HYDRO POWER STATION

Hokitika Guardian, 16 December 1925, Page 4

HYDRO POWER STATION

THE lIOHAIIOHA WORKS. AUCKLAND. Dec. 11. The Horahrra hydro-electric power -tali'.a. which derive'., its energy fp m ill" Waikato Diver, a few miles below Arupnui Works, is running al its full capacity of 10.3 CD kw.. plus an overload. Tlie original plant, purchased Iroai the Waibi Cold Mining Company, had six generating units, each of 1059 kw.. a total of 0300. Within the last Iwo years the head race lias been enlarged. two mere units, each of 2DJJ kw.. have been installed, and in addition to supplying Hie power reqwiivnieiii.-. ol the whole ol the Waikato and of Hie Waiiii Gold Mining Company. Ho vtaiion is providing tlie Auekiuhd Dower Board with 2539 kw. by day and 30:90 kw. al nlghl. Al present the Waikato Diver is running very strongly, and a considerable volume of water is pouring over the spillways at the weir and at the side of ilie head race. The body of water that, plunges through the turbines has provided an increased drop of Gin to the normal of ‘2Bft. The .sight is very stimulating to the imagination, notwiilisamling Hie lacl that tin' drop- is s, ( short by comparison with dial al many other siatims in New /calami. I'Y.r instance, that at Maugaliao is 9119 ft ; at Waipori, the Dunedin source ol power. (Lott ; and at, Arapimi it. will lie IGOIt. The Horahora scheme lias taken advantage of a short length of rapids. Originally a simple weir diverted the required amount of water into a head nice. Even during low summer flow a considerable body of water had to

take the old rocky passage down the slope, passing on i 1 way through the famous narrow cleft in the rock-, the depili of which tin- never been determined. Thus within a few yards ol each, other, one (piietly moving hotly of water took the way of I lie level head rare to give tip its power to the teeth of the turbines, while the other, a reckless vagabond torrent, vainly dissipated its energies again-t the rocky steps of its descent. Although water is now going to waste at llurahora. every deep of (lie river’s low level rapacity will he repaired to keep the turbines running ai full power. It will he necessary literally to wring it dry, so that all the industry, convenience and comfort depending upon llorahorn generation may lie guaranteed the beneficent ■‘juice.” To this end the rubble weir, already raised five feet from the original level, will not suffice. A concrete datu is necessary, and considerable. progress has been made with itconstruction during the year. Mr A. ilinnic. engineer in charge, who is also resident, Public Works official at Arnpnni. expet is to have it completed in six months.

In several respects the dam is unusual. For instance, it does not run straigh across the river course, hut abont half-way makes almost a complete right angle. It is particularly interesting, however, on account of the fact that it includes three distinct types of gates, each bO feet wide. The first is the ordinary "up and down” gate, hung to piers, a good deal higher than the .ill. which is about 18 feet high. A heavy counter balance enables it to be operated by one man. The other two gates are for automatic action, being controlled by floats within water chambers inside the piers. The whole structure is 30!) feet in length.