The Corporation Water Supply.
THE CITY SURVEYOR’S REPORT.
Mr Louffhrey, City Surveyor, has reported upon the Wainui waterworks. He agrees in the main with Mr Higginson’s report, but he differed with him on some points, especially as to his suggestions for necessary alterations and additions, and the methods of carrying these out.
He, like Mr Higginson, had been led to understand that the supply and design had been approved by Mr W. Clarke, and has therefore no remark to offer further than he considers that, as the reservoir is only intended to act as a “settling pond” and not for storage purposes, it would have been much better in the first instance had the cast-iron mains been laid direct to the reservoir, thus dispensing with the race and well — the latter more particularly, as the advantage to be gained by it appears to him very questionable in comparison with its obvious disadvantages. Amongst these was the difficulty of at all times regulating the supply so that a full head of pressure might be maintained in the well, and at the same time the waste at the bywash prevented.
Had the pipes been laid to the reservoir at a level of 10ft below the level of the present race, there would be no necessity to shut off the water from Wainui, as the flow of the river, aided by the extra quantity stored in the reservoir, would have been sufficient to meet all requirements, and the head of pressure would not have been always varying. The cost of pipes in the first instance would have been less than the cost of the race and well.
He does not consider it necessary to increase the area of bywash for the escape of floodwaters. As regards the stream, Mr Loughrey — while holding that the average annual stream is still ample for the requirements of the city — adds:
“But storage is required during the wet season, and this can be obtained at various places along the stream at comparatively small cost, as I have previously reported to the Council; and I must here beg to differ from Mr Higginson, and recommend the utilisation by storage of the present source of supply, which is as clear as crystal, and leave the Orongorongo to future generations, especially as the maximum supply possible by the present mains is 5,091,840 gallons per diem, and the Wainui stream at its largest would supply more than double this quantity.”
With regard to the construction and class of work, he points out that the only portion with which he was concerned, directly or indirectly, was (in conjunction with Mr Blackett, Consulting Engineer) in effecting the repairs to the face-wall, and laying the three 24-inch sluice pipes and the cushion wall. With those exceptions, the work was handed over to him as completed.
The interior examination of the race, he maintains, should have been entirely unnecessary, with the very slight fall (6ft 6in in a length of 2110 yards, or 1 in 600), had the work been performed with thoroughly good material in a reliable manner. The rendering of the interior, if properly done, should have made it watertight for a century with so slight a flow.
The causes for its failure to do this might be as stated by Mr Higginson, but it does not alter the fact that the workmanship at least must have been faulty. With respect to the interior, he has been through its entire length, and, as previously reported, found the bottom sunk in places, the rendering having altogether disappeared in some cases, and in others large patches having flaked off.
Mr Loughrey goes on to deal with several matters of detail, and says that in his opinion the sluice pipes are of sufficient size, although an extra one might be necessary at the lowest crossing of the Wainui. The records made proved that there is very little loss from leakage from the pipes, but water was continually running to waste in public houses and from public conveniences.
The variations in the readings of the pressure he accounts for by the well not being full. He agrees with Mr Higginson that the rules and regulations for checking waste should be much more stringent, as he suggested to the committee in his report of the 10th January last. But, as he before mentioned, the people had been educated to waste the water as they liked, and it would take some time to undo the evil.
“In conclusion,” says Mr Loughrey, “I may mention that I have, in these remarks, commented on those matters only in Mr Higginson’s report with which the committee may perhaps think I have been directly concerned, and which have been mostly reported upon by me at one time or another. The committee will bear in mind I am not making a report on the water supply; that I have not been asked by them, or at any time by the Council, to report on the supply generally or any portion of the works, so far as construction and strength is concerned; that the Wainui works, with the exception before referred to, had been completed by my predecessor, and that my instructions were to get the water turned into the city with the least possible delay.
“I had, therefore, neither time nor reason for supposing that the scheme had not been properly matured, and the whole question of strength of pipes, size and quantity of valves, etc., thoroughly considered, and ample provision made. Neither would it have been consistent with professional etiquette had I, newly taking office and without being requested by the Council, proceeded to criticise and report upon a work newly carried out by experienced engineers in the employ of the Council.
Tags: Newspaper Water Race Waterworks“With the work directly superintended by myself I have every reason to be satisfied, and it has been my constant endeavour, and that of those under me, to look after and maintain the whole works in as efficient a state as possible under the circumstances.”
