How does water get to us?

Because precipitation falls unevenly in California — almost ten feet per year drenching parts of the Coast Range and just several inches falling in deserts — water agencies have found ways to spread the resource. 

A complex system of dams, reservoirs, pumping stations and about 2,000 miles of canals supplies water to Californians that originated in the Rocky Mountains, the Sierra Nevada and the Cascades. 

For instance, when an 11-mile tunnel was drilled through the mountains of California’s North Coast in 1960, water that naturally flowed to the salmon streams and redwoods was diverted to San Joaquin Valley orchards and other farmland. This Trinity River project is one of many ambitious engineering projects that have brought water to Los Angeles swimming pools, San Diego lawns, Kern County crops and the taps of about 30 million people. 

Here are our major delivery systems:

•The federal Central Valley Project uses 20 reservoirs and 500 miles of canals to send water from the Sacramento, San Joaquin and Trinity basins into the San Joaquin Valley and the Bay Area. It provides water for about 3 million acres of farmland. 

•The State Water Project transports water via more than 700 miles of canals from the same river systems to cities and farms throughout the state, as far as San Diego. In all, it supplies 27 million people and 750,000 acres of farmland. 

•Another 4 million acre-feet per year flow via a 242-mile aqueduct from the Colorado River to Southern California farmland and cities.

•Water from the Sierra Nevada travels via canals as far as 160 miles to San Francisco and surrounding cities, and Los Angeles imports it from the Eastern Sierra in a canal system more than 400 miles long.•About 40 percent of all water used in California is pumped from underground basins in an average year. This share increases during drought years.

Between rain and snow, the state’s drainage basins receive an average of about 200 million acre-feet of precipitation each year.
Source: California Department of Water Resources