BOYS' OWN COLUMN.

Auckland Star, Volume LIX, Issue 23, 28 January 1928, Page 2 (Supplement)

BOYS' OWN COLUMN.

TRIP, TO THE WAIKATO

A RIVER AND ITS HAVOC. Dear Boys,— So much has appeared in the papers about the trouble at Horahora that I decided to go there myself to see just what was the position, in order that I might tell all my readers about it. To fully understand the difficulty we must first understand what has been taking place higher up the river at Arapuni. When the gates of the diversion tunnel were closed the waters of the Waikato banked against the new dam until they finally overflowed into the old bed which the river followed thousands of years ago, before some volcanic disturbance caused it to find a new course some 150 feet below. The construction of this dam and the subsidiary works was a wonderful undertaking, but so far as that was concerned everything went well. The trouble began when the water was finally turned into its new course—once the old bed. It was anticipated by the engineers that a quantity of silt and earth and pumice would be washed down, but they did not expect that the debris would arrive in such quantities. Whole hills of earth, pumice, and, in fact, bushes and trees on the hills, were swept away by the mighty flow of water. Nothing could stand such an onslaught. To this day the banks of the river are crumbling away and sliding into the water. And these are high banks, perhaps 50 or 70 feet high. It can easily be understood, then, what a quantity of earth has been carried away by the river. Remember, Horahora is only about six miles below Arapuni, and on the banks of the same river. Anticipating trouble, engineers at Horahora threw a boom across the river above the powerhouse site and on the top side of the headrace gates. This, however, proved to be quite insufficient and incapable of stopping the bulk of the debris, with the result that the screens in front of the turbines became almost entirely blocked. As the engineer spot told me, "We did a lot of good work, but not quite enough." Men were promptly hurried to the spot, and with long-handled rakes commenced to rake the pumice and vegetable matter away from the front of the screens. Every now and again one or more turbines had to be shut down whilst it was being cleaned out, with the result that the Horahora station was not able to supply its consumers with the amount of electricity they required. It may seem strange to you that such a large number of men as they had could not cope with the debris, but when I tell yon that the pressure of the water against the screens was nearly 30 tons it is easily understood what a job they had. A week or so ago they found it necessary to close down altogether for a few hours in the small hours of the morning and clean up the deposit of silt, _ etc. Now, however, « '*'T7i ■ ■ the position is well Aj/ f\ M in hand, and no V^VT further trouble is expected.