California has built one of the most complex and comprehensive water systems in the country. It is designed to move water around the state.
The California State Water Project contains 21 dams and over 700 miles of canals, pipelines and tunnels. All of them specifically designed to transport water from places that have it to areas that don’t.
According to the California Nevada River Forecast Center, California’s unique climate and topography means that annual rainfall ranges from over 100 inches in the redwood forests near Crescent City to fewer than five inches in parts of San Bernardino, Riverside and Imperial Counties in Southern California.
And it is true that some of the water that is contained in Lake Shasta, Trinity and Oroville does get transported to the south, very little of it actually makes it to the golf courses and swimming pools of Los Angeles and San Diego. Most, in fact, goes to agricultural use in both the Sacramento and San Joaquin Valleys.
The California Water Plan is updated by The California Department of Water Resources every four years with the latest update published in 2009. That year 69.6 million acre feet of water fell as rain in the Sacramento river drainage. Only 7.9 million acre feet were exported to other regions, most of that going to agricultural use in the San Joaquin Valley
A total of 44 million acre feet of Sacramento River water never made it to the ocean. Some of that water was evaporated throughout the year, absorbed into the water table, used by native vegetation, and/or trapped in naturally forming lakes, ponds and marshes. The remainder was used by farmers and residents in the Sacramento River Valley.
An additional 15 million acre feet is required to help keep the ocean at bay. That water is used to keep the salt water from ruining delta area farmland when summer decreases natural river volume.
Of the 7.9 million acre feet that are exported to the San Joaquin Valley, most is used in agriculture to water the crops on farms. Other water is used to maintain the health and way of life the San Joaquin Valley is known for.
By this point, the water from the Sacramento River has been mixed with water from the Merced, Tulare, Tuolumne, San Joaquin and other rivers that make up the San Joaquin Drainage. Eventually some water does get pumped to Los Angeles and San Diego, but total imports to those cities comes to 1.6 million acre feet. That’s less than 3 percent of the total rain that falls over the Sacramento River drainage.
So where does the water for the second and eighth largest cities in the US come from?
About a third of the water for Los Angeles and San Diego comes from the Los Angeles Aqueduct which connects the cities to Owens and Mono Lakes on the eastern side of the Sierra Nevada mountain range. Another third comes from the Colorado River, which also feeds Las Vegas and carved the Grand Canyon.
The final third comes from the San Juaquin Valley which could have a small fraction of water from the Sacramento River mixed in with it. But officials say it is nearly impossible to tell exactly how much water goes to LA and San Diego.
Because of their arid location, both San Diego and Los Angeles have implemented effective incentive programs to conserve water. In fact TIME Magazine reports that while Los Angeles’ population has grown by about 5 million people since 1990, its water consumption has dropped by 20 percent.
News10 in Sacramento discovered that Sacramento residents use an average of 90 gallons more water per day than their counterparts in Los Angeles. That means residents of Northern California are much less frugal when it comes to conserving water.
With southern California’s water policies and incentives to conserve water, the California Department of Water Resources says that Los Angeles is actually OK this year.
They even have enough water to make it through next year without changing many water use policies.