POWER SCHEME AT BENMORE

Press, Volume XCIV, Issue 28013, 6 July 1956, Page 12

POWER SCHEME AT BENMORE

EARTH DAM MAY BE BUILT INVESTIGATION OF TWO SITES PROCEEDING (New Zealand Press Association) OAMARU, July 5. If the lower of two sites on the Waitaki river is selected for the next hydro-electric scheme in New Zealand, the largest earth dam in the Dominion, involving many millions of yards of spoil, will be built. At this stage of investigations at Benmore it appears that one of two sites—about two miles apart—-will be chosen for the construction of a dam.

Other earth dams in the country contain not more than 21.000.000 yards. Investigations are well advanced, and at present a four mile access road from Otematata to a Bailey bridge being built over the Waitaki river is being formed. The bridge, for which the abutments are in place, is being built to carry heavy vehicles and give better access for the investigations.

The two sites being investigated are what is known as the “concrete site,” at Black Jack’s point above the confluence of the Ahuriri river, and the earth dam site which is in view of the main highway and is below the Ahuriri. The earth dam site is being examined at present, and although some work has been done at the other locality there is still further work to be carried out there.

One of the main advantages of the earth dam would be that it would enable water from the Ahuriri river to be stored. The construction would not make such a draw on cement for concreting work which would be required for only the power-house and spillways. It is known, however, that a concrete dam could be build satisfactorily on the up-stream site.

The construction of an earth dam of such proportions would call for a considerable degree of scientific skill, and soil mechanics experts now carrying out tests on the site are leaving nothing to chance. Earth samples are being taken from borings, and are being sent to various laboratories for tests of such properties as waterresistance. strength and compactness. Several hundred acres of land will be required for accommodation for un to 1000 workers and their wives and families, as well as for workshop sites, timber yards and other facilities. The village at the site may have a population of 3000 to 4000.