"NOTHING TO HIDE."

Auckland Star, Volume LX, Issue 247, 18 October 1929, Page 10

"NOTHING TO HIDE."

POSITION AT ARAPUNI. CONFIDENCE IN ENGINEERS. INSPECTION BY POWER BOARD. The Public Works Department lias nothing to hide so far as the Arapuni hydro-electric scheme is concerned, and has the task of remedying erosion below the spillway Avell in hand. This impression was gained by members of the Waitematk Electric Power Board yesterday, when they paid a visit to Arapuni, and were conducted over the works by the engineer in charge, Mr. Kabonc, and the district electrical engineer at Hamilton of the Public Works Department, Mr. T. MacLennan. "Mr. MacLennan assured us that the Department has nothing whatever to hide, and was pleased to show any interested party over the scheme," said Mr. J. W. Ilayden, chairman of the board this morning. "The whole trouble at Arapuni, of course, was caused through the delay in the erection of the powerhouse and the diverting of the water over the spillway. If the powerhouse had been built according to schedule, it is quite evident that the erosion at the falls would never have occurred, as the water would have been used at that source." "Other members and I could not help but be struck by the seriousness of the erosion that has taken place. Since our last visit to Arapuni eight chains have been eaten away, which leaves seventeen chains between the fails and the spillway. However, no erosion has taken place within the past two months. Tests aro made at the falls every two hours, and a watchful eye irs being kept on the matter.

"The main point of interest to the board was the fact that by the end of February additional penstock tunnels will be put in use at Arapuni," said Mr. Hayden. "Two of these will be employed simply to convey water from the race into the old river bed. The penstocks will be capable of taking 9000 cusecs of water, whereas the natural flow of the Waikato River is only 8000 cusecs. When the water is thus diverted the Department will be in the happy position of preventing any water going over the spillway, and still have the diversion tunnel as a secondary standby in case of heavy flooding. The salient feature of the work is that, providing thcro is no erosion between now and February, there is nothing to be alarm«d at at all. Another factor to be considered is that a long solid shelf is throwing the water at the falls forward, and further undermining of the river bed is not expected. Previously the water at the falls fell on a soft bed and undermined the harder strata above. After what we have seen, we have confidence in the Public Works engineers. Since the last generating set was started at Arapuni a

month ago, the flow over the falls has diminished by from 2ft 6in to Jitf."