Petition by Sonoma County Water Agency Requesting Approval of a Temporary Urgency Change in Permits 12947A, 12949, 12950 and 16596 in Mendocino and Sonoma Count
Summary
SCH Number
2026081176
Public Agency
Sonoma County Water Agency
Document Title
Petition by Sonoma County Water Agency Requesting Approval of a Temporary Urgency Change in Permits 12947A, 12949, 12950 and 16596 in Mendocino and Sonoma Count
Document Type
NOE - Notice of Exemption
Received
Posted
8/31/2026
Document Description
[PROJECT TITLE CONTINUED:] Counties (Applications 12919A, 15736, 15737, and 19351): 2026 Temporary Changes to Minimum lnstream Flow Requirements and Hydrologic Index of Decision 1610
The Sonoma County Water Agency (Sonoma Water) controls and coordinates water supply releases from the Coyote Valley Dam and Warm Springs Dam projects in accordance with the provisions of water rights Decision 1610, which the State Water Resources Control Board (State Water Board) adopted on April 17, 1986. Decision 1610 established Sonoma Water’s water right permits’ terms that specify the hydrologic index that determines the water supply conditions for the Russian River and the minimum instream flow requirements for the Upper Russian River, Dry Creek, and the Lower Russian River, which vary with water supply conditions based largely on cumulative inflow into Lake Pillsbury.
Located in the Eel River watershed, Lake Pillsbury is a storage reservoir for Pacific Gas & Electric Company's (PG&E) Potter Valley Hydroelectric Project (PVP), which transfers water into the East Fork of the Russian River (East Fork). The PVP operated under a Federal Energy Regulatory Commission (FERC) license that expired on April 14, 2022, and now continues operations under an annual license while PG&E proceeds though a license surrender and decommissioning. PG&E filed a Final License Surrender Application and a Final Non-Project Use of Project Lands Application on July 29. 2025. The Surrender Application includes a decommissioning plan that requests approval to remove most of the PVP’s project facilities, including but not limited to, Scott Dam and Cape Horn Dam. The application for Non-Project Use of Project Land seeks FERC’s authorization for PG&E to allow the Eel-Russian Project Authority (ERPA) to construct a proposed New Eel-Russian Facility (NERF) for the purpose of future water diversion from the Eel River through the Project’s existing water diversion system to the Russian River watershed. FERC’s proceedings on PG&E’s applications will likely take many years, meaning that it will be years before PVP operations and long-term rules governing any Eel River imports to the Russian River watershed are resolved.
Multiple changes to the PVP operations have reduced and could further reduce the transfers of Eel River water into the Russian River. Since 2021, a transformer bank failure at the PVP powerhouse has resulted in significant reductions in Eel River transfers into the Russian River. This failure caused PVP hydropower generation to cease and, with it, all associated discretionary transfers of Eel River water to the East Fork. PG&E also submitted a long-term flow regime request to amend flow requirements under the current FERC license on July 31, 2023. To reduce the potential seismic risk at Lake Pillsbury’s Scott Dam, PG&E made the decision to keep the spillway gates open atop Scott Dam indefinitely, reducing the water storage capacity in Lake Pillsbury by approximately 20,000 acre-feet. With hydropower operations no longer occurring at the project, PG&E has stated that transfers will be limited to the minimum releases to the East Fork required by its FERC license and water deliveries to the Potter Valley Irrigation District. As a result of the project no longer generating hydropower, the discontinuation of discretionary transfers of Eel River water to the East Fork have resulted in reduction of transfers by up to 456 acre-feet per day.
To mitigate the reduced storage capacity at Lake Pillsbury, PG&E has been filing temporary flow variances with FERC requesting reduced minimum flow requirements in the Eel River and reduced minimum release requirements to the East Fork. Additionally, on July 23, 2023, and supplemented on January 30, 2025, and September 26, 2025, PG&E filed an application for a non-capacity license amendment for the PVP to formalize the flow changes it has been making under temporary variance requests. On December 29, 2025, PG&E notified FERC of its intent to supplement the license amendment application by June 30, 2026, to include revisions to the proposed flow requirements that would provide a more flexible release strategy. The deadline for submitting the supplemental application has since been extended to September 30, 2026. The non-capacity license amendment is currently under review by FERC and is anticipated to take several years before it is approved.
While the license amendment application is under FERC review, PG&E is expected to continue with annual requests for a temporary variance of flow requirements due to the implications of its decision to no longer close the spillway gates on Scott Dam.
