Lake Dorothy Hydro Electric Tap

The Norwegian Lake Tap Method was successfully used to tap into the side of Lake Dorothy to allow the construction of a downstream dam.

Redpath USA Corporation (RUSAC) successfully tapped into the side of Lake Dorothy 36.5 m (120′) below the lake surface. The lake tap allowed water to flow into an access tunnel from the lake, lowering the water elevation below its natural outfall, enabling the construction of a downstream dam.

The Lake Dorothy portal site and tunnel are located approximately 25.7 km southeast of Juneau, AK, in the remote Tongass National Forest at an elevation of 701 m above sea level in the mountains above the Taku Inlet. Thirty-degree, snow-covered mountainsides and limited access by helicopter were just two of the many factors which challenged this unique project.