ARAPUNI SPILLWAY

Dominion, Volume 23, Issue 129, 25 February 1930, Page 10

ARAPUNI SPILLWAY

NO APPRECIABLE EROSION SINCE AUGUST

WORK OF DIVERTING THE OVERFLOW

Dominion Special Service

Auckland, February 24

"There has been no appreciable erosion at Arapuni spillway since the occurrence in August,” said the Minister of Public Works (Hon. E. A. Ransom) to-day. “I am very gratified to know that such is the case, and, given another month or two, we should be able to divert enough water through the penstock tunnels to enable careful examination of the spillway to be made.”

The Minister said the recent test of the by-pass tunnel had proved very satisfactory, although it was not intended to put water through that tunnel unless absolutely necessary. The penstock tunnels known as NOs. 7 and 8 had been driven with the object of taking the surplus water and he had been advised that those two tunnels together with the three penstock tunnels used for operating the three units at the power-house would practically take the normal flow of the Waikato River. If there was any water in excess of that dealt with by those five tunnels it would be necessary to use the by-pass tunnel. “Until we get the spillway area dry we do not know the precise nature of the work that will have to be undertaken.” added the Minister. “A thorough examination of the waterfall will then be undertaken. The present idea is that it will probably be necessary to concrete the spillway. “We had expected to pass water through the penstock tunnels (7 and 8) in March, but a weakness developed in one of the faces above the penstock tunnels on the powerhouse side. That face is being brought down and that work will consequently delay a little the task of diverting the water from the spillway. Three shifts are being employed on the work of bringing down the face and the excavation thus made will he useful when the time comes for an extension of the power-house.”