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Basin Boundary Modifications

The Sustainable Groundwater Management Act (SGMA) established a process for local agencies to request that the Department of Water Resources (DWR) revise the boundaries of existing groundwater basins or subbasins, including the establishment of a new subbasin. The Basin Boundary Emergency Regulation was developed through an extensive stakeholder outreach process and was adopted on October 21, 2015. The provisions of the emergency regulation go into effect on November 16, 2015.

Planning to request a modification to basin boundaries?

If you are an eligible local agency and are thinking of requesting modification to the boundaries of your basin, follow these steps:

  1. Review the Basin Boundary Modification Regulations.
  2. Submit Initial Notification within 15 days of exploring a modification – notification is preliminary and is intended to signal that a modification request may occur.  It serves to notify other local agencies, public, and the department. Use Basin Boundary Assessment Tool to explore geology and other boundaries.
  3. Determine appropriate required documents and actions to comply with regulations for modification request submission.  See the Basin Boundary Modification Resources for examples and supporting information.
  4. Submit Basin Boundary Modification Request – Submission period is open from January 1, 2016 through March 31, 2016.
How to Submit Basin Boundary Modification Requests

DWR has developed a Basin Boundary Modification Request System for use by local agencies to submit initial notification and basin boundary modification requests. The system also provides public access to view basin boundary modification information.

Important Note - One of the first steps in the basin boundary modification process is initial notification of a potential basin boundary modification. This process is described in Section 343.9 of the regulation and on the Basin Boundary Modification Request System.

When to Submit Basin Boundary Modification Requests

The following is the anticipated schedule and next steps for basin boundary modifications:

Events Schedule*
Basin Boundary Regulation Effective November 16, 2015
Basin Boundary Modification Reporting System Available For Submission of Initial Notification (Pursuant to Section 343.9) of Potential Basin Boundary Modifications November 16, 2015
Basin Boundary Modification Instructional Webinar (Presentation available below) December 17, 2015
Basin Boundary Modification Request Submission Period Opens January 1, 2016
Last Date to Submit Basin Boundary Modification Requests Within the Initial Submission Period March 31, 2016

*All dates are subject to change.

Basin Boundary Modification Resources




More Information

Click here to sign up to receive email updates on Basin Boundary Modification Requests and DWR SGMA activities.

For additional information regarding basin boundary modifications, please contact Tim Godwin at or 916-651-9223.