MORE WATER

Evening Post, Volume CXXVI, Issue 83, 5 October 1938, Page 15

MORE WATER

BIG SUPPLY SCHEME '

WIDE SUBURBAN

RANGE

LOCATING THE MAINS

The question of the ultimate water supply for an extended Wellington, to take in areas at present unconnected with the Water Board's scheme, has been-exercising the attention of both the City Council and the Water Board for some considerable time and at the meeting of the.board today it was decided, after the reading of a comprehensive preliminary report on all supply routes and possibilities prepared by the City Engineer (Mr. K. E. Luke) to seek the co-operation of the nonallied bodies (Makara County, the Johnsonville and the Lower Hutt and Petone Boroughs) in sharing the expense: of a still more complete report for the utilisation of all sources of water south of the Waikanae River, the whole question, and a big one it was shown to be, to be then reconsidered. The entry or non-entry of Petone and Lower Hutt will considerably affect the ultimate scheme. A preliminary estimate of the cost of the provision of one main.along any of the routes indicated was £750,000;

The preliminary report by the engineer covered Paraparaumu, Paekakariki, Flimmerton, Titahi Bay, Porlrua, Tawa Flat, Johnsonville, Upper Hutt. the Hutt County area between the Upper Hutt and Lower Hutt boundaries, Hutt County eastern harbour districts to Day's Bay. and Eastbourne, and in connection with these, the major problem of supplying the city. A map supplied with the report showed the alternatives of main route supplies from the various -catchment areas with reference to the serving of districts or groups of districts, one route of supply showing the possibility of serving part of the western coastline north of Tawa Flat. NORTHERN COASTLINE. Dealing with the coastline from Pu~ kerua Bay to Waikanae, and considering Paraparaumu and Paekakariki, the report, forecast a large development of a weekend and holiday character of a "ribbon" type character, but on the score of economy, .serving this area from the board's sources was not worth considering for at least fifteen years; local sources should serve in the meantime. It was estimated by the Hutt County engineer that a Quartz Creek developed supply would serve from 3000 to 4000 persons in the township of Plimmerton for the next fifteen years, but Plimmerton would be further considered in connection with the Whakatiki-Akatarawa develop- | ment.

Paremata, Titahi Bay, Poyirua. and Tawa Flat had no, ascertainable local sources suitable for use without treatment. The development of these areas would be retarded without proper water supply, and it seemed that" they would prefer to rely on city sources, or some other form of Water Board development. These places, with Plinimerton, could be served by a Whaka-tiki-Akatarawa development, while Titahi Bay, Porirua, and Tawa Flat could alternatively be reticulated back form another trunk main at the junction' of Takapu Road with the Main Nortli Road, though the latter supply could not be extended to Paremata or Plimmerton. If another trunk route of supply were adopted, these areas could be served by an extension of the city system up Ngahauranga Gorge or from Khandallah, in both cases through Johnsonville. A similar position would exist if the trunk route from the Main Hutt River wei*e used.

Johnsonville already had a 1 water supply, but: the catchment area was not protected, and the supply was not treated. It was unlikely to supply more than the present population. The supply was now pumped, and if the proposal -to absorb Johnsonville in the city was carried out, it would probably then be served by an extension of the Khandallah supply or. a feeder main up the Ngahauranga Gorge.

UPPER HUTT AND EASTBOURNE.

Upper Hutt was in the same position as Johnsonville. It had a limited catchment area, to be augmented by a well supply at Trentham. That area and the part of the Hutt County between it and Lower Hutt at present without water supply could be served from either of two trunk routes* but not without separate provision and heavy expense if two other trunk routes were utilised.

