White Horses of the Waikato

Sun (Auckland), Volume 1, Issue 103, 22 July 1927, Page 3 (Supplement)

White Horses of the Waikato

A River Tamed and Harnessed Toilers of the Gorge at Arapuni WHITE horses of the Waikato, centuries old, have tossed for countless ages between Taupo and the sea. Years ago, at Horahora, man made some of them his servants. Now he is endeavouring to make the whole stream his slave.

one hundred years ago a pioneer botanist named Bidwill made a pilgrimage up the Waikato Valley. In these days the name of his family is better known through its association with sheep, golf and one of the largest stations of the Wairarapa, than through the enterprise and courage of its forbear. But that Bidwill, one of the first investigators of New Zealand flora, ranks as one of the most notable of the early explorers, and his lonely tramp from Rotorua to Taupo, through country that was largely a wilderness, is entitled to recognition as the epic journey of an adventurous spirit impelled forward by the desire to see more, and yet more, of the strange and wonderful country opening to his advancing view. Bidwill left behind him authentic impressions of the beauty of the Waikato. Its swirling waters, inlaid with ivory in streaks and whorls and intricate patterns, held his fascinated eye. But it is doubtful if even the l'ar-seeing botanist could have pictured the river, within the span of a man's life, as the source of power for a virile community, a new nation founded on the resources and fruitfulness of the country into the interior of which he was among the first white men to venture. AGENCIES OF CHANGE Since Bidwill’s day the country about the Waikato has undergone changes, but in its upper reaches they are comparatively few. Wayside hotels have sprung up amid the fern and scrub. Here and there an iron roof gleams beneath the play of sunshine, but still the river pursues its turbulent course toward the sea. The white horses still dance at the end of every quiet reach—calm sliding placidly into restless vortices—and sentinel kingfishers bend their gaze upon the transparent shallows. But now there is, in process of construction, the greatest artificial agency of change. At Arapuni mean are building colossal formations to change the aspect of the valley for twenty miles or more. Possibly the change their works are to effect will be the greatest the river has known since vents riven by volcanic cataclysms allowed it to change its course. Geologists even consider that the river once flowed out into the Hauraki Gulf, and that the turning to the west, possibly through the thrust of epochal earth movements, was a preliminary to the formation of the morasses now known as the Piako swamps. In the memory of man there has been no parallel to such transformations, but at Arapuni the completion of the dam will create a lake 18 miles long, a corresponding metamorphosis, even though in miniature. A BIRTHRIG/HT OF BEAUTY With Arapuni completed, the Waikato Valley wiU be more than ever a place of wonders. Away back beyond Taupo, beneafih the shadow of Ruapehu, the infant Waikato twists and turns toward Lake Taupo. Near Tokaanu a bridfee crosses it, and there it is an adolescent river, a pretentious stream..

Before it lies the lake, a legend of colour toueflied in a myriad of tints. Lonely Motukaiho, island of skeletons, rises remcjrtely from the expanse of waters. Across to the west tower the tall cliffs of Karangahake, and in the dimness to the north is Rangatira Bay. Across the great basin the Waikato finds its way, perhaps guided as were the Majori navigators of old, by the plumes of steam from Kerapeti blowhole, cm its ridge above the distant

shore. And then begins its plunge seaward —a descent across lifted ledges, through cramped channels and lowering defiles. Small wonder that the white horses play gaily. Compressed into a monstrous, seething jet, the river plunges into a field of snow at the Huka Falls, and lower down it is dissected into a lacy tracery between the rocky ribs of Aratiatia. Between these many turbulent places a deep peace descends upon the waters, and the silence of the untroubled river is broken only by the murmur from cataracts round the bend. DEVELOPMENT AT ARAPUNI The many thought that hydro-elec-tric development on the Waikato meant that the Huka Falls and Aratiatia would be transfigured by the hand of the engineer. Indeed, for many years the idea of the Arapuni Gorge, as a place for potential power development, was never seriously entertained. Those who had ignored its possibilities, and disregarded the wonderful progress actually achieved to date, may be surprised to learn that the taming of the river is now all but complete. True, there is yet a powerhouse to build, but as far as the-

