Australian
Screen

Teacher’s notes

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This clip shows the construction of the Talbingo Reservoir, a rockfill dam that is part of the Snowy Mountains Hydro-electric Scheme. It shows the tunnel that diverted river water from the dam site, enabling the site to be cleared of unsuitable materials. The clip also illustrates how explosives were used to excavate the 'spillway’ and 'headrace channels’ for the dam; the explosives were packed into 50-foot (15-m) holes prior to detonation. The narrator explains that the excavated earth and rock was then hauled to the dam site for placement.

Educational value points

• The Snowy Mountains Scheme, part of which is documented here, was built between 1949 and 1974. The integrated water and hydro-electric power project was a major post-Second World War construction and engineering feat, consisting of 16 large dams, seven power stations and a pumping station. To divert water from the Snowy Mountains for use in power generation and irrigation, 145 km of tunnels and 80 km of aqueducts were constructed. The Scheme cost $820 million.

• The rockfill dam of the Talbingo Reservoir is made up of earth and rock placed in layers and then compacted. The rockfill came from the excavation of the dam’s spillway, the passage through which excess water escapes from the dam, and a headrace channel that fed water to a turbine in a power station to produce electricity. At 162 m, Talbingo is the tallest dam on the Scheme and was completed in 1972.

• The clip shows a diversion tunnel in the Snowy Mountains Scheme. Before Talbingo Reservoir was constructed, this particular tunnel diverted water from the dam site so that unwanted material such as roots, stumps, sods, topsoil and trash could be cleared from the dam’s foundations.

• Modern machinery and vehicles were essential to the Scheme. The construction of rockfill dams, such as the Talbingo Reservoir, was made possible by the availability of heavy moving equipment. At the time it was constructed, the Scheme was the largest single engineering project ever undertaken in Australia and it required a huge stock of modern heavy plant equipment and vehicles.

• Although the Scheme was an Australian Government venture run by the Snowy Mountains Hydro-electric Authority (SMA), most of the construction was carried out by public works departments and private firms from Australia and overseas. The projects, which were tendered, included the construction of dams, tunnels, pressure pipelines, power stations, turbines and generators, and transmission lines on the Scheme. The Talbingo Reservoir was built by Theiss Brothers, an Australian company.

• The clip reveals a basic adherence to industrial safety, the SMA having made wearing safety helmets mandatory in the 1960s. However, the clip also shows that workers have no ear or eye protection or obvious protection from the sun, and when the blast goes off, they simply cover their ears with their hands. The SMA developed safety guidelines for contractors, but tight deadlines meant that work sometimes continued around the clock and that people worked long shifts, which compromised their safety. About 121 men working on the Scheme died during the course of the project.

• As demonstrated by the clip, the Scheme has had serious environmental consequences for local ecosystems. The entire project spans an area of 5,124 sq km, most of which is in the Kosciuszko National Park in New South Wales. After construction was completed, the SMA undertook erosion control and rehabilitated construction sites by planting non-native grasses, willows and poplars to prevent land slippage. Today, the SMA is reintroducing native plant species.

• The clip comes from a film made to promote the Scheme. The SMA had initiated a concerted public relations campaign, including films such as this one, to explain the complexities of the Scheme and promote its benefits in response to some media opposition to the Scheme and to public concern about its vast cost.