PAPAKURA WATER SUPPLY

Pukekohe & Waiuku Times, Volume 9, Issue 497, 16 January 1920, Page 2

PAPAKURA WATER SUPPLY

i Modified scheme Adopted Proposed Loan £25,000 Engineer's Report The need of a water supply for Papakura has be p n strikingly evidenced during the last two dry summers. At the present juncture the position is very acute, and unless rain is experienced very shortly, the whole diatiict will bo " dry" tho only alternative being that the population will have to fall back on a few wells in the neighbourhood. The Town Board realised the position years ago, and although engineers' reports on the possibility of a supply from the Hunua ranges have been obtained, none have been approved until recently, when the Board was more or less compelled to take steps in the right direction A'l those cognisant with the Hunua stream, are of the opinion that it could be utilised, and would tho district for many years to coma On Juno 13th, 1919, the Board's Engineers, Messrs Lockie Gannon and McDuff, compiled an additional report, on the possibility of obtaining a water supply for Papakura from the Hunua stream. The report deals with the capacity of delivery of 6in,, 7in , and Bin. supply pipes and separate estimates of the cut of the work They collider that any of these pipes would ba sufficient to supply Papakura for many years to cowe. The size of pipe'adopted should depend upon the possible future growth of the township If the population did not exceed 5,500 a six inch supply pipe would suffice. If it reaches 8000 people, a seven inch pipe was necessary, whereas if tho population reached 11,000, an eight inch pipe wonld be required. Their observations and guagings of the stream in the drie3t of seasons, just prior to the breaking of the recent drought, show that there is an ample supply of water to provide Manurewa, as well as Papakura. As a result they found that the stream at the fork near the five mile peg, gave a combined flow of 625,000 gallons per day, the left branch contributing 500,000 gallons per day, and the right branch 125,000 gallons per day. They had completed enengineering surveys, and had taken proper levels along the proposed pipe track from the township to the Head works beyond the Hunua Falls. The route chosen commences at the intersection of Great South Road and Broadway, Marne Road, Settlement Road and up the Hunua Road to the dam site T e pipe track crosses the bridge across Hay's stream on the flat and continues up Sunua Roa-l to Newton's point. It then crosses the stream on trestles, and after passing through a short tunnel, follows the stream to the Head works. In order that the residents along the road may benefit . from the scheme, the pipe track has •been kept to the road throughout. was considered prudent whera possible, to avoid pipe laying in private property in cas9 of bursting : mains, leakage and p issible damage 'to »operty. A six inch cast iron pipe would deliver 320,000 gallons in 24 hours A seven inch 475,000 gallons and and an eight inch 690,000 gallons Allowing for friction, the pressure a' Broadway would be 651bs to the C ire inch. Ttie district was torrte in having the pressure availtl e increased coasump

WW tfftrraitted if, this would permit of the inftalla'i >n of a settling reservoir ou one of the hills in the viv-iuicy of the township. The advantages of a reservoir were manifold la case of flood a clear supply wis ensured, and in case of bursting mains, or washouts between the intake and the reserv >ir, several days supply could be drawn from the reservoir, while repairs wore being effected. \ ro?ervoir was of great advautage, but not absolutely essential to a district.

The site chosen for the -am was an ideal ona, above the fork in tho left branch of the stream, the catchment area bsing at a high altitude, and practically covered with virgin hash A dam could be erected as the valley id narrow and precipitous, and presents a good rock foundation. The foundation is such that the capacity of the dam could always be increased if desired, and stovage made for a long drought, sufficient to supply Papakura and the adjoining districts for many years to come. Surveys and levels were taken up the left branch of the stream above the dim v site iu order to ascertain the conservation area, and as a result the observations show that a dam, raising the water 20 feet, would give a storage capacity of abjut -1A million gallons—sufficient to supply the present population for 88 days, or :en times the existing population for nine days. A dam 12 feet high would store million gallons, supplying the present population for 30 days or ten times the existing population for three d ys. The quaUty of the water was excellent, and :h it it may remain so, it was absolutely essential to prevent dwellings from being erected oa the catchment ar9a, and to prevent any further destruction of the bush The reports adds: "Papakura is m )st fortunate in having a source of supply with a go >d dam site, conservation are i and wholesome supply only about 5 miles from th i centre of the Township." The report d-alt at sunn length with the re'i< u'a'.ion problem and states ' The roticulation is designed in such a manner that a good ciiculation will be obtained throughout the district. In the event of repairs being made for shutting t.ff the various sections by stop valves, thus reducing inconveniences to consumers to a minimum. Dead ends have have been avoided as far as possible. Though this part of the scheme is on a comprehensive scale -iu the interests of economy and owing to the high price of cast iron pipes, and tho possibility of a reduction in tho future, the engineers submitted an alternative scheme of reticulation and it is this that the Board decided to place before the ratepayers .iskui;; tiiem t) eaactio i a loan of £25,000 plua an extra amount for the acquirement of a catchment area.

Ia the comprehensive scheme it was proposed to use four inch cast iron pipes in practically all streets with, hydrants, sluice scour and air valves, and an eight inch cast iron supply pipe. This scheme would run into practically £33,000. In the modified scheme and the one which the Board accepted it is proposed to use in isolated street! where houses are not thickly populated, I i inch and two inch galvanised wrought iron pipes. Under the adoption of ao up-to-date water reticulation echeme in a district, a fire brigade] is soon formed and fire insurance rates are reduced to a minimim. The fact cannot be ovei looked that a good water supply is a local body's best asset. The Board decided to accept the estimate of a seven inch cist iron supply pipe, wirh the modified scheme of reticulation. Estimates were al»o submitted for eight inch and six inch pipes. KEPORT BEFORE THE BOARD. In acc irdance wi.h notice of motion given at a previous meeting Mr McLenu n moved that the Board approve of the amended water supply scheme from Huuua Gorge, as submitted by the Engineer Mr Lockie Gannon. Seconded by Dr Brookfield and carried. It was pointed out that at tho rate of 6] per cent for interest and sinking fund, a rate of about 2{d in the ; £ would have to be struck. The additional rate would make a total nte of about 4d in the £. In time it wasr stated that the revenue from the water supplVi would make the undertaking self supporting, thereby ..makings constantly diminishing rate. Members considered that water vta absolutely essential in the interests and gress of the district. It was decided to take steps to get the ratepayers to sanction a loan b! £25,000 plus an amount for the acquirement of a catchment area.