Sonoma Water - Temporary Urgency Change Petitions

Water Resources / Water Supply / Temporary Urgency Change Petition

Temporary Urgency Change Petitions

April 2025 Temporary Urgency Change Petitions

On April 10, 2025 Sonoma Water filed temporary urgency change petitions (TUCPs) with the State Water Resources Control Board Division of Water Rights. These petitions were submitted to temporarily modify the permit terms that establish the hydrologic conditions for setting the minimum instream flow requirements. The hydrologic index for the Russian River was established by Decision 1610 in 1986 for Permits 12947A, 12949, 12950 and 16596. In response to changed watershed conditions due to recent operational changes of PG&E's Potter Valley Project, these modifications are necessary to ensure alignment of the hydrologic index designations with actual watershed conditions. As required by the 2008 Russian River Biological Opinion, the petitions also request the minimum instream flow requirements be reduced to protect listed salmonids under the Endangered Species Act if the requested changes to determining the hydrologic index result in a Normal water supply condition. The current TUCP expires on April 30, 2025.

February 2025 Temporary Urgency Change Petitions

On February 19, 2025, Sonoma Water filed a temporary urgency change petition (TUCP) with the State Water Resources Control Board Division of Water Rights. The TUCP requests a change to Permit 16596 (Application 19351) to authorize a new point of rediversion associated with Sonoma Water’s Sebastopol Road Well Aquifer Storage and Recovery (ASR) Pilot Study. If approved, Sonoma Water would be authorized to recharge water diverted from the Russian River into the Santa Rosa Plain Groundwater Subbasin at the Sebastopol Road Well site from June 1, 2025, through November 27, 2025. The pilot study would operate in recharge/recovery cycles at a maximum recharge rate of 1.2 cubic feet per second. The total recharge and recovery amount would be limited to 50 acre-feet. The reconstruction of the Sebastopol Road Well and its conversion to an ASR well is a component of Sonoma Water’s Water Supply Resiliency Program.

August 2024 Temporary Urgency Change Petitions

On August 20, 2024, Sonoma Water filed temporary urgency change petitions (TUCPs) with the State Water Resources Control Board Division of Water Rights. These petitions were submitted to temporarily modify the permit terms that establish the hydrologic conditions for setting the minimum instream flow requirements. The hydrologic index for the Russian River was established by Decision 1610 in 1986 for Permits 12947A, 12949, 12950 and 16596. In response to changed watershed conditions due to recent operational changes of PG&E's Potter Valley Project, these modifications are necessary to ensure alignment of the hydrologic index designations with actual watershed conditions.

On October 31, 2024, 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 until April 30, 2025.

Weekly Hydrologic Reports

Summary reports of recent historical hydrologic conditions and forecasted rainfall for the Russian River watershed.

April 2024 Temporary Urgency Change Order

On April 19, 2024, Sonoma County Water Agency (Sonoma Water) filed temporary urgency change petitions with the State Water Resources Control Board (State Water Board), Division of Water Rights (Division) requesting approval of temporary changes to water right Permits 12947A, 12949, 12950, and 16596 (Applications 12919A, 15736, 15737, and 19351) pursuant to California Water Code section 1435. This would allow Sonoma Water to manage stream flows with a smaller operational buffer, thereby facilitating the attainment of the flow conditions that the Biological Opinion has concluded are conducive to the enhancement of salmonid habitat.

On June 6, 2024, 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 until October 15, 2024.

Weekly Hydrologic Reports

Summary reports of recent historical hydrologic conditions and forecasted rainfall for the Russian River watershed.

December 2023 Temporary Urgency Change Order

On October 12, 2023, Sonoma Water filed temporary urgency change petitions (TUCPs) with the State Water Resources Control Board Division of Water Rights. These petitions were submitted to temporarily modify the permit terms that establish the hydrologic conditions for setting the minimum instream flow requirements. The hydrologic index for the Russian River was established by Decision 1610 in 1986 for Permits 12947A, 12949, 12950 and 16596. In response to changed watershed conditions due to recent operational changes of PG&E's Potter Valley Project, these modifications are necessary to align the hydrologic index designations with actual watershed conditions.

On December 27, 2023, 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 2024.

Weekly Hydrologic Reports

Summary reports of recent historical hydrologic conditions and forecasted rainfall for the Russian River watershed.

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.