Under the Sustainable Groundwater Management Act (SGMA), Groundwater Sustainability Agencies must evaluate their Groundwater Sustainability Plans (GSPs) every five years to assess progress toward achieving groundwater sustainability. The Vina Subbasin’s first GSP Periodic Evaluation will be submitted to the California Department of Water Resources (DWR) in January 2027.

This webpage provides information related to the Periodic Evaluation, including new data, studies, and projects completed since the adoption of the GSP (see Table 1 and links below). These updates help the GSA assess whether the current plan remains effective or whether adjustments to the basin description, sustainability criteria, or management approach may be needed.  This [Annotated Outline] document is based on DWR guidance and shows the required sections of the Periodic Evaluation with notes specific to the Vina Subbasin included.

The focus of this first Periodic Evaluation is to address the Department of Water Resources’ 6 Recommended Corrective Actions (from the 2023 Determination Letter) and provide a written assessment of GSP implementation. Once submitted, DWR will complete its Periodic Review of the Vina GSP and issue a determination of the status of the Plan: Approved, Incomplete, or Inadequate.

For those interested in more detail, additional supporting materials are available:

Periodic Evaluation Supporting Documents

Strawman Proposals – for consideration and discussion

The following strawman proposals (i.e. a preliminary, rough draft intended to spark discussion and gather feedback) are provided to facilitate discussion and solicit public input on specific topics identified in the RCAs and Determination Letter.  Any input received will be incorporated into and inform materials prepared for consideration by the Stakeholder Advisory Committee (SHAC) and then brought forward to the GSA Boards for decision making.

Land Subsidence_Memo and Strawman Proposal_4.24.2026.pdf