California State Water Project

California State Water Project

Map showing major features of the project (SWP reservoirs in blue, SWP/CVP reservoirs in purple, and other connected facilities in light blue)
General statistics
Begun	1960
Storage dams	10
Additional dams	4 (reregulation) 4 (hydroelectric) 2 (flood control) 1 (mitigation/conservation)
Power plants	5 conventional 3 pumped-storage
Canals	701.5 miles (1,129.0 km)
Operations
Storage capacity	5,746,790 acre-feet (7.08856×109 m3)
Annual water yield	2,400,000 acre-feet (3.0×109 m3)[1]
Land irrigated	750,000 acres (300,000 ha)
Power plant capacity	2,991.7 MW
Annual generation	6500 GWh
Annual consumption	11500 GWh
Constituencies served	Greater Los Angeles Area Greater San Diego Inland Empire San Francisco Bay Area North Bay Santa Clara Valley South Bay Central Coast San Joaquin Valley
v t e

The California State Water Project, commonly known as the SWP, is a state water management project in the U.S. state of California under the supervision of the California Department of Water Resources. The SWP is one of the largest public water and power utilities in the world, providing drinking water for more than 27 million people and generating an average of 6,500 GWh of hydroelectricity annually. However, as it is the largest single consumer of power in the state itself, it has a net usage of 5,100 GWh.^[2][3][4]

The SWP collects water from rivers in Northern California and redistributes it to the water-scarce but populous cities through a network of aqueducts, pumping stations and power plants. About 70% of the water provided by the project is used for urban areas and industry in Southern California and the San Francisco Bay Area, and 30% is used for irrigation in the Central Valley.^[5] To reach Southern California, the water must be pumped 2,882 feet (878 m) over the Tehachapi Mountains, with 1,926 feet (587 m) at the Edmonston Pumping Plant alone, the highest single water lift in the world.^[6] The SWP shares many facilities with the federal Central Valley Project (CVP), which primarily serves agricultural users. Water can be interchanged between SWP and CVP canals as needed to meet peak requirements for project constituents. The SWP provides estimated annual benefits of $400 billion to California's economy.^[7]

Since its inception in 1960, the SWP has required the construction of 21 dams and more than 700 miles (1,100 km) of canals, pipelines and tunnels,^[8] although these constitute only a fraction of the facilities originally proposed. As a result, the project has only delivered an average of 2.4 million acre-feet (3.0 km³) annually, as compared to total entitlements of 4.23 million acre-feet (5.22 km³). Environmental concerns caused by the dry-season removal of water from the Sacramento–San Joaquin River Delta, a sensitive estuary region, have often led to further reductions in water delivery. Work continues today to expand the SWP's water delivery capacity while finding solutions for the environmental impacts of water diversion.