Flood Areas Not Known

Press, Volume CIX, Issue 32219, 11 February 1970, Page 14

Flood Areas Not Known

<N.Z. Press Association)

WELLINGTON 10. | The Ministry of Work’s chief power en-j (gineer, Wellington (Mr R. F. D. Ritchie) said( tonight it would not be possible to say on the basis of survey data presently available exactly what areas would be flooded if Lake Manapouri were raised any given amount.

He emphasised, however, that “a fairly good idea” could be obtained from M.O.W. aerial surveys of the area.

He said he could not comment on claims by Dr J. C. Burrows, senior lecturer in botany at the University of Canterbury, that there were inaccuracies on a M.O.W. map of the area because he did not know to which map Burrows was referring. Dr Burrows, recently back from Lake Manapouri, said yesterday he had found a number of inaccuracies in a map indicating the area to be flooded. The area flooded if the lake was raised to generate more electricity could be nearly double that estimated by the Electricity Department Dr Burrows said. “I would not be surprised if there are some inaccuracies in some of our maps at some points,” Mr Ritchie Said. The Manapouri area, he said, had never been mapped in great detail. If it was decided to dear the bush from the edges of the lake one of the first jobs that would have to be done was ground sur vey.

“At present we only have aerial surveys of this area,” he said. “In bush country these are never as accurate in

determining levels as in clear i: country.” There were no plans for a; ground survey of Manapouri!: in the immediate future. Such 1 a survey would be an arduous undertaking and would not be started until the M.O.W knew exactly what was reI quired.

Such purveys were not made in detail unless the area in question was to be used for a major public work or project. A very detailed

i survey of West Arm, for instance, had been made. It would be a relatively | simple matter to find out at any particular point in the lake where the lake level would come to in relation to a particular beach or village. “But there is over 100 miles of shoreline at Lake Manapouri and this would take a pretty extensive survey,” he said. “We don’t undertake that kind of task until it is required.’*