City Estimates of Water “Haphazard & Misleading"

Sun (Auckland), Volume I, Issue 249, 11 January 1928, Page 9

City Estimates of Water “Haphazard & Misleading"

ENGINEER’S FIGURES ATTACKED

CLAIMING that the figures supplied by the city engineer, Mr. W. E. Bush, in connection with the city’s assured water supply are haphazard and misleading, the Mount Eden borough engineer, Mr. J. Rogers, who has previously disagreed with the city authorities, has adversely reported to the Mount Eden Borough Council upon the present situation as regards Auckland’s water supply. He also states that the city should be in a position as would avoid the existing fiasco and remove all restrictions.

Tl/TR. ROGERS has submitted a report to the Mayor of Mount Eden, in which he states:

“After perusal of the account respecting the water supply outlook, together with the report thereon, submitted to the Water Supply Committee by the city engineer, I am of opinion that your own request to the residents of Mount Eden to refrain from the use of hose for watering gardens should be withdrawn.

“The engineer states that from October 1 to December 31 last,' a period of 92 days, there was a total consumption of 792 million gallons. Of that quantity 332 millions were taken from the reservoirs at Waitakere and Nihotupu, leaving 460 millions, or an average of five million gallons a day, supplied from running water. RESTRICTIONS NOT WARRANTED

“It must be evident from these figures, more particularly with running water at five million gallons a day, when the average total consumption is given at 8,600,000, that the restrictions are not warranted. There is an apparent discrepancy in the engineer’s report, which I think needs some explanation, for while the engineer states that five million gallons a day were available in December from running water, and that during 25 days up to December 31 there had been 40,551,000 gallons pumped from the Western Springs, equal to 1,620,000 gallons a day, making a total visible supply of 6,620,000 gallons, yet at the present day, the enginer states, assuming that the present dry weather continues, and allowing that the running water in Waitakere and Nihotupu and the quantity pumped from the Western Springs will equal three million gallons a day, a quantity approximately one mil lion below what is being drawn from tEese sources at the present time, there is sufficient supply available to give Si million gallons a day to March 23 next, and still leave 47 million gallons in storage. “Now if this assumption and computation is extended proportionately, the visible supply at Waitakere and Nihotupu will entirely disappear, as you

will observe that the engineer’s four million gallons a day includes 1,620,000 gallons from the Western Springs, which leaves a balance of 2,380,000 as being available from running water at Waitakere and Nihotupu, showing a loss from these sources of 2,620,000 gallons over a period of 10 days; consequently if this shrinkage continues it is a natural assumption that in another 10 days the latter quantity must disappear.

“I think the engineer's assumed available supply to March 23 next may be verified, but on the other hand these assumptions at the present juncture are haphazard and misleading, and the present acute position should be definitely stated and not assumed.

“I understand that gauges have been established on the streams supplying the reservoirs at Waitakere and Nihotupu, therefore it is quite a simple computation to arrive at the daily run off and the percentage of loss a day; without rain the daily reduction will increase rapidly due to absorption and intense evaporation. INFORMATION WANTED “At the present crisis in Auckland’s water supply the following information should be supplied for the information of your council and the residents oi the borough:—(l) The actual quantity of water pumped from the Western Springs; (2) the actual quantity of water (from surveys) now available at the Waitakere and Nihotupu reservoirs; (3) the gauged quantity of water flowing into the reservoirs; and (4) the gauged quantity of water flowing down the Huia stream at site of proposed dam. “With this information before you the true position will be manifest, and the assumed computations may be disregarded; but it is both unreasonable and unjust to expect ratepayers to restrict their supply and depreciate the value of their own property, if such restrictions are unwarrantable from actual facts. “I have consistently maintained that the city engineer’s assumptions and calculations were too generous, and his rainfall allowance of 45 inches, together with the daily run-off under such assumption, would not be borne out under practical test, and bis engineering theory that an ideal reservoir should be such as to stand the strain of a drought and become just empty at the breaking of the longest possible drought, leaves no margin of safety whatever. I must respectfully emphasise this fact, that the City Council should be in such a position as would avoid the existing fiasco and remove all restrictions on the consumption of water, particularly at dry seasons, when an increased consumption should be expected and provided for.”