Libby Dam flow on high
Libby Dam operations are on track despite higher than average rains.
The dam is running all five turbines to a powerhouse capacity of 26,300 cubic feet per second to provide spawning flows for the Kootenai River endangered white sturgeon downstream of the dam in Idaho.
Last weekend, the Bonners Ferry gauge, measuring the area’s general river height, was up about one foot after Saturday’s 5,000 cfs outflow increase, according to Amy Reese, hydrologic engineer in the Reservoir Control Center in the Seattle District of the Army Corps of Engineers.
“We were interested in how the rain and snow level was going to play out,” said Reese, who coordinates operations out of the Northwestern division that includes Libby — from the upper Columbia Basin to Yakima, Wash.
Total precipitation for June 2007 was .83 inches; through June 11, the precipitation has been 1.07 inches.
“The river is high because of the sturgeon request and the rain — annually we make a request for flows to help make sturgeons spawn. We increased our outflow to help with their recovery in the Kootenai River,” she said, noting the dam recorded a half an inch of rainfall on Tuesday.
The Sturgeon Flow Augmentation Operation has been tracking the flow of the spawning sturgeon since early June.
“We’ve got some sonic tagged fish that we observed moving into reach of the river near Bonners Ferry, where spawning could be successful,” said the Corps’ Greg Hoffman — a good sign.
We haven’t been able to document substantial natural reproduction and the population is heading toward instiction, so we are trying to determine the river conditions that these fish need to spawn successfully.”
Currently there are not enough sturgeon in the river to attach any statistical significance, according to Hoffman. He hopes to get conditions for spawning up to speed by the time the Kootenai Tribal hatchery reach maturity around 2025.
“We’ll have fish that came from the to spawn,” Hoffman said, adding if the don’t spawn in the wild, they’ll capture the adult fish and spawn them in the hatchery to produce families of fish.
“When those fish get old enough to spawn we want the conditions to be right,” said Hoffman, noting temperature and flow come into play. “What we would call a success is when the fish are produced naturally and are large enough that we could capture them with experimental gill nets.”
Currently, the dam’s sturgeon operations group is working in conjunction with the Kootenai Tribe, and the states of Idaho and Montana.
“It’s still a very cold spring, but we’re providing a steady temperature,” said Hoffman.