On May 14, 2026, FERC issued an order approving PG&E’s January 30, 2026, temporary variance request. In the order, FERC approved changes to the minimum release flows in the Eel River and the East Fork that included: (1) a reduction in minimum release flow requirements for the Eel River below Scott Dam to the critical water year type requirement of 20 cubic feet per second (cfs); (2) a reduction in minimum release flow requirements for the East Fork triggered by the cessation of Lake Pillsbury spillway flows, to a range of 25 and 5 cfs based on a flexible management flow release strategy. After September 30th, the termination of the order will be dependent on when Lake Pillsbury storage exceeds 36,000 acre-feet.
Sonoma Water is petitioning for temporary urgency changes to its four water-right permits used to provide wholesale water to cities and water districts in Sonoma and Marin counties. The historical link between the two watersheds upon which Decision 1610 is based is no longer applicable. The hydrologic index of Decision 1610 is not a reliable metric for Russian River water supply conditions without the historical large inter-basin transfer and will not function as intended. The request includes changes to the hydrologic index as well as modifications to the minimum instream flow requirements. The hydrologic index changes are necessary to ensure that the designated water supply condition and corresponding minimum instream flow requirements in the Russian River watershed are aligned with actual watershed hydrologic conditions, which is essential to maintain sustainable reservoir and river operations protecting municipal water supply and listed salmon species. Additionally, changes to reduce the dry season minimum instream flow requirements are necessary under a designated Normal water supply condition to comply with the findings of the 2025 Russian River Biological Opinion issued by the National Marine Fisheries Service (NMFS) on April 29, 2025, (2025 Russian River Biological Opinion) and its predecessor issued on September 24, 2008 (2008 Russian River Biological Opinion).
NMFS’ 2008 Russian River Biological Opinion required changes to the Decision 1610 minimum instream flow requirements to enable alternative flow management scenarios that will increase available rearing habitat in Dry Creek and the Upper Russian River, and provide a lower, closer-to-natural inflow to the estuary between late spring and early fall, thereby enhancing the potential for maintaining a seasonal freshwater lagoon that will likely support increased production of juvenile steelhead and salmon. As required by the 2008 Russian River Biological Opinion, in September 2009 Sonoma Water filed petitions with the State Water Board to make permanent changes to the Decision 1610 minimum instream flow requirements. These petitions were withdrawn and replaced with new petitions filed in August 2016, which are presently pending before the State Water Board. The State Water Board will not act on these petitions until the necessary environmental impact report is prepared and the water-rights issues associated with these petitions are resolved.
The 2025 Russian River Biological Opinion has a 10-year term and covers the U.S. Army Corps of Engineers and Sonoma Water’s operations and maintenance activities, including water supply, flood control, channel maintenance and habitat restoration in the Russian River watershed. The 2025 Russian River Biological Opinion finds that continued restoration of freshwater habitats for listed salmon and steelhead is reliant on the adjustments to existing flow requirements of Decision 1610. It concludes that Sonoma Water should continue to petition the State Water Board for changes to Decision 1610 minimum flows during Normal hydrologic conditions in a manner consistent with the Reasonable and Prudent Alternative from the 2008 Russian River Biological Opinion. These changes were included in the Proposed Action to avoid potential take of listed salmonids. NMFS determined that these actions will improve water reliability and benefit salmon and steelhead through enhanced cold-water storage resulting in sustained cooler water temperatures during the summer and fall rearing season and greater flexibility to release water to facilitate fish migration.
As with the previous NMFS’ 2008 Russian River Biological Opinion, the 2025 Russian River Biological Opinion requires petitions for temporary changes to minimum instream flows on the mainstem Russian River, and not on Dry Creek. These petitions do not seek any changes in the Dry Creek minimum-flow requirements adopted in Decision 1610.
In accordance with the terms and conditions of the 2025 Russian River Biological Opinion and in response to changed watershed conditions due to recent operational changes of PG&E’s PVP, Sonoma Water is filing temporary urgency change petitions (TUCPs) with the SWRCB. The petitions request that the SWRCB make the following changes to Sonoma Water’s water rights permits. From November 16, 2026, for a period of 180 days, Sonoma Water requests the use of a hydrologic index based on storage thresholds in Lake Mendocino to establish water supply conditions as identified in the 2025 Russian River Biological Opinion. For the period from May 1, 2027, until the end of the order (or October 15, 2027, whichever is first)) under a Normal water supply condition, Sonoma Water requests to: (a) reduce the required minimum instream flow in the Russian River from the confluence of the East and West Forks to the river’s confluence with Dry Creek from 185 cfs to 125 cfs; and (b) reduce required minimum instream flow in the Russian River from its confluence with Dry Creek to the Pacific Ocean from 125 cfs to 70 cfs.
