Thursday, October 2, 2008

Snowy Mountains Scheme

The Snowy Mountains Scheme, one of the largest engineering and construction projects in the world, extends over 2,700 square miles (7,000 square kilometers) in Australia’s Snowy Mountain Range. The “Snowies,” as they are known, form part of the Australian Alps, a southern extension of the Great Dividing Range that stretches parallel to the east coast from northeastern Queensland to Victoria. The highest peaks reach about 7,250 feet (2,300 meters). The government-financed scheme is complex but conceptually straightforward. Aqueducts and dams collect melted snow and rainwater from the upper reaches of the Snowy River and its tributary the Eucumbene, store it in reservoirs, and then divert it westward via underground tunnels. On the way, it falls 2,625 feet (800 meters) and passes through a series of power stations that generate 3,740 megawatts of electricity—approximately 16 percent of the generating capacity of southeast Australia—for the Australian Capital Territory, New South Wales, and Victoria. The water is finally released to augment irrigation along the vast inland Murrumbidgee-Murray River system for use by New South Wales, Victoria, and South Australia. The Snowy Mountains Scheme, begun in October 1949 and completed on time and under budget in 1972, involved the construction of 16 dams, 7 hydroelectric power stations, about 90 miles (145 kilometers) of tunnels, and 50 miles (80 kilometers) of aqueducts. The capital cost was $A820 million. In 1967 the American Society of Engineers listed it among the seven engineering wonders of the modern world. Thirty years later, the American Society of Civil Engineers recognized the scheme as an International Historical Civil Engineering Landmark, ranked with the Panama Canal and the Eiffel Tower.

As early as 1884 there were proposals for using the Snowy’s waters to supplement the inland rivers and relieve frequent drought conditions. In the early twentieth century, when Canberra was chosen for the site of the national capital, the river’s potential for hydroelectric power production was also considered. After protracted negotiations between the federal government and New South Wales and Victoria, in 1947 a joint federal-states technical committee was established to investigate the latent economic value of the Snowy River. The Snowy Mountains Hydroelectric Power Act was passed two years later, and an agency was created to investigate, design, and construct the Snowy Mountains Scheme.

There were not enough workers in Australia to achieve the task, so the Snowy Mountains Authority recruited migrant workers from over thirty countries. They made up nearly 70 percent of the 100,000 people engaged on the scheme during the entire construction period; the size of the workforce peaked at 7,500 in 1969. Belgian, British, French, Italian, Japanese, Norwegian, Swiss, and U.S. companies were contracted for parts of the work, as engineering technology was imported from international centers of specialized engineering excellence. In all, about forty major contracting firms and many smaller companies built the Snowy Mountains Scheme.

The Guthega Dam and Power Station was the first stage of the project. Built by Norwegian contractors between 1951 and 1954, Guthega Power Station became operational in April 1955. The scheme’s biggest reservoir, Lake Eucumbene (with nine times the volume of Sydney Harbour), feeds the two main sections of the scheme, the Snowy-Tumut Development and the Snowy-Murray Development, through underground tunnels. Construction began on the Tumut project in 1954 and lasted until 1973. The water it diverts to the Murrumbidgee River flows via tunnels to Tumut 1 and Tumut 2 underground power stations and to Tumut 3, the largest station in the system. The Murray project, which sends water to the Murray River, was commenced in 1961. Dams and tunnels were built at Jindabyne and Island Bend. The Murray project comprises Geehi Dam, Murray 1 and Murray 2 Dams and Power Stations, Khancoban Dam, and a pumping station at Jindabyne. To construct and operate the scheme, about 500 miles (800 kilometers) of new roads were built, and nearly 190 miles (300 kilometers) of existing public roads were widened and improved.

New engineering practices were developed during construction. Rock bolting was used to strengthen the walls of the subterranean tunnels and power stations in the Tumut project. The Snowy Scheme was among the first enterprises to use computers for engineering design. Other gains included an increased knowledge of rock mechanics, advances in concrete and cement technology, improved quality of steel manufacture and welding techniques, improved diamond-drilling techniques, and advanced corrosion-protection paint systems. Workers set and reset records for hard-rock tunneling.

The Snowy Mountains Scheme also saw sweeping changes that improved the performance of the Australian construction industry: an internal supervisor training program, recognition of the workers’ role, and improvements to working conditions and industrial relations. But there were social and personal costs as well: some farms and grazing lands were acquired and flooded by new lakes and reservoirs, and the mountain townships of Adaminaby and Jindabyne were moved to new sites. Although the scheme had a relatively excellent safety record and despite major efforts to provide safe working conditions, 121 men died building it. In 1981 a memorial was dedicated to these men in the town of Cooma.

Since 1991 a systematic multimillion-dollar upgrade of the turbines, generators, and pumps has been in progress, and a new integrated control system has been installed. The Snowy Mountains Hydro Electric Authority, based at Cooma, is presently (2001) responsible for maintenance of the huge network on behalf of the Snowy Mountains Council, formed in 1958 to direct the scheme. Plans are in hand to corporatize the authority, after which the council and the scheme will be managed by a new corporation, Snowy Hydro Limited.

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