California issues accelerated groundwater recharge permits

California’s State Water Resources Control Board issued the last of nine groundwater recharge permits for this wet season, bringing the total amount of water authorized for underground storage to nearly 43,000 acre-feet, or enough to supply over 128,000 households for a year.

The State Water Board approved all the permit applications it received in recent months, including two 180-day and seven 5-year permits, the highest number of the longer-term permits issued for one season since they became available in 2020.

Most of the permittees relied on the board’s streamlined approach that includes lower fees and a faster processing option. The process has reduced the approval time for recharge permits to about 4 months, down from the previous average of up to 1 year. It also directly assists groundwater sustainability agencies in high and medium-priority basins by allowing them to move and use surface water, decreasing reliance on groundwater.

Permits were granted to water districts and groundwater sustainability agencies for recharge projects in the Sacramento, San Joaquin, Shasta, and Scott River watersheds. Two other 5-year permits issued in 2023 are still in effect.

The longer-term permits allow for recharging aquifers for five successive wet seasons without further authorization. This enables larger amounts of water to be stored annually without additional approvals.

The Scott Valley Irrigation District, for example, obtained four 180-day permits for the same project, beginning in 2016, before transitioning to the 5-year permit in December 2025. The longer permit allows the district to divert 5,400 acre-feet through March and is the largest amount authorized this season. The project involves extracting water from one location on the Scott River and spreading it onto farmland and into the ground via an unlined canal. The stored water then flows naturally from the basin into the river over the course of a few months.

To protect groundwater from contamination by pesticides or animal waste, the board’s permits require that recharge projects move water into a basin on fallow or dormant agricultural land. Permits also protect California’s limited water supplies and large number of water rights holders by ensuring that no other parties have rights to the water being diverted.

In addition to Scott Valley, the board also issued permits this season to the Sierra Valley Groundwater Management District, the Stockton East Water District, the Corning Subbasin, Modoc and Lassen County groundwater sustainability agencies, and the Siskiyou County, Tehama County, and Yolo County flood control and conservation districts. All permits are subject to public review and comment before being issued.

Permits are not required to move floodwaters in emergency situations. More information about groundwater recharge and flood recharge can be found on the board website.