THE New Zealand Herald AND DAILY SOUTHERN CROSS FRIDAY, JUNE 27, 1930. THE REPORT ON ARAPUNI.

New Zealand Herald, Volume LXVII, Issue 20601, 27 June 1930, Page 12

THE New Zealand Herald AND DAILY SOUTHERN CROSS FRIDAY, JUNE 27, 1930. THE REPORT ON ARAPUNI.

The first comprehensive and authoritative statement on Arapuni since trouble developed there has been made available in the report of the geologists who have investigated what happened. What it discloses is serious, indeed, very serious. There was no reason to expect it would not be, and with the facts stated, it is now necessary to face them, with all their implications. The report, though technical, is not beyond the grasp of the lay mind. The geologists find that a block of country between the overflow channel and the gorge has moved, or been bent, as they put it, causing the crack which is the main visible sign, and allowing the leakage of water, a development which aggravated the trouble. The first causo suggested, which they consider the most probable, is that the country was in a state of natural tension. .Excavation for the power-house, coupled with the pressure of water above, overcame its power of resistance, causing the movement. Tho move caused the crack, which in turn allowed the percolation of water. Two other possibilities, percolation of water before the movement and an earth tremor, are mentioned, but not considered probable in the absence of evidence. Another conclusion deserves special emphasis—"the whole occurrence might well be unforeseen." It was. Even the doubts about the powerhouse site were not that its excavation might weaken the rest of the scheme, but that stability could not be reached in that place. The re-

port describes a situation and suggests a cause which are entirely new. It is different in principle from anything that has been said of the scheme before. To illustrate this it must be repeated that the country became leaky, according to the report, because of the earth movement. The power-house became involved, not because its foundations had not been secured—they are said not to be affected—but because of a much more extensive development to which excavation of those foundations was a • contributory cause. Those are the main lines of the report. The geologists say further buttressing of the whole block would ap pear to be necessary to prevent a recurrence of the movement and leakages In their opinion, therefore, the country can be made secure by a process they term buttressing. To pronounce on this point, what the means should be, and the probable cost, is not in the province of geologists, but of engineers. That is, \one expert estimate should be fol-

lowed by another of a different class. The Government has seen the force of this, and has taken steps to secure abroad the services of an engineer thoroughly qualified for the work. Nothing less is needed. If one opinion does not seem adequate, more than one should be obtained. The question is extremely technical. The issues involved are so important that no half measures can be tolerated, nobody can be allowed to approach the task with his mind already half made up, and particularly nothing but the purely technical and scientific side of the question should be allowed to enter. For this reason, an inquiry by a Parliamentary committee with expert advisers, as suggested to the Government, is the last course the country should tolerate. ~ Members of Parliament have their own duties to do, and to pronounce opinions on what is in essence an engineering and a geological problem is neither within their province nor, indeed, their competence. The disturbance of public opinion about Arapuni—the one nontechnical and non-financial point to be considered—is not likely to be allayed or in any other way affected by any finding a Parliamentary committee could bring on the subject. The geological side has been considered by men of proved qualifications. If that is not held sufficient, let more geologists be sent to make a survey. For the next step nobody but an engineer, or engineers, could be expected to be of any practical use.

Whatever else happens, Arapuni is obviously out of commission for a long time to come. The future must be considered in relation to power demands already existing. The Public Works Department, which must necessarily cease activities at Arapuni in tho meantime, has another plain duty to perform. It should surely review the whole power situation in the North Island, estimate what can be expected at most from the State's two working plants—Waikaremoana and Mangahao—and from all the other resources at its disposal. Then the country should be told exactly what the position is. New Zealand has developed very much in the past decade into a power-using and a power-demanding country. It has been encouraged to do eo by the promise of a bountiful supply from the State schemes. Arapuni was tho chief unit in the system, but not the whole of it. Current was supposed to flow from the south northward if needed. Now that Arapuni has to be left out of consideration for some time to come, the department might well say how it is faring with its other schemes, what prospect there is of their meeting in part the position created by this dislocation of the original plan. the least the North Island public can expect as it resigns itself to the future plainly outlined in the geological report on Arapuni.