The State Water Resources Control Board is warning that the Bureau of Reclamation’s draft Sacramento River Temperature Management Plan may not do enough to protect winter-run and fall-run Chinook salmon, citing concerns that low end-of-September storage in Shasta Reservoir could leave too little cold water for spawning.
On May 15, the Board submitted comments on the April 29 draft plan, which Reclamation is preparing under State Water Board Order 90-5. The order requires Reclamation to manage Sacramento River temperatures to protect fish species, including winter-run and fall-run Chinook salmon.
The Board’s letter points to Reclamation’s projection that Shasta Reservoir could end September with 2.2 million acre-feet of storage, despite relatively high storage earlier in the spring. The draft plan also indicates that the volume of the coldest water in Shasta could be similar to 2015, which was a difficult year for temperature management.
“There is significant uncertainty this year in the level of protection that will be provided to winter-run and fall-run Chinook salmon and the actions that should be implemented to improve conditions this year, as well as going into next year,” the letter states.
“Specifically, Board staff’s previous understanding – based on Reclamation’s description of the Proposed Action for LTO that was evaluated by the 2024 Biological Opinion (BiOp) – was that the EOS carryover storage objective for a year such as 2026 would be at least 2.4 MAF based on the high EOA storage of 4.2 MAF,” the letter states. “However, Reclamation has recently indicated that as a result of LTO changes in 2025 Reclamation would not provide for an EOS carryover this year of 2.4 MAF.”
The letter says increasing Shasta’s end-of-September carryover storage to at least 2.4 MAF could both preserve cold water longer in 2026 and leave more water in reserve if 2027 is dry. The letter also calls on Reclamation to strengthen the final temperature management plan to better protect winter-run and fall-run Chinook salmon, potentially through higher end-of-September storage. The Board is also asking for more detail on the storage target, modeling approach, weather assumptions, and the difference between Reclamation’s mortality estimates and Southwest Fisheries Science Center’s.
