Lake Margaret Power Station

Lake Margaret Power Stations
Company type	Hydroelectric power stations
Industry	Energy
Founded	1911
Founder	Mount Lyell Mining and Railway Company
Headquarters	Western Tasmania, Australia
Products	Electricity generation (hydroelectric)
Owner	Hydro Tasmania
Website	https://web.archive.org/web/20060819111901/http://www.hydro.com.au/home/Energy/Cultural%2BHeritage/Conservation%2BManagement%2BPlans.htm

The Lake Margaret Power Stations comprise two hydroelectric plants situated in Western Tasmania, Australia, and form an integral part of the King–Yolande Power Scheme. These facilities are owned and managed by Hydro Tasmania and include the Upper Lake Margaret Power Station, a traditional hydroelectric installation, alongside the Lower Lake Margaret Power Station, a smaller-scale mini-hydro plant, positioned approximately apart.

Erected by the Mount Lyell Mining and Railway Company between 1911 and 1914, the Upper Lake Margaret station incorporates a concrete dam, pipeline infrastructure, powerhouse, transmission lines, and machinery overseen by Chief Mechanical Engineer George W. Wright. Ownership transferred to the Tasmanian Hydro-Electric Commission in 1984. The station was taken offline in 2006 but resumed operation in 2009 following an extensive multimillion-dollar upgrade.

The Lower Lake Margaret Power Station was constructed in 1931 by the same company and ceased operations in 1995. It was brought back online in 2010 after a mini-hydro initiative launched in 2009. Together, these stations play a vital role in Hydro Tasmania’s renewable energy assets.

Technical details

As components of the King–Yolande scheme, which consists of three hydroelectric stations, the Lake Margaret Power Stations harness water from Lake Margaret, which was dammed in 1914 to enhance storage capacity and hydraulic head. A notable element is a 2.2 km woodstave pipeline that connects the dam to a steel penstock supplying water to the power station. In 2009, this pipeline was replaced with one made from Alaskan Yellow Cedar, succeeding the original 1937 King Billy Pine construction.

Following its recommissioning by Hydro Tasmania in 2009, the upper power station operates six Boving Pelton turbines rated at 1.2 MW each, alongside one James Gordon Pelton turbine also rated at 1.2 MW, delivering a combined output of 8.4 MW. These turbines were installed between 1914 and 1930 and are linked to open wheel generators equipped with motorised inlet valves and dedicated circuit breakers. The facility produces roughly 48 GWh annually.

The lower power station, reactivated in 2010, is equipped with a three-jet Turgo turbine generating up to 3.2 MW. Water flows through a 1.9 km woodstave pipeline followed by a 254 m Fibre Reinforced Plastic penstock before reaching the turbine. Its yearly generation is approximately 21 GWh.

History

In 1911, the Mount Lyell Mining and Railway Company aimed to expand electrical supply for its Queenstown smelting operations, selecting Lake Margaret on Mount Sedgwick as the source catchment.

Construction commenced that year on a dam that elevated the lake’s level by six meters. Water was transported via a 2.2 km woodstave pipeline constructed by the Australian Woodpipe Company. Although native King Billy Pine was initially considered for pipeline construction, inconsistent wood density led to its rejection; instead, Oregon Pine (Douglas Fir) imported from Canada was used. The timber arrived at Strahan before being transported via the Abt Railway to Lake Margaret.

The original pipeline suffered rapid deterioration and was replaced in 1938 with a locally sourced King Billy Pine woodstave pipeline that remained operational until the scheme’s closure in 2006.

This woodstave pipeline fed into two steel penstocks measuring 29 inches in diameter that descended 330 meters to the power station located in Yolande Valley. A second penstock was added in 1919; both were replaced in 1969 by a single steel pipe of 48 inches diameter installed by John Holland. This upgrade coincided with major refurbishments including transmission line replacements and post-stressing of the dam wall.

The Lower Lake Margaret Power Scheme was commissioned downstream of the main station in 1931, utilizing water previously passed through the upper turbines. It contained a single Boving-Francis turbine that could be remotely operated from the main station—an innovative feature within Tasmanian power generation at that time. The lower scheme was deactivated during the early 1990s.

Closure

The facility generated a maximum output of 8.4 MW from seven Pelton turbine units, with an average production of approximately 5.5 MW, constrained by the variability of rainfall. Initially, four turbines were commissioned in 1914, followed by the addition of two more in 1919, and a final unit installed in 1930.

By 2005, the power station remained fully functional but was subject to ongoing discussions. The Lake Margaret Precinct and Power Station were put forward for state heritage recognition, reflecting their distinctive contribution to the history of the West Coast, setting them apart from many other decommissioned industrial sites.

The station ceased operations on 30 June 2006 due to escalating maintenance expenses and the degradation of the King Billy Pine pipeline. At the time of shutdown, five turbines were operating at full load, one was inactive because of insufficient water pressure, and another was offline for maintenance involving turbine bucket replacement.

Upon closure, the pipeline was experiencing a leakage rate near 10%. By early 2007, this leakage had caused Lake Margaret’s water level to drop by roughly 10% during periods of low rainfall, although the pipeline system remained pressurized despite the plant no longer being in service.

Hydro Tasmania suggested a refurbishment plan aiming to restart operations around 2009–10. Community input strongly supported upgrading the existing turbines and replacing the pipeline with a new wood stave design rather than installing new turbines or steel piping.

The refurbishment was expected to incorporate automatic shutdown mechanisms to eliminate the need for continuous on-site staffing, aligning with Tasmania’s long-standing practice since the 1950s of operating hydroelectric stations remotely or retrofitting them for unmanned control.

Back to Lake Margaret Day

On 18 March 2007, Hydro Tasmania organized 'Back to Lake Margaret Day' at the hydroelectric site. This occasion welcomed former inhabitants and workers to revisit the mothballed power station along with two cottages dating back to around 1914.

Historic photographs were displayed in the village hall, where visitors shared memories and experiences from their time at Lake Margaret. The event coincided with the Mount Lyell Twenty-Five Year Reunion Dinner held in Queenstown, drawing numerous former employees connected with Lake Margaret. Attendance reached approximately 200 individuals.

Reopening

In June 2008, a decision was reached to reinstate the Lake Margaret Power Station’s operational status. Following advocacy from community members and stakeholders, restoration work proceeded, leading to reopening in 2009. This process involved reconstructing the 2.2 km wood stave penstock feeding the Upper Power Station. The upper facility resumed generation on 12 November 2009, with the lower station recommencing operations on 23 July 2010.

2014 Queenstown Heritage and Arts Festival

During October 2014, the Queenstown Heritage and Arts Festival (currently known as The Unconformity) showcased a series of events and artistic displays within the Lake Margaret precinct, emphasizing its cultural heritage and historical importance.

Engineering heritage award

The hydroelectric scheme was honored with a Historic Engineering Marker by Engineers Australia through its Engineering Heritage Recognition Program, recognizing both its technical achievements and historical significance.

External links

https://web.archive.org/web/20060819111901/http://www.hydro.com.au/home/Energy/Cultural%2BHeritage/Conservation%2BManagement%2BPlans.htm