Background and Formation Documents

Basin Boundary Modifications

Department of Water Resources 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.

Groundwater Sustainability Agency (GSA) of Tehama County

Submitted Jurisdictional Consolidation Basin Boundary Modification Request

  • Jurisdictional Consolidation of Portion of Vina Subbasin Within Tehama County Into the Los Molinos and Dye Creek Subbasins, Submitted on 09/27/18 (Read more)
  • Jurisdictional Consolidation of the Rosewood and Bowman Subbasins, Submitted on 09/27/18 (Read more)
  • Jurisdictional Consolidation of Portion of Millville Subbasin Within Tehama County Into The South Battle Creek Subbasin, Submitted 09/27/18 (Read more)

Groundwater Sustainability Agency (GSA) of Tehama County

  • Jurisdictional Consolidation of Portion of Vina Subbasin Within Tehama County Into the Los Molinos and Dye Creek Subbasins, Submitted on 06/12/18 (Read more)
  • Jurisdictional Consolidation of the Rosewood and Bowman Subbasins, Submitted on 06/12/18 (Read more)
  • Jurisdictional Consolidation of Portion of Millville Subbasin Within Tehama County Into The South Battle Creek Subbasin, Submitted 05/10/18 (Read more)
  • Jurisdictional Consolidation of Portion of Colusa Subbasin Within Tehama County Into The Corning Subbasin, Submitted 02/18/16 (Read more)

Initial Notification of Potential Basin Boundary Modification Requests

Groundwater Sustainability Agency (GSA) of Tehama County

The finalized Basin Boundary Modification Request (described above) was submitted to DWR on March 29, 2016. DWR confirmed that the application is complete on April 11, 2016, this started a 30 day public review period during which DWR will be taking public comment on the completed modification requests through the Basin Boundary Modification Request System (BBMRS). In early June, DWR will host public meetings to present the draft final basin boundary modifications and to hear any additional public comment. For more information and resources regarding Basin Boundary Modification Requests please visit the website here.

Following the technical review of the requested basin boundary modifications and included public input, DWR will publish a Draft Approved Basin Boundary Modification list on their website. The public comment will be summarized and presented to the California Water Commission, which will hear the modifications and provide the public an opportunity to comment. Following consideration and potential incorporation of comments heard, DWR will publish the final basin boundary modifications on their website. Per SGMA, these new basin definitions will be evaluated under the basin prioritization process and documented in the interim update of Bulletin 118. DWR is planning a second opportunity to request basin boundary modifications in 2018.

Submitted Basin Boundary Modification Request

Basin Boundary Modification Frequently Asked Questions (FAQ)

Is it mandatory to participate in Basin Boundary Modifications requests? How can I be notified when Basin Boundary Modifications related actions happen? Does DWR provide maps that may assist with Basin Boundary Modifications? What are the types of basin modifications?

2018 SGMA Basin Prioritization

Following the release of the 2016 Basin Boundary Modifications, DWR began the 2018 SGMA prioritization of California’s 517 groundwater basins (Water Code 12924(b)) defined in Bulletin 118. Prioritization has changed for some basins due to the consideration of impacts from local habitat and local streamflows, the change in area of basin as a result of boundary modifications, and incorporation of newly available data sources. DWR will conduct public meetings to present the draft results and solicit public comments.

Bulletin 118 Subbasin Boundaries

SGMA Map

Stream Gauges