Groundwater Info Center
2016 Bulletin 118 Interim Update

In response to the Section 12924 of the California Water Code, and the Sustainable Groundwater Management Act (SGMA) of 2014, DWR has completed an interim update of Bulletin 118, addressing time-sensitive information important to implementation of the SGMA Program.  The 2016 B-118 Interim Update is available in multiple formats:

  • For download of the document in PDF format, click here.
    • For download of B-118 basin boundary GIS data and detailed individual basin descriptions, click here.
  • Print copies will be available in 2017, by request.

An addendum to Interim Update 2016 (expected release: Fall 2017) will include updated Basin Prioritizations.  In 2020, and every 5 years thereafter, DWR will be releasing comprehnsive updates of Bulletin 118.

How the content of the 2016 B-118 Interim Update relates to SGMA

The 2016 Bulletin 118 Interim Update provides Groundwater Sustainability Agencies (GSAs) with three critical pieces of information to develop and implement groundwater sustainability plans (GSPs) or alternatives to GSPs (Alternatives):

  1. Critical Conditions of Overdraft – SGMA requires that GSAs complete a GSP by January 31, 2020 if the groundwater basin under the GSA’s jurisdiction has been identified by DWR as a high- or medium-priority basin (see “Basin Priority” below) and that basin has been identified in Bulletin 118 as being critically overdrafted.  GSAs for all other high- and medium-priority basins must have a GSP by January 31, 2022.

    Under SGMA, DWR has until January 1, 2017 to update Bulletin 118 for critically overdrafted groundwater basins, otherwise, the list of 11 critically overdrafted basins originally published in Bulletin 118-80 and subsequently adopted in to Bulletin 118 - Update 2003 applies. Click here for more information on critically overdrafted groundwater basins.


  2. Basin Boundaries – SGMA includes provisions for local agencies to request revisions to groundwater basin boundaries described in Bulletin 118. DWR developed regulations for the submittal and consideration of those requests. These regulations require DWR to incorporate basin boundary revisions into Bulletin 118 updates.

    DWR has evaluated local agency requests for basin boundary modifications and has finalized approved boundary modifications here. Since GSAs are based on groundwater basins, and because GSAs must be formed by June 30, 2017, basin boundary changes have been published in Bulletin 118 Interim Update 2016. Click here for more information on the groundwater basin boundary revision process.


  3. Basin Priority – In 2009, prior to SGMA, the Water Code was amended to require DWR to prioritize California's groundwater basins according to certain criteria. In June 2014, DWR completed the basin prioritization process by sorting the 515 groundwater basins described in Bulletin 118, Update 2003 into four priority categories—high, medium, low, and very low.

    Additional groundwater basin prioritization criteria were included in the Water Code, in September 2014, with the passage of SGMA. Statutes were also added requiring DWR to reassess the priority of a groundwater basin after any boundary modifications by DWR. DWR is currently reassessing the priority of all of the state’s groundwater basins in accordance with the amended criteria in the Water Code, and in relation to the basin boundary modifications currently underway. Click here for information on the groundwater basin prioritization project.

    As noted above, compliance with the requirements of SGMA is mandatory for high and medium priority groundwater basins, although low and very low priority basins may elect to participate as well. Basins that change from either low- or very-low priority to medium- or high-priority as the result of the basin priority reassessment must have a GSA within two years of the change in priority. GSPs must then be developed for these basins within 5 years of GSA formation. Conversely, basins that change from either high- or medium-priority to low- or very-low priority would not be required to have a GSA and GSP.

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