The Serpentine Dam, together with the Edgar Dam and the Scotts Peak Dam, are three major dams that form the headwaters for the Gordon River Power Development Scheme. The dam is located near Lake Pedder's most northwesterly point where the Serpentine River descends from the Frankland Range into what is now known as the Pedder Reach. At the southern end of the Lake Pedder, the Scotts Peak Dam impounds the upper reaches of the Huon River. The Edgar Dam forms a saddle dam at Lake Pedder's most easterly point. The water in Lake Pedder provides around 40% of the water used in the Gordon Power Station. The water flows to Lake Gordon via McPartlan Canal.[2] Water from Lake Gordon then exits through the Gordon Power Station releasing via the tailrace into the Gordon River.
Built on a foundation of rock and soil, the Serpentine Dam wall was constructed with 127 thousand cubic metres (4.5×10^6 cu ft) of rockfill and faced with concrete. The dam wall is 38 metres (125 ft) high and 134 metres (440 ft) long. At 100% capacity the dam wall holds back 2,937,930 megalitres (103,752×10^6 cu ft) of water. The surface area of Lake Pedder is 241,330 hectares (596,300 acres) and the catchment area is 734 square kilometres (283 sq mi). The dam wall has a controlled spillway capable of discharging 242 cubic metres per second (8,500 cu ft/s).[1]
The construction of the Serpentine Dam resulted in the loss of one of the significant sub-populations of the endangered Centrolepispedderensis (a small herbaceous plant), while the nearby Gordon Dam caused the loss of another. It is now only known to exist in one location on the Frankland Range. One sub-population existed along the Serpentine River and is now inundated as a direct cause of the creation of this dam.[5]
