WATER FOR NORTH SHORE

New Zealand Herald, Volume LXIV, Issue 19744, 17 September 1927, Page 12

WATER FOR NORTH SHORE

SUPPLY FROM WAITAKERE.

BOARD APPROVES SCHEME.

PIPE-LINES ACROSS HARBOUR.

COST ESTIMATED AT £236,500

The North /Shore Boroughs' Water Board yesterday decided that a major pebeme for the supply of water to North Shore boroughs should be embarked upon in the direction of taking the necessary preliminary steps of submitting it to the combined borough councils, and that the Waitakere scheme be the scheme submitted. The board's engineer, Mr, F. E. Powell, was asked to report on the Rangitopuni and Waitakere schemes and also on the continued use of Lake Pupuke under the conditions suggested by the recent water commission. Mr. Powell recommended the Waitakere scheme. In his report, Mr. Powell said the effer of the City Council to supply water at 6d per 1000 gallons was a very favourable one. The water would have to be taken at the break-pressure tank, which was 212 ft. below the water-level of the Waitakere dam, and then run in pipes through 'Swanson: and Hobsonville, and across the harbour to a point near Birkdale. From there it would be conveyed to a dam to be built at Birkenhead, and then distributed throughout the boroughs. Delivering Maximum Supply. The break-pressure tank was situated roar Swanson and the pipe-lines wOuld ran through country that would prevent no engineering difficulty beyond the usual bridging of gullies and small streams. The cost of this scheme was estimated at £220.000, which, in addition to the first year's interest, would bring the price up to £236,500. With an 18in. main, a total population ©f 35,000 could ,be served when the main •was working at its full capacity by gravitation only. By the installation of a boosting-pump at the lowest level of, the main it could be made to deliver the maximum quantity Waitakere could ever supply, or sufficient water for 70,000 people, with a comparatively small increase in cost. Regarding the Lake Pupuke supply, he considered the pumping-stations should -be retained and kept in order, so that, in the event of a breakdown lasting longer than the storage time bt the various local reservoirs, Lake Pupuke could be relied upon as a source of supply. Assuming that all the residential area of the watershed was properly sewered and the water supply chlorinated, no risk to health would result. He estimated that under favourable conditions the Waitakere scheme could be in full operation in two years, assuming preliminary work could be put in band while the necessary legal matters were being framed. Cost of Eangitopuni Scheme. The main objections raised by the commission to the Rangitopuni scheme Were that the water came from a contaminated area and that in the first stages of development the shallowness of the dam reservoir would tend to the growth oi vegetation and algae which might be detrimental to the itaste of the water, He estimated the total cost of the Rangitopuni scheme as £263,300. Mr. Powell's comments on these objections indicated tho possibility of neutralising the risk of /contamination aud removing all traces of discolouration and taste. With regard to Lake Pupuke, Mr. Powell dealt with the proposal of the commissioners, which was to employ only one pumping-station and to carry the suction pipe-line well out into the lake. The cost of this work would be at least £7900, and it was estimated the cost of the water would be 6d per 1000 gallons. The chairman .of the board, Mr. E. lAldridge, Mayor of Devonport, 6aid they lad come to the time when they had to face a future water supply for the North Shore. Various schemes had been suggested, and there were factors in the problem which staggered one's sense of responsibility. The Lake Pupuke supply was uncertain and opeu to contamination, and it was absolutely necessary that they she old give the people a pure supply of water at a cheap rate. Consulting the Councils.

The reasonable course was to place any scheme they agreed to before the borough councils concerned. The responsibilities were too heavy to shoulder them without obtaining the opinion of those whom they represented. They snould take the borough councils into their confidence. Regarding Lake Pupuke, they were faced with a falling level and different boroughs .were embarking on: sewerage schemes which would still further diminish the supply.

When the meeting was asked to- carry a recommendation of the board-in-commit-tee, that a major scheme should be embarked upon, Mr. A. E. Greenslade, Mayor of Northcotc, said be considered they should not rush the matter, but should look round for every available source of supply. Mr. Aldridge: For the past six years we lave been discussing a source of supplj\ Mr. Greenslade: Now we are going to jump., : i -

Mr. E. G. Skeates, Mayor of. Birkenhead, said they were considering a scheme that was to cost a-qnarter of a million. He felt it was a ridiculous expenditure and they should investigate every source beforehand.

Mr. J. W. Williamson, Mayor of Takapuna, said he felt thev must go ahead with it. Defeat of an Amendment. Referring to Mr. Aldridge's suggestion that they were faced with a tailing supply in Lake Pupuke, Mr. Greenslade said ho could bring figures to prove that on the contrary the water was at a higher level now than it was at the same time last year. "I am strongly of opinion we should decide on the Waitakere scheme and place it before our respective borough councils," stated Mr. Aidvidge. "We are simpiv trying to give the people a lead. The question will have to come before the ratepayers and the Local Government Leans Boards" In the ordinary course of events the whole scheme would be forwarded by the Loans Board to the Public Works Department. and thoroughly investigated by competent and impartial engineers. Before the resolution was put to the lueeiing, Mr. Greenslade moved as an amendment that the word "embarked" Should I>e. substituted by the word "considered." The amendment was defeated. Mr. Skeates and Mr. Greenslade votinc in favour of it. It was then unanimously de oided that the Waitakere scheme should bp submitted.

It was slated a meeting of ronresenta fives of ihe four borouch councils would Shortly he called when Mr. Powell would explain the scheme fully, and then it ■would he referred to individual councils for their consideration.