Keeping tap water flowing to millions of homes in Southern California takes more than one approach. Stormwater recharge is one way that water agencies capture rainwater to add to our water supply.

Southern California has an unpredictable climate, which makes it harder to guarantee that water will always be available when it is needed. Water professionals across the region are investing in stormwater recharge projects to build a more reliable, local supply. These investments increase water security for your household and community, even during dry years.

Let’s go back to the basics and learn what stormwater recharge means. When it rains, the water flowing from streets and land is collected by specialized infrastructure. The captured water is directed to recharge basins where it slowly soaks into the ground. As it moves through layers of soil, the water is naturally filtered by the environment before refilling groundwater sources. Water agencies then take that water, treat and test it before delivering it on tap for you.

Stormwater Recharge in Action

One acre-foot of water equals about 325,900 gallons of water. Across Your SoCal Tap Water member agencies, recharge projects and infrastructure capture thousands of acre-feet each year, which means more local drinking water available for you and your neighbors.

Let’s review some of the systems that bring this effort to life.

Santa Ana River Enhanced Recharge Project
In collaboration with several water agencies, San Bernadino Valley Municipal Water District successfully completed one of the region’s largest recharge projects in 2025, the Santa Ana River Enhanced Recharge Project. This project created 20 groundwater recharge basins that annually capture and recharge nearly 15,400-acre feet of stormwater, providing additional water to the regional supply.

San Bernadino Valley Municipal Water District partners with Western Water, San Bernardino Valley Water Conservation District, City of Riverside Public Utilities and the State Department of Water Resources on this project.

Inland Empire Groundwater Recharge System
A system of underground pipes within the Inland Empire region turns massive volumes of stormwater runoff into long-term water resources. The Inland Empire Groundwater Recharge System collects between 15,000 to 25,000 acre feet of stormwater runoff each year. The water is then sent to 19 recharge sites where it sits and slowly soaks down through the ground to refill the underground water supply. This recharge system is simply another way for the agency to contribute to a lasting supply of water.

Inland Empire Utilities Agency partners with Chino Basin Watermaster, Chino Basin Water Conservation District and San Bernardino County Flood Control District on this project.

Victoria Recharge Basin
Western Water’s Victoria Recharge Basin proves that even a single facility can make a huge impact on water security. The facility recharges nearly 2,500 acre feet of water each year; that’s the same as filling about 1,200 Olympic sized pools. The basin not only improves groundwater quality but also reassures the region that there’s plenty of water for drinking and other uses.

Your Tap Water, Secured
A big portion of captured stormwater eventually reaches your tap. These investments aren’t just about storing water for the future. They’re working right now to keep your drinking water supply full, affordable and reliable for you and generations to come.

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