A massive project

Press, 19 May 1981, Page 32

A massive project

Few New Zealanders. are aware of the magnitude or significance of the Upper Waitaki Power Development. Situated in the remote Mackenzie Basin in the shadow of the Southern Alps, it is largely hidden from the public eye, yet it is currently New' Zealand’s largest hydro.

■ scheme — large even by world standards. It is an ambitious project, linking Lakes Tekapo, : Pukaki and Ohau by a series of canals and power stations, : to utilise the water over and over again through a chain of power stations. /Forover half a century,

hydro construction has been undertaken in the Waitaki Valley with the building of Waitaki, Benmore and Aviemore power stations. Linked with this has been the construction of Tekapo A power station, and the old Pukaki storage dam.

Some working on the Upper Waitaki have worked on projects as far back as Roxburgh, Manapouri and the Hawea storage dam. The Upper Waitaki Power Development is thus a culmination of years of experience in the hydro construction field.

The Ministry of Works and Development is the construction agent for the Ministry of Energy, and along with private contractors, has been working on the Upper Waitaki since the late 19605. The first task was construction of the township of Twizel, to house workers employed on the scheme. Hand in hand came the construction of the Tekapo canal to take water from the old Tekapo A station (25 megawatts) to the new power station on the shore of Lake Pukaki-Tekapo B (160 megawatts).

The Tekapo canal, completed in 1977, is 25 kilometres long. The Pukaki high dam was constructed, raising Lake Pukaki 37 metres to provide water for the Pukaki canal, and additional storage for the Benmore, Aviemore and Waitaki stations.

An 8.75 kilometre canal from Lake Ohau joins with the 12.2 kilometre Pukaki canal to feed the largest power station on the scheme,

Ohau A (264 megawatts) which is completed' and operating. Ohau A currently discharges into the old Ohau riverbed, area soon to be converted into a lake with the completion of the Ruataniwha earthdam about this time next year. The water at present is diverted through the concrete Ruataniwha spilway while the earthdam is being constructed. A 2.8 kilometre canal takes the water from Lake Ruataniwha to the Ohau B power station (212 megawatts). This station is scheduled to produce first power around this time in 1982.

To complete the scheme, a further 7.3 kilometre canal will take the water to Ohau C (212 megawatts) before discharging into Lake Benmore.

Construction of the project by the Ministry of Works is a large undertaking, and involves an equally large undertaking from the private sector both in indirect involvement on the job, and in the service industries — indicative in the selection of industries featured here.

The Ministry of Works is proud of its achievements and New Zealand should be proud to know it has the expertise, equipment and manpower to complete this scheme.