Stormwater Capture: Strengthening the Resilience of Our Water Supply

Even as we’ve been calling on our customers to conserve water, we have also been doing our part to strengthen our ability to safeguard the resilience of our water supply during dry conditions. Key among those efforts is expanding our capacity for capturing stormwater runoff, which is an important strategy in ensuring our city remains water strong into the future. In fact, we already have invested more than $130 million in expanding stormwater capture infrastructure to recharge our groundwater and replenish our current water supply.

And after weeks of rain pounded Los Angeles and the greater Southern California region in January, those stormwater capture investments paid major dividends in replenishing our groundwater basins. We estimate the cumulative amount of stormwater captured for the current rainy season, from October 1, 2022, through the fourth week of January 2023, is nearly 49,000 acre-feet. That translates to about 15.8 billion gallons—enough water to serve over 194,300 households for a year or equivalent to filling 24,000 Olympic-size swimming pools.

As part of these infrastructure investments, we have joined with multiple partners to build more than 20 large-scale and community stormwater capture projects. These range from smaller green street stormwater capture projects to larger spreading grounds and dam improvement projects, like the Tujunga Spreading Grounds Enhancement completed in 2022. 

All together, these investments have increased LADWP’s total stormwater capture capacity from about 64,000 acre-feet per year (AFY) in 2015 to over 82,600 AFY. This represents 55% of the City of Los Angeles’ 2035 goal of 150,000 AFY, or 48.9 billion gallons, of stormwater capture capacity.

A wide range of benefits stems from capturing and managing stormwater. Beyond replenishing local groundwater aquifers, it is a reliable and sustainable way to reduce urban flooding. It also improves the quality of water in downstream water bodies, such as rivers, lakes, and the ocean.

For more information about stormwater capture and our expansion of local water resources, please visit www.ladwp.com/waterstrong.