State Water Board adopts resolution, will return Kern County Subbasin to DWR oversight after staff verification

The State Water Resources Control Board on Sept. 17 adopted a resolution to return the Kern County Subbasin to Department of Water Resources oversight after staff verifies that the subbasin’s amended 2025 Groundwater Sustainability Plans (GSPs) address three priority items identified by staff.

The action followed a daylong continuation of a probationary hearing on the subbasin under the Sustainable Groundwater Management Act (SGMA). State board staff and representatives of the subbasin’s 20 groundwater sustainability agencies (GSAs) presented technical revisions to the 2025 plans and described expanded monitoring networks, revised minimum thresholds, and new well‑mitigation programs. Derek Yurosick, chair of the Kern County Subbasin Coordination Committee, told the board: “We took to heart the direction given by the board at the February 20 probationary hearing. You asked for a series of revisions. We listened. We delivered.”

Why it matters: The Kern County Subbasin ranked as a critically overdrafted basin and in 2023 received an inadequate determination from the Department of Water Resources (DWR). A probationary designation by the State Water Board would have required the board to collect extraction data and could have led to an interim plan if local agencies did not correct deficiencies. Returning the subbasin to DWR oversight is a procedural step that lets DWR continue technical review while local GSAs focus on implementing the revised GSPs and mitigation measures.

What the board decided and why Board staff presented a review of the 2025 draft GSPs and told the board they recommended return to DWR oversight if GSAs resolved three prioritized issues: (1) an adequate mitigation program for drinking water wells impacted by any constituent for which a minimum threshold is established in the GSPs (including 1,2,3‑trichloropropane, or 1,2,3‑TCP); (2) an adequate mitigation program for state small water system wells or domestic wells with more…