6/72022 Update on Curtailment Status of Water Rights and Claims in the Delta Watershed

This message 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 8, 2022, unless and until the State Water Board advises that this determination has been updated:

1. Water rights and claims on the following Sacramento River tributaries:
   • Post-1914 appropriative water rights and pre-1914 appropriative water right claims in the Putah Creek subwatershed outside of the Legal Delta with a priority date of 1850 or later;
   • Post-1914 appropriative water rights and pre-1914 appropriative water right claims in the Cache Creek subwatershed with a priority date of 1859 or later;
   • Post-1914 appropriative water rights in the Bear River subwatershed with a priority date of 1942 or later; and
   • Post-1914 appropriative water rights in the Stony Creek subwatershed with a priority date of 1957 or later.

1. Water rights and claims on the following San Joaquin River tributaries:
   • 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;
   • All post-1914 appropriative water rights, pre-1914 appropriative water right claims, and riparian water right claims in the Chowchilla River subwatershed; and
   • 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.

1. 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 14, 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. Reimposition of curtailments based on the subwatershed-scale analysis.  As opportunities to divert limited snowmelt pass, the Deputy Director for Water Rights has determined in the exercise of his discretion under section 876.1, subdivision (d) of the Drought Emergency Regulation that the curtailments imposed today will 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 consistent with contractual agreements applicable this year and San Joaquin River Exchange Contractor demands were increased to account for demands for San Joaquin River water due to reduced deliveries of water from the Sacramento River watershed provided by Reclamation.
3. No curtailment of rights and claims within the Legal Delta.  In coordination with the Office of the Delta Watermaster, Division of Water Rights staff are in the process of updating several technical assumptions regarding water unavailability within the Legal Delta.  Pending completion of those updates, rights and claims within the Legal Delta will not be curtailed pursuant to the Drought Emergency Regulation.  Term 91 curtailments will continue to apply to rights within 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 7, 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.

This is a message from the State Water Resources Control Board 

This message 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 May 18, 2022, unless and until the State Water Board advises that this determination has been updated:  

1. A subset of four post-1914 appropriative water rights associated with the Central Valley Project in the San Joaquin River watershed, specifically the Upper San Joaquin River and Stanislaus River subwatersheds.  

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, and the next curtailment status update will be provided by email and web posting no later than May 24, 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 Water Unavailability Methodology for the Delta Watershed continues to indicate that local water supplies may be insufficient to satisfy all water rights in multiple headwater subwatersheds. However, curtailments based on the subwatershed-scale analysis could affect several rim reservoirs that generally have more junior storage rights in the subwatersheds.  Curtailing those users would not make water available to senior upstream diverters and could result in the requirement to bypass needed storage as the limited snowpack continues to melt.  Accordingly, consistent with the Board’s direction to consider opportunities and needs to replenish stored water supplies, the Deputy Director for Water Rights has determined in the exercise of his discretion under Section 876.1 subdivision (d) of the Drought Emergency Regulation that today’s curtailments will continue to be based only on watershed-wide conditions, not the analysis of water unavailability at the subwatershed scale. Regardless of curtailments, all right holders are reminded that they must abide by the terms of their water right and ensure that downstream senior water right holders are not harmed by their diversions. If water right holders or claimants believe their water rights are being impacted by the suspension of curtailments, they may notify the State Water Board by emailing Bay-Delta@waterboards.ca.gov with specific details regarding their concern, or they may file a formal complaint with the Division of Water Rights Enforcement Program.  

The above curtailments factor in 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. The water unavailability analysis supporting current curtailments also accounts for demands of the San Joaquin River Exchange Contractors from the Upper San Joaquin River subwatershed in May, as well as estimated agricultural and municipal return flows based on CalSim 3 results for 1976.  Today’s curtailment status update is based on the output of the Water Unavailability Methodology for the Delta Watershed for the calendar month of May. As such, today’s update considers observed water supply data and forecasts from the California Nevada River Forecast Center (CNRFC) that were updated on May 17, 2022.  The 50% exceedance water supply forecast was selected to determine curtailments at this time.  Curtailment statuses will be reassessed next week (or earlier if appropriate) based on daily water supply observations and updated forecasts.  Demand data informing curtailments continue to be based on reported diversions from 2018.  

Notice of Expected Wide-Scale Curtailments in the Near Future  

Water right holders and claimants are advised that, based on current hydrologic forecasts, curtailments are expected to increase progressively through the spring and summer and continue through the early fall until significant precipitation occurs. Accordingly, water right holders and claimants should plan for reduced supplies even if your water right or claim is not currently curtailed.  

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.  

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.  

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.