NEW POWER STATION

New Zealand Herald, Volume LXXII, Issue 22179, 5 August 1935, Page 11

NEW POWER STATION

HORAHORA REPLACEMENT TEST SHAFTS ON RIVER BANK SITE OF FUTURE DAM [from our own correspondent] CAMBRIDGE, Saturday Tests nre at present being carried out by the Public Works Department on the Waikato Uiver, about five miles upstream from Cambridge, between Maungatautari and Karapiro, with a view to determining the possibilities of building a new power station there to replace Horahora, and to relieve the Arapuni power station from overloading. Test shafts to ascertain the nature of the river banks and the depth of solid rock from the surface are at present being sunk. Surveyors have been busy taking levels for some time past, and the vicinity of the site for the proposed new dam is marked out with surveyors' pegs. A special gang of tunnellers was sent from Arapuni last Thursday to sink the test shafts. Men are camped on both sides of the river. Of the five shafts sunk on the Karapiro (the right hand) side of the river, solid rock lias been encountered in two places at a depth of only two or three feet, and in a third instance at eight or nine feet. A fourth shaft has been sunk to a depth of eighteen feet, but the rock at this point seems to be covered by a thick layer of sand. No Immediate Development While it is not suggested that anything will be done immediately regarding the commencing of the work of building a new dam, it is evident that the department is investigating the site thoroughly, with this in view, if the locality proves suitable. The Waikato Uiver at the point selected flows through a deep winding bed, and the banks rise in terraces forming a natural basin for several miles back, which would make an ideal site for a lake similar to Arapuni Lake, without the necessity of destroying any land beyond the fern-covered river bank. The banks where the test shafts have been sunk show outcrops of hard rock, the left bank being almost vertical. Above the river on this side a quarry was recently established, but it is understood that the owners have been instructed not to remove any more stone pending the completion of the present investigations. Suitability of Stone The rock has been tested by two of the department's Wellington engineers, who, it is understood, have pronounced it very suitable for concrete making. There is an ample supply of sand in the vicinity. It is understood that the maximum peak load of Horahora is in the vicinity of 12,000 k.w., while one of the present generators at Arapuni is capable of producing up to 18,000 k.w. The newest type of generator, which would be installed in the event of a new power plant being built at Maungatautari, can produce up to 24,000 k.w., so that the greater efficiency to be gained by replacing the Horahora station is apparent. It is understood, too, that one or two other sites near Taupo have been surveyed, but the Cambridge site would have first consideration, on account of the obvious saving in haulage costs, its proximity to the Arapuni-Auckland power lines, which pass within two hundred yards, and the fact that there is ample material at hand for the building of a dam. DEPARTMENTAL COMMENT "UNDER CONSIDERATION" TEST SHAFT SINKING DENIED [by telegraph—OWN correspondent] WELLINGTON, Sunday There is no prospect of any construction work being carried out on the suggested hvdro-electric scheme on the Waikato Hirer, near Maungatautari, within the next three to five years, according to Mr. P. T. M. Kissel, Chief Electrical Engineer of the Public Works Department. When the matter was referred to him to-day he said the process outlined had been under consideration by the officers of the department for the last three years and, during that time, surveyors had been engaged on the area, and were probably still on that work. This part of the investigation would in all likelihood continue for the next two or three years, and in that time and probably longer no construction work would be undertaken. Mr. Kissel also said that no test shaft sinking was being done.