Southern California banking on water storage in a changing climate

To prepare for a climate-changed future, water systems in Southern California are introducing innovative measures to ensure their long-term water supplies meet demand during future droughts, which are anticipated to increase in intensity, duration and frequency. 

One such measure is the High Desert Water Bank (HDWB), a new groundwater storage project (pictured right) near the California Aqueduct in the Antelope Valley, located in the western Mojave Desert. It will significantly increase the reliability of the region’s water supply with a storage capacity of 280,000 acre-feet.

The water bank project is a partnership between the Metropolitan Water District of Southern California (Metropolitan) and the Antelope Valley-East Kern Water Agency (AVEK). Its first stage recharge basins were completed in October 2023 after three years of construction. The bank is already storing water, enabling the region to take advantage of the historic precipitation in 2023. 

“The High Desert Water Bank improves water supply reliability during dry years or emergencies and provides greater operational flexibility to balance supplies and demands,” said Kira Alonzo, Metropolitan’s water resources management team manager. “The project captures supplies in surplus years to use in dry years when supplies may be limited.”

The HDWB allows Metropolitan to transport State Water Project supplies to AVEK-owned property, where it can percolate into the Antelope Valley groundwater basin. Metropolitan can access 70,000 acre-feet a year from the basin, enough to serve the annual needs of 210,000 Southern California homes and bolster water availability during extreme droughts or emergencies. 

“Metropolitan is proud to have completed this stage of the project in time to take advantage of the past historically wet year, so that we are more prepared for the next inevitable dry year,” said Alonzo.

Regional scope key to long-term supply

With the shared goal of regional water supply reliability, Metropolitan and AVEK formed a strong partnership that was instrumental in the project’s success. 

“This project really showcases what two agencies can accomplish when they collaborate on projects that can provide mutual benefits to their constituents,” said Matthew Knudson, AVEK general manager. “The public benefits from that collaboration.”

Metropolitan is providing capital funding for the project, which is located on AVEK property, and storing its imported water supplies in the bank for later use within its service area. AVEK led the design and construction of the HDWB and will manage the facility’s operation, including recharge basins and recovery wells. AVEK also holds second-priority access to unused capacity the bank, enabling them to store surplus water for the Antelope Valley community.

Construction of the second stage of recharge basins is currently underway, and the project will be fully operational in 2027.

“With unpredictable weather changes caused by climate change, we need to invest in new projects that allow us to adapt and better manage our water resources from year to year,” said Adel Hagekhalil, Metropolitan general manager.

“Increasing storage will be critical as we adapt to climate change, providing a path forward to develop new sustainable supplies, promote conservation and improve our ability to move water,” he added.