Edgar Dam
| Company type | Earthfill saddle dam |
|---|---|
| Industry | Hydroelectric power infrastructure |
| Founded | 1973 |
| Founder | Hydro Tasmania |
| Headquarters | Australia |
Area served | South West Tasmania |
| Products | Water retention for hydroelectric power generation |
The Edgar Dam is an earthfill saddle dam constructed without a spillway, situated offstream in the South West region of Tasmania, Australia.
Together with Scotts Peak Dam and Serpentine Dam, it contributes to the reservoir system of Lake Pedder. This lake, which submerged the original fault scarp pond known as Lake Edgar, was established in 1973 by Hydro Tasmania as a component of the Gordon River Power Development Scheme, aimed at generating hydroelectric energy at the Gordon Power Station. Water from Lake Pedder is transferred to Lake Gordon, created by the Gordon Dam, through the McPartlan Pass Canal.
Location and features
Edgar Dam, in conjunction with Scotts Peak and Serpentine Dams, forms part of the headwater infrastructure for the Gordon River Power Development Scheme. Positioned near the eastern section of Lake Pedder within the upper Huon River catchment, this dam is integral to hydroelectric power production. Scotts Peak Dam impounds the Huon River at the southern extremity of Lake Pedder, while Serpentine Dam retains water from the Serpentine River at the lake’s northwestern side. Approximately 40% of the water utilized by the Gordon Power Station originates from Lake Pedder, flowing through McPartlan Canal into Lake Gordon before being discharged via the Gordon Dam.
The Edgar Dam consists of an earth core embankment designed to retain a volume of water at maximum storage. The dam reaches a height of and extends for in length. Its reservoir spans a surface area of , with a catchment area covering . It is important to note that this dam does not incorporate a spillway.
The dam derives its name from the now-submerged Lake Edgar.
Lake Edgar Fault
The Lake Edgar Fault is a north–south trending geological scarp located within Southwest National Park that shapes local water systems by creating a fault-bounded basin where Lake Edgar formed. In 2001, a seismic event measuring 3.2 on the Richter scale occurred near this fault adjacent to Edgar Dam, resulting in minimal impact.
In 2002, evaluations conducted by Hydro Tasmania’s dam safety manager together with a geophysicist from the University of Tasmania concluded that the probability of earthquake-induced failure at Edgar Dam is extremely low, confirming its structural integrity despite its proximity to an active fault line.
See also
Further reading
- Reid, Vern (1976) Edgar Dam Black and white photograph located between pages 248 and 249 (not indexed) in the Tasmanian Year Book No.10 1976. Australian Bureau of Statistics Tasmanian Office ISSN 0082-2116