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-Editorial
As California enters the winter rain season, state and local agencies are taking coordinated steps to capture and store stormwater to bolster the state’s water supply and prepare for future dry periods.
Following three weeks of dry weather across most of the state, reservoirs have the capacity to manage incoming rainfall. Lake Oroville, the State Water Project’s largest reservoir, is currently at 54 percent of its capacity, providing officials with space to store additional runoff from winter storms. Water managers say capturing water during the rainy season is crucial to support communities, agriculture, and ecosystems during the state’s dry summer months.
Local stormwater-capture projects have already demonstrated the benefits of these efforts. In Los Angeles, November storms generated billions of gallons of water captured through existing infrastructure, enough to supply tens of thousands of households. Officials say additional projects currently under construction are expected to further increase the state’s capacity to retain water from winter storms.
California is also expanding its flood management and groundwater recharge programs. The state has partnered with 14 local agencies in the Sacramento and San Joaquin regions to divert flood flows and prepare land for recharge into underground aquifers. Preparations include pre-deploying 20 large-capacity pumps and clearing over 650 acres of land. These efforts aim to reduce flood risks while improving the state’s long-term water storage capabilities.
Along the Sacramento River Basin, the Big Notch fish passage project has begun operations. The project, designed to modernize infrastructure while protecting juvenile endangered winter-run Chinook salmon, is part of the State Water Project’s ongoing effort to balance environmental protection with water supply needs for millions of Californians.
In August, the state committed an additional $219 million to the Sites Reservoir project. The reservoir is designed to capture water from the Sacramento River during wet periods and store up to 1.5 million acre-feet of water—enough to supply approximately 4.5 million homes for a year. The investment is part of the state’s broader strategy to maintain a resilient water supply amid climate change, extreme weather, and ongoing drought conditions.
Groundwater recharge remains a key component of California’s water management strategy. Data from the Department of Water Resources show that aquifer levels have improved over the past several years due to efforts to capture high flows during winter storms, expand recharge basins, improve monitoring, and coordinate among local agencies to reduce excessive groundwater pumping.
State officials emphasize that these measures, combining surface water storage, groundwater recharge, and infrastructure investments, are designed to ensure water is available when it is needed, protect communities from flooding, and support long-term resilience against climate variability and water scarcity.
