California Water Projects Feeding Southern California

Map of California Water Projects

California Aqueducts


The California State Water Project (SWP)

This section is taken from the Wikipedia article on the CSWP or SWP, but specialized to the path of the water to Southern California.

The SWP has 5.75 million acre-feet of storage.  In a normal year it has 2.4 million acre-feet per year of water delivery.  The energy used to do this is 11,500 giga watt hour (GWh) of which 6,500 GWh are supplied by the project.  The California aqueduct carries between 1-3.7 million acre-feet per year southward.

From the aqueduct the West Branch goes through Pyramid and Castaic lakes.  That carries 537,000 acre-feet per year.

The Colorado River Aqueduct

The Colorado River Aqueduct was built in the depression era to bring Colorado River water to the Southern California area.  It runs 242 miles from Lake Havasu to the east side of the Santa Ana mountains.  It is managed by the Metropolitan Water District.  It carries 1.2 million acre-feet per year.  California gets 27% of the output of the Colorado River.

The Los Angeles Aqueduct

This can supply half of the water for Los Angeles.  It takes water from the Owens Valley and Owens River.  It was developed by William Mulholland, and is run by the LADWP.  It ends at the Upper Van Norman Lake.  The Lower Owens River is now rewatered, and 40-50% of the water is used for ecological resources.  It used to supply 480,000 acre-feet/year.  According to one source, LA now uses 50% MWD water, and only gets 13% from the Aqueduct.

The Central Valley Project 

This is a federally funded project to deliver water to the Central Valley.  It usually delivers about 7 million acre-feet per year, mostly for Agriculture.  The State has just dropped supplying water to junior water rights users.

Proposals for New Water Projects

One proposals for what could be built to add more water is the Peripheral Canal to take water from the Sacramento River, bypassing the Delta.  That would provide 1 million acre-feet mostly to the Central Valley, and also to Silicon Valley and Southern California.

Tunnels under the Delta would provide safety against Delta dike ruptures causing earthquakes.  The cost of that is estimated to be $25 billion to $30 billion.  Delta farmers say it is cheaper to strengthen the dikes, and that they are earthquake safe.

The other proposal is the Sites Reservoir in Sacramento Valley which would hold 1.8 million acre-feet of water, which could supply 470,000 to 640,000 new acre-feet of water a year.

Proposition 1 passed in November 2014 will give $7.5 billion to water projects.

Normal Water delivery by California Water Projects:

(Excerpted from Wikipedia)

  • Central Valley Project (federal). Delivers about 7 million acre-feet (MAF) per year. Constructed in 1930s – 1950s.
  • State Water Project (state). Delivers about 2.3 MAF / year. Constructed in 1960s – early 1970s.
  • All-American Canal (local). Delivers 3 MAF / year. Constructed in 1930s
  • Colorado River Aqueduct (local). Delivers 1.2 MAF / year. Completed in 1941
  • Los Angeles Aqueduct (local). Delivers 200,000 AF / year. Completed in 1913.
  • Mokelumne Aqueduct (local). Delivers 364,000 AF / year. Completed in 1929. Second aqueduct completed in 1949.
  • San Francisco Hetch Hetchy Project (local). Delivers 330,000 AF / year. Completed in 1923.



About Dennis SILVERMAN

I am a retired Professor of Physics and Astronomy at U C Irvine. For a decade I have been active in learning about energy and the environment, and in lecturing and attending classes at the Osher Lifelong Learning Institute (OLLI) at UC Irvine.
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