Snowy Mountains Scheme

From Wikipedia, the free encyclopedia

Talbingo Dam

The Snowy Mountains Scheme is a hydroelectricity and irrigation complex in south-east Australia. The waters of the Snowy River and its tributary, the Eucumbene, are captured at high elevations and diverted inland to the Murray River and the Murrumbidgee River, through two tunnel systems driven through the Snowy Mountains. The water falls 800 metres and travels through large hydro-electric power stations which generate peak-load power for the Australian Capital Territory, New South Wales and Victoria.^[1]^[2]

The Scheme was completed by 1974, after twenty-five years of construction, and is the largest engineering project undertaken in Australia.^[1]^[3] The Scheme's construction is seen by many "as a defining point in Australia's history, and an important symbol of Australia's identity as an independent, multicultural and resourceful country."^[4]

1 Background
2 Snowy Mountains Hydro-Electric Scheme
3 Environmental concerns
4 Power stations
5 Recent developments
6 References
7 External links

[edit] Background

The Snowy Mountains Hydro-electric Power Act of 1949 gave the Snowy Mountains Hydro-electric Authority the responsibility for the final evaluation, design and construction of the Snowy Mountains Scheme. The plan was to divert the Snowy River to provide increased electricity generating capacity and to provide irrigation water for the dry west. It was "greeted with enthusiasm by the people of Australia" and was seen to be "a milestone towards full national development". In April 1966 the first diversion of water was made from the Snowy River to the Murray River.

[edit] Snowy Mountains Hydro-Electric Scheme

The associated Snowy Mountains Hydro-Electric Scheme, is one of the most complex integrated water and hydro-electric power schemes in the world and is listed as a "world-class civil engineering project" by the American Society of Civil Engineers.^[5] The scheme interlocks seven power stations and 16 major dams through 145 kilometres of trans-mountain tunnels and 80 kilometres of aqueducts. The scheme virtually reverses the flow of the Snowy River from its natural course toward the ocean and directs it inland. The Scheme is in an area of 5,124 square kilometres, almost entirely within the Kosciuszko National Park. The design of the scheme was modelled on the Tennessee Valley Authority.^[5]

Tumut 3 generating station.

The Scheme was managed by the Snowy Mountains Hydro-Electric Authority, now called Snowy Hydro Limited, and took 25 years to build, from 1949 to 1974,^[5] at the historical cost of AUD$800 million, a dollar value equivalent in 1999 and 2004 to AUD$6 bn.^[6] ^[7] It employed over 100,000 people from over 30 countries in its construction, providing valuable employment for a large number of recently arrived immigrants, and was important in Australia's post-war economic and social development. The Scheme built several temporary towns for its construction workers, several of which have become permanent: Cabramurra (the highest town in Australia); and Khancoban. Additionally, the economy of Cooma has been sustained by the Scheme.^{[citation needed]}

The Scheme is the largest renewable energy generator in mainland Australia and plays an important role in the operation of the national electricity market, generating approximately 3.5% of the mainland grid's power. The Scheme also has a significant role in providing security of water flows to the Murray-Darling Basin. The Scheme provides approximately 2,100 gigalitres of water a year to the Basin, providing additional water for an irrigated agriculture industry worth about $5 bn per annum, representing more than 40% of the gross value of the nation's agricultural production.^{[citation needed]}

[edit] Environmental concerns

The original plan was for 99% of the water of the Snowy River's natural flow to be diverted by the Scheme below Lake Jindabyne. Releases from the Scheme were only based on the needs of riparian users and took no account of ecosystem needs; it soon became known that the lower reaches of the river were in environmental crisis. An extensive public campaign led to the Snowy Water Inquiry being established in January 1998. The Inquiry reported to the New South Wales and Victorian Governments in October of that year, recommending an increase to 15% of natural flows. The two Governments were equivocal about this target; aside from economic considerations there was a view that the health of the Murray is more important than that of the Snowy and any extra environmental flows are better used there instead.^{[citation needed]}

In 1999 the seat of East Gippsland was won in the Victorian election by an independent, Craig Ingram, based in large part on his campaign to improve Snowy flows. In 2000, Victoria and NSW agreed to a long-term target of 28%, requiring $375 million of investment to offset losses to inland irrigators. In August 2002 flows were increased to 6%, with a target of 21% within 10 years.^{[citation needed]}

A major spillway upgrade is being constructed to facilitate these flows. site plan

[edit] Power stations

As of 2006 there were seven power stations. These are in alphabetical order :

Blowering which was completed in 1967
Guthega which was completed in 1954
Murray 1 which was completed in 1967
Murray 2 which was completed in 1969
Tumut 1 which was completed in 1958
Tumut 2 which was completed in 1961
Tumut 3 which was completed in 1974

[edit] Recent developments

In late 2005 there was a proposal by the federal and state governments to sell their shares in Snowy Hydro Limited. The proposal was abandoned in 2006.^[8]

In 2007, due to the recent drought in Australia, water levels in the scheme were their lowest on record.^[9]. Credit rating agency Moodys downgraded Snowy Hydro's outlook from stable to negative in the same month.