Kootenai River Flows up to 32,400 cfs
June 9, 2006
Story by KLCB News, Libby
The Corps of Engineers has ramped the Kootenai River up to 32,400 CFS, adding a volume of 8,000CFS over the spillway to the already capacity flow through the power hose of 24,000 CFS. A spill the Corps said in May they had no intentions of this season. According to the Reservoir Control Center, the in-flow to Lake Koocanusa is 12,000 CFS greater than expected.
The June 1 updated forecast for Lake Koocanusa indicates approximately 50 percent of the watershed's high elevation snow pack remains in the mountains. As a result of this updated forecast, U. S. Army Corps of Engineers water managers say they need to begin a limited flood control spill at Libby Dam as early as June 10.
The Corps opened the spillway gates at 5pm June 8th.
This limited flood control spill is expected to maintain adequate flood control storage in Koocanusa to reduce the risk of a larger flood control spill later in June or early July, says the Corps. An objective of the Corps' planned operation is to avoid exceeding Montana's water quality standards for total dissolved gas saturation, however, speaking with a representative of the Corps in Seattle, the Corps was in contact with the Montana Fish, Wildlife, and Parks, and the Montana Department of Environmental Quality last week to alert them that the Corps would be exceeding the gasification limits.
According to the Corps, much of the high elevation snow pack remains even after May's unusually warm weather and the subsequent low elevation runoff during the past two weeks, and caused near flood-stage high water in the Kootenai River below Libby Dam and flooding on the Yaak and Moyie rivers in Montana and numerous rivers in Idaho.
However, according to information released today by the Natural Resources Conservation Service , most streams and rivers have reached their snow melt peaks for this year and will not crest higher without significant rain.
Mid-May temperatures were well above average and caused early rapid snowmelt. Remaining mountain snowpack was well below average for June 1, but well above last year. Snowpack west of the Continental Divide was below average, says the Natural Resources and Conservation Service.
This spill is within the window set by the Fish wildlife service sturgeon mitigation window for high river flow.
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