In 1960, California voters approved financing for construction of
the initial features of the State Water Project (SWP). The
project includes some 22 dams and reservoirs, a Delta pumping
plant, a 444-mile-long aqueduct that carries water from the Delta
through the San Joaquin Valley to southern California. The
project begins at Oroville Dam on the Feather River and ends at
Lake Perris near Riverside. At the Tehachapi Mountains, giant
pumps lift the water from the California Aqueduct some 2,000 feet
over the mountains and into southern California.
The 1,440-mile-long Colorado River passes through parts of seven
states, several Indian reservations and the Republic of Mexico.
California is entitled to 4.4 million acre-feet of water annually
from river. Most of that water irrigates crops in the Palo Verde,
Imperial and Coachella valleys, located in the southeastern
corner of the state, but the Colorado also is a vital source of
water for urban southern California. Urban supplies are
distributed by the Metropolitan Water District of Southern
California through its Colorado River Aqueduct.