By Robert Katherman, treasurer, Water Replenishment District
Climate change is creating enormous global challenges for the delivery of life-giving water.
When Governor Newsom recently declared emergency water rules for 41 of the state’s 58 counties, it was clear drought conditions had become California’s “new normal.” Fortunately, the Water Replenishment District (WRD) has been preparing for this challenge by building a drought-proof sustainable groundwater system that provides about half of the drinking water in southern Los Angeles County.
WRD is a groundwater management agency responsible for replenishing and protecting groundwater resources for more than 4 million residents or 11% of California’s population. WRD’s service area covers a 420-square-mile region of southern Los Angeles County, including 43 cities. For more than 60 years, WRD has been committed to providing, protecting and preserving a safe and reliable high-quality groundwater supply.
The key to a sustainable drought-proof water future lies under our feet. Though we can’t see them, groundwater aquifers are an immense natural underground reservoir—currently with empty storage space that can hold nearly 150 billion gallons of water. WRD is working to fill that storage with reclaimed water that can be used during dry years.
Impeding that aquifer storage in the South Bay is a 500,000-acre plume of salty brackish water. This water is about one-tenth as salty as the sea. Due to over pumping of the groundwater basins before WRD was established, seawater pushed into the West Coast basin and polluted the groundwater. To help visualize the scale of this plume, one acre foot of water is equivalent to one football field covered in a foot of water. This means there is enough brackish water in the South Bay to cover 500,000 football fields in a foot of water.
Through our Regional Brackish Water Reclamation Program (RBWRP), WRD will clean this brackish water and create new space in the aquifer to store fresh water for future use. Specifically, the facility will produce up to 20 million gallons of fresh water a day. Advanced technologies and reverse osmosis will be used to treat the contaminated water so it may be used as drinking water.
WRD has a successful track record with groundwater desalination projects. The WRD Desalter located in the city of Torrance was commissioned in 2001 and expanded in 2018. The facility treats up to 5 million gallons per day of brackish groundwater, which is put directly into the city of Torrance potable water system.
The RBWRP builds upon the success of the Torrance WRD Desalter and will help to create a new supply of “drought-proof” water. Even during dry years, this water will be available to be extracted, treated and made available to water suppliers in the South Bay. This water will help reduce the region’s need for imported water. It will also help us to plan for a more drought-resilient future and ensure we’re more prepared for challenges that climate change may bring.
For more information on the Regional Brackish Water Reclamation Program, please visit https://www.wrd.org/content/regional-brackish-waterreclamation-program.