Last Updated: May 15, 2026

FERC Approves the 2026 Flow Variance, effective 5/15/26

On May 14, 2026, FERC issued the order approving the 2026 temporary flow variance for the Potter Valley Project flows from the Eel to the Russian River. This means that starting today, May 15th, flows to the Russian River will remain at 25 cfs (rather than increasing to 75 cfs) and will fluctuate between a range of 5-25 cfs based on Lake Pillsbury storage forecasts and water temperature data.

This will directly impact water availability for water rights along the Russian River. To establish the degree of impact to specific water right(s) outside of a Flood Control District contract, review your water right documentation carefully and use the State Water Resources Control Board Supply and Demand Assessment tool for the Russian River. An instructional video is posted on this same website.

PG&E will utilize a flexible flow release approach to reservoir releases to provide adequate flows and cooler water temperatures in the Eel River.  PG&E states that the variance is necessary due to the reduced water capacity in Lake Pillsbury as a result of its seismic-risk-related storage restriction, which has reduced the available water stores by approximately 18,200 acre-feet. PG&E has an objective of maintaining 25,000 acre-feet in Lake Pillsbury on October 1, 2026, which it calculates will allow it to meet its dam safety obligations and to preserve the cold water pool to ensure cooler water release temperatures. The initial flow release into the East Branch Russian River will remain at the current 25 cfs.  PG&E will then adjust releases to the East Branch Russian River between 5 and 25 cfs based on Lake Pillsbury storage forecasts using available hydrologic forecasting tools and runoff forecasts, historical water temperature data and water temperature modeling, and other flexible water management criteria.  Adjustments made to the East Branch Russian River releases will be made in consultation with the PG&E Drought Working Group. If Lake Pillsbury storage is below the 36,000 acre-feet after September 30, releases to the East Branch Russian River will be limited to 5 cfs.  When Lake Pillsbury storage gets above 36,000 acre-feet after September 30, the variance will end and PG&E will release flows as required under its license. 

Check back for postings of periodic reports by PG&E.

 February 2026

FERC opens the public comment period on the 2026 Flow Variance.

Deadline for filing comments, motions to intervene, and protests:  March 23, 2026, 5:00 pm Eastern Time.

PG&E Files Supplemental Information to Request

PG&E submitted a supplemental filing to FERC for the 2026 Minimum Instream Flow Variance Request Due to Restricted Storage.

“Overall, the modeling results indicate that both the timing of variance approval and the magnitude of [East Branch Russian River] EBRR flows play important roles in shaping thermal conditions in the Eel River below Scott Dam. When variance approval is delayed EBRR flows must be reduced to the minimum proposed for Project facility safety and have a negligible effect on water temperature in the Eel River (Scenario 1). Early approval of the variance (e.g. May 15 [Scenarios 3 and 4]) provides the greatest potential for reducing summer water temperatures in the Eel River across EBRR proposed flow range and allows for flexible flow release management.”

January 2026

PG&E’s Files Temporary Flow Amendment (Variance) to FERC for Potter Valley Project

On January 30th, PG&E filed a request for a Temporary Flow Amendment (Variance) for the Potter Valley Hydroelectric Project, Federal Energy Regulatory Commission (FERC) No. 77.

In 2023, PG&E determined that the seismic risk to Scott Dam is greater than previously understood and a 10-ft elevation restriction was placed on Lake Pillsbury reservoir indefinitely, reducing the water storage capacity from approximately 70,800 acre-ft (AF) to 52,600 AF for safety purposes. This loss of 18,200 AF of potential storage above the spillway further compounds the challenges to meet license-required flows. This has resulted in annual flow amendments (variances) that reduce minimum instream flow requirements to the East Branch Russian River during summer months.

Proposed Flexible Management Flow Release Strategy 
With the reduction in Lake Pillsbury storage capacity and cool-water pool storage, PG&E’s strategy will be to manage [East Branch Russian River] EBRR diversions to (1) ensure dam safety, and (2) minimize impacts to the Lake Pillsbury reservoir cool-water pool and subsequent elevated release temperatures to the Eel River. Accordingly, PG&E will retain the range of spring/summer/fall EBRR diversions in the 2026 Variance as has been used in recent years (25-5 cfs). If hydrologic conditions are favorable from a dam safety standpoint and cool-water pool impacts appear minimal, PG&E, in consultation with the Agencies and the [Drought Working Group] DWG, may keep EBRR releases at 25 cfs, or reduce to as low as the 5 cfs minimum depending on reservoir storage projections and water temperature conditions. As a dam safety measure in the event of a delayed wet season, PG&E will aim to maintain a storage target of at least 25,000 AF on October 1, 2026.

The flexible management flow release strategy includes the following:

• While Lake Pillsbury is spilling, Russian River diversions will follow license flows.

Once spilling ends:

• Diversions to the East Branch Russian River will initially be set at 25 cubic feet per second (cfs) with the exception of critical water years.
• The diversions will then be adjusted between 5 and 5 cfs to support management aims.
• After September 30, EBRR releases will continue to range between 25-5 cfs until Lake Pillsbury reservoir storage exceeds 36,000 ac-ft, ending the Variance. Thereafter, EBRR flow releases will return to the license-required flows (35 cfs in Normal and Dry years, 5 cfs in Critical years). The 36,000 AF storage threshold would support the reservoir meeting minimum flow obligations through January 2027, including a possible Block Water release in the late fall/early winter 2026 if needed, if inflow is extremely low in late fall/early winter.

Management Aims:

• Prioritize facility safety with a storage target of 25,000 acre feet on October 1st and a minimum storage set at 12,000 acre feet.
• Preserve cool-water pool/limit water temperature increases.

PG&E has requested this temporary variance be approved by FERC no later than May 15, 2026, which would be 2 full months prior to the 2025 approval and implementation.

"When Variances are approved after May 15 (when EBRR flows increase to 75 cubic feet per second [cfs] in a Normal Water Year [WY]), it reduces the ability of the Project to achieve the goals of dam safety and aquatic resource protection. In recent years, delayed implementation of the Variance has required PG&E to take urgent action to reduce EBRR flows immediately after FERC approval of the Variance to the minimum allowable to 
prevent Lake Pillsbury reservoir from reaching critical storage levels and impacting dam safety. In addition, the delayed approval and associated elevated EBRR diversions drain the cool-water pool through the summer, elevating Scott Dam release water temperatures and negatively impacting aquatic resources in the Eel River."

The variance would end when Lake Pillsbury storage is greater than 36,000 af after September 30th. 

PG&E is also pursuing a license amendment for long term permanent flow requirement changes. A filing was made a year ago but PG&E provided notification that it would supplement the license amendment application, which is underway. See https://rrfc.specialdistrict.org/potter-valley-project-license-amendment-2025-2026 for more information on the license amendment.