Decision 1610 established the minimum instream flow requirements for Dry Creek and the Russian River (see Figure 1). These requirements vary based on defined hydrologic conditions. If approved, the requested reductions in Russian River instream flow requirements will be in effect starting May 1, 2027 under a Normal water supply condition. To improve its efforts at achieving the optimal habitat conditions in the Lower Russian River and to optimally manage flows in the entire river, Sonoma Water has requested in these TUCPs (as in previous ones) that these minimum instream flow requirements be implemented on a 5-day running average of average daily streamflow measurements with the condition that instantaneous flows on the Upper Russian River be no less than 110 cfs and on the Lower Russian River be no less than 60 cfs. No temporary change in the Dry Creek minimum instream flow requirements is proposed. The proposed temporary changes in Russian River minimum instream flow requirements will not result in any unusual circumstances, because the proposed minimum instream flow requirements are within the range of those that already occur during Dry and Critical water supply conditions under Decision 1610.
During the period that the proposed temporary flow changes are in effect, Sonoma Water will also monitor water quality and fish and collect and report information and data related to monitoring activities, to be in accordance with NMFS’ 2025 Russian River Biological Opinion.
Contact Information
Name
Connie Barton
Agency Name
Sonoma County Water Agency
Job Title
Senior Environmental Specialist
Contact Types
Lead/Public Agency / Project Applicant
Phone
Location
Cities
Unincorporated Area
Counties
Mendocino, Sonoma
Regions
Countywide, Northern California
State Highways
Redwood Highway 101
Waterways
Russian River
Other Location Info
The project will occur in Mendocino and Sonoma counties at Lake Mendocino, in the Upper Russian River from Coyote Valley Dam/Lake Mendocino to the confluence with Dry Creek, and in the Lower Russian River from its confluence with Dry Creek to the Pacific Ocean. Figure 1 shows the minimum instream streamflow requirements for the Russian River system. Communities and cities along the Russian River include Ukiah, Hopland, Cloverdale, Geyserville, Healdsburg, Forestville, Mirabel Park, Rio Nido, Guerneville, Monte Rio, Duncans Mills, and Jenner.
Notice of Exemption
Exempt Status
Categorical Exemption
Type, Section or Code
Sections 15307, 15308, 15301(i)
Reasons for Exemption
The project is statutorily exempt under the California Environmental Quality Act (CEQA) Statute 21080(b)(4) and categorically exempt from the California Environmental Quality Act (CEQA) under the State CEQA Guidelines Sections 15307, 15308, and 15301(i).
A. Actions by Regulatory Agencies for Protection of Natural Resources and the Environment
The California Public Resources Code, Division 13, Section 21080(b)(4) provides that specific actions necessary to prevent or mitigate an emergency are exempt from CEQA. The emergency conditions are due to an urgent need to implement the proposed changes as a result of the drastic reduction of potential Eel River water imports through the PVP resulting from the inoperability of the powerhouse for the foreseeable future and PG&E's decision to keep the spillway gates open atop Scott Dam indefinitely, consequently revising the operations at Lake Pillsbury, and filing a long-term flow regime request to modify flow requirements. The volume of Eel River water that can be transferred to the Russian River is no longer correlated to cumulative inflow into Lake Pillsbury. An evaluation of the hydrologic condition in the Russian River is more appropriately established by conditions in its watershed. Without the proposed changes, the applicable minimum instream flow requirements may require releases of water from Lake Mendocino and Lake Sonoma at levels that would risk significant depletions of storage levels. Such depletions in storage could cause serious impacts to human health and welfare and reduce water supplies needed for fishery protection. The required change is urgent and cannot be accomplished within the timeframe required for completion of the Environmental Impact Report (already in process) that evaluates broader proposed changes to Decision 1610.
B. Actions by Regulatory Agencies for Protection of Natural Resources and the Environment
CEQA Guidelines Sections 15307 and 15308 provide that actions taken by regulatory agencies to assure the maintenance, restoration or enhancement of a natural resource and the environment are categorically exempt from CEQA. Sonoma Water is proposing temporary urgency changes to its water right Permits 12947A, 12949, 12950, and 16596 that the State Water Board, as the regulatory agency, will consider and potentially approve. Those changes are necessary to ensure an accurate evaluation of water supply conditions that would maintain viable operations to support municipal use and protect listed salmon species. Approval of the TUCPs would provide alternative storage thresholds and criteria for determining minimum instream flow requirements for the Russian River that would be based on a more accurate assessment of water supply conditions in the Russian River watershed. This would result in minimum instream flow requirements that more likely can be sustained with releases from Lake Mendocino and Lake Sonoma without the risk of severely depleting storage and potential harm to natural resources and the environment. These changes avoid potential take of listed salmonids. NMFS determined that these actions will improve water reliability and benefit salmon and steelhead through enhanced cold-water storage resulting in sustained cooler water temperatures during the summer and fall rearing season and greater flexibility to release water to facilitate fish migration.
