Above normal rain and snow is creating a situation where the peak Lake Pend Oreille elevation and peak Pend Oreille River flows downstream of Albeni Falls Dam are likely to exceed flood stage as early as next week.
The U.S. Army Corps of Engineers is operating Albeni Falls Dam with all gates open in a free flow operation. Free flow is when the river flow control switches from Albeni Falls Dam to the natural restriction between Lake Pend Oreille and the dam. This 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 above sea level for a week or more. Areas downstream of Lake Pend Oreille, such as Cusick, Newport, and Usk could be affected by high flows while Albeni Falls Dam is on free flow.
Current snowpack upstream of Lake Pend Oreille ranges between 125-175 percent of normal. Given the above normal snowpack, people residing in flood-prone areas should take precautions and be prepared for flooding.
“Corps modeling using National Weather Service River Forecast Center hydrologic forecasts suggest we could see peak Lake Pend Oreille elevations ranging between 2,062.5 and 2,063.7feet, and outflows exceeding 100,000 cubic feet per second,” said Kristian Mickelson, an Upper Columbia Water Manager for the Army Corps of Engineers. “The lake is currently at about 2,060.6 feet as measured at the Hope gage.”
The lake will likely reach an initial peak in the first 10 days of June and then may be drafted down below 2,062 feet by mid-June to conserve space for late June rain events. The lake will be in its summer operating range of 2,062 to 2,062.5 feet by July 4.
The Corps is closely monitoring National Weather Service provided weather and snowpack conditions, lake inflow and forecasted releases and level of Lake Pend Oreille. The Corps will continue to operate Albeni Falls Dam to minimize flood damage.
Current flows for Northwest river basins may be found at: http://www.nwd-wc.usace.army.mil/nws/hh/www/index.html Our website with Pend Oreille flow update information is: http://www.nws.usace.army.mil/Missions/CivilWorks/LocksandDams/AlbeniFallsDam.aspx
For official forecasts please visit the National Weather Service Spokane Forecast Office webpage: http://www.weather.gov/spokane
Release no. 14-024