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Basin Boundary Modifications

New!Download Final 2016 Bulletin 118 Groundwater Basin Boundaries - Zipped shapefile of the boundaries (meant for use in GIS applications). KMZ of the boundaries (meant for use in Google Earth).
New!Map of Basin Boundary Modifications - to view basin boundary modifications select the "Bulletin 118 Basins (2016 Edits)" layer.
New!List of 2016 Final Basin Boundary Modifications - explanation of recommended modifications and link to original BBMRS submittal.

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 went into effect on November 16, 2015.

Following the adoption of DWR’s Basin Boundary Emergency Regulations, DWR provided an online Basin Boundary Assessment Tool (BBAT) to inform local agencies and the public about the existing Bulletin 118 groundwater basins and other relevant geologic and geographic data. DWR’s Basin Boundary Modification Request System (BBMRS) enables local agencies to submit their requests for basin boundary modifications online and the public to view those requests and provide comment.

Final 2016 Basin Boundary Modifications

The Final 2016 Basin Boundary Modifications were developed through DWR's technical review of basin boundary modification requests and public comment made during the submission period, January 1, 2016 through March 31, 2016. DWR then held a series of public meetings to present the Draft Approved Basin Boundary Modifications, provide an overview of the BBMRS and technical review process, answer clarifying questions and receive further public comments on the Draft Approved Basin Boundary Modification submissions. After a technical review of the requests and public comments, DWR developed the list of 2016 Final Basin Boundary Modifications. The new basin boundaries will be included in the interim update of Bulletin 118, due January 1, 2017. Following the formation of GSAs, another basin boundary modification request period may be held in 2018, based on demand from local agencies and or GSAs. 

Next Steps
Events Schedule*
Final Basin Boundary Modifications Published October, 2016
Interim Update of Bulletin 118 Due Jan 1, 2017
Presentation of Final Approved Basin Boundary Modification to CWC October 18, 2016
Next Basin Boundary Submission Period Tentatively Early 2018

*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.