NOTICE: June 21 Weekly Update on Curtailment Status of Water Rights and Claims in the Delta Watershed

From the State Water Resources Control Board:

This notice contains important information about the curtailment status of water rights and claims of right within the Sacramento-San Joaquin Delta (Delta) watershed pursuant to Initial Orders Imposing Water Right Curtailment and Reporting Requirements in the Delta Watershed (Order for water rights/claims under 5,000 acre-feet and Order for water rights/claims over 5,000 acre-feet).

The following water rights are curtailed, effective June 22, 2022, unless and until the State Water Board advises that this determination has been updated:

  1. Water rights on the following Sacramento River tributaries:
    1. Post-1914 appropriative water rights in the Bear River subwatershed with a priority date of 1942 or later; and
    2. Post-1914 appropriative water rights in the Putah Creek subwatershed outside of the Legal Delta with a priority date of 1945 or later.
  2. Water rights and claims on the following San Joaquin River tributaries:
    1. All post-1914 appropriative water rights, pre-1914 appropriative water right claims, and riparian water right claims in the Calaveras River subwatershed outside of the Legal Delta;
    2. All post-1914 appropriative water rights, pre-1914 appropriative water right claims, and riparian water right claims in the Chowchilla River subwatershed; and
    3. Post-1914 appropriative water rights and pre-1914 appropriative water right claims in the Merced River subwatershed with a priority date of 1859 or later.
  3. Post-1914 appropriative water rights and pre-1914 appropriative water right claims in the San Joaquin River watershed outside of the Legal Delta with a priority date of 1900 or later.

Curtailments are expected to continue through the summer and early fall until significant precipitation occurs.  Water supply forecasts will continue to be evaluated regularly to determine if, when, and to what extent the further re-imposition or suspension of curtailments may be appropriate.  The next curtailment status update will be provided by email and web posting no later than June 28, 2022.  Please check the Delta Watershed Curtailment Status List for the current curtailment status of each water right and claim in the Delta watershed.

The above curtailments consider the following technical and policy inputs to the Water Unavailability Methodology for the Delta Watershed (methodology):

  1. Curtailments based on the subwatershed-scale analyses.  Curtailments account for both local water unavailability in headwater subwatersheds and watershed-wide conditions.
  2. Modification of demands for water rights and claims associated with contractual agreements with the U.S. Bureau of Reclamation (Reclamation) and the California Department of Water Resources.  Sacramento River Settlement Contractor and Feather River Contractor demands were reduced compared to 2018 consistent with contractual agreements applicable this year and San Joaquin River Exchange Contractor demands were adjusted to account for demands for San Joaquin River water due to reduced deliveries of water from the Delta provided by Reclamation.
  3. Legal Delta.  Current analyses do not support curtailments in the Legal Delta for non-Project right holders. Analyses do indicate some unavailability for Project rights in the Legal Delta.  However, based on the Coordinated Operations Agreement (COA) for the Projects, curtailments will not be implemented for Sacramento River Watershed Project rights if unavailability at the Sacramento River Watershed scale is only indicated amongst Project rights in recognition of the COA’s provisions for sharing limited Project supplies. Term 91 curtailments will continue to apply to rights within and outside the Legal Delta containing Term 91.

The above curtailments factor in estimated agricultural and municipal return flows based on CalSim 3 results for 1976 and reduced demands associated with Central Valley Project and State Water Project exports from the Delta under the State Water Board’s April 4, 2022 Order Approving Temporary Urgency Changes to Water Right License and Permit Terms Relating to Delta Water Quality.

Today’s curtailment status update is based on the output of the methodology for the calendar month of June.  As such, today’s update considers observed water supply data and forecasts from the California Nevada River Forecast Center (CNRFC) that were updated on June 21, 2022.  The 50% exceedance water supply forecast was selected to determine curtailments at this time.  Other than modifications identified above, demand data informing curtailments continue to be based on reported diversions from 2018.

The determination of water unavailability used to inform curtailments is based on the Water Unavailability Methodology for the Delta Watershed.  The data used to support curtailments and other relevant information is available on the State Water Board’s FTP site.  To access the documents posted on the FTP site, please email Bay-Delta@waterboards.ca.gov to obtain login credentials.

Water right holders and claimants are responsible for monitoring their curtailment status online on the Delta Watershed Curtailment Status List.  Notice of changes to curtailment status will not be mailed.  For those with limited internet access, a pre-recorded curtailment summary can be heard on the Delta Curtailment Status phone line at (916) 323-4643.

For more information about drought in the Delta watershed, please visit the Delta Drought webpage.  For more information about curtailment compliance and responses to the Initial Orders Imposing Water Right Curtailment and Reporting Requirements in the Sacramento-San Joaquin Delta Watershed, please visit the Curtailment Compliance and Responses webpage.  The Curtailment Compliance and Responses tracker is updated regularly and can be filtered to see the latest changes.  If you have any questions, you may send an email to Bay-Delta@waterboards.ca.gov or call the Delta Drought phone line at (916) 319-0960.