59

D.—l

It was estimated that it would take ten years to carry out this work, and that the annual cost, allowing 1\ per cent, for capital charges (interest, depreciation, and sinking fund) and £220,000 per year working-expenses, would be £5-9 per horse-power year— practically £8 per kilowatt-year. The present actual costs are proving to be over 50 per cent, in excess of pre-war costs instead of 12 per cent., and the following statutory authorizations have been made enabling this whole North Island scheme to be undertaken :— Electric Power Works Loan Act, 1919—- £ Arapuni Electric-power Works .. .. .. 4,500,000 Mangahao Electric-power Works .. .. .. .. 1,600,000 Horahora Electric-power Works .. .. .. .. 412,500 Waikarernoana surveys .. .. .. .. .. 30,000 Finance Act, 1920— Waikarernoana Electric-power Works. . .. . . .. 2,600,000 Kaituna River Electric-power Works .. .. .. 150,000 Other surveys and investigations .. .. .. .. 30,000 £9,322,500 Towards the carrying-out of this programme the position at the end of the financial year under review is as follows :— The Horahora plant (8,4.00 h.p.) and main transmission-line to Waihi (50 miles) have been purchased from the Waihi Gold-mining Company for £212,500, and the extensions of the lines to Cambridge, Hamilton, and Te Awamutu have been carried out. It is also proposed to extend the Horahora power plant by the addition of another two units of 2,600 h.p. (2,000 kw.) capacity each, bringing the total capacity of the plant up to 13,600 h.p., for which capacity water will be available except for limited periods in exceptionally dry years. Supply was commenced to Cambridge on the 28th April, 1921, to Hamilton on the 31st May, 1921, and to Paeroa (through the Thames Valley Power Board) on the 29th March, 1921. Lines have also been erected to To Awamutu and Te Aroha, and the necessary material is on order for the first of the main 110,000-volt lines to Auckland. This will be supplied in the meanwhile by power from Horahora, giving an emergency supply for the essential industries of the city. Negotiations for a substation site near Penrose are in hand. Mangahao. —The Mangahao headworks have been pushed on during the year. Tenders were invited for the pipe-lines, but owing to the falling market it was decided to call fresh tenders closing on the Ist November, 1921. Specifications for the balance of the plant have been ready for some time, but for the same reason were held back until it was anticipated more reasonable prices would be available, and tenders were invited accordingly, and closed on the 29th November, .1.921. The transmission-lines poles are being delivered. The land for the main substation for the Wellington District has been secured. Arapuni. —At Arapuni Gorge further investigations and exploration drives have been carried on throughout the year. The results were submitted to a committee of engineers, on whose suggestions the quantity of concrete in the proposed dam has been increased to render it safe as a gravity dam apart from its strength as an. arch dam, and this work is now ready to be proceeded with. Suitable deposits of sand, shingle, and rock have been located for the necessary concrete. Waikaremoana. —At Waikarcmoana the approach roads and bridges are in hand, and the power house surveys carried on. The two permanent exciter units of 500 h.p. each have been ordered, and it is proposed to erect these in a temporary power-house as soon as they arrive, and to utilize them for the construction of the permanent works and for commencing supply to the Wairoa Electric Power Board. Portions of this material have already arrived in the Dominion. At Rotorua (Kaituna River scheme) surveys have been completed, but owing to the financial stringency and to the fact that the supply to Rotorua requires augmentation before this scheme could be completed, tenders have been called for a 200 h.p. Diesel engine plant for installation in the town. The total expenditure on all the North Island schemes and surveys to the 31st March last is as follows :— Expended during Total Expenditure the Year ended to 31st March, 31st March, 192.1. 1921. Works — £ £ Horahora .. .. .. .. .. 73,768 294,742 Mangahao .. .. .. ~ .. 120,361 143,110 Arapuni. .. .. .. .. .. 5,291 11,276 Waikaremoana .. .. .. .. 2,184 2,907 Surveys and investigations— Hutt River (including purchase of land) .. .. 2,779 Tauherenikau River .. . . .. .. .. 880 Kaituna River .. .. .. .. 109 1,217 Aratiatia Rapids . . .. . . .. . . 376 Huka Falls .. .. .. .. .. 10 413 Wairua River .. .. .. .. .. 236 Makuri River .. .. .. .. .. 38 £201,723 £457,974