Historic flooding possible on the Moyie
April 6, 2011
During the May meeting of the Local Emergency Planning Committee, Emergency Management Director Dave Kramer told those in attendance of the risk of major flooding on the Moyie River, particularly in Eastport, as spring warms up, and Jay Baker, Idaho Bureau of Homeland Security, said the risk was extremely high region wide.

According to Katherine Rowden of the National Oceanic and Atmospheric Administration, there is a 90-percent probability that the Moyie River will exceed flood stage this spring, based on peak flow forecasts for Eastport.

"The more interesting news," she wrote, "is that the model suggests a 50-percent chance that flows will exceed 11,600 cubic feet per second, which is greater than the flood of record."

That record was set in 1916, when the flow was 10,600 cubic feet per second. Flood stage assessment data tops out at 11,000 cubic feet per second, so there's no accurate way to predict what conditions on the river will be if that flow is exceeded.

"The River Forecast Center is working on extending the curve mathematically," she wrote, "which may not accurately reflect real world conditions, but will help give some guidance."

The highest flow at Eastport in the last 30 years came in 2002, when the Moyie rose to 10.46-feet with a flow of 9,310 cubic feet per second. Flood stage on the Moyie River at Eastport is nine feet.

Currently, Rowden said, work is being done for potential floods on the Kootenai River at Bonners Ferry as well, particularly if the Yaak, Fisher and Moyie Rivers all flood simultaneously.

Kramer said the county has been preparing for the worst, stocking an extra supply of sandbags, which are available at the landfill. Last month, county commissioners sent a letter to Eastport property owners in the areas expected to be hardest hit, reminding them that the responsibility for protecting private property falls on the property owner, and encouraging absentee landowners to make arrangements to have someone, either a neighbor or a contractor, look after their property.