Los Angeles’ Blueprint for Storm Water Management

Driven by years of drought and new, unprecedented restrictions on water use, Los Angeles is taking an innovative approach to reduce future reliance on imported water, in addition to taking preventive measures for a predicted weather trend of heavier, more intense precipitation. The Santa Fe Spreading Grounds, located off the San Gabriel River, is one of 26 such facilities operated by the Los Angeles County Flood Control District for groundwater recharge. During an average year of rainfall, the District returns close to 85 billion gallons of storm water, recycled water and imported water to groundwater basins; enough to supply two million County residents for a year. Nearly 71 billion gallons (220,000 acre-feet) of that total is storm water.

The approach to this new plan will be to revise and conquer.  Instead of allowing up to 10 billion gallons of water from a single storm from simply surging into the Pacific Ocean, the plan includes three large-scale projects in the San Fernando Valley that would capture the valuable resource in basins or washes and be filtered through an aquifer recharge process. Centralized Storm water Capture Facilities are designed specifically to divert large amounts of runoff into underlying groundwater aquifers. The Los Angeles Department of Water and Power (LADWP) has entered into several cooperative agreements with the Los Angeles County Flood Control District to assist with spreading ground facilities that recharge groundwater for the City of Los Angeles’ future use. Another facet of the storm water plan involves water-permeable surfaces, which would be scattered throughout the city on public, private and commercial properties to help recharge the San Fernando Valley groundwater basin.  An average of 27,000 acre-feet of rainwater is collected in Los Angeles each year. Under the new plan, it is estimated that the city will collect 100,000 to 200,000 additional acre-feet of rainwater each year by 2035.


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