Temporary Urgency Change Petition

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, respectivelyThis 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 Report

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

Russian River Water Quality Status Report



December 2021 Temporary Urgency Change Order

On November 16, 2021, Sonoma Water filed Temporary Urgency Change Petitions (TUCPs) with the State Water Resources Control Board (State Water Board) Division of Water Rights (Division) requesting a change in the hydrologic index used to establish the water supply condition in the Russian River watershed. Sonoma Water's water rights permits require the maintenance of minimum instream flows downstream of Lake Mendocino and Lake Sonoma. The minimum instream flows are specified for the three major managed regulatory reaches--Upper Russian, Lower Russian and Dry Creek--by season and water supply conditions as set by the hydrologic index. The hydrologic index in Sonoma Water's water rights permits is based on the cumulative inflow into Lake Pillsbury on the Eel River, which reflects the contribution of inter-basin transfers of Pacific Gas & Electric's (PG&E) Potter Valley Project (PVP) hydroelectric facility to the East Fork of the Russian River.

In October 2021, PG&E reported a major equipment failure of the transformer bank at the facility, which is anticipated to severely reduce the inter-basin transfers through the upcoming years. Due to the unexpected shutdown in the PVP hydroelectric plant operations, Sonoma Water requested in its TUCPs that the water supply conditions in the Russian River be established based on storage thresholds in Lake Mendocino. While there are limited inter-basin transfers that are expected to continue to flow into the East Fork of the Russian River upstream of Lake Mendocino, the magnitude of these transfers doesn't approach the historic contributions upon which the selection of Lake Pillsbury cumulative inflow as the hydrologic index was based on.         

On December 10, the State Water Resources Control Board issued an order that approved the requested changes of the TUCPs with various terms and conditions. See the links below for copies of the TUCPs and the associated order.  

Russian River Hydrologic Status Report

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

Russian River Water Accounting Reports

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



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