Legal Alerts Jul 21, 2015

Draft Basin Boundary Regulations Released

Public Comments Due Sept. 4

Draft Basin Boundary Regulations Released

The California Department of Water Resources has released draft emergency regulations governing how groundwater basin boundaries may be modified or redrawn under the state’s Sustainable Groundwater Management Act. Public comments on the draft regulations will be accepted until Sept. 4.

The historic SGMA legislation, adopted last year, marked the first time California has attempted to comprehensively regulate groundwater and bring groundwater basins into a sustainable pattern of pumping and recharge.

Existing groundwater basin boundaries are defined in California’s Groundwater, Bulletin 118. The proposed regulations lay out the process that local agencies must follow when seeking to modify established groundwater basin boundaries. Under the proposed regulations, DWR will consider granting two types of modifications:

  • Those based on scientific considerations (aka Scientific Modifications), supported by geologic and /or hydrologic evidence of basin conditions.
  • Those based on jurisdictional considerations (aka Jurisdictional Modifications), aimed at enabling more effective basin management by local agencies.                     


The draft regulations require that a requesting agency meet a number of notification, consultation, public hearing and technical information requirements when submitting a basin boundary modification request. A critical element will be broad local support for each request because of the likelihood that such support will lead to more effective basin management.

DWR will consider two types of scientific modification requests:

  • External Boundary Modification, which modifies the boundary between the subject groundwater basin and the area outside the basin
  • Hydrogeologic Barrier Modification


Three types of jurisdictional boundary modification requests will be considered:

  • Internal Boundary Revisions, which would adjust the location of a boundary between subbasins, within a basin or the shared boundary between adjacent basins.
  • Basin Consolidations, which would reduce the number of subbasins within a basin, or merge two or more adjacent basins, but would change only shared boundaries. Included within the basin consolidation process is also a “county basin consolidation” process that would consolidate all contiguous basins or subbasins within a county into a single basin or subbasin with boundaries not extending beyond those of the subject county.
  • Basin Subdivisions, which would increase the number of subbasins within a basin or subbasin.


At a briefing before the California Water Commission on July 15, DWR staff explained that basin subdivisions are generally not desired and will have to meet a high bar for approval because of concerns about potential fragmentation of basins. Approved boundary changes will be published in California’s Groundwater, Bulletin 118, 2017 Update.

DWR will hold three public meetings to solicit input on the proposed regulations: Aug. 31 in Sacramento, Sept. 2 in Bakersfield and Sept. 3 in Santa Ana. The public comment period ends Sept. 4, with adoption by the California Water Commission slated for October or November.

Under SGMA, all groundwater basins deemed high priority or medium priority must be governed by one or more “groundwater sustainability agencies" by June 30, 2017. These groundwater sustainability agencies must adopt a groundwater sustainability plan for the basin or basins they govern by Jan. 31, 2022. For basins subject to critical overdraft conditions, the plan must be adopted by Jan. 31, 2020. Sustainability plans must include long-term planning, objectives and goals to achieve basin sustainability within 20 years of implementation. The Act allows for state intervention when local agencies are unwilling or unable to manage the state’s groundwater basins.

If you have any questions about the draft regulations or how they may impact your agency, please contact the attorney authors of this legal alert listed to the right in the Environmental Law & Natural Resources practice group, or your BB&K attorney.

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Disclaimer: BB&K legal alerts are not intended as legal advice. Additional facts or future developments may affect subjects contained herein. Seek the advice of an attorney before acting or relying upon any information in this communiqué.

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