| Edgar Dam | |
|---|---|
  Edgar Dam Location of the Edgar Dam inTasmania | |
 Interactive map of Edgar Dam | |
| Country | Australia |
| Location | South WestTasmania |
| Purpose | Power |
| Status | Operational |
| Opening date | 1973 (1973) |
| Owner | Hydro Tasmania |
| Dam and spillways | |
| Type of dam | Embankment dam |
| Impounds | Off stream |
| Height | 17 metres (56 ft) |
| Length | 460 metres (1,510 ft) |
| Dam volume | 96×10 |
| Spillways | 0 |
| Reservoir | |
| Creates | Lake Pedder |
| Total capacity | 2,937,930 ML (103,752×10 |
| Catchment area | 734 km2 (283 sq mi) |
| Surface area | 241 km2 (93 sq mi) |
| Maximum water depth | 43 m (141 ft) |
| Website hydro | |
TheEdgar Dam is anearthfillembankmentsaddledam without aspillway, located offstream in theSouth West region ofTasmania, Australia.
The impoundedreservoir, also formed with theScotts Peak Dam and theSerpentine Dam, is calledLake Pedder which floodedLake Edgar, a naturally formingfault scarp pond. The dam was constructed in 1973 by theHydro Electric Corporation (TAS) as part of the Gordon River Power Development Scheme for the purpose of generatinghydro-electric power via theGordon Power Station. Water from Lake Pedder is diverted toLake Gordon (formed by theGordon Dam) via the McPartlan Pass Canal.[1]
The Edgar Dam, together with the Scotts Peak Dam and the Serpentine 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 easterly point[2] in the upper reaches of theHuon River where the river descends from the Marsden Range and descends into what is now known as the Huon Basin. Also at the southern end of the Lake Pedder, the Scotts Peak Dam impounds the Huon River. At the northwestern end of the lake is impounded by the Serpentine Dam across theSerpentine River. 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.[1] Water from Lake Gordon then exits through the Gordon Dam.
The Edgar Dam wall, constructed with 96 thousand cubic metres (3.4×10^6 cu ft) of earth core, is 17 metres (56 ft) high and 460 metres (1,510 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 does not have a spillway.[3]
The dam draws its name from the flooded Lake Edgar.
The Lake Edgar Fault is a 30-kilometre (19 mi) long north–south trending scarp that occurs within the boundary of theSouthwest National Park. The scarp traverses the button grass of the Huon Plains and is notable because faulting resulted in the defeat of westerly flowing drainage and the consequent formation of the fault-bound sag pond of Lake Edgar.[4] In January 2001 a tremor measuring 3.2 on theRichter magnitude scale occurred near the Lake Edgar fault, which runs adjacent to the Edgar Dam, however damage was negligible.[5][6][7][8][9]
In 2002 it was reported that a dam safety manager from Hydro Tasmania, was confident that the eventuality of the Edgar dam being destroyed by an earthquake was an extremely remote possibility, with a University of Tasmania Geophysicist agreeing that the risk of collapse was remote.[10]
