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Big Winter Run Trips EWA
In the wake of this spring's large salmon kills at the State Water Project pumps -- which lead to news headlines proclaiming the abject failure of a new water account meant to protect fish -- CALFED agencies are searching for an explanation.
Approximately 20,000 juvenile endangered winter-run salmon died at the state pumps this spring, far exceeding the 7,404 "red light" limit established for this year by the National Marine Fisheries Service under the Endangered Species Act. The large "take" occurred during the first months of operation of the Environmental Water Account, created by CALFED, the state-federal effort to restore the Delta environment while ensuring water supplies for cities and farms. The account is meant to allow fisheries agencies to reduce water project diversions from the Delta during fish migration periods, replacing curtailed diversions with account reserves set aside in the San Luis Reservoir. Despite the losses EWA managers say the take may have been more of a public relations disaster than an environmental one.
"The notion that the EWA resulted in the killing of these fish is a serious misconception," says Jim White of Cal Fish and Game, one of the agencies responsible for determining when and how EWA water is used. "The use of the EWA greatly reduced the number of fish that were lost from what it otherwise would have been."
According to White and others, the crux of the issue is that there were simply many, many more winter-run in the system this year during the crucial period from February to April than anyone had anticipated "None of the monitoring data that we saw suggested that this large number of fish would show up - it looked like an average year," says the Department of Water Resources' Curtis Creel.
The result, says CALFED's Dave Fullerton, is that EWA water budgeted for salmon migration was spent before the unexpectedly high numbers of salmon appeared at the pumps. "When the fish started to come down the river we thought 'here they come,' then spent a fair amount of water," he says. "Then all of a sudden the densities [number of salmon per acre-foot of water pumped] just kept going up and up and up. After a certain point we couldn't justify spending more water."
The EWA is authorized to purchase 380,000 acre-feet/year and the agencies felt they had to retain some water in the account to aid other species, such as Delta smelt, later in the year, says Fullerton. If in fact the agencies grossly underestimated the number of winter-run in the system this year, it's not only good news for the Estuary's most endangered salmon run, it also means that the red-light number (which requires water managers to resume consultations with fisheries agencies, not necessarily to stop pumping) may also have been much too low. "If this is what happened then the high take is totally understandable," says Fullerton. "Of course you are going to have higher losses if you are awash in winter-run." The red-light number is supposed to represent two percent of the young fish entering the system in a given year, calculated from an estimate of spawning adult salmon and other factors. If, as some data indicate, the actual number of winter run salmon spawning last year was in the range of 5-10 times the official estimate, then the actual number of juvenile fish produced would have been proportionately higher. In that case the true red-light number for this year would have been between about 35,000 and 70,000, substantially more than the winter run loss at the pumps.
The apparent undercount has prompted deep soul searching among those responsible for the juvenile production estimate and is likely to bring changes in the way future estimates are made, says National Marine Fisheries Services biologist Bruce Oppenheim. The juvenile production estimate is based on an estimate of the number of adults spawning, which is based on a count of adults salmon at Red Bluff Diversion Dam. "We will be looking at how can we narrow uncertainty on that estimate, what's the best data to use," says Oppenheim.
This year's unusual hydrology may also have contributed to the high take. "Whereas in higher flow years the fish move through more quickly and are less vulnerable to the pumps, what may have occurred this year is that as flows dropped, the fish slowed their migration and got more vulnerable," says Creel. "That's merely a theory, but there is some evidence to support it."
Regardless of how many fish there were, or what may have brought them to the pumps, some EWA watchdogs contend that more could have been done to save them. The Bay Institute's Tina Swanson blames an inherent contradiction between the EWA implementation structure and the tiered fish protection scheme outlined in the CALFED Record of Decision is to blame. Under the ROD, three tiers of assets are supposed to be available to meet endangered species requirements. Tier 1 consists of baseline protections such as those set forth in the state water quality control plan. Tier 2 is the EWA and CALFED's Ecosystem Restoration Program. Tier 3 is the commitment of CALFED agencies to make additional water available if it is needed to meet endangered species requirements. Swanson says that although she suggested that the managing agencies invoke Tier 3 protections after the EWA water budgeted for winter-run salmon was exhausted, they did not do so because the EWA still had water that it was saving for other species. "It's a real Catch-22," she says. "CALFED needs to clarify the conditions under which Tier 3 can be requested and implemented."
Swanson and the EWA managers seem to agree on the need to establish Tier 3 and that more operational flexibility would also have been helpful. "When we got to the point where we couldn't use any more EWA water we looked at other actions we could use, one of them being the joint point of diversion," says Oppenheim. "We thought we could divert pumping from the state side to the federal side decrease take." Although the ROD identifies the joint point as a tool that EWA mangers can use to protect fish, regulations such as surface water elevation requirements constrained its use this year, as did the fact that certain state and federal environmental permissions have not yet been obtained. Work is already underway to eliminate these obstacles for the future.
These issues, says Fullerton, are among the kinks that will be worked out as the EWA matures. "It's very unfortunate that we got hit with an extremely difficult year four months after we hit the ground," he says "If this had happened in three or four years when we were fully functioning we could have done more in a year like this, even if nothing else were different." Nevertheless, he notes that the EWA probably saved 20 to 25 percent of the fish that would otherwise have been lost. "It did make a dent in the take, we just were not able to hold the levels that we would have liked to." He defends CALFED's decision to go ahead with the EWA this year, despite the fact that not every i has been dotted. "This is how you learn." The EWA agencies will continue to review the spring's actions throughout the summer; a workshop on their findings is planned for the fall.
Contact: Dave Fullerton (916) 653-4539; Tina Swanson (415) 721-7680 CH
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