The Evening Star MONDAY, JUNE 16, 1930. ARAPUNI.

Evening Star, Issue 20511, 16 June 1930, Page 8

The Evening Star MONDAY, JUNE 16, 1930. ARAPUNI.

Arapuni power house has been closed down indefinitely. This represents a severe set-back to industry in the Auckland province, and air to the taxpayers of New Zealand, for between two and three millions sterling of capital has been invested in this scheme. A few days ago the ‘ Auckland Star ’ said editorially: “ It now remains to save Arapuni, if it is worth saving.” That is a vital point to decide, and the question is who shall decide it. Hamilton, the nearest town in the Waikato Valley to the now idle headworks, has a very direct interest in the matter, and it is significant that the Hamilton Char, 'ter of Commerce is urging the Government to .appoint a Royal Commission, comprising two independent engineers and a Supremo Court judge, to investigate. In, the meantime the Public Works Department is dewatering the channels designed for the conveyance of water, and making tentati-e effort to find whether the water has been making short-cuts of its own and honeycombing what was assumed to be solid earth—an assumption on which the value and permanence of the work is based. Such work is necessary and 1 e Public Works Department is the right body to carry it out: but after thwk stage is completed the department should be asked to stan aside and await the verdict of an tside body such as the proposed Royal Commission, so selected that there can be no question of it competence and freedom from pressure or influence from any source whatever. Under ordinary circumstances this might be construed by the Public Works Department as a declaration of want of confidence in it and a slight such as no self-respecting body of officials could accept. But the circumstances are 'not ordinary, ns reference to the history of Arapuni from its inception will show. About a quarter of .a century ago,

when the rulers of New Zealand were waking up to tho possibilities of harnessing the water power of the country, a number of possible schemes were considered. Among them was Arapuni. At first glance it was attractive, because Nature appeared to have already roughed out a schema to which the hn,.c! o. man needed only to put the finishing touches. But it was not long before it was suspected that there was “ a catch in it,” A few days ago we. published a locality plan of Arapuni showing primarily the ancient course of tho Waikato River, which later was deserted b; it in iarour of the gorge to the east. The main feature ol the power development scheme was the routili.sation of that ancient course. The success of the scheme is dependent on the stability and non-permeability of the long and relatively narrow strip of country between the two ] Ivor beds, so that there should bo absolutely no communication between them lor the water except at tho designed places—from the spillway dam either through the penstock and tunnels to die power house m the dried-up gorge below, or along the overflow channel to its junction with the river bed at a point between Arapuni and Hamilton lower down the river. .Events have proved that this communication has been taking place. Having once discovered routes back to the river bed of its preference, the water has established its superiority to the strata relied on to defy it, and, left alone, that superiority would bo steadily developed and extended into a rout and consequent disaster.

This possibility was foreseen from the begr in and was regarded by the early investigators into New Zealand’s water-power resources as such a live possibility that an otherwise seductive scheme must be ruled right out. In October, 1925, this was disclosed by Mr LI. W. Holmes, a former Engineer-in-Chief of the Public Works Department. He put it' on record that his then chief, Mr P. S. Hay, considered Arapuni and condemned it because of the unreliable nature ot the country, and Mr Heines too part in the investigation and concurred in the decision, describing the country as volcanic debris permeated with fissures due to shrinkage or to volcanic or earthquake causes. How came it, then, that the Arapuni scheme was afterwards authorised? Mr Holmes indicates that Auckland inlluenco was brought to bear about 1920 to secure political intervention. Whoever made the decision to proceed with Arapuni must surely have acted in ignorance of the risks attached. For, according to Mr Holmes, about 1920 a shaft was sunk on either side of the Waikato River and tunnels were driven from each to connect with each other under the river bed. But these tunnels were never connected because fissures in the country being pierced wore encountered. The first crack was plugged with concrete, but the second crack admitted so much water to the tunnel that it had to be abandoned. On the test question being put to her .Nature thus gave as answer a very decided negative. “ Shortly after this,” wrote Mr Holmes, “ the Government decided to construct the scheme.” It is hardly necessary to recall more than the bare outlines of Arapuui’s subsequent history. A contract was let to a British engineering construction firm, whose last section of the job was the erection of the power house. To test the foundations for this the contractors bored 263 ft down, and results were so unpromising that they declined to proceed unless the Government accepted all responsibility for the safety of the structure. On such a guarantee not being forthcoming the cent - t was terminated. The Public Works Department itself took over construction, and undeniably showed resource and pertinacity. But instead of its labours being crowned with lasting success and the scheme thenceforward operating uninterruptedly, power development has been peremptorily stopped, complete dewatering is in progress, ami the work which should have been done before the first pound of the two or three millions was spent will now have to bo done—a thorough examination of the country which serves as a foundation for the scheme. By now it is known that the foundation is unreliable. What it is wanted to discover is whether it can bo made reliable. To do this would bo in the nature of a “ patching up ” job. Possibly it could bo done. Should it bo deemed feasible in the engineering sense there remains the question of cost. Arapuni’s original seductiveness was the apparent low capital cost per unit generated. That has already proved a delusion, and it is for tho most expert and unbiased judges to say whether it shall bo pursued further. It would bo only natural for the Public Works Department to urge its claim to throw good money after" bad, and seek in some way to retrieve its name with the public. But such n right cannot be conceded. So many warnings have been disregarded that tho country cannot afford further costly risks to bo authorised. No time should be lost in ascertaining from outside if tho clement of risk can be altogether eliminated, and, if so, at what expense.