CA and Feds Still Plan to Drain Reservoirs & Kill Salmon

The State and Feds must act now to increase reservoir storage and take other actions to reduce water temperatures that kill salmon and steelhead.

Updated water supply allocations announced last week would still drain upstream reservoirs in order to deliver 4.5 million acre feet of water to the contractors of the federal Central Valley Project (CVP) and State Water Project (SWP), devastating fish and wildlife. This week, the fisheries biologists at the National Marine Fisheries Service projected that these planned operations are likely to result in lethal water temperatures that will kill 89% of endangered winter-run Chinook salmon below Shasta Dam this year. This mortality estimate is even worse than what was observed in 2014 and 2015, when salmon populations were devastated by warm water in their spawning grounds. But it doesn’t have to be this way if the State and Feds act now to increase reservoir storage and take other actions to reduce water temperatures that kill salmon and steelhead.

The State and Federal water projects in California announced changes to their initial water supply allocations this week, but both are still planning to deliver more than 4.5 million acre feet of water this year to their contractors. They’ll do so—according to their own modeling—by draining upstream reservoirs throughout the Central Valley to extremely low levels, which will almost certainly cause devastating impacts to salmon and steelhead. The changes announced by the Department of Water Resources and the Bureau of Reclamation would only reduce water allocations by the CVP and SWP by around 300,000 acre feet in total. Even with these reductions, the CVP and SWP are planning to allocate more than 4.5 million acre feet of water to their contractors this year, including:

  • More than 750,000 acre feet to contractors on the Stanislaus River (100% allocation);
  • Nearly 1.6 million acre feet to the Sacramento River Settlement Contractors (75% allocation);
  • Nearly 700,000 acre feet to the San Joaquin River Exchange Contractors (75% allocation);
  • Approximately 500,000 acre to DWR’s Feather River Settlement Contractors (50% allocation).

The table below shows the Bureau of Reclamation’s allocation (online here). I’ve highlighted in yellow the one change announced this week, freezing the 5% allocation to Westlands and other South of Delta CVP contractors. Assuming that conditions remain dry and they don’t deliver that water, subtracting that amount from the total water this year would still leave more than 3.8 million acre feet in water deliveries by the CVP:


Reducing water supply allocations was inevitable given the hydrologic reality this year. Yet the minimal reductions to date are wholly insufficient, because these 4.5 million acre feet of water deliveries to contractors will drain reservoirs across the Central Valley. The latest modeling from Reclamation shows most Central Valley reservoirs will have even less water in storage at the end of this water year than was estimated last month (and discussed in my last blog), meaning that California is woefully unprepared if 2022 is also dry. 

The very low storage in upstream reservoirs that result from these allocations are likely to devastate salmon and steelhead. DWR predicts significant water temperature impacts to salmon and steelhead may occur and/or are likely on the Trinity River, Clear Creek, Feather River, American River, and Sacramento River. Fall run Chinook salmon—the backbone of the State’s salmon fishery—are likely to get hammered this year, as they did in 2014 and 2015. Salmon fishermen are already facing a very limited fishing season this year, and this year’s grim news in terms of temperature mortality of salmon means more bad fishing seasons are likely in a couple years.  Spring run salmon (ESA-listed) are also likely to get hammered, and the federal National Marine Fisheries Service has estimated that lethal water temperatures will kill 89% of the endangered winter run Chinook salmon that spawn below Shasta Dam in the Sacramento River—the only population on earth of these remarkable fish. 

It does not have to be this way. Two weeks ago, a coalition of Tribal, fishing, and conservation groups petitioned the State Water Board to require DWR and Reclamation to model alternative operations that reduce these allocations in order to improve reservoir storage and water temperatures, and to consider other actions like hydropower bypasses, in order to avoid a repeat of the disaster of 2014 and 2015 for salmon. With the Bureau of Reclamation planning to significantly increase water releases from Shasta Dam starting in April in order to deliver water to the Sacramento River Settlement Contractors, the clock is ticking for the State Water Board to act.

Related Blogs