CITY WATER SUPPLY.

Dominion, Volume 6, Issue 1751, 16 May 1913, Page 6

CITY WATER SUPPLY.

RECENT DAMAGE. BY SLIPS AND STORMS, A report which was presented to tlio City Council lust evening by the City Engineer (.Ur. \V. il. .Morton) showed that the clt'ccts of the recent storm und of the big blip at Ngahauranga were, so tar us the Wainui water mains are concerned, ot serious inuimnt. Willi regard to uiu break in tho Hl-iuch pipes ul (lie onl water main at tlio engineer stated that the supply ol the city has not been intertemi witn, as alt water is now coining through the 21-inch main and the new Hell Road reservoir. Tho water in tho old main was l'or tiio time being shut oil' at -Ngaliauranga to enable the pipes being shifted into their new pusitiun at tho lioro-Koro Stream and Hie Jlutt and Waiwetu Urnlges. This workis now practically completed. The water supply to the abattoirs, however, and to .Nganaurauga, lias been interfered with as tlio water was supplied back lrom the city to these places. "The present condition of allairs indicates clearly," said Mr. Morton, "the advisability of constructing the new main, unite apart from the incapacity of the old one to supply the whole of the needs of the city." Serious Damage at Wainui. Hitch more serious is the position of affairs arising from the effects ol the recent downpour in the Wainui Valley on •Uav 1 last. Tlio rainlall, which was something phenomenal in the district, topped both reservoirs during the night and at tlio new dam scoured out a large amount of filling at tho back of tho dam on both sides of the stream. It also broko away ;i considerable quantity ot the training wall and iloor and basin below the .spillway. At tho old reservoir the water topped tho dam and the custodian's family had to leave tho house at about 3 o'clock in the morning. Tlio earth over the main which was constructed somo twelve years ago has fallen in in many places, tho timbering of the tunnel having rotted away. "This," said Mr. Morton, "was foreseen sonic little tiiuo back as likely to occur, and provision made for tho protection of the pipes - , tlio 'places where tho ground lias fallen in can now, 1 think, bo filled in with safety.

"The most serious trouble of the lot occurred where the main crosses the Wai-nui-o-mata River at a point nearly opposite Mr. Wood's house. Tho river here shifted its course and undermined a length of about fifty feet of the 30-inch main. These pipes ou Sunday last were still supporting themselves, although a conplo of joints showed signs of weakening and' the pipes had been carried out of lino consequent upon the pressure of water on the upstream side. Arrangements were immediately made to endeavour to get the river back to its original coursj in order to. minimise the quantity .ot water flowing under the main," and also for temporary supports to be placed under the main as soon as' possible. Up to 'Sunday last it had not been possible to do anything with regard to supporting .the pipes, but considerable progress had been ' made in getting the river back into its original position. At a point lower down where tho main again crosses tho river, the pipes were intact and no serious erosion or change in tlio course of tho stream had occurred. _ "It will bo remembered that in the ,£IOO,OOO loan for the duplication of tlio main provision has bceii made for the construction of a bridge in this locality, l'roni present appearances it will look as though tho bridge will require to be much longer than was originally thought necessary, but I propose having a survey and drawings made showing what- is required to ensure the safety of thoinain in this particular place. Tho liability oi this .stream to' change its course is one which occasions a considerable amount of anxiety concerning tho pipes which are placed in its bed. Repair V/ork Between £600 and £700. ; ,"Qn,,th<M ,£11)0,000, j votpd; for the duplication of 'the main there is an unex?>eiid : ed. balance of ,£BOOO. The only work remaining now to be done is tlio completion of tho work in shifting tho old main on to tho new' Ilutt and Waiwotu Bridges and at the Koro-Koro Stream. This work is almost complete,. and tho only work to bo done will bo the construction of the bridge above refcrrc.d to." The estimate of eost of reinstating and making good the damage done at the reservoirs and to tlio main at Wainui-o-Jlata is between .£6OO. and .£7OO, which sum does not include the, cost of construction of the bridgo and pipes over the stream referred to. Tlio report was adopted,