Groundwater Sustainability Plans

A map of California highlighting the status of GSPs throughout the state.
Current Status of GSPs

Map of California and the current status of reviewed GSPs. Last updated February 2025.

The Sustainable Groundwater Management Act (SGMA) requires local Groundwater Sustainability Agencies (GSAs) in the state’s high and medium priority basins to develop and implement Groundwater Sustainability Plans (GSPs) or Alternatives to GSPs. These GSPs and Alternatives provide roadmaps for how groundwater basins will reach long-term sustainability.

On February 27, 2025, the Department completed the initial GSP review for 16 groundwater basins. This release marks a significant SGMA Milestone – it completes initial Plan determinations for all high and medium priority basins in California that are required to comply with SGMA. In total, 86 basins are now operating under an approved GSP or alternative GSP. These 86 basins accounted for 78 percent of statewide groundwater use in Water Year 2023. Seven basins have been deemed inadequate by the Department.

GSAs are required to begin implementing their GSPs upon their submittal to the Department. If a basin’s GSP is approved, plan implementation continues, and the GSA has 20 years to achieve sustainability within the basin. Basins that are determined to be inadequate are referred to the State Water Resources Control Board for possible State Intervention.

Regardless of determination status, basins are required to submit annual reports following adoption of a GSP or Alternative. Periodic evaluations are also due at least every five years for approved basins. For further details, see the Department’s guidance document on what is expected to be included in annual reports and periodic evaluations, as well as plan amendments. These reports are reviewed by the Department to determine if GSP implementation is on track and likely to lead to basin sustainability within 20 years of implementation.