D.—l

50

Power available. The areas mentioned include several large consumers, particularly factories dealing in milk products, and as in some cases it will be found desirable for the Department to supply direct to these concerns it is proposed to reserve 500 h.p. of the available supply to meet demands from these consumers. The total power installed at Horahora is 6,300 kw., or 8,400 h.p., which will be dealt with as follows :— Horse-power. Spare standby unit .. .. .. . . .. .. 1,400 For Waihi Gold-mining Company .. .. .. .. .. 3, 300 For Arapuni construction-works . . .. .. . . .. 200 For special industries .. .. .. . . .. . . 500 For losses in transmission .. .. .. .. .. .. 600 Available for local authorities .. .. . . .. 2, 400 8,400 Allocation of Power available. In allocating the power the population and other considerations such as existing installations have been taken into account, and the following allocation is the result of a careful investigation into the whole of the factors :— Horse-power, Thames Valley Power Board .. .. .. .. .. .. 900 Te Awamutu Power Board .. . . .. . . .. .. 600 Cambridge Power Board .. .. . . .. .. .. 200 Central Power Board.. .. .. .. .. .. ' .. 350 Hamilton Borough Council .. .. .. .. .. .. 300 Waihi Borough Council .. .. .. .. .. .. 50 2,400 The capacity of the existing steam plants in the district is also being carefully investigated, as it is probable that arrangements will be made whereby a supplementary supply of power will be obtained during peak-load or low-water periods, thus enabling the water-power to be utilized to its fullest extent. Distribution. Contracts for supply of material for erection of lines and substations to a value of approximately £50,000 have been entered into. Some of this is now coming to hand, but delay owing to the shipping difficulty has arisen regarding the delivery of the main contracts, particularly those for poles. In the meantime line routes and points of supply are being determined, and negotiations completed with the various consumers, and the staffs and plant are being assembled in readiness to proceed vigorously with the distribution-lines as soon as the material comes to hand. North Island Scheme. The general scheme of the North Island distribution provides for supply from three main powerstations —viz., Mangahao, Waikaremoana, and Arapuni -together with a complete reticulation joining up these three sources of power. Mangaliao. Substantial progress has been made with the works at Mangahao during the year. The roadformation is practically complete, and the testing of the foundations for the dams is under way. Great delay has been experienced in the delivery of the construction steam-power plant, the boilers for which have been erected. The sawmill has been erected, and has started cutting timber for the housing of the staff, and four of the permanent staff cottages have been erected. Arapuni. Extensive exploration work was required at the site of the proposed dam, and is now nearing completion. In testing the character of the rock and its suitability for foundations, and the distance to which the concrete-work should extend, a total of 3,474 ft. of shafts, stopes, drives, and adits has been put in at the site of the dam, gate-wall, and spillway weir. One of these drives runs right under the river, and will be used eventually to form a cut-off wall at the base of the dam. Another drive runs the greater part of the length of the diversion tunnel which will be required to carry the river during the period of construction of the dam. Important tests are nearing completion to determine the waterproofness and the strength of the rock which forms the sides and bottom of the gorge, and other tests arc in hand to determine the suitability for use in concrete of the stone and sand available in the district. A geological report has been made by the Geological Survey Department, and chemical tests are being carried out at the Dominion Laboratory. Owing to shortage of staff nothing has been done during the year in connection with the Waikaremoana and transmission-line surveys. South Island Main Schemes. During the year a detail survey has been completed of the proposed Central Otago schemes, the results of which are now being prepared. Owing to shortage of staff it has not been possible to carry the general South Island scheme any further during the year. Electric-power Boards. The policy of the Department generally is to supply power in bulk, leaving the, reticulation and retail supply in the hands of the local authorities. In the past the only local authorities available have been the cities, boroughs, counties, and Town Boards ; but with the extension of electric supply into the country areas a stronger organization became necessary, and this has beec provided under