Temporary Urgency Change Petition

October 2022 Temporary Urgency Change Petition

On October 31, 2022 Sonoma County Water Agency (Sonoma Water) filed temporary urgency change petitions (TUCPs) with the State Water Resources Control Board Division of Water Rights. The TUCPs were submitted to address significant reductions in flows into the East Fork Russian River through Pacific Gas and Electric Company’s (PG&E) Potter Valley Project (PVP) due to a transformer bank failure, as well as continuing drought conditions in the Russian River Watershed. The TUCPs requested the implementation of a hydrologic index based on Lake Mendocino storage values, rather than the index based on cumulative inflow into Lake Pillsbury in the water right permits.

On December 14, 2022, the Division of Water Rights issued an order that approved the requested changes of the TUCPs with various terms and conditions including fisheries habitat and water quality monitoring. The order will remain in effect through June 11, 2023.


June 2022 Temporary Urgency Change Order

On May 25, 2022, Sonoma Water filed Temporary Urgency Change Petitions (TUCPs) with the State Water Resources Control Board (State Water Board) Division of Water Rights requesting changes to establish a Critical water supply condition in the Russian River. Under Critical water supply conditions, the Russian River would have minimum instream flow requirements of 25 cfs and 35 cfs in the upper and lower river, respectively. This change allowed Sonoma Water to continue the minimum instream flows that the river was operating under and preserve water supply in both Lake Mendocino and Lake Sonoma. It also helps avoid violating the Incidental Take Statement for Dry Creek established in the Russian River Biological Opinion. Additionally, Sonoma Water and its water contractors have committed to reducing total diversions from the Russian River by 20% compared to the same period of 2020 from July 1 through October 31.

On June 17, 2022, the  State Water Resource Control Board (State Water Board) Division of Water Rights issued an order that approved the requested changes of the TUCPs with various terms and conditions.

Diversion Reduction Requirement (Term 12) Report

Term 12 required Sonoma Water to reduce river diversions at its facilities by 20% compared to 2020 based on cumulative diversions from July 1 through October 31. The final monthly diversion reduction report documents the achieved cumulative diversion reduction of 30.5%  and compliance with the term requirement. 

Russian River Water Accounting Reports

Issued weekly on Mondays. Includes more detailed analysis on reservoir operations and river flows. 

Russian River Hydrologic Status Reports

Issued weekly on Mondays. Includes information on reservoir operations, river flows, historic and forecasted rainfall. 

Russian River Water Quality Status Reports


Minimum in-stream flow background:

Sonoma Water controls and coordinates water supply releases from Lake Mendocino and Lake Sonoma to implement the minimum instream flow requirements in water rights Decision 1610, which the State Water Resources Control Board adopted in 1986. Decision 1610 specifies minimum flow requirements for the Upper Russian River, Dry Creek, and the Lower Russian River. These minimum flow requirements vary based on water supply conditions, which are also specified in Decision 1610. The Decision 1610 requirements for the Upper Russian River and Lower Russian River are contained in term 20 of the Water Agency’s water-right Permit 12947A (Application 12919A). The Decision 1610 requirements for the Lower Russian River are contained in term 17 of the Water Agency’s water-right Permit 12949 (Application 15736) and term 17 of the Water Agency’s water-right Permit 12950 (Application 15737). The Decision 1610 requirements for Dry Creek and the Lower Russian River are contained in term 13 of the Water Agency’s water-right Permit 16596 (Application 19351).

Sonoma Water’s operations are also subject to the Russian River Biological Opinion issued by the National Marine Fisheries Service on September 24, 2008.


More Information:

View TUCP Archive

View Previous Years' TUCP Information on the State Water Resources Control Board website