Columbia Power Corp. has begun work to complete cleaning up the tailrace of its 120-MW Brilliant Expansion hydroelectric project, which began commercial operation in 2007.
Columbia Power and Columbia Basin Trust own the project, on the Kootenay River near Castlegar, immediately downstream of 145-MW Brilliant Dam. (HNN 9/17/07)
During construction of the new powerhouse, a concrete berm and sheetpile wall were built downstream to keep river water out of the powerhouse excavation site. Although most of the berm and sheetpile wall were removed before the powerhouse began operation, remnants of the berm were left in the river.
Columbia Power said Aug. 6 it awarded a contract to JJM Construction Ltd., Delta, B.C., to complete the cleanup. The first part of that job involves building an access road to the river. Beginning the first week of September, workers plan to construct a temporary rock berm from which they will use heavy equipment to remove what is left of the old berm and loose rock from the tailrace area.
A permanent, 40-meter-long deflection wall also is to be built in the river on the north side of the new powerhouse to keep cross flows from Brilliant Dam from washing additional loose rock into the tailrace area. Cleanup, including removal of the temporary berm, is to be completed by Nov. 30 to minimize effects on fish populations.
Removing loose rock and building the deflection wall are to improve generation at both Brilliant Dam and Brilliant Dam Expansion by lowering the tailrace level and increasing head, Columbia Power Communications Director Audrey Repin said. However, the specific amount of improvement will not be known until after the work is completed, she added.