Schweitzer criticizes Libby Dam spill
June 17, 2006
Montana Gov. Brian Schweitzer is criticizing an ongoing spill over Libby Dam, suggesting it could have been avoided if not for pressure to store water for Columbia River salmon.
The U.S. Army Corps of Engineers has been releasing water over the dam's spillways since June 8, and with recent heavy rains, it's expected to continue well into next week.
The spill of about 14,000 cubic feet per second has elevated gas levels in the Kootenai River below the dam, causing "gas bubble trauma" in fish that is expected to become more severe as the spill continues.
"While the short-term decision this last weekend to spill at Libby was probably necessary for flood control, it begs the question of how the feds operate the dam year round," Schweitzer said in a press release Wednesday.
"If the federal government operated the dams with the primary objective of not harming the residents who live near them, a secondary objective of providing for the resident fish, and lastly to assist the recovery of salmon hundreds of miles away in the Columbia River, we wouldn't run into these situations."
Although the Corps operates Libby Dam, it does so under direction from biological opinions developed by other agencies, including the U.S. Fish and Wildlife Service. One requirement is that Lake Koocanusa reach its full pool elevation by June 30 to ensure there's enough water for salmon flow augmentation.
Bruce Measure, one of Montana's representatives on the Northwest Power and Conservation Council, also criticized the June 30 refill date.
"Instead of working with other knowledgeable agencies and scientists to prepare a biological opinion for operations that we know would stabilize the situation at Libby and benefit both resident and anadromous fish, they insist on a fixed refill date that does not take annual weather hanges into account."
Lake Koocanusa is managed under a "variable discharge" policy known as VAR-Q, in which releases fluctuate based on changing forecasts for inflows. Measure contends that the fixed refill date is incompatible with that approach.
Brian Marotz, fisheries projects manager for Montana Fish, Wildlife and Parks, has a similar view.
"VAR-Q is incompatible with a fixed refill date," he said. "It was designed with a sliding refill date in mind."
Marotz said the Corps of Engineers couldn't have operated Libby Dam any better than it has since May 16, when the dam started releasing water at full powerhouse capacity. But he predicts there will be considerable analysis of the inflow forecasting before that date.
"Unfortunately, because the reservoir was held high enough to accommodate flow augmentation, there wasn't enough storage to handle an average runoff," he said. And this year's runoff was indeed average.
The difficulty in forecasting, he said, is predicting the "shape" of inflows into the reservoir. Some years, an average runoff involves long and steady inflows, but this year it involved erratic, peaking inflows.
Mick Shea, Libby Dam project manager for the Corps of Engineers, agrees that this summer's spill will be studied closely.
"There are things we know now that we couldn't have foreseen, but that doesn't mean we shouldn't ask ourselves some questions," he said. "I know we will be doing that internally and I know the public will be doing that as well."
Lake Koocanusa inflows were steady at about 40,000 cfs for most of this week. But with recent rain, the Corps is forecasting that inflows will increase to 50,000 cfs.
"We are going to continue to maintain discharges at about 38,000 cfs, and we expect the pool to start filling again," Shea said.
The reservoir is projected to crest within 6 inches of full pool by Saturday.
Shea said the Corps is being cautious about increasing spill because of concerns about the river approaching flood stage at Bonners Ferry, Idaho.
Nonstop high flows since mid-May have caused levee damage and crop damages from groundwater seepage in the Bonners Ferry area. With crop damage estimated at $2.5 million, Idaho Gov. Jim Risch declared a state of emergency for the area last week.
Meanwhile, gas levels are causing harm in the river below Libby Dam.
Marotz participated Monday in monitoring the river for impacts on fish after just five days of spill. About 36 percent of the rainbow trout on the eastern bank below the dam, where gas concentrations are highest, had symptoms of gas-bubble trauma. That percentage will increase, along with the severity of the symptoms, as spill continues, Marotz said.
After seven days of an unplanned spill in the summer of 2002, 70 percent to 80 percent of the varying species below the dam -- including threatened bull trout -- had gas-bubble trauma, Marotz said. Although fish often recover, it's unknown whether there is long-term harm.
Fish that are entrained in the spillway are being killed or seriously battered.
"Most of the fish that people are seeing floating by (on the river) are kokanee that weren't killed by the gas, they were killed by the ride over the spillway or the turbulence below the spillway," Marotz said.
The Columbia Basin Bulletin, Weekly Fish & Wildlife News, June 16, 2006 Issue No. 355, https://cbbulletin.com/Free/171392.aspx
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