Eastern harbour districts and Eastbourne were now taking artesian water by arrangement with the Lower Hutt Borough, and for the immediate future the cheapest procedure would be for the eastern bay districts to take water from the Eastbourne main which traversed their length. There was a possibility of Day's Bay developing a water supply \ from within its own area, but; unless treated, this supply

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would be open to constant suspicion jon account of the possibility of conI tamination. Should it ultimately prove desirable to supply Eastbourne from a source other than the artesian sup- ■ ply, arrangements could probably be made to tap either the Wainui or Orongorongo supplies where those I mains intersect the Day's Bay Road lat Gracefield. This would not be possible until some major development I supplying water in compensation was | available to the city. i ROUTE SELECTION. i Having outlined the possibilities of i supplies from trunk route locations ; already established leading, from catch- ' ment areas controlled by the Water j Board to the city, it would be seen, ■said the report, that the problem largely rested on the selection of the trunk ! routes —a coastal route, an inter- | mediate route, or one of the two routes ! leading down the Hutt Valley. The logical route would be down the two last named, apart from the question of j artesian supply, as they led through well built-up areas capable of expansion immediately. This would enable the Upper* Hutt Borough and the Hutt County area mentioned to be economically served. Both Hutt County and the Upper Hutt were actual members ;of the board, whereas Titahi Bay, | Porirua, Tawa Flat, and Johnsonville had no representation on it. Against Ithat two other routes would provide Wellington City with a trunk main away from the Hutt Road, along which all the existing mains lie. From the city's point of view this alternative trunk main location would certainly possess many advantages. PETONE AND LOWER HUTT. "It becomes evident," continues the report "that a decision as to which route the main should follow will depend largely, if not entirely, on the attitude of the two authorities in the Hutt Valley now usipg artesian wat^r. X Petone or Lower. Hutt.propose the abandonment of their artesian supplies .within a reasonable period of years, or if they consider they will require to augment these from the board's sources within the near future, then it would appear that a selection of valley routes would justify separate provision to extend a supply from city sources to serve areas along the Main North Road to Titahi Bay. The board should now take steps to ascertain the attitude Lower Hutt and Petone will adopt towards the proposal the board is now considering, whether they wish to be joined in the investigation now in hand, and whether they will require in future supplies of water from the, areas now under the board's control. ... Within the next fifteen years financial considerations would limit the construction of trunk mains to one only of the routes indicated. The construction of a main along any of the routes indicated, with provision for supplies en route, would require £750.000. The board is seriously handicapped in preparing a comprehensive water supply for Wellington by the exclusion of the Hutt Valley artesian supply -from consideration. Under the Act, it lies without the board's jurisdiction. ■ . SALIENT FACTS. The main facts which emerged from the engineer's report, reported the Town Clerk (Mr.E. P. Norman) were that the cost of either of the two main schemes (Whakatiki and main Hutt Rivers) would be very large, and it did not seem financially feasible to attempt more than one main development within the next fifteen or twenty yeaiw. The engineering characteristics of the two main schemes differed so much that it would not be practicable to lay one main large enough to take the maximum of both developments, even if the Hutt Valley district did not come into th 6; scheme; the drawoff from;'the systjein would not justify such an expenditure,.and. by the time a steel main of.such a size was required its economic life would, have been largely used up.

If the Hutt Valley did no,t come, into the first scheme of development the Whakatiki .development with routes escaping the Hutt Road, and possible, disruption of the service if an earthquake destroyed that road, contained also the advantage of cheapness so far as supplying the city was concerned, but branch mains to Upper Hutt'and the Hutt County areas in the Hutt Valley would cost more. Limitations of the airtesian supply should be investigated so that all areas could obtain a fair share of what was available. Increased settlement in the Valley would increase the risk of contamination of artesian supplies. Investigation of the schemes would cost much, and Lower Hutt and Fetone should be asked to share in them, without committing themselves to any policy of surface water supply. Should they decide not to do so, investigations in the first place should be limited to the development of the Whakatiki, and the supply of areas lying between the city and Titahi.

With electioneering publicity going on all around, every spot that will serve as a "billboard" is utilised by One side or the other, says the Wanganui correspondent of "The Post." Even the newly-painted girder over the Wellington Road subway has not escaped. > Written in large chalk letters are the words, "Vote for Ormond Wilson and Labour." The writer failed to notice that a sign immediately underneath, in large red letters, reads, "Extreme danger." • ■ ■