PROPOSED WATER WORKS FOR PORT CHALMERS.

Otago Witness, Issue 1158, 7 February 1874, Page 11

PROPOSED WATER WORKS FOR PORT CHALMERS.

The all-important question of an abundant and pure supply of water for the town of Port Chalmers has for years past been a moot point amongst the inhabitants, and at the Municipal Council board. The existing urgent necessity for providing such a supply was admitted on all sides, but opinions clashing upon the relative superiority of the two schemes wh.icb.ha4 beeu propounded—andopi-

nions, moreover, being pretty evenly balanced — neither scheme received practical effect until within thelast few months, when the supporters of what is termed the Sawyer's Bay scheme succeeded in so far advancing i as to obtain the sanction of the Corporation to the preparation of plans, and ths calling of tenders for tke construction of the necessary works. But the final and definite adoption of this scheme is not yet quite decided upon, and will not be until an accurate estimate of the cost is known ; and even then, if that cost should happen to be excessive, it may meet with rejection at the eleventh hour. Moreover, the claims for compensation on the part of certain land holders through whose property the line of works must pass have yet to be considered, and may prove a fatal stumbling block in the way of the adoption of the Sawyer's Bay scheme. The other scheme — that of bringing in water from Carey's Bay — we have nothing to do with at present, our purpose merely being to give a rough description of the proposed works in connection with the Sawyer's Bay scheme. AYe base our remarks upon the plans and specifications that have been prepared by Mr C. D. Irvine, C.E., and very kindly placed by him at our disposal. According to those plans, the Sawyer's Bay AVater Works will involve the construction of a large reservoir, and the laying of about two miles of mains to convey the water to the Port. The proposed site of the reservoir has been selected in a very advantageous position, about one mile up the main creek of Sawyer's Bay, where two or three smaller creeks meet, and form the large one. The natural features of the locality are exceedingly favourable for the proposed work, constituting as they do, an extensive basin that only needs the finishing touches of man's skill and ingenuity to render it suitable for the purpose in view. The site has long time been occupied by Messrs Carston and Harris's sawmill. Its formation is stiff clay, whilst abundance of stone for masonry purposes exists near at hand. It is proposed to develope the above basin into a suitable reservoir by the construction of a substantial dam across the gully — the dam to consist of a main bank, with a puddle wall. The length of the dam will be 400 feet, height 50 feet, and depth of water in the centre, 30 feet. The area of the reservoir will be about four acres, and its estimated capacity eight million gallons. The supply of water in the driest season is set down at 40,000 gallons per diem. , which can be increased to 60,000 gallons by bringing in another creek that exists in the immediate neighbourhood. A well tower of substantial masonry, through which the supply pipe will, pass, is to' fie built in the centre of ; the reservoir, and will be connected with a culvert of masonry passing outwards to the face of the dam. The supply pipe, which, of course, will also pass through this culvert, is to be 9in. diameter, whilst the diameter of the mains will be only sin. Two smaller dams are also to be constructed across where two of the creeks will flow into the reservoir, andsoform subsidiary reservoirs in which the water will undergo partial filtering. The larger of these subsidiary reservoirs will have an area of 3500 square feet, and the smaller an area of 1600 square feet. A small well tower is to be constructed in the larger, so that in the event of anything going wrong with the main supply pipe, the supply of water to the town may be kept up. Stormwater channels will run froua each of the smaller reservoirs, and a capacious bye-wash from the main. one. AYe are assured by Mr Irnne that the construction of the proposed works will be comparatively easy, and that although the elevation of the reservoir above sea-kvel is 250 feet, the gradient is so gradual as to offer easy facility for laying down the main line of pipes. We are very glad to find that in connection with a water supply for their town, our Port Chalmers friends have advanced so far in the desired direction ; and we hope that whether or not the scheme under consideration becomes fully matured, the subject will not be allowed to rest until every house in the town has a lap of the pure clement ready to turn on at any moment, and the town itself is in possession of the only sxire aid against fire.