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Manapouri Raising Impossible

Survey Says Dam can not be built

Lake Manapouri will not be raised. The Government's Parliamentary Select Committee to consider the Save Manapouri Petition is due to report next week. It now seems almost certain to recommend that Lake Manapouri be kept at its present level because of the effect that raising it would have on the ecology of the region.

Sources close to the committee predict that the Committee's report will recommend in similar terms to the Nature Conservation Council's submissions.

It is unlikely that the Committee's report will even mention the real reason for the Government's decision to not raise the lake — that the high dam required can not be constructed in a volley filled with over 700 feet of alluvial gravel.

So Lake Manapouri has been saved! Not by any conservation or ecology minded Government decision, but by the geology of the Waiau Valley, where the Ministry of Works and the New Zealand Electricity Department had hoped to build the high dam which would have raised Lake Manapouri by 27 ft.

In January, Salient photographer Alan Browne, visited the site of the proposed dam, just south of where the Mararoa River meets the Waiau River. Here the M.O.W. have already constructed a stone weir as a preliminary stage to establishing complete control of the Waiau River and the level of Lake Manapouri. Behind one of about 30 worker's huts already on the site, was a large sign saying "Mararoa Dam Site".

Obviously the M.O.W. intended constructing a dam there, provided the geological survey found that it Was possible. It didn't informed sources at Manapouri said that the survey dulls, operated by a private firm under contract to the M.O.W. had been down to a depth of 700 ft. without finding any solid base on which a high dam could be built.

A similar situation exists at the outflow of Lake Te Anau, where excavations have already been made, the site of another construction to control the level of Lake Te Anau.

This leaves the Government with a face-saving way out of a difficult situation. Now it can tell the people that it is taking note of then concern for ecology and conservation, and is not going to allow Lake Manapouri to be drowned, and thus win back some badly needed popularity.

At the same time it is allowing the people to believe that it believes in conservation of the environment, it can tell Comalco and the N.Z.E.D. the truth — that raising Manapouri is impossible and that the extra 8% more power that would have been the result of raising the lake will now Have to be generated elsewhere.