AN EARLY ADVOCATE

Greymouth Evening Star, 20 September 1932, Page 6 (Supplement)

AN EARLY ADVOCATE

There has been no lack of advocates of the Arnold River, as a source of electrical energy, and one of the earliest in the field was Mr. S. S. Fry, who unsuccessfully contested the first election as one of the candidates representing the Borough of Brunner. Delivering a pre-election address at Dobson, on December 11, 1922, Mr. Fry stated: — The best power for generating electrical energy is hydraulic power, and New Zealand is well provided with water resources. This applies with ; greater emphasis in the case of the I West Coast, with its abundant rainfall and rapidly-running streams.) Greymouth itself has an annual rainfall of about 80 inches per annum, and the headwaters of some s-.reams running through the County of Grej’ are gathered from a tract of country in which the yearly fall is 200 inches or over. The largest stream within, or, at any rate,, on the boundary of this county, is the Teremakau River, which has a flow of about 1000 Government heads of water (1000 cubic feet per second). It may yet be utilis-' ed, but the stream which demands the '

very first consideration is the Arnold, which flows out of Dake Brunner. This lake is a fine sheet of water with an area of 14 square miles (slightly larger than Dake Coleridge), and it has 17 square miles of drainage area, a little more than double that of Coleridge. The Arnold meanders around its course from Dake Brunner to its junction with the Grey River, for 17 miles, though the length of a straight line between these points would be only 11 miles. The ordinary flow of this stream was given, some i years ago, as 1750 cubic feet per second, but the amount as measured by Mi- P. G. Morgan, Director of the Geological Survey, at a time when the river was low, proved to be GOO subic feet per second. The gross amount of horse-power in the stream would, therefore, be about 15,900. The net amount availablej then, may be taken roughly at 10,000 brake horse-power, which would be sufficient to supply a district population of 50,000 inhabitants, by making the estimate with an outlook of ten years ahead, or 100,000 inhabitants, having regard only to present requirements. I am not in possession of the census figures for the Grey ■

County, but assuming that the population is, say, 20,000, then the smallest possible scheme would be one involving 2000 brake horse-power, costing from £lOO,OOO to £150,000, while the more ambitious scheme of providing 4000 brake horse-power would cost, say, £200,000 of capital expenditure. If the Arnold scheme is undertaken, the Power Board will have to choose, broadly, between two alternatives; one in which the water would be taken into a conduit at the lake, or close to it, and conveyed to Stillwater, or at any rate well down towards it, in which case a comparatively small quantity would be required, and additional conduit capacity provided when required; or a dam might be built at some comparatively steep part of the liver, and a larger portion, or the whole of the stream, used at a low head. The first-mentioned scheme would have a greater outlook to the future, and would provide water free from silt, and thus in the best con-' dition for flow through flumes or pipes without appreciable wearing action on ■ them, but the primary cost might be higher than in the alternative scheme. It would have to be taken into consideration, too, that a dam would be gradually filling with shingle, involving the cost of dredging it out. Other schemes will be brought forward, and the Power Board will have to solve the problem as to which is the best, from all points of view.