TUNNELLING THE HILL

Evening Post, Volume XCII, Issue 41, 17 August 1916, Page 2

TUNNELLING THE HILL

TO OROKGORONGO FOB WATER

Referring to the reservation of the Orongorongo basin as a. water catchment area, a reporter asked the Mayor today if the work of tunnelling the hill to make the supply available would be commenced at an early date. Mr. Luke re-, plied that the council would decide without delay upon ways end means to be used. Though not an expensive undeu taking, the tunnelling of the hill will occupy much time, since much labour cannot be employed on the faces. There are three considerations to be borne in mind when coming to a decision regarding work—money, men, and 'material. Since the money will not be required all at once it should not be a great obstacle in the way of an early start. . Men, however, will not be easy to find. Experienced miners or. tunnellers are scarce in Xew Zealand at present. Very many of them have gone to the war. The material will probably be obtainable without difficulty when it is required. Pipes will be laid through the tunnel to carry the water to the Wainui-o-Mata dams.. In Colorado the experiment has been tried of diverting water through anil without pipes, but this is liable to be difficult and ultimately expensive, uness the rock pierced is" of a specially hard character, so that the walls of the tunnel are not subject to erosion. Should there be erosion, and the water not ,be piped, the stream would have to be a»aiu directed before the damage could" be repau-ed. With pipes ..laid in a fairly high and wide tunnel, no difficulty would be experienced in this direction The tunnel will have to be fairly high to permit qf horses being used to truck out the spoil. It is estimated that the tunnel will be over two miles in length.