Corps expects flood stage to be exceeded
Coeur d'Alene Press | UPDATED 13 years, 8 months AGO
SANDPOINT - Lake Pend Oreille and the Pend Oreille River downstream of Albeni Falls Dam are expected to exceed flood stage this spring because of cooler than normal temperatures and above-normal rain and snow.
The U.S. Army Corps of Engineers plans to release the full capacity of Albeni Falls Dam until the lake reaches its peak elevation, projected to be sometime in June. The normal maximum elevation for the lake during summer is between 2,062 and 2,062.5 feet above sea level.
Current snowpack in the northern Panhandle is 162 percent of normal and snowpack levels upstream of Lake Pend Oreille range from 152 percent of normal in the Upper Clark Fork Basin to 182 percent of normal in the Flathead Basin, according to the corps.
The National Oceanic & Atmospheric Administration forecast is for cooler than normal temperatures through June with continued higher than normal precipitation through May.
"Forecasts suggest we could see peak Lake Pend Oreille elevations ranging between 2,062.5 and 2,066 feet, and outflows exceeding 100,000 cubic feet per second," said Joel Fenolio, Upper Columbia senior water manager for the corps. "The lake is currently being operated between 2,055 and 2,055.5 feet as measured at the Hope gauge, until the project goes on free flow."
The dam has been operating within a 1-foot band above 2,055 feet throughout the winter, Fenolio said.
Free flow is when the hydraulic control point for releases switches from Albeni Falls Dam to the natural restriction between the lake and the dam. The operation is meant to help keep the lake level down and to mitigate for some of the potentially high releases through the spring.
Lake elevations could be above 2,062.5 feet for several weeks, corps officials said. Areas downstream of the dam - namely the Washington state communities of Newport, Usk and Cusick - could be affected by high releases while the dam is on free flow.
Due to the above-normal snowpack, the corps is recommending people in flood-prone areas should take precautions for flooding this spring.
The corps said it is closely monitoring weather and snowpack conditions, lake inflow and forecasted releases, and the level of the lake. The corps will continue to operate the dam to minimize flood damage.