Anyone who wants to object to Sonoma Water’s request to cut the Russian River’s minimum flows again next year has until 4:30 p.m. Monday, Oct. 19, to tell the State Water Resources Control Board and Sonoma Water.
Sonoma Water, formally the Sonoma County Water Agency, filed temporary urgency change petitions with the board in late August, asking it to temporarily change the river’s minimum flow rules. Under a normal water year, they would lower the required minimum flow in the lower Russian River, from where Dry Creek flows in to the Pacific Ocean, from 125 cubic feet per second to 70 cfs, starting May 1, 2027. That stretch runs past Guerneville to Jenner.
The upper river, from where the East Fork joins it down to Dry Creek, would drop from 185 cfs to 125 cfs, according to the board’s public notice.
Under these petitions, the lower minimums would last only until the board’s order expires, around mid-May 2027, the notice says. Temporary orders expire after 180 days unless the board renews them, according to the board’s May order. Sonoma Water’s website describes the flow request as running from May 1 to Oct. 15, 2027.
The same cut as this year
The board approved the same changes for this year, in an order dated May 21 that runs through Nov. 16.
Under it, the river at the U.S. Geological Survey’s Hacienda Bridge gauge near Guerneville averaged about 110 cfs in July, August and September and dropped to about 70 cfs on July 1, according to provisional USGS daily data.
Sonoma Water would measure the minimums as a five-day running average. Flow at any moment couldn’t drop below 110 cfs on the upper river or 60 cfs on the lower river, the notice says.
A second change starts sooner
The petitions also replace the yardstick that decides whether a year counts as normal, dry or critical. Decision 1610, the board’s 1986 ruling that sets the river’s minimum flows, bases that call on how much water flows into Lake Pillsbury on the Eel River. Sonoma Water wants to use how much water is stored in Lake Mendocino instead. That change would last 180 days, starting Nov. 16, or later if the board’s order comes after that.
Sonoma Water says inflow to Lake Pillsbury no longer reflects conditions on the Russian. Water moved from the Eel through PG&E’s Potter Valley Project now averages less than 40,000 acre-feet a year, down from an average of 150,000 acre-feet when Decision 1610 was issued, the agency told the board, according to the May order.
Why lower flows
The flow cuts come from the National Marine Fisheries Service’s April 29, 2025, biological opinion on the Russian River, which covers protected salmon and steelhead.
The fisheries service’s earlier 2008 opinion found the summer flows Decision 1610 requires are too high for young salmon and steelhead, the May order says. Faster current shrinks the slow water where young fish feed and grow. Releases to meet the flows drain cold water from Lake Mendocino, which warms the river. And in the lower river, the flows push extra water into the estuary, which means breaching the sandbar at the river’s mouth to prevent local flooding.
The 2025 opinion requires Sonoma Water to petition for the cuts every year until the board rules on its request to change the flows permanently, the May order says.
What objectors said last time
Objections to the spring petitions were due April 27. The board got a letter of support from the Mendocino County Russian River Flood Control and Water Conservation Improvement District, which also holds rights to store water in Lake Mendocino, and comments from Barbara Delonno and Russian Riverkeeper, according to the May order.
Delonno commented that the historical 125 to 140 cfs flows in the lower river did more for water quality and recreation than 70 cfs. She questioned whether the lower flows had shown a benefit to aquatic life. Sonoma Water answered that the cuts had improved summer habitat for steelhead and coho salmon by slowing the water where they rear, and had saved cold water in Lake Mendocino.
Russian Riverkeeper argued that revising Decision 1610 through temporary petitions once or twice a year sidesteps adequate review under the California Environmental Quality Act. The group urged the board to require ongoing water conservation and asked Sonoma Water for a timeline on the environmental report it’s preparing to support permanent changes.
The board said that report has been complicated by uncertainty over PG&E’s decommissioning of the Potter Valley Project.
How to object
The notice asks objectors to send their objections to both of these contacts by 4:30 p.m. Monday:
- Ken Emanuel, State Water Resources Control Board, Division of Water Rights, P.O. Box 2000, Sacramento, CA 95812-2000, Kenneth.Emanuel@waterboards.ca.gov
- Grant Davis, general manager, Sonoma County Water Agency, 404 Aviation Blvd., Santa Rosa, CA 95403-9019, Grant.Davis@scwa.ca.gov
The board may approve or deny the petitions before the notice period ends, the notice says, and it may amend an order to address objections it receives. As of Monday morning, Sonoma Water’s petition page listed no order on the August petitions.