LETTERS TO THE EDITOR

Dominion, Volume 8, Issue 2413, 19 March 1915, Page 7

LETTERS TO THE EDITOR

ONSLOW WATER SUPPLY. Sir, —It is gratifying that at last the Mayor of Onslow has come down with some definite statement upon the above subject, and it would, appear from his letter of the 15th inst. that he bases all his calculations upon the rainfall. Mr. Crump says, all authorities agree with him, and immediately goes on to say that after consulting them he allows 40 per cent, for evaporation, seepage, and overflow (tljo last-mentioned is a thing ho must calculate on his own authority, as it is of necessity a matter that can only be determined b„Y the actual rainfall in a given time, and would vary). Now I would refer Mr. Crump to "The Municipal Engineers' Specification," an English standard authority, and he will discover that seepage, vegetation and evaporation, absorb from 50 per cent, to 75 per cent, of rainfall—not 40 per cent, as Mr. Crump states, but of course "small" matters like these do not count with advocates of any scheme. You will therefore see. Sir, that it is not wise to' calculate on less than 60 per cent., a fair estimate for practical purposes, for losb in that way,' this leaves 40 per cent, of the rainfall available for storage, or, say, 9000 gallons per acre for each inch of Tain. The area, according to Mr. Crump, from which'he will be able' to obtain the. water, is 130 acres, so that there will be on his figures of 46 inches of rain about 52 million _ gallons for storage (if it can all be impounded), and not 78 millions as Mr. Crump olaims. But unfortunately for Mr. Crump only 30.35 inches of rain fell during 'the twelve months from March, 1914, to February, 1915, and the result is that for that year we would only have some 35 million gallons to meet our probable present requirements of "36 million gallons. Our needs are some three million gallons per month, but in August, September, October, November, 'December, January, and February only about two million gallons are available for .supply each month, whilst' March, April,June,_ and July would just about supply the right quantity, and the fall in May would fill the proposed reservoir and allow _ a few million gallons to overflow. Is it necessary to say more to show the absurdity of the scheme?. I think I have shown that the rainfall required is not there for last year at least, and Mr. Crump will, as ho states in his letter, agree with me that "the scheme is a fallacy. Mr. Crump in Mb figures allows 40 gallons per head, but taking , the township of Carterton,- with a population of about 2000, it is found that a'so- - allowance is not sufficient, and in the residential area of the Thames basrn the quantity used is 60 gallons. ■l ij 'k/ therefore, that our Mayor should be more, generous and allow us at least 60 gallons (if he is mean with his. allowance before the water is laid on what oan we expect afterwards?). Our 2000 population would therefore require 36 mulion gallons' for the year," and if we can look forward a population of, say, 5000, at least 90 million gallons will be needed, and if Mr. Crump can show how some 'of us will avoid boiufT thirsty, on a. 62 million or a 3o million gallon (in a dry year) catchment area he will be able to-give us some interesting information. Dealing with the proposed reservoir which is supposed to be of two months' capacity, I would refer Mr. Crump to an authority which in his search he ha appears to have overlooked—"Hurst's Surveyors' Handbook"—and he will find that this'authority definitely states that the minimum storage capacity should be equal to the estimated maximum consumption for four months, so that for ft, population of 2000 tne reservoir should store 12 million gallons in order to be on the safo side, instead of th© five millions as proposed. All that has been stated above only applies.. with more force ' should the population increase, and on the incomplete information supplied by the Mayor,.the ratepayers will be justified m withholding their authority from the council for them to waste money on a fanciful scheme. • One word in reference to Mr. Crump's assertion as to those opposed to his scheme bemg afraid to come out into the open, let me say, Sir, that at the publio meeting at Khandallah those.who were prepared to take tho open platform were prevented by him from domg so.—l am, ©to., _ A. B. BUDD, . . Hon. Seo, Committee of Ratepayers Opposed to Scheme. Khandallah, March'lß, 1915