Separate studies look at Libby Dam spills

By JIM MANN

The Daily Inter Lake

The U.S. Army Corps of Engineers is developing an "after action" report on this summer's uncontrolled spill at Libby Dam, and the state of Montana is preparing a similar but separate report.

The Corps intends to review the impact on levees in Boundary County, Idaho, where the spill caused significant flood damage, along with damage in the Troy and Libby areas.

The report "will review this year's operations and implementation decisions for the 2006 spring runoff event," the Corps said in a press release.

"Record temperatures, rapid snow melt and significant rainstorms contributed to flooding in the Kootenai Valley in June," the press release states.

The "spring flood event" raised the Kootenai River to 2.5 feet above flood stage at Bonners Ferry, and it caused extensive gas bubble trauma to fish in the river just below the dam.

According to Jim Barton, chief of the Corps Water Management Division, the May forecasts for Libby Dam predicted an average water supply and the Corps planned operations based on those forecasts.

"However, the actual inflows into the reservoir in May were 142 percent of average, in large part because of unusually warm temperatures melting a significant amount of the snowpack," Barton said.

The report is expected to be released in the fall. Brian Marotz, fisheries projects manager for Montana Fish, Wildlife and Parks, said this week that he will issue a report on behalf of the state at about the same time.

The two-part report will evaluate the effect of the spill on fish in the Kootenai River, and it will "review the operation to learn as much as possible so we can avoid uncontrolled spills in the future," Marotz said.

That review will be based largely on computer modeling that makes use of the information available to dam operators in the months leading up to the spill, which started June 8 and ended June 27.

As a result of the spill, the Corps spent more than $1.4 million on flood response, mostly involving emergency levee repairs and providing 80,000 sandbags in Idaho's Boundary County and Montana's Lincoln County.

"The report will include a discussion of the emergency response, the types of emergency assistance provided, coordination with other federal, state and local agencies, an analysis of the effectiveness of the emergency response and a description of the water management operation of Libby Dam in 2006," the Corps press release states.

Reporter Jim Mann may be reached at 758-4407 or by e-mail at jmann@dailyinterlake.com