Lake Pedder, once a glacial outwash lake, is a man-made impoundment and diversion lake located in the southwest of Tasmania, Australia. In addition to its natural catchment from the Frankland Range, the lake is formed by the 1972 damming of the Serpentine and Huon rivers by the Hydro-Electric Commission for the purpose of hydroelectric power ge…Lake Pedder, once a glacial outwash lake, is a man-made impoundment and diversion lake located in the southwest of Tasmania, Australia. In addition to its natural catchment from the Frankland Range, the lake is formed by the 1972 damming of the Serpentine and Huon rivers by the Hydro-Electric Commission for the purpose of hydroelectric power generation. Consequently, the lake is also known, somewhat derisively, as the Huon-Serpentine Impoundment.