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Basin Boundary Regulations

Adopted Basin Boundary Emergency Regulations
Notice of Proposed Emergency Regulatory Action
Finding of Emergency

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 a groundwater basin, including the establishment of a new sub basin. California’s groundwater basins and subbasins are defined in the DWR’s Bulletin 118-Update 2003 – the definitions for each is as follows:

  • A groundwater basin is defined as a three-dimensional alluvial aquifer, or a stacked series of alluvial aquifers, with reasonably well-defined boundaries in a lateral direction and a definable bottom.
  • A groundwater subbasin is created by dividing a groundwater basin into smaller units using geologic and hydrologic barriers, or institutional boundaries.

By January 1, 2016, DWR is required to adopt emergency regulations that specify the information required to comply with Water Code 10722.2, which outlines the process that local agencies shall follow when requesting modifications to existing boundaries of groundwater basins and subbasins. The basin boundary regulations will also identify the methodology and criteria that will be applied by DWR when reviewing and approving the modification requests. In general, local agencies will be required to address all of the following:

  • How to assess the likelihood that the proposed basin can be sustainably managed.
  • How to assess whether the proposed basin would limit the sustainable management of adjacent basins.
  • How to assess whether there is a history of sustainable management of groundwater levels in the proposed basin.
Timeline for Adopting Basin Boundary Emergency Regulations

The following is the anticipated schedule and next steps for adopting the regulations:

Events Schedule*
Presentation of proposed emergency regulations to CWC for adoption October 21, 2015
Formal Notice of Proposed Rulemaking and supporting information October – November, 2015
Submission of adopted emergency regulations to Office of Administrative Law October – November, 2015
Basin boundary modification requests accepted by DWR within 90 day period January 1, 2016

*All dates are subject to change.

Approach for Developing Basin Boundary Emergency Regulations

DWR has established a comprehensive, multi-phased outreach approach to better understand issues and topics and collect information associated with the development of the basin boundary regulations. Insights gained through the outreach process has informed the proposed regulation framework for basin boundary modification statewide, while simultaneously recognizing the intricacies and uniqueness of each basin and its boundaries. In an effort to advance the communication and outreach efforts related to this task, DWR has regularly met with SGMA advisory groups and conducted public meetings and webinars to gather perspectives from other statewide stakeholders, partners, and local agencies.

Phase 1 – Scoping (Collection of Issues)

There are many complex issues and challenges associated with the existing Bulletin 118 – Update 2003 basin boundaries.  DWR has and continues to meet with various organizations, agencies, and individual experts to receive input on these basin boundary issues and challenges that create potential difficulties with SGMA implementation. DWR has and will continue to consider these basin boundary issues and challenges throughout the rule‐making process.

Phase 2 – Draft Discussion Paper and Public Listening Sessions

Between April 28th and May 1st of 2015, DWR completed three public listening sessions and one webinar related to the Basin Boundary Regulations. The presentation given during the listening sessions and a recording of the webinar are available for viewing in these internet links.

Based on the feedback collected during the scoping period, which included substantial communication and outreach with numerous local agencies and advisory groups to better understand local perspectives related to boundaries, DWR released a Basin Boundary Regulations Discussion Paper in April 2015.

More info...

Phase 3 – Draft Regulations and Public Meetings

Local agencies and interested parties will have the opportunity to provide input to DWR during the preparation of the draft basin boundary regulations and before the regulations are adopted. DWR will be holding three required public meetings in late August. The draft basin boundary emergency regulations are posted bellow.

Basin Boundary Public Meetings - August 31

All public comments on the draft regulations have been posted online here.

Phase 4 – Proposed Regulations and Adoption

The proposed emergency regulations have been refined based on public and Commission comments.

The proposed emergency regulations will be presented to the California Water Commission for adoption at its October Meeting. Once the emergency regulations are adopted the Notice of Proposed Emergency Rulemaking will be distributed and posted on this website and then the emergency regulation package will be submitted to the Office of Administrative Law.