Under the Sustainable Groundwater Management Act (SGMA), Groundwater Sustainability Agencies (GSAs) must periodically review and update their Groundwater Sustainability Plans (GSPs). These updates help ensure the plan reflects current groundwater conditions, incorporates new data, and continues to guide sustainable groundwater management in the Wyandotte Creek Subbasin.

This page provides information related to Periodic Evaluations and Plan Amendments, including draft documents available for public review.

GSP Periodic Evaluation

SGMA requires GSAs to complete a Periodic Evaluation every five years to assess progress toward achieving groundwater sustainability. The Wyandotte Creek Subbasin’s first Periodic Evaluation will be submitted to the California Department of Water Resources (DWR) in January 2027.

The Periodic Evaluation reviews monitoring data, groundwater conditions, and new information collected since the GSP was adopted to determine whether updates to the plan are needed.

Periodic Evaluation Documents

• March 2026 | Draft Periodic Evaluation: Draft five-year evaluation of the Wyandotte Creek GSP.
• March 2026 | New Information Summary: Summary of new data, monitoring results, and technical information collected since GSP adoption.
• Fall 2026: Public Comment Materials: Materials related to public review and feedback.

Links will be added when documents are available. 

GSP Plan Amendments

A Plan Amendment is used when updates to the Groundwater Sustainability Plan are needed based on new information, regulatory requirements, or changes to the basin’s management approach.

Plan Amendments may include updates to:

• Basin setting information
• Monitoring networks
• Sustainable Management Criteria
• Projects and management actions

Plan Amendment Documents

• March 2026 | Draft GSP Plan Amendment: Proposed updates to the Wyandotte Creek Groundwater Sustainability Plan.
• March 2026 | Amendment Summary: Overview of proposed changes to the GSP.

Links will be added when documents are available. 

Public Participation

Public input is an important part of the GSP amendment process. Draft documents will be posted here for review once available, and opportunities for public comment will be announced through the Wyandotte Creek GSA website and meetings.