Ashburton Gurdian MAGNA EST VERITAS ET PRÆVALEBIT. WEDNESDAY, JULY 31, 1907. AN EXAMPLE IN WATERWORKS.

Ashburton Guardian, Volume XXIX, Issue 7243, 31 July 1907, Page 2

Ashburton Gurdian MAGNA EST VERITAS ET PRÆVALEBIT. WEDNESDAY, JULY 31, 1907. AN EXAMPLE IN WATERWORKS.

Some examples are. to be followed, others to be avoided; and it would seem that, with respect to waterworks, the example set> by Invercargill stands in the second of these categories. Yet the Invercargill water supply has, off and on, been spoken of as a model for Ashburton. Perhaps the central principle of the scheme might be acted on hero with advantage; but it may be well to know that Invercargill itself is at present contemplating a complete change in the matter. This is due to. several causes, one of which, at least, might not operate in Ashburton, as it_ consists in the excessive percentage of iron held in solution in the water, used in the supply. The natural conditions here might exchido this contingency, but other factors in Invercargill's scheme would probably be met with sooner or later by any municipality which happened to adopt the general plan. This consists in pumping by steam into a tank in a water-tower. Apart from the presence of an undesirable percentage of iron in the water, Invercargill lias found the scheme unsatisfactory, especially,.\yi+-V respect to sufficiency qf.i-lie supply at all seasons. ;Tho ■Invercargill water-tower is a Hundred feet in height; its tank holds, approximately, 60,000 gallons, and the supply is raised by means of a steam pump from a level that lies eighty feet below the surface. Latterly there has been little rain even in Southland, and the people of Invercargill have been brought to ( feel that, without, assured assistance trolil the rainfall, they could not depencV 'on the supply in the water-tower tank from the eighty-feet level. Yet last year the coal and labour required in connection with the steam pump cost the town £1118. The experience thus Sained has led the Invercargill Town Council to consider the installation ot a larger and more secure supply, drawn from the Oreti river, and impounded in . a reservoir which will hold seven million gallons, which will be carried by pipes, to the town for a distance of thirty-eight miles. The approimate estimate of its cost provides for —

38 miles of 15jn spiral pipe (not including cost of trenching or carrying of pipes from Bluff) at £1600 per mile £60,800 Trenching, 38 miles at 25s per chain or £100 per mile 3,800 Railway carriage from Bluff to average 40 miles, 2500 tons at 16s per ton 2,000 Head works, including inlet pine, reservoir to hold ?.- ---000,000 gallons, filter beds, etc., say' 10.000 .Purchase'of land 2,000 Engineering inspection, and contingencies, 10 per cent. 7,800 Total £86,400 Reticulation of suburban boroughs '. 86,563

Grand total £112,263 The supply to be thus provided would be sufficient for the needs of-a population of 24,000 persons, and is on a scale far in excess of Ashburton's requirements; but, in view of the early introduction of an adequate supply for Ashburton, the ratepayers, and their representatives in the Borough Council, will probably be none the worse for knowing something about the past experiences and present proposals of Invercargill.