Gain From Lake Raising ‘Small’

Press, Volume CX, Issue 32379, 19 August 1970, Page 1

Gain From Lake Raising ‘Small’

(Hew Zealand Preu Aesoeiatlon)

WELLINGTON, August 18. The increase in power to be gained by raising Lake Manapouri was so small compared with New Zealand’s projected power expansion that it was hard to see why anyone should regard it as vital, the Commission of Inquiry was told today by Professor J. N. Dodd, Beverley professor of physics at Otago University.

He was presenting a submission for the Otago branch of the Royal Society. Equivalent power and energy could be developed by advancing all projected development by a few months, Professor Dodd said. The long-term value to New Zealand of increased electrical generating ability achieved by raising the lake was in the extra 250 gigawatt hours a year of energy rather than in the provision of extra peak power capacity, he said. It was important to remember that this 250 gigawatt hours was only part of the total which would have to be created in the future, and less than 2 per cent of that projected to be installed in the next 10 years. The extra cost to New Zealand of supplying 250 gigawatt hours from other schemes was about sl.2m a year.

A decision not to provide this by raising Manapouri would mean that other power schemes would have to be brought forward, not built as an alternative, he said.

Professor Dodd submitted that 250 gigawatt hours could be obtained by advancing by about two months schemes already projected. The value to New Zealand of keeping Manapouri and Te Anau in their natural state might be even greater than the costs of these schemes, he said. In the Cabinet committee report, visitor flow to the area in 1978-79 was estimated at 147,000. “If one-tenth of these are overseas tourists who are persuaded to stay an extra day because of the accessibility and unparalleled beauty of the area, New Zealand would gain by about $300,000. “The figure was based on the supposition that each tourist would spend $2O a day,” Professor Dodd submitted. He maintained that overseas people would stay If the area were accessible and beautiful, but would not extend their stay to see a power scheme. The annual cost to the country of keeping a natural level for Lake Manapouri was a decreasing cost relative to the population of New Zealand.