Winchester Lake Dam recently went through some modifications that will result in lower lake levels in the future. According to an Idaho Department of Fish and Game news release, due to safety concerns, the breakaway walls on the spillway were removed. The breakaway walls were designed to capture spring runoff and hold the lake water level about 3 feet above the spillway.
If unusually high spring flows occurred and overtopped the breakaway wall, it was designed to fail and greatly increase the volume of water that could pass down the spillway and protect the integrity of the dam. The concern was that if the breakaway wall overtopped and failed (as designed to do) a surge of water would flow down the canyon below and potentially flood some of the roads. With the breakaway wall removed, that is no longer a concern.
However, the department will not be able to capture the spring runoff which will mean lake levels will be around 3 feet lower than traditional levels. Lower lake levels may make some of the docks less beneficial, but officials expect there will be minimal affects to the fishery.
Plans are in place to upgrade the spillway and dam in the future. Fish and Game hopes the upgrades will occur within the next five years to return lake levels back to normal. Anyone with questions can contact the Clearwater Regional office at (208) 799-5010.
