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Study calls for New Melones draw-down

Walt Cook, The Union Democrat
December 10, 2010

The head of the Oakdale Irrigation District dropped a bombshell at a meeting in Sonora on Monday that left local political leaders stunned: Due to new federal management plans to release water aimed at flushing out the delta and thus improving habitat for several fish species, New Melones Reservoir could be empty 18 percent of the time.
  
    Steve Knell, general manager of the Irrigation District, made the announcement before the Tuolumne County Chamber of Commerce’s Governmental Affairs Committee. Knell, also the president of the Oakdale Chamber of Commerce, said getting the word out is part of a public outreach effort.

    His claim is based on analysis of an 844-page “biological opinion” put out by scientists with the National Oceanic and Atmospheric Administration. The effects on Melones that Knell cited were determined by hydrologist Dan Steiner, a consultant for the Oakdale Irrigation District.

    The purpose of the 2009 NOAA biological opinion is to identify — and implement — practices that will help native fish like the steelhead and the threatened chinook salmon and delta smelt, survive.

    The report calls for diversions of 200,000 acre-feet in normal years and as much as 600,000 acre-feet in dry years. An acre-foot — 325,851 gallons — is enough to meet the needs of a family of four for a year.

    New Melones has a capacity of 2.4 million acre-feet, meaning diversions could range from just under 5 percent of capacity to far higher.
    Although little publicized, Knell said diversions called for in the biological opinion have already begun.

    The Oakdale Irrigation District has challenged the opinion in federal court.

    The once-plentiful chinook salmon and steelhead, which live part-time in the ocean and lay eggs in fresh water, face a number of obstacles in their upstream travels, including dams like New Melones that block their way, altered water temperatures, pollution from runoff and depredation. Delta smelt populations, meanwhile, are threatened by development at the San Joaquin-Sacramento River Delta, and by irrigation pumps that suck the fish up.

    The Delta is the confluence of the San Joaquin and Sacramento rivers and ocean saltwater. It is a source of water and drainage for much of the state.

    The concern for the fish species has to do, in part, with the food chain: Larger fish eat the thumb-size smelt and, once in the ocean, whales and other predators eat the larger fish. Scientists say that wiping out a species can have unforeseen impacts on species higher up in the food chain — potentially even humans.

    “What is at stake here is not just the survival of species but the health of entire ecosystems and the economies that depend on them,” wrote Rod Mcinnis, southwest regional director  for NOAA’s Fisheries Service, of the biological opinion.

    The opinion’s solution to increase the fishes’ numbers is to send more water down the Stanislaus River from New Melones, as well as water from the other reservoirs throughout the state, to refresh the Delta.

    That is what worries Knell and why his hydrologist, Steiner, predicts that New Melones could, in future years, periodically become a puddle.

    To come up with his analysis, Steiner used New Melones diversions called for by the biological opinion and projected them out 80 years. According to his results:

    • New Melones would go empty 13 times during that period, whereas, under normal conditions, it would have gone dry only once.

    • It would drop below 500,000 acre-feet — the level at which, district officials say, trout begin to die off — 22 times, whereas it would have dropped to that level only four times normally.

    • The Oakdale Irrigation District and South San Joaquin Irrigation District could lose 200,000 acre-feet of water to the diversions annually, or more in dry years. The two districts have combined rights to 600,000 acre-feet of water in New Melones, which can hold 2.4 million acre-feet.

    In addition, Knell said the amount of hydroelectric power generated by New Melones could be impacted. This is power that is purchased at discounted rates by Tuolumne and Calaveras county governments.

    He added that the area’s trout fishery could be wiped out, which would hurt tourism in Stanislaus, Tuolumne and Calaveras counties.

    Knell’s stark predictions riled up Tuolumne County Supervisor Dick Pland, who expressed his concerns at Tuesday’s board meeting.

    “This is a huge issue that I don’t think anyone really knows about,” Pland said. “This is Draconian.”

    Knell criticized the science behind the biological opinion.

    First, he said, diverting water from New Melones would wipe out the rainbow trout fishery between New Melones and Oakdale because it would result in warmer waters in which the fish couldn’t survive. He also said rainbow trout are essentially the same species as steelhead, with one exception: They don’t traveled to the ocean and back.

    “They’ll be destroying native species,” Knell said.

    Steelhead are the species the biological opinion focuses on for the Stanislaus River.

    Knell said other factors are likely impacting the native fish population, including predation by nonnative bass species and sewage pollution.

    “If you don’t focus on the stressors and just dump water down the river, you haven’t cured the problems,” he said.

    The biological opinion notes that some impacts could indeed be in store for the New Melones area.

    “These may include, in some years, localized water shortages necessitating groundwater use, water conservation measures, or other infrastructure improvements in the New Melones service area,” the opinion states.

    NOAA officials weren’t available by press time to comment on the document.

    Jerry Cadagan, a retired attorney and local environmentalist who made a name for himself fighting the creation of New Melones in the late 1970s, weighed in on the issue

    “The important thing here,” he said, “is that these are professional fisheries biologists who gave their best professional opinion. And that opinion is needed to help the fish.”

    “I’m not saying cut the farmers off,” Cadagan added. “It’s good that we have an agricultural industry in the Central Valley. But at some point you reach a point of diminishing returns and you just can’t keep pumping water down there.”