The Bastyan Dam is a concrete-faced rock-fill embankment dam across the Pieman River, located near Tullah, in the West Coast region of Tasmania, Australia. Completed in 1983, the resultant reservoir, Lake Rosebery, was established for the purpose of generation of hydroelectricity via the adjacent Bastyan Power Station, a conventional hydroelectric power station. The dam, its reservoir, and the power station are owned and operated by Hydro Tasmania.
| Bastyan Dam | |
|---|---|
  Bastyan Dam Location of the dam in Tasmania | |
 Interactive map of Bastyan Dam | |
| Country | Australia |
| Location | Western Tasmania |
| Coordinates | 41°44′08″S 145°32′01″E / 41.735534°S 145.533485°E |
| Purpose | Power |
| Status | Operational |
| Construction began | 1974 |
| Opening date | 1983 |
| Owner | Hydro Tasmania |
| Dam and spillways | |
| Type of dam | Rock-fill dam |
| Impounds | Pieman River |
| Height | 75 m (246 ft) |
| Length | 510 m (1,670 ft) |
| Dam volume | 570×103 m3 (20×106 cu ft) |
| Spillways | 1 |
| Spillway type | Uncontrolled |
| Spillway capacity | 2,806 m3/s (99,100 cu ft/s) |
| Reservoir | |
| Creates | Lake Rosebery |
| Total capacity | 123.52 GL (100,140 acre⋅ft) |
| Catchment area | 1,397 km2 (539 sq mi) |
| Surface area | 74.4 ha (184 acres) |
| Normal elevation | 154 m (505 ft) AHD |
| Bastyan Power Station | |
| Coordinates | 41°43′48″S 145°31′48″E / 41.73000°S 145.53000°E |
| Operator | Hydro Tasmania |
| Commission date | 1993 |
| Type | Conventional |
| Hydraulic head | 61 m (200 ft) |
| Turbines | 1 x 81 MW (109,000 hp) Fuji Francis-type |
| Installed capacity | 81 MW (109,000 hp) |
| Capacity factor | 0.85 |
| Annual generation | 405 GWh (1,460 TJ) |
| Website hydro.com.au | |
| [1] | |
Dam and reservoir overview
editThe concrete-face rockfill dam wall is 75 metres (246 ft) high and 510 metres (1,670 ft) long. When full, Lake Rosebery has capacity of 123.52 gigalitres (100,140 acre⋅ft) and covers 744 hectares (1,840 acres), drawn from a catchment area of 1,397 square kilometres (539 sq mi). The uncontrolled spillway has a flow capacity of 2,806 cubic metres per second (99,100 cu ft/s).[1]
Located adjacent to the rock-fill embankment dam is the off-stream Bastyan Levee, an earth-filled saddle embankment that is 14 metres (46 ft) high and 55 metres (180 ft) long. The levee also impounds Lake Rosebery.[1]
Reservoir
edit
Lake Rosebery is fed by both the Murchison and Mackintosh rivers and their confluence formed the Pieman River, submerged below the lake's surface following the damming in 1983.[2] At the time of the dam's construction, the Emu Bay and the Wee Georgie Wood railway lines were diverted to run close to the reservoir's shore.
In January 2025, 4,000 to 5,000 litres (880 to 1,100 imp gal; 1,100 to 1,300 US gal) of oil entered the reservoir after a tank on private property leaked in heavy rain.[3]
Hydroelectric power station
editPart of the Pieman River Power Development scheme that comprises four hydroelectric power stations, the Bastyan Power Station is the third station in the scheme. The power station is located aboveground at the foot of the dam wall. Water from the lake is fed to the power station near the centre of the dam wall by a 150-metre (490 ft) single penstock tunnel.[4]
The power station was commissioned in 1983 by the Hydro Electric Corporation (TAS) and the station has one Fuji Francis-type turbine, with a generating capacity of 81 megawatts (109,000 hp) of electricity. The station output, estimated to be 405 gigawatt-hours (1,460 TJ) annually,[1] is fed to TasNetworks' transmission grid via a 13.8 kV/220 kV Fuji generator transformer to the outdoor switchyard.[5]
The water discharged from the Bastyan Power Station is impounded by the Reece Dam into Lake Pieman for use in the Reece Power Station.
See also
edit
References
edit- 1 2 3 4 "Register of Large Dams Australia-2015" (Excel. Requires download. Rows 21-22). ANCOLD. January 2022. Retrieved 5 March 2026.
- ↑ "Map of Lake Rosebery, TAS". Bonzle Digital Atlas of Australia. Retrieved 21 June 2016.
- ↑ Powell, Sandy (25 January 2025). "Popular Tasmanian lake off-limits after oil spill but is someone to blame?". ABC News. Retrieved 25 January 2025.
- ↑ "Pieman". Energy. Hydro Tasmania. Retrieved 4 July 2015.
- ↑ "Bastyan Power Station: Technical fact sheet" (PDF). Pieman Catchment. Hydro Tasmania. Archived from the original (PDF) on 18 June 2023. Retrieved 18 June 2023.
Further reading
edit- Hepper, Marriott & Associates (1984). Lake Rosebery recreation development plan. Hobart: Hepper, Marriott. ISBN 1-86252-515-3.
External links
edit- "Pieman Sustainability Review: Information review of the Anthony-Pieman hydropower scheme" (PDF). Hydro Tasmania. February 2015. Archived (PDF) from the original on 18 June 2023. Retrieved 18 June 2023.
- "Tullah, Tasmania". Western Wilderness. West Coast Council. 2018.
- "Lake Roseberry". Inland Fisheries Service