UTILISATION OF WATER POWER.

Wanganui Herald, Volume XXXX, Issue 12002, 20 October 1906, Page 7

UTILISATION OF WATER POWER.

Extract from Public Works Statement. Results of Surveys. (Per Uaited Press Association). WELLINGTON, October 20. In delivering the Public Works Statement in the House last night, the Minister dealt very exhaustively with the question of the utilisation of water power. He said: — Though the year has been a very unfavourable one for field work, surveys have been completed (except in one case) for schemes to utilise the power available at Huka Falls, Rotoiti Lake, Mangahao, Tauherenikau and Hutt Rivers, Clarence River at Hanmer Plain, Lake Coleridge, and Opihi Gorge. The alternative surveys at Huka Falls and at Rotoiti and Kaituna (though the latter survey is not quite complete in some details) show that it would be more profitable to generate power on the Kaituna than at Huka. The conditions in favour of Kaituna are the shorter distance to transmit the power, the much greater fall available, and the smaller quantity of water to be handled to get a given power, while the adverse condition is the longer conduit, but the power should be delivered vi Auckland and en route at about 15 to 20 per cent, less cost than from Huka, and the cost of power from Kaituna would also be less than from any other scheme to utilise the rapids on the Waikato, at Aniwhaaniwa, Ateamuri, Horahora, or elsewhere, where the low fall available would be a handicap. It appears best at Kaituna to adopt a conduit about five miles long, where 530 feet of fall is available, giving about 30,000 brake horse-power on the turbine shafts for continuous working. Another scheme could subsequently be developed to use the remainder of the fall, perhaps as much as 300 feet. The country falls somewhat too fast to enable all the available fall of 900 feet £q be utilised in one scheme without very, long pipe lines. A preliminary survey just finished near Shannon •hows that by diverting the Mangahao through the range between its irpper valley and the plains, falls from 600 ft up to about 1000 ft may be got, giving probably 8000 to 10,000 brake horse-power. For alternative schemes, also, about 3000 to 40(H) horse-power could be got from the Tokomaru stream by storing the water, for water from the two rivers could be utilised in one powerhouse, though at different pressures, which would be advantageous. This power scheme is favourably Hit v a ted near several centres of population. At the combined powerhouse 11,000 to 12,000 horse-power could be obtained. The survey of the Tauherenikau River shows that with a conduit about five miles long about 340 ft of fall is obtainable. At Feathcrston the flood water would have to be stored in as large a volume as possible, for though the flow is large considering the area of the watershed, yet at times a low flow may obtain. Sometimes the flood flow is very great, and to store it would be excessively costly, yet enough to give up to about 10,000 horsepower continuously could be got without excessive cost. The survey for the Hutt power scheme shows that with a high dam water for two to three months' use can be stoned, and sufficient to enable 20,000 horse-power for part time (working eleven or twelve hours a day) to be got. Though high, the dam would be of no great length. The nearness of the power station to the Hutt, Petone, and Wellington renders this scheme a most valuable one. It will be more favourable to develop power here for Wellington than from the Tauherenikau or other more remote scheme. The country is favourable for the construction of a transmission line,

and there would be but little risk of interruption from the ordinary causes of breakdown. Judging from the present large and ever-increasing amount ol power Uhcd in Wellington, there should bo little fear of getting a ready sale for all the energy. Surveys of tho Clarence scheme at llanmer .showed that 1080 teei of fall can be got at Jollied Pa»s, which appears to be the most favourable point at which to divert the water. Storage water is obtainable at Lake Tennyson, but the area of the lake is small, just under one square mile at ordinary level. The length of the conduit would only be about three miles and a quarter, and about 22.000 horsepower on the Pelton wheel shafts would be obtainable. This is an excellent source of power, and one which could be readily increased by the construction of dams. These, however, would be relatively costly, as there are no very narrow gorge? in which dams could be cheaply built. The survey of Lake Coleridge has been finished, but the data have not yet been quite reduced to such a form as to enable a final decision to be come to as to whether it would be preferable to have one central poiirer station at Coleridge for Canterbury, or two — one at llanmer and another at Opihi. A close comparison of the first cost, the relative cost of power delivered, and the extent of country that can be economically served, have to be carefully considered lvcfore arriving at a decision. A survey of several possible ways of utilising the water in the Opihi and Opuhas shows that a much larger scheme than was at first thought possible is obtainable. At a power station at the lower end of Ophir Gorge a reservoir to store a large quantity of water can be formed. At the upper end of the gorge and by the diversion of the Opuhas into_this reservoir a large amount of power is obtainable, up to about 16,000 horse-power continuously, and proportionately greater for part time working. The length of the conduit would be about four miles and a half, and the effective fall about 200, feet. ThK power station would command the southern districts of Canterbury, and, worked in con junction with the Clarence scheme at Hanmer. the whole of Canterbury would be \ery effectively supplied with power. Plans for works to develop these various schemes are being prepared, a ftl very shortly it will be possible to invite offers for the supply of plant. Information as to the probable cost of the plant has already been obtained by the High Commissioner, but in addition detailed information for each particular scheme will now be ascertained. The question of the advantageous use of the power available has also received some attention, as besides the supply of power to existing industries, other uses must be found for it if we are to take full advantage of the resources available. The question of the artificial production of nitrates is receiving much attention from scientificmen and others. It is e.-timated that in the next quarter of a century or so the world's consumption of nitrates will be many times the present rate, viz., about one million and a half tons per year, and processes are being perfected for their production in hydro-electric work.s. A considerable measure of success appears to have been attained, and in Sweden it is claimed that with the cost of energy at from one to two pounds per horse-power per year nitrates can be artificially manufactured at a profit. There are many places in New Zealand where the power can be got within the above limit of cost at a power-houae, and in addition some of our schemes would have the power-house on the sea shore, within easy reach of limestone deposits available for sea transport. If present anticipations a.s to the development of nitrate industries are realised , there is no reason why New Zealand should not be able to manufacture and export many million txnmds worth of the product. Some districts now desolate may yet become centres of industry, supporting, directly or indirectly, a considerable population. It may be interesting to state that Sweden has passed an enactment conserving to the State the ownership of all water power, and it appears to be the intention to charge substantial royalties, in any case where private persons or companies aye allowed to use same, the amount proposed to be charged per horse power per year being about the same as has already been suggested for similar proposals in New Zealand. Except as they may be modified by the amount of power found to bo available or to supply more power for shorter periods, the estimates previously given for the various schemes proposed to be undertaken do not appear, after more complete surveys, to require much modification. The cost of the power scheme, where the storage of water is possible, will vary greatly with the nature of the machine, etc., up to twice or more that of the plant for continuous working, that is to .say, the cost of energy to conanmers using the power intermittently in small quantities must be higher than those using large volumes of power continuously. The costs at various centres in New Zealand to which it is proposed to deliver the power may be taken at from £6 to £8 per horse power per year for the full time of working of 168 hours per week. There would be proportionate increase in the rates for small quantities, for power intermittently used. Those rates increase up to two and half and even three times in some power services. It is not possible yet to say whether the rates in this colony would require to be framed on quite the same basis, but I hope to place some further information before honourable members prior to the close of the session. The expenditure last year under the head of Utilisation of Water Power amounted to £982, but as it i-, hoped to make a start with some of the works this year, a sum of .£53,000 is now asked for.