VIEWS OF ENGINEERS

Auckland Star, Volume LVII, Issue 86, 13 April 1926, Page 5

VIEWS OF ENGINEERS

EXISTING AND FUTURE SUPPLIES, j Subjoined are interviews on the sub-: ject of Auckland's water supply with Mr.; •T. Carlaw. who was for 46 years waterworks engineer to tho Auckland City Council, and Mr. F. D. C. Allen, who is i the managing director of a London fil-1 tration firm, with which the council has I been in treaty in connection with its. filtration plant. Both gentlemen discuss! the existing sources of supply, and both] take the view that ultimately, when i Taupo becomes a source of supply, the | existing facilities will still continue as. at present, thus reducing the cost of) trunk main, and providing an alternative; source of supply in the event of acci-, dent. ! "In reporting some years ago on Taupo," remarked Mr. Carlaw, "it was not my intention to condemn the water policy of the council in the Waitakeres, being of the opinion that the money had been wisely spent, and nothing would be- lost even if the Taupo scheme was adopted, as both could ' be worked in conjunction, and, in case of accident to either, the other would be available. In my opinion it is necessary to proceed with at least the Huia gravitation scheme in order to provide for the rapid growth of the city and suburbs." English Engineer's Views. "I have followed the controversy on this subject with considerable interest," observed Mr. Allen, when asked for hifi views on the water supply question. '"Possibly the views of an English engineer may be of interest to you. "The advocates of the Taupo scheme claim that the Taupo water is of better quality than the Waitakere water, and this would be true if no scientific colourremoval and filtration process were available. With the treatment that the council proposes, the Waitakere water will be better than the Taupo, as not only will it be as pure and uncoloured, but it will have far less action on pipes. Most people do not realise that the Taupo water would have a seriously corrosive action on their pipes, which would caoise discoloration of the water through rust, whereas the treatment of the Waitakere water proposed by the council includes that which is necessary to neutralise the existing corrosive action of the water. "Finally, I do not think that many people realise that, with the filtration plant, the water will not need chlorination. When Auckland reaches the size of Sydney, no doubt the Taupo water will be required, but the existing water supplies will then be used in conjunction with Taupo. The weakness of the case for the Taupo scheme is the suggestion of scrapping the existing supplies."