RIVER MOVED

New Zealand Herald, Volume LXXVIII, Issue 24000, 25 June 1941, Page 8

RIVER MOVED

WAIKATO DIVERSION

VAST TAUPO RESERVOIR WATER FOR ARAPUNI Before the disbelieving eyes of tattooed old Maori women squatting by its banks the Waikato River is taking on a new course just below Lake laupo. |„ a few days it wiJl be flowing i» two channels and by September there will be firm level ground where water now, swirls in the old course 40ft. deep. ; The change is part of the scheme, for controlling the water from Lake! Taupo to secure a more uuifomi of the Waikato to feed the turbines at Arapuni. Bv erecting a dam at tl lake outlet it will ho possible to con IJno the water which flows, uselessly in or the Arapuni spillways in spring release it, in autumn t . (Imv 0 f water is in some seasons .nsuijieient to keep the power units working at full pressure. Water in New Canal A start was made just a year ago with the cutting of a canal -400 ft. g and 14ft. deep, beginning a ew h»n dred vards below the lake outlet ther j 330.000 cubic yards of spoil were ta - from this cut and piled up in huge , heaps 50ft. high in places on the banks. , Near the upper end of the canal a concrete flam was built. . The canal remained dry until a fe dnvs ago as narrow banks at cither S .™ not oxcnv;itP'!. to keep out the river water Ihe upp' bank lias now been blasted s that water has filled the j'week the lower earth darn will be - larlv removed and pari of the me, water will flow through the canal instead of taking the old course. Alreadv huge bulldozers have made a start with pushing the spoil from Hie canal into the old river channel and as the weeks pass more and inoic " at , will be diverted to the canal until b old course is completely blocked. I <>i the greater part of its length the old channel will be filled in h>vel with the surrounding country. This will inyohe the removal of the present rnei bin gc. Boiling Water Encountered A double-track traffic roadway along the top of the dam bridges the cana . i The flow of water from the hake u | be controlled by means of six 10-ton Uates in the centre of the dam. I are' now re.ady to place m position. Operated by electric niaelnnery betvvee, the two traffic lanes they can he laiseci or lowered according to the amount of water to be allowed into the river A small boat lock lias also been built through the centre of the dam. will allow boats up to about 16tt. in length to pass either way from one level to the other. T( ; improve the flow of wafer from the lake the riverbed above the cana is being dragged, while tor severs, miles downstream sandbars, rocks and other obstructions are being remo\ed. At Totara Rapids, four miles from the lake, the course is being altered to secure a better flow by a similar method to that used near the outlet. Ins canal, however, will be only 400 ft. long. A novel feature of the work in this cut has been the discovery of flows of boiling water and stones curiously coloured by thermal action. The scheme will make Lake Taupo a huge re.servoir and as it allows for the lake level to he raised a maximum of oft , the amount of extra w-ater whicn can be impounded' in its 238 square miles is more than 1,800,000.000 cubic vards.