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and would pass through a good mining district where some power may reasonably be expected to be used. Waikato Eivbb. Huka Falls. The places in the river where it is possible to get power-installations, so far as ascertained, are Huka Falls, Aratiatia Eapids, Orakeikorako Rapids, the gorge between Orakeikorako and Aniwhaniwha, the Aniwhaniwha Falls, Atiamuri Rapids, also the lower Aniwhaniwha Rapids near Cambridge. The flow of water in the Waikato was measured in October last and found to be 6,378 cubic feet per second. Taking the relative high- and low-water levels of the lake as given by Taupo residents the corresponding flow of the river at these levels would be 7,300 cubic feet and 5,200 cubic feet per second. Adverse winds interfere with the flow by heaping the waters on the Tokaanu shore. For this and other reasons the minimum flow for water-power purposes must be taken at no more than 5,000 cubic feet per second, or perhaps somewhat less, unless the outflow is regulated by a dam of suitable height. The mean flow from Taupo appears from the data obtained to be about 5 cubic feet per second per square mile of drainage-area. This, as might be expected, is much lower than the flow from the southern lakes. Rainfall-records are available for a station at Taupo Township, but only for a period of two years and a half previous to the. gaugings. The mean fall for this period was 49-5 in. per annum. With a run-off equal to 100 per cent, this rainfall over the lake-basin would give only 3-6 cubic feet per second running off. Taking note of evaporation from land and lake it appears clear that the rainfall on the mountainous portions of the lake-basin must be very great, as on the lake itself and along the lake-margin there is no reason for supposing that the average rainfall differs much from that at Taupo Township. The top of the rapids at Huka Falls was 13-8 ft. below the lake-level at the time the levels were taken ; the drop from the top of the rapids to the pool below the falls was 50 - 8 ft. The low-water flow of the river would give about 22,000 b.h.p. for this fall. A weir would have to be built across the race forming the rapids either at the upper end or any lower point that full investigation shows to be best, and the water would be taken to the power-house by canal and pipes. There would be somewhat heavy works involved in the weir, canal, and power-house excavations, and subsidiary works. If a dam were built just above the falls to hold up the lake-water to a sufficient height to get the mean flow of the river all the year, the power obtainable would be about 38,000 b.h.p. The dam would be about 18 ft. to 20 ft. high above the water-level at the top of the rapids, and at least 540 ft. long, and should be as near the falls as possible to diminish the length of pipes. The works required in this case would be a dam, pipes, excavations for power-house, and subsidiary works. In both cases there would likely be some troublesome work involved in closing the " race " as the rock may be deeply fissured and also decayed, as is sometimes found in such cases. Damming the river in this way would submerge some of the geysers on the river-bank at the Spa, but this would not likely be injurious in any way, as there are supposed to be some submerged hot springs under the river; at least some deep dark pools are pointed out as such. Assuming the power at the Huka Falls developed to give the various amounts of power stated in the table below, the probable relative total cost for each scheme and the probable annual revenue would be as given, the energy being distributed to various points north of the falls up to a distance of 150 miles, and, of course, assumed to be all sold. Brake Hours Cost. Revenue. Horse Power. per Day. £ £ 10,000 .. .. .. .. ..24 300,000 72,000 22,000 .. .. .. .. ..24 550,000 158,000 38,000 .. .. .. .. ..24 1,030,000 273,000 76,000 ..< .. .. .. ..12 1,900,000 273,000 These figures may be taken as an approximate indication of the potential value of the Huka Falls for power purposes, and of the magnitude of the works likely to be required for their development. As the utilisation of the Huka Falls involves dealing with a large volume of water with a relatively small fall, it may be of interest to compare the figures given for the schemes above merely outlined with some similar figures for an installation to utilise the water from the Rhone at Lyons, now working and known as the " Jonage." The information is from the " Annales dcs Ponts et Chaussees." Feeder canal, 329 ft. wide at bottom, 9 - 8 miles long. Draw-off canal, 329 ft. wide at bottom, 1-9 miles long. Fall, variable with state of river, 27-88 ft. to 39-36 ft. Power, 12,100 b.h.p., supplemented by 7,800 b.h.p. during periods of four to nine hours each day. Cost of canals, 22,015,000 francs—say £880,000. Electrical installation, £364,000. Capital at start, 40,000,000 francs —say £1,600,000 —subsequently increased to 50,000,000 francs £2,000,000. (Extra capital taken up wholly by first shareholders.) Works begun in 1894, finished 1898. Network of distribution has a total length of 330 kilometres (204 miles). Tn 1901, 7,000-horse power and 100,000 lamps supplied.

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