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any distance along the valley, a considerable amount of power could be got. It is too far away from any industrial settlement at present to make it of any value. Possibly it might be used in the event of the North Island Main Trunk Railway being worked by electricity. Mangawheeo. The Raukawa Falls on this river would give a small power scheme of about 2,400 b.h.p. at very small cost, if the flow in the stream is as great as has been given—viz., 300 cubic feet per second — a fall of about 90 ft. in a few chains can be obtained. A much lower estimate of the flow has been given, but I think it is too low. The drainage-area above the Raukawa Falls is 212 square miles, which would give a result somewhat nearer the higher estimate, in view of the situation of the river-basin and the fact that it rises in Ruapehu. The Wangaehu has been gauged when very low ; the flow was 333 cubic feet per second ; its drainage-area is 291 square miles. The proportional flow of the Mangawhero would be 243 cubic feet per second. The Wangaehu, however, drains more of Ruapehu, and perhaps its flow per second per square mile of drainage-area should be somewhat greater than that of the Mangawhero. The Raukawa Falls are given as 1,050 ft. above sea-level, also as being 950 ft. The Wanganui River opposite the falls at Koriniti is 48 ft. above sea-level, with a flood-rise of about 52 ft. Between the two rivers there is a range near the Mangawhero, with spurs leading to the Wanganui. The range would be pierced by a drive, and a conduit could be taken along a spur to a point about three-quarters of a mile above Koriniti. Allowing for fall in the conduit, if Raukawa is 1,050 ft. above sea-level, about 900 ft. of fall should be obtainable. Probably it would be best to take the water from the Mangawhero at a point some four miles above the falls, where the river is nearest the Wanganui —about five and a half miles distant. The conduit would in this case be taken to near Galatea. The Wanganui does not rise much in the extra distance, but the Mangawhero rises rapidly up to Raetihi. Probably a greater fall could be obtained by this alternative. So far as I can learn at present there seems every probability, from information supplied by the Surveyor-General, that a conduit can be got from the Mangawhero to the Wanganui. The length of conduit would likely be seven or eight miles. Along the spurs it would be drive, flume, or race, as the ground required. The power obtainable should be 20,000 to 24,000 b.h.p., unless the flow is much less than given above. If dams could be built to store a sufficient quantity of water, still better results could be got by increasing the water available over the minimum flow and by enabling a plant to work part time in a week, while all the weekly flow is conserved. The power-station would be in a fairly central position. It would be near to one large centre — Wanganui—which would be distant by river about thirty-seven miles, and more directly by land about twenty-four miles. The scheme would conveniently command all the country from New Plymouth to Palmerston North, the distance to New Plymouth, vid the river and railway being, say 125 miles, but shorter if a transmission-line can be taken across country by Waitotara. The distance to Palmerston North would be, say eighty-four miles, but only about sixty miles if a cross-country route is possible. It would be conveniently placed for electric traction on the Wellington-New Plymouth Railway should this ever be adopted. This scheme is worthy of close examination, first to determine the possibility of getting a conduit from Mangawhero to the Wanganui, and, if that is possible, the Mangawhero Valley should be examined to ascertain if a storage-reservoir could be got at reasonable cost, and also to determine if water can be easily diverted from any of the branches of the Wangaehu into the Mangawhero, and a large scheme be thereby obtained. The power-station would only be about twenty-five miles distant from the ironsand deposits at Nukumaru, where a large part of the energy could be used for electric smelting. Manganui-a-te-ao. This river has been suggested as one from which a considerable amount of power could be got. The flow of water should be fairly good. The water would be taken from the river at about the junction of the Euatiti Stream. This would give about 180 square miles of drainage-area. At the Pakenga junction, a little way above this point, the river is about 1,000 ft. above sea-level, and about 850 ft. above the Wanganui at the Manganui-a-te-ao junction. The distance from the Euatiti junction to the Wanganui would be between ten and eleven miles, and perhaps 650 ft. to 700 ft. of fall could be got. At a power-station on the banks of the Wanganui perhaps 10,000 b.h.p. or more could be got, depending on the flow of water in the river. The works for a race would likely be heavy in this country. Wangaehu. This river might be available for power purposes but that it carries acids or other chemical constituents from the volcanoes which quickly corrode iron. If used, the hydraulic motors would require renewing more frequently than in pure streams. A low-water flow has been measured, amounting to 333 cubic feet per second. No systematic examination has been made so far, but in one section of the river, three miles long, the fall is given as 70 ft. A race of this length on this reach of the river would give, say, 1,500 b.h.p. A power-installation here would be somewhat costly, but probably better schemes would he found on search. The impurity of the water is likely to prevent the use of the river for power purposes, unless machinery could be got of non-corrosive metal as cheaply as of iron.

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