Water securityL.A. could achieve independence from imported water

Published 19 March 2018

During the height of the California drought that began in late 2011, Los Angeles imported 89 percent of its water from more than 200 miles away — an energy-intensive process. After a yearlong reprieve, Southern California is again under severe water scarcity conditions: Only 2 1/2 inches of rain have fallen in Los Angeles during the past twelve months. This time around, could Los Angeles shift its dependence from imported water to local water? A new report says the city could, eventually — if it does a better job of capturing local stormwater, increases the use of recycled water, cleans up groundwater and steps up conservation measures.

During the height of the California drought that began in late 2011, Los Angeles imported 89 percent of its water from more than 200 miles away — an energy-intensive process. After a yearlong reprieve, Southern California is again under severe water scarcity conditions: Only 2 1/2 inches of rain have fallen in Los Angeles during the past twelve months.

This time around, could Los Angeles shift its dependence from imported water to local water? A new report by UCLA researchers says the city could, eventually — if it does a better job of capturing local stormwater, increases the use of recycled water, cleans up groundwater and steps up conservation measures.

“It will take a lot of work, but 100 percent local water is possible by 2050,” said Mark Gold, UCLA’s associate vice chancellor of environment and sustainability and one of the study’s authors. “Los Angeles needs to reduce local water demand while also transforming its water supply infrastructure to maximize recycled water, groundwater supply and stormwater capture.”

UCLA says that the report also suggests that the city could increase the supply of local water in groundwater basins, which the city uses as water storage reservoirs, by undertaking projects to improve the management of stormwater. Los Angeles also could bank recycled water or water imported from northern California or the Colorado River during times of plenty by letting it seep into groundwater basins.

The study, co-authored with researchers from the Colorado School of Mines, is the last in a four-part series on sustainable water management in the city of Los Angeles.  This study assesses the water landscape of the entire city, taking into account greenhouse gas emissions, stormwater pollution, groundwater management, conservation and the costs and benefits of various city water supplies. The authors also offer several policy recommendations for the city.