Bonners Ferry Local Guide including all of Boundary County Idaho

Montana to open dam floodgate

Friday, April 27, 2007; GM

With the snowpack at record levels in some parts of British Columbia and Washington State, the U.S. Army Corps of Engineers is preparing to raise the outflow of the Libby Dam in Montana. The 130-metre-high dam on the Kootenay River, spelled Kootenai in Montana, controls the level of the Koocanusa Reservoir south of Cranbrook, a major recreational area for local campers and boaters in the summer months. But recreation is not what's on the mind of the corps now with the concern being the possibility of flooding when the mountain snowpack melts in late May and June. The corps issued a news release saying it will increase the Libby outflow to 793,000 litres a second, the maximum amount allowed by law, as soon as the spring rise begins on Kootenay Lake. After passing through the Libby Dam, water from the Koocanusa Reservoir passes through Bonners Ferry, Idaho, and the Creston Flats before entering Kootenay Lake and flowing on to Nelson and Castlegar downstream. In June of 2006 there was flooding downstream of the Libby Dam triggered by a hot spell in mid-May and heavy rain in early June. This is just the kind of "perfect storm" scenario the corps and many others are hoping will not be repeated this year. However, the latest snowpack readings are a bit ominous. As of April 1, the snowpack in the Koocanusa Reservoir was 108 per cent of normal, which isn't too bad except that it's been cold and damp most of the month and the upper level snowpack is still increasing instead of going down, Ken Soderlind, a hydraulic engineer and flood forecaster with the corps in Portland, Ore., said. "There's still some snowpack buildup and there's been no change down since the end of March and it's starting to bump back up again," he said. This has flood forecasters concerned all over northwest Canada and the United States because of the potential for a sudden melt resulting in a flood, Mr. Soderlind said. That's why the corps is increasing outflows now in an effort to avoid potential downstream flood impacts later in the season. Meanwhile, preparations are taking place all over British Columbia in anticipation of possible flooding this spring. Some 87 flood protection projects are on track to be completed by mid-May with the province spending $33-million on the measures. Cranbrook public works manager Les Hunter said that the city has 10,000 sandbags in storage for possible flooding on Joseph Creek. City crews have already been working on the creek to clear debris and willow jams that could cause flooding if the creek gets high. - Full Story