ARAPUNI TROUBLE

Rotorua Morning Post, Volume 2, Issue 320, 6 September 1932, Page 5

ARAPUNI TROUBLE

ENGINEER SAYS LEAK CAUSED BY A CULVERT

Hamilton, Monday. RCpair work to the damaged lining in the headrace at Arapuni is well advanced, and is expected to be completed by Wednesday. During a visit by the. Hon. J. A. Young, Minister of Health, at the week-end, the engineer-in-charge explained to hina the work that had been done during the past few weeks. Mr. Rabone said that in order to aseertain whether fin underground passage of water existed near the cutoff walls, a wall 50ft deep was sunk within the headrace, near the cut-off wall. The result was the definite estabiishment of the non-existence of an underground channel. The level of the water in the well was 25ft lower than the water in the headrace, and in ©very 24 hours it was rising only three-quarters of an inch. It was also definitely established that the water in the. headrace had no connection with the water in the well. Horizontal bores had been sunk, and advantage was taken of these to grout the country, with the result that tlie counti-y was discovered to he impei'vious and tight. Mr. Rabone stated that a 9in pipe eulv-ert in the underground drainage system had caused the subsidence in the headrace lining. The culvert had probably been overtaxed by the pressure of stormwater. From observations made twice daily the engineer said that he felt certain that the leakage had its oource in the wall within the coffer lam, and that the fault would be remedied with the repair work now in 'land. To prevent the possibility of mistake, however, the coffer dam would he replaced by an island coffer dam to enable thorough examination of the headrace floor. In order to rerluce the current the diversion tunnel would be closed and the level in :he hdadrace raised.