TESTS AT ARAPUNI

Waipa Post, Volume 35, Issue 2100, 22 December 1927, Page 5

TESTS AT ARAPUNI

DIVERSION FROM OLD COURSE.

RIVER TO TAKE SPILLWAY.

For the first time since the work at the Arapuni dam site was undertaken the Waikato River is to be diverted, during the next fortnight, along the spillway course sluiced out at an early stage in the operations. The impetuous waters, which have been held almoskiihamping behind the dam for somlweeks, will be made to respond to the bit, and take a new direction. They will leave their age-old bed at the dam where they will gradually be allowed to well up until on a level above, and after emptying themselves over the weir will enter the river-bed again some half-mile downstream. The intervening bed, which has been under the rushing green water for centuries, will be exposed and practically dry. The gates in the diversion tunnel have been partially closed for some weeks, sufficient water being allowed through the tunnel to enable the Hora Hora electric plant to be run at full capacity. Owing to the liability of the Waikato River to fall on account of the dry weather there will be practically no surplus water flowing in the river over and above the normal requirements of the, Hora Hora power station. To expedite the filling of the dam the Public Works Department has decided to close the diversion tunnel gates completely .for brief periods during the week commencing at midnight on December 24th. The total volume of water required to fill the lake to the 320 ft. level, at. which it will beg-in to flow over the spillway weir is 5,100,000,000 cubic feet, and it is expected that the water will back up a distance of 18 miles above the dam when this volume is impounded. In stooping the flow of the river during the Christmas period the department has. accepted an alternative less calculated to interfere with the business of electricity consumers than would be the case if the time allowed for filling the lake was extended over an indefinite period. It is proposed during the time the operations are in progress to reduce the flow of the river from 8000 cubic feet per second to 2800 cubic feet per second. It is expected that this reduction will considerably diminish the quantity of electricity generated at Hora Hora, and the department seeks the co-ope-ration of all consumers to reduce their requirements of electricity to a minimum next week. If the demand on Hora Hora is in excess of the power available it might be necessary to cut off the current completely.