By Scott Hamilton, President, Hamilton Resource Economics
Water management in California is often perplexing. Earlier this year, state and federal pumps were brought to minimal levels to reduce salvage of steelhead. Perhaps only a small percentage of the steelhead population was turning up at the pumps – no one knows as there are no estimates of the population. The fish that were caught were diverted into holding tanks before they reached the pumps and released back into the Delta to continue their journey to the ocean. So, if the fish were being salvaged, why was there a need to reduce pumping in the first place?
The combined permitted water project pumping capacity in the south Delta is 10,880 cubic feet per second (cfs) – 6,680 cfs for the State Water Project and 4,200 cfs for the CVP. In the first half of the year, flows in Old and Middle rivers towards the pumps are reduced to 5,000 cfs to reduce the entrainment of Delta smelt at water project pumps. Typically, the projects pick up 1,000 cfs from the San Joaquin River so the projects can pump around 6,000 cfs from February through June when their permitted capacity is 10,880 cfs – a difference of nearly 5,000 cfs or 10,000 acre-feet per day, 300,000 af/month, 1.5 million af for the 5 months of the protection period.
But Delta smelt is now very rare. For the last several years, U.S. Fish and Wildlife Service (USFWS) has added tens of thousands of hatchery Delta smelt to Delta waters. Despite that, none — not one — has been sampled in the Fall Midwater Trawl since 2017. In 1993, the year Delta smelt was added to the endangered species list, there were over 1,000 Delta smelt sampled in the Fall Midwater Trawl. The logical question: why are we still restricting water project pumping to protect Delta smelt? Patrick Sullivan, Professor Emeritus in the Department of Natural Resources and the Environment at Cornell University, asked essentially that same question at a National Academy of Science Committee meeting — why not mitigate the take of Delta smelt at the pumps by producing more hatchery fish, rather than restrict pumping?
And in the fall, we have yet another action to protect Delta smelt. It is known as the “Fall X2 action.” It involves releasing additional water from reservoirs in the Sacramento Valley in wetter than normal years to increase the area in the Delta with salinity that is suitable for Delta smelt. In 2023, the last time the action was implemented, the California Department of Water Resources estimated that the action cost around 600,000 acre-feet.
This year is a wetter than normal year, but the action is going to be implemented in September and October despite the SWP having a 40% allocation and CVP south of Delta contractors having a 50% supply. Perhaps this might make some sense if the action provided real benefits for the fish. But the original science on which the action was based was flawed. And Delta smelt can’t survive in the Delta because there is too little food in summer, not because their salinity field is restricted. Recently, a structured decision-making process was implemented to identify the best actions to help Delta smelt. In that process, all four computer models found zero benefit to Delta smelt for the current fall X2 action. And, in a recent draft biological opinion, the USWFS confirmed that the Fall X2 Action did not improve survival rates of Delta smelt.
Reasonable efforts should be made to recover endangered species. Those efforts should be informed by the best available scientific information. There is a plethora of good science to inform the recovery of Delta smelt. It is, however, being ignored while ineffective, costly actions continue to be stubbornly implemented.
