Rowallan Dam

Rowallan Dam
Rowallan Dam is located in Tasmania
Rowallan Dam
Rowallan Dam
Location of the dam in Tasmania
Interactive map of Rowallan Dam
CountryAustralia
LocationNorthern Tasmania
Coordinates41°43′51″S 146°12′55″E / 41.73081°S 146.215357°E / -41.73081; 146.215357
PurposePower
StatusOperational
Construction began1963
Opening date1967
OwnerHydro Tasmania
Dam and spillways
Type of damRock-fill dam
ImpoundsMersey River
Height43 m (141 ft)
Length579 m (1,900 ft)
Dam volume497×10^3 m3 (17.6×10^6 cu ft)
Spillways1
Spillway typeUncontrolled
Spillway capacity665 m3/s (23,500 cu ft/s)
Reservoir
CreatesLake Rowallan
Total capacity130.49 GL (105,790 acre⋅ft)
Active capacity121 GL (98,000 acre⋅ft)
Catchment area345 km2 (133 sq mi)
Surface area886 ha (2,190 acres)
Normal elevation480 m (1,570 ft) AHD
Rowallan Power Station
OperatorHydro Tasmania
Commission date1968
TypeRun-of-the-river
Hydraulic head49 m (161 ft)
Turbines1 x 10.5 MW (14,100 hp)
(Maier Francis-type)
Installed capacity10.5 MW (14,100 hp)
Capacity factor0.95
Annual generation45 GWh (160 TJ)
Website
hydro.com.au

The Rowallan Dam is an earthen-faced rockfill embankment dam across the Mersey River, 25 kilometres (16 mi) south of Liena, in the northern region of Tasmania, Australia. Completed in 1967, the resultant reservoir, Lake Rowallan, was established for the purpose of generating hydro-electric power via the Rowallan Power Station, a run-of-the-river hydroelectric power station.

The dam, its reservoir, and the power station are owned and operated by Hydro Tasmania.

Dam and reservoir overview

The Rowallan Dam comprises two earth and rockfill embankments either side of a free overflow reinforced concrete spillway. The dam wall is 43 metres (141 ft) high and 579 metres (1,900 ft) long. When full, Lake Rowallan has capacity of 130.49 gigalitres (105,790 acre⋅ft) and covers 886 hectares (2,190 acres), drawn from a catchment area of 345 square kilometres (133 sq mi). The single uncontrolled spillway is capable of discharging 665 cubic metres per second (23,500 cu ft/s).

In 2010, it was reported that the embankment was leaking; and in 2013, that the dam wall was moving. Repairs to stabilise the spillway were completed during 2012 and 2013; and rebuilding of the top seven metres (twenty-three feet) of the embankment occurred during 2015.

Reservoir

The associated Lake Rowallan is 11 kilometres (6.8 mi) long with a surface area of 9 square kilometres (3.5 sq mi), is 488 metres (1,601 ft) AHD and is bordered by Clumner Bluff and Howells Bluff. The reservoir is managed by the Tasmanian Inland Fisheries Service as a trout fishery; and is stocked with both brown and rainbow trout; there are also native climbing galaxias, spotted galaxias and river blackfish. Lake Rowallan is also the starting point for walks into nearby highland areas including the Walls of Jerusalem National Park.

Hydroelectric power station

The Rowallan Power Station is part of the Mersey–Forth scheme that comprises seven run-of-the-river hydroelectric power stations and one mini-hydro power station. The first station in the scheme, the Rowallan Power Station is located in the river's upper reaches, approximately 200 metres (660 ft) downstream of Rowallan Dam, which forms Lake Rowallan. The dam is one of the two main headwater storages in the Mersey—Forth scheme and assists in regulating the water supply to four downstream power stations.

The power station was commissioned in 1971 by the Hydro Electric Corporation (TAS) and the station has one Maier Francis-type turbine, with a generating capacity of 10.5 megawatts (14,100 hp). The station output, estimated to be 45 gigawatt-hours (160 TJ) annually, is fed to TasNetworks' transmission grid via a 22 kV/110 kV transmission line to the switchyard transformer. Following use in the power station, water is returned to Lake Parangana.

An upgrade of the power station occurred during 2023 and 2024. Between 2021 and 2024, Hydro Tasmania was granted an exploration licence to assess the possibility of installing a pumped-storage plant near the existing conventional power station. The pumped-storage project did not proceed.

Etymology

The dam, power station, and lake are named in honour of Thomas Corbett, 2nd Baron Rowallan, the former Governor of Tasmania.

See also

References

  1. 1 2 3 "Register of Large Dams Australia-2015" (Excel. Requires download. Row 434). ANCOLD. January 2022. Retrieved 5 March 2026.
  2. ↑ Ricketts, Andrew (21 March 2010). "Rowallan Dam fears: Is it being kept secret?". Tasmanian Times. Retrieved 30 April 2026.
  3. ↑ "The Hydro after 100 Years" (PDF). EHA Magazine. March 2015. p. 19. Archived from the original (PDF) on 21 August 2022.
  4. ↑ Bryan, Selina (24 April 2013). "Moving walls prompt remedial work". ABC News. Australia. Retrieved 30 April 2026.
  5. ↑ Daws, Brian (3 October 2013). "TAS – Rowallan Dam". ANCOLD. Retrieved 30 April 2026.
  6. ↑ Topham, Chris (30 June 2015). "TAS – ANCOLD Study Tour to Rowallan Dam". ANCOLD. Retrieved 30 April 2026.
  7. ↑ "Rowallan Dam receives upgrade". Engineers Australia. 20 May 2015. Retrieved 30 April 2026.
  8. ↑ McIntyre, Damian (17 April 2015). "Rowallan dam to last another 150 years after multi-million-dollar upgrade". ABC News. Australia. Retrieved 30 April 2026.
  9. 1 2 "2006 Legislative Council elections—dates announced" (PDF) (Press release). Tasmanian Electoral Commission. 23 March 2006. Retrieved 3 July 2015.
  10. ↑ "Lake Rowallan". Inland Fisheries Service. Tasmanian Government. n.d. Retrieved 30 April 2026.
  11. ↑ "Lake Rowallan - Devonport & Cradle Mountain Natural Attractions". Archived from the original on 7 July 2011. Retrieved 26 February 2011.
  12. ↑ "Mersey - Forth". Energy. Hydro Tasmania. Retrieved 3 July 2015.
  13. ↑ "Rowallan Power Station: Technical fact sheet" (PDF). Mersey-Forth Catchment. Hydro Tasmania. Archived from the original (PDF) on 24 March 2012. Retrieved 3 July 2015.
  14. ↑ "Upgrading Rowallan Power Station: a testament to teamwork and innovation" (Press release). Hydro Tasmania. 24 November 2024. Retrieved 30 April 2026.
  15. ↑ "EL14/2019 Rowallan Exploration Licence– Final Report" (PDF). Hydro Tasmania. 10 August 2023. Retrieved 30 April 2026 – via Mineral Resources Tasmania.