M&A Experts Instrumental in Kaweah Groundwater Subbasin’s Release from State Intervention

Montgomery & Associates (M&A) played a pivotal role in the December 2, 2025, decision by the State Water Resources Control Board to return the Kaweah Groundwater Subbasin to the Department of Water Resources’ (DWR) jurisdiction under the Sustainable Groundwater Management Act (SGMA).

Background

After nearly 3 years of state intervention, the Kaweah Subbasin was released from probation following substantial technical and collaborative efforts by local Groundwater Sustainability Agencies (GSAs) and their consultants. The State Water Resources Control Board’s (State Board) decision recognizes the subbasin’s progress in revising and implementing its Groundwater Sustainability Plans (GSPs).

M&A’s Contributions

Thanks to M&A’s leadership and expertise, the team made substantial contributions in the following areas:

• Technical Leadership: M&A led the development of land subsidence modeling and groundwater level management targets, helping the GSAs address critical deficiencies identified by both DWR and the State Board.
• Groundwater Modeling: M&A updated and refined the subbasin groundwater model to better support sustainable management decisions and address regulatory requirements.
• Groundwater Market: M&A designed trading rules that underpin the Kaweah Subbasin’s groundwater market, ensuring fair and transparent allocation of water resources.
• GSP Amendments: The Mid-Kaweah GSA’s Second Amended GSP, authored by M&A, in collaboration with the other GSA amended GSPs, provided the technical foundation for the subbasin’s reforms and compliance with SGMA requirements.
• Stakeholder Engagement: M&A staff contributed expertise at key events, including the “State of the Subbasin” meeting, and participated in numerous technical advisory sessions with state regulators.

With oversight returned to DWR, M&A continues to support the Mid-Kaweah GSA in groundwater monitoring implementation, subsidence mitigation strategies, and managed aquifer recharge. The Kaweah Subbasin’s success serves as a model for collaborative groundwater management across California.

For more details, contact the Mid-Kaweah GSA or Montgomery & Associates project team leaders Georgina King, P.G., C.Hg., Principal Hydrogeologist; and Derrik Williams, P.G., C.Hg., Principal Hydrogeologist.

State Board members and staff, GSA Managers, staff and GSA Board member, Self-Help Enterprise staff, NGO representative, and MKGSA consultant celebrate the State Board’s decision at the conclusion of the State Board meeting on December 2, 2025.