REPORT BY MR MESTAYER.

Poverty Bay Herald, Volume XXVIII, Issue 9098, 16 March 1901, Page 4

REPORT BY MR MESTAYER.

WANGANUI WATER SUPPLY.

Air R. L. Alestayer, m his report to the Wanganui Borough, strongly urges the necessity of supplementing the existing supply which is drawn from the Westmere and Virginia lakes, and is altogether unequal to standing the strain occasioned by a largo influx of floating population during the tourist season, especially when combined with a hot dry summer. The population supplied from, the Lakes at the present time is about 10,000, and the daily consumption amounts to 60,000 gallons, or 60 gallons per head. The Lakes are too femiul and are liable to contamination; they are practically stagnant pools. Air. Mestayer deals at length with the question of an artesian water supply, and says: "As a purely temporary addition to the present supply, this arrangement would probably be about the cheapest that can be devised, but there are so many elements of uncertainty about it that I do not feel sufficient confidence m its ultimate success • to recommend its adoption." He points to the uncertainty of getting good water at any definite depth, the uncertainty m the cost of sinking, and the uncertainty of the supply proving to be permanent. In Christchurch, for instance, there has been a distinct fall m the level of the artesian water, which is now 10 feet lower than formerly. He then proceeds to make this interesting statement: — The water bearing beds are all composed of saud or sandy shingle, and m course of time the quantity of sand removed by the water will be considerable, causing more or less settlement of the over-lying elastic clay beds ; this will certainly af- ( feet the supply, even ii insufficient to cause any surface disturbance. The evil effects of removing solid matter from strata underlying a town have been strikingly exemplified of late years m the town of Northwich m Cheshire, one of the centres of the salt industry m England. 'The salt is dissolved m the beds m which it occurs by means of water, and is then pumped to the surface ih the form of brine, for treatment. Owing to the removal of the salt, and the consequent settlement of the strata overlying the salt beds, Nirthwich is now practically m ruins, not a house remaining unaffected, the ground m some places having sunk as much as 20ft. An artesian supply drawing from solid beds such as the chalk is not open to this objection, which however applies with more or less Jorce to *U1 those which, as m the present case, tap beds of sand underlying elastic impermeable beds, and the better the supply m quantity the greater will be the amount of material removed. Mr. Mestayer then proceeds to recommend the drawing of the supply from the Wanganui river at a point 25 miles up. The scheme includes pumping power, reservoir, filter beds, and main, the approximate estimate for the whole being: — Eight miles of 15in. ci. pipe, £30,000 ; Euinping station, engine foundations, and ouse for engineer, £2000; 120 h.p. oil engine, and pump, £2500 ; pumping main, valves, pipes, etc., for filters, £1300; reservoir to hold 1£ million gallons, £2500; filters on Fischer system, to pass \ million gallonß per day, £6500 ; engineering, legal expenses, and contingencies, £6700; total, exclusive of land, £51,500. . Mr. Alestar«\ concludes: — "The advantages of the river scheme over an artesian supply are , m my opinion, so great as to render comparison between them almost impossible. (1) The supply is inexhaustible, and can be extended to any extent from time to time as the.necessity arises. (2) No uncertainty exists either as to the quantity tHiich can be obtained, the quality o the water, or the works required to get it.. (3) A very great improvement will be effected m the present supply to the town, and the 15in. main will supply the maximum odemaud whilst maintaining the full pressure of 150 feet. . . . . (9) With a practically inexhaustible supply such as would rtieu be available, considerable revenue might be derived from the sale 'of water for power. (10) Considerable revenue might also be derived from the supply of water to residents along the

eight miles traversed by the 15in. main, and this would go far towards paying the interest on its cost. (U) The pressure m the town mains could be increased to about 500 feet by closing the valves connecting the river supply with Vinniiia Lake. In my opinion the advantages of the river supply ore so overwhelming that I have not the slightest hesitation m advising your Council to adopt it." ■