TONGARIRO POWER SCHEME APPROVED

Press, Volume CIII, Issue 30398, 24 March 1964, Page 1

TONGARIRO POWER SCHEME APPROVED

Cheaper Electricity For North Island (New Zealand Press Association) WELLINGTON, March 23. The Tongariro power development scheme has been approved in principle by the Government, subject to its being satisfied that suitable arrangements can be made to preserve the interests of parties which would be adversely affected by the scheme.

This was announced tonight by the Minister of Electricity (Mr Shand).

The complete development would provide about 2300 million units of electricity—roughly the amount generated in the South Island in the year 1962-63.

He said the combined report of the Electricity Department and the Ministry of Works said power developed from the Tongariro scheme would be available more cheaply than power from any other scheme remaining to be developed in the North Island and, after allowing for transmission costs, from any future South Island scheme.

The possible exception was the Wanganui river scheme, investigations of which could not be completed until the end of this year. Mr Shand said the Tongariro scheme was of a type new to New Zealand as all previous hydro-electric schemes had been straightforward projects involving the use of the water of one stream only. The Tongariro scheme, which would be developed in stages, involved collecting water from a number of streams and passing it down through the existing series of power stations on the Waikata river. Flood Levels Mr Shand said flood levels on the Waikato river would not be affected but the expected rise of four inches in the Waikato under low flow conditions would add seriously to the drainage problems of the lower reaches. ‘The estimated cost of the projects allows for the cost of dealing with these problems but before the Government gives final approval of the scheme one of the immediate tasks is to negotiate with the Waikato Valley Authority,” said Mr Shand. '

He said serious problems also arose for the people of Taumarunui, possibly affecting their power supply, their water supply and their sewerage.

This too had been allowed for and must be a matter for negotiation with the people of the area so that the Government might be assured that their interests were properly safeguarded. Mr Shand said the likely effect upon Wanganui Harbour of the reduction of 8 to 10 per cent in the mean flow of the Wanganui river was exhaustively investigated by Sir Alexander Gibb and Partners who reported that this did not pose any insoluable problem. Effect on Fishing

“People interested in the tourist industry of New Zealand, fishermen in particular, will be anxious to know the effect upon the fishing resources in the area, particularly in the Tongariro river. ‘The proposal allows for a continued flow in the Tongariro river which expert advisers assure us will be adequate to maintain the present excellent fishing and the level of Lake Rotoaira will not be substantially affected.”

Mr Shand said the scheme involved, in addition, the creation of several new lakes each of which it was hoped would contribute to the available fishing spots. Waters of the Whangaehu which had poisonous qualities would not be used. He said the detailed investigations by Sir Alexander Gibb and Partners, a British firm of consultants, extended over a number of years. Their findings were considered by the planning committee on electric power development which recommended in its 1963 report that the first three stages of the proposed development should be included in the power construction programme. River Diversion

The first stage of development involved the diversion of water from some of the tributaries of the Wanganui River into Lake Rotoaira and thence into Lake Taupo thereby increasing the amount of energy which could be produced by the existing station on the Waikato River.

“In the second stage a power station at Tokaanu will

utilise the 680 feet head of water available between Lake Rotoaira and Lake Taupo,” Mr Shand said.

The third stage visualised the diversion of the headwaters of the Moawhanga river (a tributary of the Rangitikei) and several spring fed tributaries of the Whangaehu river (which are not contaminated by water from the Whangaehu itself) into the Tongariro river and thence into Lake Rotoaira, except for the flow maintained in the Tongariro for fishing purposes.

Mr Shand said this additional water into Lake Rotoaira would permit increased generation at Tokaanu station and at all stations down the Waikato river.

Later stages provided for the building of power stations to be known as Rangipo and Kaimanawa, on the Tongariro river above the point where the river would be delivered into Lake Rotoaira.