C. Existing Facilities
Guidelines Section 15301(i) provides, generally, that the operation of existing facilities involving negligible or no expansion of use beyond that existing at the time of the lead agency’s determination is categorically exempt from CEQA. There are no changes to the Russian River storage and diversion facilities. Subdivision (i) of Section 15301 specifically includes maintenance of streamflows to protect fish and wildlife resources. Sonoma Water’s petition to the State Water Board to change to the minimum instream flow requirements as specified in the 2025 Russian River Biological Opinion does not request and will not expand Sonoma Water’s use or increase the water supply available to Sonoma Water for consumptive purposes. The proposed change in Russian River minimum instream flow requirements still will be within the existing operational parameters established by Decision 1610. There are no unusual circumstances and there are no significant impacts from cumulative impacts.
Exempt Status
Emergency Project
Type, Section or Code
Sec. 21080(b)(4); 15269(b)(c)
Reasons for Exemption
The project is statutorily exempt under the California Environmental Quality Act (CEQA) Statute 21080(b)(4) and categorically exempt from the California Environmental Quality Act (CEQA) under the State CEQA Guidelines Sections 15307, 15308, and 15301(i).
A. Actions by Regulatory Agencies for Protection of Natural Resources and the Environment
The California Public Resources Code, Division 13, Section 21080(b)(4) provides that specific actions necessary to prevent or mitigate an emergency are exempt from CEQA. The emergency conditions are due to an urgent need to implement the proposed changes as a result of the drastic reduction of potential Eel River water imports through the PVP resulting from the inoperability of the powerhouse for the foreseeable future and PG&E's decision to keep the spillway gates open atop Scott Dam indefinitely, consequently revising the operations at Lake Pillsbury, and filing a long-term flow regime request to modify flow requirements. The volume of Eel River water that can be transferred to the Russian River is no longer correlated to cumulative inflow into Lake Pillsbury. An evaluation of the hydrologic condition in the Russian River is more appropriately established by conditions in its watershed. Without the proposed changes, the applicable minimum instream flow requirements may require releases of water from Lake Mendocino and Lake Sonoma at levels that would risk significant depletions of storage levels. Such depletions in storage could cause serious impacts to human health and welfare and reduce water supplies needed for fishery protection. The required change is urgent and cannot be accomplished within the timeframe required for completion of the Environmental Impact Report (already in process) that evaluates broader proposed changes to Decision 1610.
B. Actions by Regulatory Agencies for Protection of Natural Resources and the Environment
CEQA Guidelines Sections 15307 and 15308 provide that actions taken by regulatory agencies to assure the maintenance, restoration or enhancement of a natural resource and the environment are categorically exempt from CEQA. Sonoma Water is proposing temporary urgency changes to its water right Permits 12947A, 12949, 12950, and 16596 that the State Water Board, as the regulatory agency, will consider and potentially approve. Those changes are necessary to ensure an accurate evaluation of water supply conditions that would maintain viable operations to support municipal use and protect listed salmon species. Approval of the TUCPs would provide alternative storage thresholds and criteria for determining minimum instream flow requirements for the Russian River that would be based on a more accurate assessment of water supply conditions in the Russian River watershed. This would result in minimum instream flow requirements that more likely can be sustained with releases from Lake Mendocino and Lake Sonoma without the risk of severely depleting storage and potential harm to natural resources and the environment. These changes avoid potential take of listed salmonids. NMFS determined that these actions will improve water reliability and benefit salmon and steelhead through enhanced cold-water storage resulting in sustained cooler water temperatures during the summer and fall rearing season and greater flexibility to release water to facilitate fish migration.
C. Existing Facilities
Guidelines Section 15301(i) provides, generally, that the operation of existing facilities involving negligible or no expansion of use beyond that existing at the time of the lead agency’s determination is categorically exempt from CEQA. There are no changes to the Russian River storage and diversion facilities. Subdivision (i) of Section 15301 specifically includes maintenance of streamflows to protect fish and wildlife resources. Sonoma Water’s petition to the State Water Board to change to the minimum instream flow requirements as specified in the 2025 Russian River Biological Opinion does not request and will not expand Sonoma Water’s use or increase the water supply available to Sonoma Water for consumptive purposes. The proposed change in Russian River minimum instream flow requirements still will be within the existing operational parameters established by Decision 1610. There are no unusual circumstances and there are no significant impacts from cumulative impacts.
County Clerks
Mendocino, Sonoma
Attachments
Notice of Exemption
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