UPDATE: October 11 Weekly Update on Curtailment Status of Water Rights and Claims in the Delta Watershed

From the State Water Resources Control Board:

This email 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 October 12, 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:
   1. 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; and
   2. Post-1914 appropriative water rights in the Putah Creek subwatershed outside of the Legal Delta with a priority date of 1948 or later.
2. Post-1914 appropriative water rights in the Sacramento River watershed outside of the Legal Delta with a priority date of 1960 or later.
3. 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;
   3. Post-1914 appropriative water rights and pre-1914 appropriative water right claims in the Fresno River subwatershed with a priority date of 1855 or later;
   4. 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;
   5. Post-1914 appropriative water rights and pre-1914 appropriative water right claims in the Mokelumne River subwatershed outside of the Legal Delta with a priority date of 1890 or later;
   6. Post-1914 appropriative water rights and pre-1914 appropriative water right claims in the Stanislaus River subwatershed outside of the Legal Delta with a priority date of 1897 or later; and
   7. Post-1914 appropriative water rights and pre-1914 appropriative water right claims in the Tuolumne River subwatershed with a priority date of 1914 or later.
4. Post-1914 appropriative water rights in the San Joaquin River watershed outside of the Legal Delta with a priority date of 1919 or later.
5. Post-1914 appropriative water rights in the Legal Delta with a priority date of 1960 or later.

Term 91 curtailments will continue to apply to rights within and outside the Legal Delta containing Term 91.

Today’s update considers observed water supply data and forecasts from the California Nevada River Forecast Center (CNRFC) that were updated on October 10, 2022.  The 50 percent exceedance water supply forecast was selected to determine curtailments at this time.  Demand data informing curtailments are based on reported diversions from 2018 as adjusted through an ongoing QA/QC process.

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.

The State Water Board will continue to closely monitor forecasted precipitation and hydrologic conditions in order to issue updates to the curtailment status of water rights and claims in the Delta watershed.  The next curtailment status update will be provided by email and web posting no later than October 18, 2022.  Please check the Delta Watershed Curtailment Status List for the current curtailment status of each water right and claim in the Delta watershed.

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.