cascade-Trinity Mountains near Redding in the north to the Tehachapi Mountains near Bakersfield in the south, a total distance of roughly 500 miles.

·       Consists of 20 dams and reservoirs, 11 power plants, and 500 miles of major canals, conduits, tunnels, and related facilities. 

·       Annually delivers about 7 million acre-feet of water for agricultural, urban, and wildlife use.  

·       Provides about 5 million acre-feet for farms, enough to irrigate about 3 million acres or approximately one-third of the agricultural land in California. 

·       Furnishes about 600,000 acre-feet for municipal and industrial use, enough to supply close to one million households with their annual water needs. 

·       Dedicates 800,000 acre-feet per year to fish and wildlife and their habitat, and 410,000 acre-feet to state and federal wildlife refuges and wetlands as stipulated by the Central Valley Project Improvement Act (CVPIA).  

·       During an average water year, generates about 4.8 billion kilowatt hours of electricity to meet the needs of 2 million people.

Water Rights Primer

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The State Water Project


The California State Water Project was approved by the legislature in 1959 and bonds for its construction were narrowly approved by California voters in November 1960 (Proposition 1). The California Department of Water Resources maintains this profile for the State Water Project:


Project Facts and Figures
Number of storage Facilities 33
Lakes/Reservoirs (primary) 21
Total Reservoir Storage 5.8 million acre-feet = 7.2 cubic kilometers
Largest Reservoir Capacity 3.5 million acre-feet = 4.3 cubic kilometers
Largest Reservoir Surface Area 15,810 acres
Longest Reservoir Shoreline 167 miles
Highest Dam Structure 770 feet = 235 meters
Largest Dam Structure 80 million cubic yards = 61 million cubic meters
Longest Dam Crest 42,000 feet = 12,802 meters
Highest Dam Crest Elevation 5,785 feet - 1,763 meters
Length of Canals and Pipelines 701 miles = 1,128.15 kilometers


California Aqueduct
Starting Maximum Pumping/Canal Volumes 10,670 cfs /10,300 CFS
Largest Pumping Capacity 15,450 cfs
Largest Canal Capacity 13,100 cfs
Widest Part of Canal 110 feet
Deepest Part of Canal 32.8 feet
Highest Pump Lift/Volume 1,926 feet = 587 meters/4,480 CF

The Department of Water Resources claims the overall "Table A amounts" of the State Water Project contractors total 4.23 million acre-feet of water per year, but the project has never delivered that much water at any time in its history; in fact, during the peak years of 2005 and 2006, it delivered no more than about 3.7 million acre-feet. Deliveries dropped dramatically in subsequent – and drier -- years. In 2007 the SWP delivered about 2.98 million acre-feet, and it delivered 1.96 million acre-feet in 2008.

For more detailed information about the State Water Project see the Department's bond prospectus from 2009 about the Project's operations and financial performance.  Read about the Failure of the State Water Project at

During the drought of 1991, the SWP was able to deliver only .5 million acre feet of the 4.2 million acre feet of water under state contract.  Controversy over the project's capacity during droughts led to adoption of the secretly negotiated "Monterey Agreement" in 1994 and project contract amendments in 1995.

Water Rights Primer