SPECTACULAR ARAPUNI

Sun (Auckland), Volume I, Issue 203, 16 November 1927, Page 1

SPECTACULAR ARAPUNI

Finishing Touches at Dam

incidentals OF PRELIMINARY TEST

IX a corner of the Arapuni lay-out is a battle-ground of waters, contrasting strangely with the serenity of the reservoir above, and introducing still more spectacular elements into the dam construction enterprise. No clash of forces could be more startling than the tumult created where the resentful Waikato, freed from bondage, crashes from the partly-closed diversion tunnel into a heaving field of spray.

rpHIS Waikato was ever a study in contrasts —the majesty of Taupo and the grim grandeur of the Huka—bat the contrasting pictures at Arapunl are now more startling than any along its course. Held since Sunday by the narrowing „{ the tnnnel, the river above the dam i, a 10-mile zig-zag of serene water, broken here and there by tree-tops, and raffled only by the catspaw winds [jut penetrate to the gorge. Fifty vards above the dam its calm surface notes uneasily, and a fleck of froth is drawn into the green depths. There, jinister spot, is hidden the entrance to the diversion tunnel. Across the tunnel, like a half-drawn portcullis of old, hangs the twin gate : jut has mastered the Waikato. Beneath it thunders the swift fugitive, an escaping river fleeing from the pressure of countless tons behind, answering the imperative call of gravity and the sea —and yet only a cousin to the current that gurgles down the waste-pipe of a bath. VIOLENT CURRENTS With such violence does the water diverse the tunnel that its protests are transmitted aloft on the valve gsar, so that the high-tension connecting rods sing the river’s war-song 200 feet above. So charges the Waikato to battle. Its field starts at the outlet of the tunnel, and for a furlong the ravine is tumult. Even the Huka falls are eclipsed in this snowy orgy. Masses of water leap to the tree-tops, and fall in changing cataracts, and the bosom of the waters explodes and is furrowed, recedes, contracts, and mounts again as the currents wrestle in the ravine. By comparison the din of the workings Is placid. The dam is not yet at a uniform level, the east wing having still a dozen feet to rise, so the clangour of concrete-mixers still rolls across the landscape, and metal from the Muku quarries is still swung across-.the gorge on thß airy cable-way, ready for transportaion by light railway to the scene of major operations at the spillway. This week’s trial of the dam is only a preliminary, but the imminence of the reality is reflected in the feverish activity at the spillway, where three shifts are working daily, and the penstock entrances are ready for gates and screens. Reticence Is a stock commodity at Arapuni, but with the spillway ready—and it will be ready by Christmas—there will be nothing to hinder the permanent filling of the dam. Then the gates in the diversion tunnel will be closed, perhaps for ever —and fabulous power will run to waste until the powerhouse is built. HUGE CONCRETE MASS For the present the dam is merely on trial, and despite the notch in its eastern flank, and the lumber which litters its crest, its immensity and symmetry grip the perceptions. Downstream the face is an immaculate sweep of concrete, crowned by blind arches supporting the overhanging parapet. Upstream the fall is sheer, and the white concrete and jadesreen water meet at a perfect rightangle.

Adding the finishing touches, the toilers of Arapuni are still on nerve-

trying jobs. Yesterday some were working in the inspection drives, sultry pits and galleries that honeycomb the dam. Others bestrode swinging planks and casually prized used moulding frames from the mountain they had helped to form; and for a space one daredevil got the thrill of a lifetime working on a ladder hung directly above the outlet of the diversion tunnel.

Vast development has been effected at Arapuni since June, when the strike among the workmen last focussed public attention on the undertaking. Headrace, spillway and outdoor transmitting station are practically in their completed form, and for the advance on the dam-works the trial flooding speaks eloquently. Yesterday the water was just above the 255-ft. datum mark, at which level there was an enormous volume of water impounded, though the future will see a reservoir of immeasurably greater extent. Even at the relatively low level the water had backed up for several miles. Five miles above the dam the ropeway to the quarries crosses a swamp on three tall trestles, called the Three Sisters, Faith, Hope and Charity, and these ladies will rise from a wide expanse of water when the inundation is completed. CANOE ON THE DAM During the past three days the gauge on the control tower of the tunnel-gates has been steady at 6ft 6in, and through an opening of that height the constricted Waikato poured on to Hora Hora. In the lower reaches a sand-bar exposed near Rangiriri was typical evidence of the reduced flow, bilt this will cease when the reservoir is emptied, a development likely to occur tomorrow. During the trial both the dam and the flooded country have been under test. The honour of swimming in the reservoir for the first time was shared by several parties, and an enterprising canoe crew was soon afloat. From the upper reaches the craft was paddied to the dam, and in brief ceremonial the pioneers touched the wall before returning upstream.