Biologists braved a morass of mud and fish carcasses
in early October while investigating a section of the Poudre River
near Fort Collins, Colo. More than 4,000 fish were killed when an
irrigation company drained its reservoir to check water gates at
the bottom of the dam.
Mike Cola, a dam-safety
engineer for the Colorado Division of Water Resources, says the
suction created by the open gates pulled out tons of sediment that
had accumulated at the bottom of the
reservoir.
“It’s like something out of Pompeii,”
says Dave Nickum, Southern Rockies conservation director for Trout
Unlimited. The muddy water smothered a three-mile section of the
river where deep river pools had supported a prized trout fishery,
says Nickum.
Steve Puttmann, the state Division
of Wildlife’s senior fisheries biologist, believes the situation
could have been prevented. “If I had seen what was happening with
the sediment, I would have asked the dam folks to shut their
gates,” he says.
Duane Aranci, acting manager for
the North Poudre Irrigation Company, says, “The whole thing’s been
blown out of proportion.” He predicts the silt will eventually move
downstream.
But state officials think it will
take years for the mud to dissipate and are discussing ways to
speed up the process. Puttmann says they’re considering trenching
the river with backhoes or flushing it with a series of high-water
releases.
Puttmann also warns that sediment is
accumulating in thousands of small reservoirs all over the
Intermountain West, and that more disasters will occur. “It’s not a
matter of if, just when.”
* Patrick Dowd, HCN
intern
This article appeared in the print edition of the magazine with the headline Reservoir unleashes more than water.
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