Over the Spillway

Sun (Auckland), Volume I, Issue 242, 3 January 1928, Page 1

Over the Spillway

Complications at Arapuni Waikato Carving New Course HYDRAULIC forces released in a spectacular fury produced unexpected sequels when the Waikato river rose over the spillway at Arapuni. Enjoying the freedom of a holiday week-end, thousands watched the partial consummation of the major plan, and saw the fretful waters change the face of acres of landscape.

TT was elemental drama on a grand scale, with the river presenting a series of impressive pictures. First, the stately cascade over the high, white wall o£ the spillway; then its sluggish hesitation in a broad lagoon formed immediately below; and lastly, a furious onset which wrecked the serenity of a peaceful valley. Hillsides crumpled under the attack of the diverted river, and astonished onlookers, drenched in spray if they ventured over-close to the cataracts, saw islands and quaking mudflats take shape before their eyes. They saw, too, the resistance offered by isolated bastions of rock. Full in the path of the fuming waters, a giant boulder held its place, and turned the current while about it the softer country was demolished. Trees, slices of scrub, and thousands of tons of pumice laud went down with the torrent, to be deposited below in an expanse of sludge, or to float on to lower reaches or the lesser hydroelectric works at Hora Hora. HORA HORA EMBARRASSED Not the least of the unexpected complications provided by the occasion was the trouble caused at Hora Hora by the enormous quantities of water-borne debris. For this some provision had been made by the construction of a floating barrier swung across the stream above the Hora Hora works, but it proved altogether inadequate, and on Sunday masses of vegetation pressed against the intake streams, restricting the flow, and seriously embarrassing the turbines. A hastily-raised corps was sent from Arapuni, in the afternoon, to help with the clearing of the screens, and they discovered that the crust of debris was so firm as easily to bear the weight of a man. The rubbish was cleared away from time to time, and power was fed

back from Auckland to bolster up the Hora Hora supply, but even with these measures the trouble at times became so acute that for short periods the station was partly closed down, and Waikato farmers forced to hand-milk their cows, or to suspend operations with the radio, knew all about Arapuni on these occasions. TURGID WAIKATO The lower Waikato, usually clear and green, was of a muddy hue, and picnic parties along its banks, like the citizens of Hamilton, whose water supply is discoloured, regarded it with distaste. Hundreds of motor-cars were driven to Arapuni during the week-end, and the spectacular scene was viewed by an assorted crowd. Up to a point the river, once over the spillway, did all that was expected, but beyond that it performed unexpected pranks, and the ease with which it carved holes in the country suggested the possibility that it may eat back unpleasantly close to the spillway. Already it has switched into the main channel at a spot higher than anticipated, and the deposit of mud at this point was so extensive as to cause backing-up toward the power house site. To check this tendency the gates in the diversion tunnel were opened wider, and the greater flow of water helped to clear much of the silt.

The next few days at Arapunt will be highly interesting, and charged with momentous issues. Should the plan proceed according to programme, the water from the spillway will find an easy descent, and mould It to its requirements. Meanwhile the process, so far as it has advanced, is proving amazingly spectacular. Spray hangs in misty columns above the new cataracts, and the river roars with a thunderous note that is in tune with the Importance of the occasion.