THE TASK AT ARAPUNI.

New Zealand Herald, Volume LXIV, Issue 19663, 15 June 1927, Page 8

THE TASK AT ARAPUNI.

POWER HOUSE FOUNDATION

CONDITION OF PRESENT SITE.

MANY DIFFICULTIES MET.

OPINIONS OF MR. J. PARK.

The difficulties causing the delay to the Arapuni hydro electric scheme were discussed by Mr. J. Park, a member of the Auckland Power Board, yesterday. He expressed the opinion that boring operations now being carried out at the power house site at Arapuni had proved that the strata beneath the surface were quite incapable of supporting the foundations which would have' to bear the huge weight of the building and plant, and that it would probably he necessary to alter entirely the plans concerning this part of the scheme. Mr. Park said he had taken a keen interest in the development of the Arapuni scheme since its inception, and his conclusion was arrived at after numerous visits to the scene of operations. His opinion was a personal one, and was not expressed in his capacity as a member of the Power Board. "The fact that the foundations are not suitable must bo admitted by the Government, which selected the site, and the contractors," said Mr. Park. Otherwise how can they explain the delay which has occurred for the purpose of further investigation. It is now known that the country beneath the site is not what it was originally hoped it would be. 1 have watched bores being put down to great depths, and in the majority of cases nothing solid was brought up at all. On the contrary, silt was brought up of a sandy-gravel nature. Edge of River Bed. "I would not like to predict when we will get power from Arapuni if it were found that the entire locality were unsuitable. It would be a very serious matter if the situation of the power-house had to be changed. However, lam not sure anything so serious will occur. "One hears many statements that it is only a question of finance which is preventing difficulties being overcome, but these statements are absurd. "While many sites may allow of a raft formation as a foundation on which to rest a building, the site at Arapuni is differently situated. They are there working on the edge of the Waikato Eiver bed, and unless the greatest care is exercised, even after the completion of what may appear on the surface to be thoroughly safe foundations. disastrous results may occur. "The Government and the contractors are working under tremendous difficulties, but the Government i 3 inclined to evado its responsibilities. On the other hand, the contractors are making careful investigations for themselves and the Government so as not to be hurried into doin" something which would reflect on the engineering ability of all parties in future yearS ' Much Time Involved. •'As one who has had to deal with treacherous foundation work. I am thoroughly convinced that although the power house may be erected on the present site, it will not be placed on th. oioot pooltion contemplated in the original plans. This b"ing so. considerable time must be Lent in boring operations, alterations to plans and in obtaining material necessary to complete the alterations. The opinion has been voiced in the Waikato and in Auckland that directly the dam and spillway are finished and the r.vSr diverted over the spillway, the difficulties incurred by constant flooding of the power house site will be easily overcome. "I am of the opinion this will not affect the position a great deal, if at all, for I have seen the site when PU™P ln K °P era " tions have been suspended and the area flooded with water. Doubv, is then cast upon the accuracy of any statement that the.water is finding its way through the coffer dam into the power-house site from the river adjacent. As a matter of fact, the "river outside the coffer dam remains at a higher level than the covering the power-house site. I hat naturally gives rise to the assumption that the water is gaining access to the site through fissures from the river further downstream, where the level corresponds with that which accumulates at the flooded site." , By observation at the power-house and 'dam sites it was easy to understand that those carrying out the original investigations concluded that both sites were on country of similar formation, continued Mr. Park. Looking at the banks of the river through which the flumings of the turbines were to be placed, it was natural to conclude that the two sites were composed of tuffaceous beds. Unfortunately this had not proved to be the case where the power-house was to be placed. Meeting the Demands. It was to be hoped for the sake of the Government and the contractors that, should it bey considered advisable to cut further into the cliff, suitable foundations would be found for the huge weight. If such were found it wouid simply question of arranging for the cost of the alterations, which was a question entirely for the contractors and the Government. While all interested deeply regretted the present position it was gratifying to know that no stone was being feft unturned to hasten the work to a successful conclusion. Mr. Park said he did not think power from Arapuni would be available until the end of 1929, but any restriction of power extension in the meantime would put the province back for many years in the use of electrical energy for domestic and industrial purposes. Last Week's conference of power board 3 at Hamilton probably marked the turning point in a very serious position. Sufficient had been said already concerning the likely price of power and the quantity needed. It was probable the Government would have to spend a minimum of £50,000 on plant to meet demands for the next two years, and it was apparent that power board contributions would not return more than 30 per cent, of this cost. The expenditure of this money was forced through unforseen circumstances at Arapuni, and this should be taken intu consideration by the public in considering charges for power in the meantime. These charges, in Mr. Park's opinion, would not be in the least affected, as the power boards would be willing to lose the difference between the price charged by the Government to the boards and that by the boards to the consumer.