Murchison Dam

Murchison Dam
Murchison Dam
Location of the dam in Tasmania
Interactive map of Murchison Dam
CountryAustralia
LocationWestern Tasmania
Coordinates41°46′56″S 145°38′46″E / 41.782169°S 145.646031°E / -41.782169; 145.646031
PurposePower
StatusOperational
Construction began1978 (1978)
Opening date1982 (1982)
Built byHydro-Electric Commission (TAS)
OwnerHydro Tasmania
Dam and spillways
Type of damRock-fill dam
ImpoundsMurchison River
Height (foundation)93 m (305 ft)
Length217 m (712 ft)
Dam volume910×10^3 m3 (32×10^6 cu ft)
Spillways1
Spillway typeUncontrolled
Spillway length160 m (520 ft)
Spillway capacity1,910 m3/s (67,000 cu ft/s)
Reservoir
CreatesLake Murchison
Total capacity96,910 ML (78,570 acre⋅ft)
Catchment area750 km2 (290 sq mi)
Surface area408 ha (1,010 acres)
Normal elevation222 m (728 ft)
[1][2]

The Murchison Dam is a concrete-faced rock-filled embankment dam across the Murchison River, located near Tullah, within the northern part of the West Coast Range, in the western region of Tasmania, Australia. Completed in 1982 by the Hydro-Electric Commission (TAS), the resultant reservoir, Lake Murchison, was created for the purposes of generation of hydroelectricity as part of the Pieman Power Development. In addition to impounding the Murchison River, the dam's reservoir is also fed by the George Creek, the Anthony River, and discharge from the Tribute Power Station.

The dam is owned and operated by Hydro Tasmania.

Location and features

The concrete-faced rock-filled dam wall is 93 metres (305 ft) high and 217 metres (712 ft) long. When full, the reservoir has capacity of 96,910 megalitres (78,570 acre⋅ft) and covers 408 to 450 hectares (1,010 to 1,110 acres), drawn from a catchment area of 750 square kilometres (290 sq mi). The uncontrolled spillway has a flow capacity of 1,910 cubic metres per second (67,000 cu ft/s).[1][3] The spillway is 13 metres (43 ft) wide at the base, 10 metres (33 ft) high, 160 metres (520 ft) long, and is cut into dolerite bedrock.[4]

Water from Lake Murchison is diverted to Lake Mackintosh and the Mackintosh Power Station by the 2-kilometre-long (1.2 mi) Sophia Tunnel,[5] as part of the Pieman power development that was completed in 1987.[6]

Upstream of the Murchison Dam is the White Spur Lake and dam, Henty Dam and its reservoir, Lake Newton and dam, Lake Plimsoll and Anthony Dam, and the Tribute Power Station. Downstream from the Murchison Dam is Lake Mackintosh, Tullabardine Dam, Mackintosh Dam, Mackintosh Power Station, Lake Rosebery, Bastyan Dam, Bastyan Power Station, Lake Pieman, Reece Dam and the Reece Power Station.

Hydro Tasmania completed an A$31–million upgrade of the dam wall and spillway to improve flood capacity. The crest wall was raised by 3 metres (9.8 ft), completed in 2020; and the spillway's right chute wall was raised between 2 to 5 metres (6 ft 7 in to 16 ft 5 in), completed in 2025. Given the remote location of the dam wall, access to the facility proved challenging.[4][7][8][9]

Etymology

The name of the dam is derived from the Murchison River and the adjacent Mount Murchison.

See also

References

  1. ^ a b "Register of Large Dams Australia-2015" (Excel. Requires download. Row 370). ANCOLD. January 2022. Retrieved 5 March 2026.
  2. ^ "Map of Lake Murchison, TAS". Bonzle Digital Atlas of Australia. n.d. Retrieved 21 June 2015.
  3. ^ "West Coast power stations | Pieman power scheme". Hydro Tasmania. 2026. Retrieved 21 April 2026.
  4. ^ a b "Upgrading Murchison Dam". International Water Power and Dam Construction. 5 September 2024. Retrieved 21 April 2026.
  5. ^ "The Pieman Catchment". Hydro Tasmania. Archived from the original on 4 December 2004. Retrieved 21 April 2026.
  6. ^ Project Pieman: Murchison (Map). Hydro-Electric Commission and the Dept. of Lands and Surveys (Tasmania). 1970. Sheet 51. § C. Retrieved 9 June 2015 – via Trove. National Library of Australia.
  7. ^ "$31 million upgrade for West Coast's Murchison Dam". Hydro Tasmania. 23 May 2025. Retrieved 21 April 2026.
  8. ^ "Murchison Dam Spillway Upgrade". Hazel Brothers. 2025. Retrieved 21 April 2026.
  9. ^ Giudici, Oliver (20 March 2024). "News from Tasmania – Murchison Dam Spillway Upgrade". ANCOLD. Retrieved 21 April 2026.