California Cities to Reduce Water Imports From the Colorado River and Bay-Delta

Residents of a community in Camarillo, California, are alerted to the use of recycled water for landscape irrigation. Using water more than once — for example, for indoor home use and then irrigation — is one way a number of southern California cities are reducing their dependence on water imported from the Colorado River and the San Francisco Bay Delta. Photo by Susan Embree-Davis

The history of water, especially in the western United States, is largely one of reaching further out to distant water sources as population grows and local supplies get tight.

But five southern California cities that today rely heavily on water transferred hundreds of miles from the Colorado River and the San Francisco Bay-Delta are reversing this trend: they aim to cut their dependence on long-distance water imports by ramping up conservation, recycling and reliance on local supplies.

Collectively, water agencies serving Santa Monica, Camarillo, Ventura County, Long Beach and Los Angeles plan to cut their water imports by more than 40 billion gallons a year, enough to meet the annual household demands of 1.1 million people, according to a recent analysis by the Natural Resources Defense Council (NRDC).

Santa Monica, which now relies on imported water for 84 percent of its supply, has the most ambitious goal: to reduce that dependence to zero by 2020.  The city is investing in local groundwater sources, which it expects to tap for 72 percent of its future supply needs, along with a mix of recycling, stormwater capture, and rainwater harvesting for the other 28 percent.

In addition to making its supply more reliable, Santa Monica’s shift from imported to local water sources is expected to save its residents money. Whereas water imported from the Colorado River and the Bay-Delta costs the city $794 per acre-foot (one acre-foot equals 325,850 gallons), tapping its own groundwater will cost $330 per acre-foot, 58 percent less.

Camarillo, a town of about 66,000 people located northwest of Los Angeles, plans to slash its reliance on water imports from 53 percent of its supply to 7 percent, also largely by tapping local groundwater. The town is now constructing a desalting plant to turn its brackish underground water into a drinkable supply.

Nearby Ventura County also plans to rely on desalted groundwater in the future as it cuts its dependence on imported water from 78 percent of its water needs to 20 percent.

The Los Angeles Department of Water and Power (LADWP), which serves 3.9 million residents in the greater L.A. area, plans to diversify its water supply portfolio as it cuts its dependence on imported Colorado River and Bay-Delta water by 35 percent.  The LADWP will boost investments in conservation, recycling, stormwater capture and water transfers to make up the difference.

By the city’s calculations, over time imported water will cost 17-30 percent more than local recycled water, so projects that enable the reuse of water for non-potable purposes, such as landscape irrigation, are an important part of the mix.

The NRDC study’s authors, Kelly Coplin and Kate Poole, note that a “diverse coalition of water districts and municipalities, business groups, local elected officials, and environmental groups have urged California to follow the lead of the five water agencies highlighted here by investing in sustainable, local water supply solutions.”

As with any plan, successful implementation is key.

But if these pioneering five can show that greater reliance on conservation, efficiency, recycling and local water sources can cost-effectively and sustainably reduce dependence on water imports – and inspire other western cities to follow suit – perhaps there is hope for rejuvenating the suffering ecosystems of the San Francisco Bay-Delta and the Colorado River Basin.

Sandra Postel is director of the Global Water Policy Project and Freshwater Fellow of the National Geographic Society. She is co-creator of Change the Course, the national freshwater conservation and restoration campaign being piloted in the Colorado River Basin.

Help restore water to the Colorado River by joining Change the Course. Sign up online or text ‘River’ to 77177.

Sandra Postel is director of the Global Water Policy Project and author of Replenish: The Virtuous Cycle of Water and Prosperity. From 2009-2015, she served as Freshwater Fellow of the National Geographic Society. Sandra is also co-creator of Change the Course, the national water stewardship initiative awarded the 2017 US Water Prize for restoring billions of gallons of water to depleted rivers and wetlands. The recipient of several honorary degrees, she works to bridge science, policy, and practice to promote innovative ways of securing water to meet both human and ecosystem needs.
  • Rogene Reynolds

    Metropolitan Water District which wholesales to many Southern California urban districts states in its “Integrated Water Resources Plan 2010 Update”: “In future dry cycles, Southern California’s largest ‘supply’ will be the water it no longer uses. The lowering of demand through numerous conservation and water use efficiency programs will provide a greater contribution to water reliability than the Colorado River, State Water Project or any other single supply.”
    Southern Californians CAN conserve. They are leading the way!
    Thanks for the opportunity to comment. Rogene Reynolds, South Delta

  • Ron Wildermuth

    West Basin Municipal Water District is reducing its dependence on imported water by 50% by 2020. It’s program, called Water Reliability 2020, will double conservation, double recycling and add 10% of its future water supply portfolio from ocean water desalination. Of note, West Basin is the only water agency in the U.S. that makes 5 different types of usable water from sewer water: irrigation water, cooling tower water, low pressure boiler feed water, high pressure boiler feed water and indirect drinking water to recharge local aquifers. Also its environmental research with wedgewire screens in protecting marine life have been very successful.

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