California`s Central Valley Basin includes two major watersheds--the Sacramento River on the north and the San Joaquin River on the south--plus the Tulare Lake Basin. The combined watersheds extend nearly 500 miles from northwest to southeast and range from about 60 to 100 miles wide. These two river systems join at the Sacramento-San Joaquin Delta and flow through Suisun Bay and Carquinez Straits, into San Francisco Bay, and out the Golden Gate to the Pacific Ocean.
Watersheds that drain through the Delta and San Francisco Bay.
California has more than 1,400 named dams and 1,300 reservoirs that help with flood management, water storage and water transport. Dams are owned, maintained and operated by federal, state and local agencies.
Two of the world’s largest water transport and storage systems are both located in California: the Central Valley Project and the State Water Project. A short summary of these two important systems, with overview maps, follows here:
Two of the world’s largest water transport and storage systems are both located in California: the Central Valley Project and the State Water Project. A short summary of these two important systems, with overview maps, follows here:
Central Valley Project (CVP)
Efforts at developing a comprehensive plan for the Central Valley date back to 1873, when the Army Engineers prepared a report on irrigation in the San Joaquin and Sacramento Valleys and Tulare Basin. In 1919, a plan was submitted to the Governor of California for coordinated development of the water resources of the Central Valley. In 1931, the Division of Water Resources submitted to the legislature the State Water Plan, which included a comprehensive plan for using the water resources of the Central Valley. The state legislature passed the Mid-Pacific Region California Central Valley Project Act in 1933, which authorized the sale of revenue bonds to construct the project. However, during the Great Depression, bonds didn't sell. With the Rivers and Harbors Act of 1935, the federal government assumed control of the project and its initial features were authorized for construction by the U.S. Army Corps of Engineers. When the Rivers and Harbors Act was reauthorized in 1937, Reclamation took over CVP construction and operation, and the project became subject to Reclamation law.
Work began in 1937 with the Contra Costa Canal, which began delivering water in 1940. The next facility built was Shasta Dam, the keystone of the project. Work on the dam began in 1938, and water storage started even before its completion in 1945. Congress subsequently passed 13 separate measures to authorize the development of other major project facilities over the next three decades. The final dam, New Melones, was completed in 1979. Today the Central Valley Project is operated by the U.S. Bureau of Reclamation. Its 22 reservoirs have a combined storage of 11 million acre-feet, of which 7 million acre-feet, or about 20% of the state’s developed water, is delivered in an average year. In comparison, the SWP's 20 major reservoirs can hold
5.8 million acre-feet, with annual deliveries averaging up to 3 million acre-feet. CVP water irrigates more than 3 million acres of farmland and provides drinking water to nearly 2 million consumers. More than 250 contractors in 29 out of 58 counties have long-term CVP contracts.
Work began in 1937 with the Contra Costa Canal, which began delivering water in 1940. The next facility built was Shasta Dam, the keystone of the project. Work on the dam began in 1938, and water storage started even before its completion in 1945. Congress subsequently passed 13 separate measures to authorize the development of other major project facilities over the next three decades. The final dam, New Melones, was completed in 1979. Today the Central Valley Project is operated by the U.S. Bureau of Reclamation. Its 22 reservoirs have a combined storage of 11 million acre-feet, of which 7 million acre-feet, or about 20% of the state’s developed water, is delivered in an average year. In comparison, the SWP's 20 major reservoirs can hold
5.8 million acre-feet, with annual deliveries averaging up to 3 million acre-feet. CVP water irrigates more than 3 million acres of farmland and provides drinking water to nearly 2 million consumers. More than 250 contractors in 29 out of 58 counties have long-term CVP contracts.
Central Valley Project Map (source: USBR)
FAST FACTS ABOUT THE CVP:
- Reaches some 400 miles, from the Cascade Mountains near Redding in the north to the Tehachapi Mountains near Bakersfield in the south.
- Consists of 22 dams and reservoirs, 11 power plants, and 500 miles of major canals, as well as conduits, tunnels, and related facilities.
- Manages some 9 million acre-feet of water.
- 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 1 million households with their water needs each year.
STATE WATER PROJECT (SWP)
In November 1960, California voters approved the issuance of bonds to construct the nation’s largest state-built water and power development and conveyance system, the State Water Project. Authorization of construction was passed by the California Legislature in 1959 through the Burns-Porter Act, and signed into law by Governor Pat Brown. The SWP diverts an average of 2.5 million acre-feet of water from the Feather River to the Central Valley, South Bay Area and Southern California.
The project nearly spans 600 miles from northern California to Southern California, delivering on average 2.4 million acre-feet of water through an interconnected system of 34 storage facilities, 20 pumping plants, four pumping-generating plants, 5 hydroelectric power plants, and about 700 miles of canals, tunnels and pipelines. Construction began after passage of the Burns-Porter Act, with Oroville Dam completed in 1967. The South Bay Aqueduct was the first State Water Project delivery system completed, with water being delivered to Alameda County in 1962; water reached Santa Clara County in 1965. Delta facilities were completed in 1968, but it wasn't until the Edmonston Pumping Plant was completed in 1971 that water finally reached Southern California. By 1973 initial facilities were completed. The Coastal Branch was completed in 1997.
To reach Southern California, the water must be pumped 2,000 feet over the Tehachapi Mountains, the highest water lift in the world. A key feature of the SWP is the 444-mile long California Aqueduct that can be viewed from Interstate 5. Today, about 30% of SWP water is used for irrigation, mostly in the San Joaquin Valley, and about 70% is used for residential, municipal and industrial use, mainly in Southern California but also in the Bay Area. SWP is the state’s fourth largest generator of electricity but is also the state’s largest user of electricity, primarily to lift water over the Tehachapi Mountains. SWP was constructed and is operated by the Department of Water Resources.
The project nearly spans 600 miles from northern California to Southern California, delivering on average 2.4 million acre-feet of water through an interconnected system of 34 storage facilities, 20 pumping plants, four pumping-generating plants, 5 hydroelectric power plants, and about 700 miles of canals, tunnels and pipelines. Construction began after passage of the Burns-Porter Act, with Oroville Dam completed in 1967. The South Bay Aqueduct was the first State Water Project delivery system completed, with water being delivered to Alameda County in 1962; water reached Santa Clara County in 1965. Delta facilities were completed in 1968, but it wasn't until the Edmonston Pumping Plant was completed in 1971 that water finally reached Southern California. By 1973 initial facilities were completed. The Coastal Branch was completed in 1997.
To reach Southern California, the water must be pumped 2,000 feet over the Tehachapi Mountains, the highest water lift in the world. A key feature of the SWP is the 444-mile long California Aqueduct that can be viewed from Interstate 5. Today, about 30% of SWP water is used for irrigation, mostly in the San Joaquin Valley, and about 70% is used for residential, municipal and industrial use, mainly in Southern California but also in the Bay Area. SWP is the state’s fourth largest generator of electricity but is also the state’s largest user of electricity, primarily to lift water over the Tehachapi Mountains. SWP was constructed and is operated by the Department of Water Resources.
Central Valley Project
(source: https://en.wikipedia.org/wiki/User:Shannon1/Maps)
FAST FACTS ABOUT THE SWP:
- SWP is the nation’s largest state-built, multi-purpose, user-financed water project.
-