blocking of the river goes, the more difficult phases of the task have successfully been accomplished, and the massive mountain of masonry is now rising steadily across the path of the ancient stream. All this is to the credit of the workers on the job—the toilers of the gorge, whose industry, fortitude and patience will have an abiding monument when the great undertaking is finished. In all weathers, by night and by day, they have worked in the Waikato’s cleft. Three were killed by the misadventure inseparable from operations of such magnitude. Others have suffered ailment or injury, the discomfort of toil under exacting conditions, and the irritation of concrete burns, which sear the skin. Features of the Arapuni scheme are the facilities it offers for further development. At present only three penstock tunnels have been driven. From the.headrace which will carry the water along the plateau, at high level, they dive through the rock to reach daylight again at river level, deep in the gorge. Years hence there may be eight or ten tunnels, each feeding ponderous turbines at the bottom of the slope. TALKING IN MILLIONS Construction costs were originally computed on the basis of so much for the dam and so much for the penstocks, powerhouse, and transmitting station, and the total was something like one million and a quarter. The original estimate of costs is likely to be exceeded, as serious difficulty has been encountered at the powerhouse site, and the recent strike was a further factor in raising the cost of executing the plan. Arapuni has been so much in the public eye that its broad outline is now fairly well known. Features not so familiar to the public are the methods by which the huge reservoir will be filled, the installation of enormous steel gates in the diversion tunnel, and the intricate system of honeycomb passages through the bulky structure of the dam itself. Not until the Waikato had been diverted could the main dam be started, and to dry the bed of the gorge the river was diverted through a short tunnel under the eastern side of the ravine. While the cutting of the tunnel was in progress the water was kept out by means of “dumplings,” buttocks of rock left at each end. When the tunnel was driven, and lined, the dumplings were blown up, and the Waikato then coursed, for the first time in its history, through an artificial channel. Before the dam can fill, thus lifting the water to that level from which, having traversed the head race, it will plunge to the turbine blades, the tunnel must be blocked, and the natural supposition would be that its roof should be shattered by explosives. REGULATING THE FLOW 1 thought desirable, however, that the tunnel should always be kept open so that the water in the dam can be regulated. Moreover, it is imperative that the dam should be filled gradually, so that the flow at Hora Hora will not be cut off.

To allow the flow through the tunnel to be regulated, huge steel gates, made in Sweden, are being installed of a deep shaft dropping 180 ft, from the ground level above the rim of the gorge, to the roof of the tunnel. In this concrete-lined pit the huge gates, each 27 tc*ps in weight will be mounted, and when the great day comes a hydraulic device will lower them across the tunnel, partly closing it, so that the dam will then begin to fill. At present this particular section of the job makes the uninitiated shudder. Away down in the depths of the shaft roar the waters of the imprisoned river. Men who clamber down the steel rungs, planted in the concrete, risk a slip that would end their lives. But the Arapuni workers are not deficient in nerve. Otherwise they would never tackle the jobs that confront them—vigils in moist gloom at the bottom of deep wells, and acrobatic feats, in high places, that would try the nerve of a steeplejack. On the main dam the concrete work has been hurried forward by some of the most efficient gangs that have ever tackled that class of work in this country. Separate phases of the undertaking, such as the erection of the timber frames into which the liquid concrete is moulded, each call for high skill and accurate calculations. CATACOMBS OF THE DAM Casual visitors have been puzzled by the application of a black treatment to the joints in the dam. Actually, it has been built in three blocks, and between the different blocks is a film of special paint which will take up any expansion or contraction. The sectional construction, it is anticipated, will prevent the development of cracks and flaws through changes in the temperature. Further to guard against the occurrence of structural weaknesses, an elaborate series of corridors has been constructed, and these narrow passages honeycomb the heart of the dam. Deep down in its wide butt they will allow periodical inspection parties to examine the man-made fabric, and on different levels the same series extends to and fro across the block. When not used, of course, many of these passages will fill with water, but there will be pumps installed in all of them, so that when it is desirable the water and any foul air may be extracted. Thus safeguarded, inspection parties will move, in ghostly procession, through the eerie depths of the concrete mountain. All this is for the future. For the present the gnomes who are taming the Waikato are still at work upon the constructional phases of the project. WHITE HORSES AT WORK The day will come when all the vast rotors, tubes, and valves are in position —when a ceremonial party gathers above the dam, and the signal is given for the action which will arrest the stream. A wheel may be turned, and there is sure to be a flagon tlung at the serene wall of the dam. Yea, there may even be a toast or two, and kind words will be said. At man’s impudent command the Waikato will start to store its waters—a mockery, this, of Toupo, scores of miles above. But it will be a useful mockery, for then turbines will whizz, and wires strung over dale and upland will vibrate with unexpected life. Lights in a distant city will wink Arapuni’s message to an unheeding multitude, and housewives will launder homely linen with the white horses of the Waikato. Yes, that will be a great day.