WATER SUPPLY

Manawatu Standard, Volume XLVIII, Issue 58, 6 February 1928, Page 2

WATER SUPPLY

SCHEME FOR-IMPROVEMENT,

REPORT TO THE MAYOR. The Mayor to-day handed us the following report which he has received from the borough engineer, Mr J. RHughes, in connection with the water supply:— . in accordance with your instructions I submit herewith my reply to Mi Edwards’s remarks on the above matter. Let me at the outset say that Mr Edwards’s criticism is beside the point, merely made to create an atinospheie, and in keeping with his usual “red herring” tactics. To my knowledge none of the experts called in by the council have stated that the Tintea stream is inadequate. Quite the opposite. Messrs Toogood, Holmes and myself have reported at some length on this point, proving that the stream is adequate for double the present population if the winter flow of the stream is stored up for use during dry weather periods. As. however, Mr Edwards has made certain statements regarding the stream flow I will state the actual facts as they obtain at present. The timber weir which I have had placed across the stream above the present reservoir is built in accordance with recognised practice, extra care having been taken to sink it to a good depth, and sealing the upstream side with well pugged clay. I have been informed by the waterworks caretaker who built a weir in 1913 under Mr Jickell’s instructions that the present one is 50 per cent more efficient. Regarding Mr Edwards s supposed natural weir, let me say frankly I do not think he could have found one for natural measuring weirs do not exist. There are too many contributing factors to be taken into' account which preclude the possibility of obtaining accurate measurements or stream flow in the manner suggested by him. Will Mr Edwards take-a qualified engineer and again measure the flow in his presence at the site of his supposed natural weir ? To get down to actual facts, my weir was installed on 26th January and from Box’s Hydraulics—presumably known to Mr Edwards—we find that the flow was at the rate of 1,455,000 gallons per day, and on 4th February the flow was 9(2,000 gallons. The meter on the supply main shows that the actual amount drawn from the reservoir on 26th January was 1,764,500 gallons and on 4th February 1,782,500 gallons, a deficiency on the former date of 309,500 gallons and on the latter date 810,500 gallons. If the stream flow at the present time is three times the amount of draw-off (Mr Edwards’s statement) why in the name of common sense does the reservoir level still continue to fall in an alarming fashion? There is no mystery about the matter at all.

Now with regard to town consumption, as before mentioned, the amount of water which passed through the meter on January 26th was 1,764,500 gallons. 'ike present filter plant requires 38,500 gallons per day for washing purposes; we thus have 1,726,000 gallons passing to town in the 24 hours.

The population of the area supplied both inside, and outside the borough is 20,500. This gives a per capita consumption- of 84 gallons which for colonial towns is not out of the way. The fact that if the consumption was 50 gallons per capita, the draw-off would be so much is no argument; we are concerned with actual facts not mere assumptions. Mr Edwards says that the Wellington domestic consumption is from 21 to 25 gallons per capita, vide Messrs Holmes’s report, but what he does not tell you is that this is the consumption at one particular residence. Can he tell us the average over the whole, city ? In 1924 I had meters placed on three residences in Palmerston North and ascertained that the consumption averaged 69 gallons per capita. But what of the agricultural, industrial and public users, not to mention provision for fire fighting purposes. One public user in town alone draws 61,500 gallons per day. With regard to the capacity of supply mains, the draw-off is 1,726,0ui> gm lons per day, but this is not spread uniformly over the 24 hours; there are times when the flow is as high*as 1472 gallons per minute. With this quantity passing through the mains, the loss from the dam to Linton Road is 128 feel, but in the section fjom Linton Road to College Street the loss is 175 feet, making a total of 303 feet. The available head is 350 feet; therefore, the balance of 47 feet which converted to pounds per square inch gives 20.2 lbs., is totally inadequate. The obvious remedy is increased size of supply main from Linton Road and the laying of feeder mains. This is the pincipal item in the loan proposal of £55,700, not £200,000 as stated by some of the newspaper correspondents. Yours faithfully, JOHN R. HUGHES, M.N.Z. Soc. C.E., Borough Engineer.