WATER FROM WAINUI.

Dominion, Volume 4, Issue 1064, 1 March 1911, Page 3

WATER FROM WAINUI.

THE TROUBLE AT THE DAM. A TEJIPOIUHY CHECK. Hopes were entertained until recently that before this time the new dam :ii Solomon's Knob would have been taken over by the City (Jjuncil I'nin (he contractors, Messrs. Martin, "llurrell, and .Snnddoii, and that the reservoir would ore now have contained the 112 million gallons of water for which it has an estimated capacity. No f ilr Uiop hopes have not been realised. The bed of Hie re-er-voir, which has an area of % acres, is at the present time almost dry. A reporter, who accompanied the council visit of inspection to Waiimi ypsterday, found a score of men busily engaged 111 excavating a trench that will lay bare portion of (he foundation wall (if the reservoir. The trench extends la the valve -tower for nfcout 150 feet towards the cast?rn end of tho dam. It varies at present-from twelve to twenty feet in depth, and when it is completed, about 0 week hence, will hnvo an opprjximai? flepih throughout its length of twenty feet. The men engaged are making use ot an aerial tramway in removing the spoil from the trench. The work of excavation is complicated by the fact that soaknge water from the reservoir basin, which has been several times partly filled, is constr.ntly flowing into the trench, and lias to ha lifted by a steam pump, through a length of flexible hose, to one of the scour pipes which conimunicite between the reservoir and the stream outside the d:im.

Ihe exhiiiisiive examination now in jirogress of a portion of the dam iiuiula-l-ioii has been docmeirnccrssary owing to the fact that when tested it nrovwl to bo not quite watertight. The '■(leek" , of the tlam, as the great sloping face is termed, is neatly finished, and presents everywhere a smooth, firm surface. The same applies to the overflow hank, a massive sloping anrun of concrete, curving down on either side of the dam at its western end, and in fact to nearly all the innumerable concrete faces and walls that the (lam in its various sections pre.-.ents. Un the f:\ee of the uinssivo foundation wall which has now been laid bar?, however, it can be seen that the concrete in' some places is more or le-s porous. There are no visible holes or gaps of any importance, but apparently the slightly open texture of the wall in some spots nas permitted the passage of water to a certain 0.-tent. One of the contractors, Mr. Ilnm-11, when questioned by the reporter v.lio viewed tno dam, displayed" a certain amount of reticence, and remarked tint he would prefer not to say anything until the excavation ;n j.ronress had been craned to the bottom of the foundation wall and the precise importance of tho deisct discovered, lie was abb b state, however, that the defect w-.is not of auy verv great importance, and would not' ccu<-'-any very lengthy delay in the final completion and handing over ot the dam ln= City Engineer Olr. IV. 11. Jlor.'on) on being questioned, snu'ilv stated that ho cxainination of the buiid'ition then being mads had been ordered because it had been lound that the wall was not sufficiently impervious to the passage of water, koine water had come, not up from underneath, but through the wall. The contractors would be rcouiml to make the wall watertight beforo the dam was taken over by the council. As recently as Sunday last the new reservoir was filled to a depth of 25 feet I)V tho .heavy rainfall which occasioned damage 111 various parts of Wellingtor. The surface of the wntc? harnessed by the dam reached to within 13 feet of the ton ot tno ovorHott- bank. The w.t excrete stTuetnue is not a whit 'the worse tor I his experience. As shaving the. great extent of tiip Waimii simply it may lie meiilicncl ih.-ii: although '.he reservoir filled !.., {|.n | IP ;,,i lt ( stated during the heavy rainfall at (litend of last week, the main out'et pip* and four big sluice nines that communicate directly with the "stream outsids ti,dam were open and nmniiiß free duri'i" tho whole time that the fillin- w-s 'in progres-.

Tim bed of the reservoir is now ticnllj- ready for the reception of (lie water, but a certain amount cf vrueHbln growth v.-ill h? bumf o ff l'sfore !)<e fnnl harnessing is ncconriliVhecl.