Challenge: To help the East Kaweah Groundwater Sustainability Agency (EKGSA) and the Kaweah Subbasin (Subbasin) exit state intervention and avoid losing local control via probation through the development of a defensible, groundwater sustainability plan (GSP) under California’s Sustainable Groundwater Management Act (SGMA).
Solution: INTERA was engaged by the East Kaweah Groundwater Sustainability Agency at a critical juncture, immediately after the Kaweah Subbasin received notice that its latest GSP was determined inadequate and the Subbasin would be entering state intervention with oversight by the State Water Resources Control Board. EKGSA recognized the need for a hydrogeologic specialist capable of helping the Subbasin respond to state concerns while maintaining local control over groundwater management decisions. Although initially retained by EKGSA, INTERA rapidly became a key technical contributor and collaborator in the Subbasin, working with the other GSAs and consultant teams firms on several Subbasin-wide technical working groups, serving as the lead on the Groundwater Level, Well Mitigation, Groundwater Quality, and Interconnected Surface Water core teams.
As part of this collaborative effort, INTERA helped create a unified technical and planning approach focused on coordination, transparency, and problem-solving. INTERA led the Subbasin’s groundwater level, water quality, and interconnected surface water analyses, which served as a foundational component for evaluating coordinated sustainable management criteria (SMCs) using the best available data and modeling tools. The team conducted dry well susceptibility analyses to identify groundwater level thresholds that would avoid significant and unreasonable impacts while still providing operational flexibility for agricultural groundwater users. We also evaluated remote-sensed, areal imagery, and groundwater level data to assess the presence of interconnected surface water (ISW) and relationships of ISW with habitat and ecosystems in the Subbasin. We also served as a technical coordinator across consultant teams, ensuring that analyses, assumptions, and recommendations aligned across agencies and technical disciplines.
In parallel, INTERA worked closely with Self-Help Enterprises, a non-profit that expands access to affordable housing and water infrastructure in disadvantaged communities, to develop a mitigation program designed to address drinking water impacts from declining groundwater levels and groundwater quality degradation induced by groundwater management activities after SGMA was enacted. The program established rapid-response emergency drinking water measures and long-term mitigation pathways for affected well owners.
Results: INTERA’s efforts helped the Kaweah Subbasin successfully avoid probation, with the State Water Resources Control Board determining that a probationary hearing was unnecessary based on the progress made in the updated 2024 GSP. Today, we continue to support implementation efforts across the subbasin while helping stakeholders maintain a collaborative, science-driven approach to sustainable groundwater management.
View the State announcement: Kaweah Subbasin to exit state intervention after improving SGMA groundwater plans | California State Water Resources Control Board
