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 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.
About 30 percent of California’s total annual water supply comes
from groundwater in normal
years, and up to 60 percent in drought years. Local communities’ usage
may be different; many areas rely exclusively on groundwater
while others use only surface
water supplies. Contrary to popular opinion, groundwater does
not exist in underground lakes.
