D.—i

XI

system and to be available to absorb power from Waikaremoana. The percentage earned is lower than in the other schemes mainly on account of the higher capital cost, and in 1927-28, in particular, on account of the need of purchasing steamgenerated power to supply the demand during a period of exceptional drought. The decided drop in capital cost per kilowatt in 1929-30 is due to the fact that Waikaremoana power-station came into operation. The cost here was less than at Mangahao, but the main reason for the drop in the curve is that now the power-station capacity has been increased without any appreciable addition to the transmission and substation costs. Growth on the system will show an improving position, mainly on account of the growth of load possible without very expensive additions to the substation and transmission costs. Power-house extensions will be cheaper than the original, but much less markedly than would apply at Arapuni. Professor P. G. Hornell has been requested to make a separate report on possible methods of developing the further stages at Waikaremoana, which presents some peculiar geological features. Lake Coleridge. £ Capital investment at end of year .. .. 1,622,199 Revenue . . . . .. .. .. 196,648 Operating-expenses .. . . .. .. 36,808 Balance .. .. .. .. £159,840 The balance has been used in payment of interest, £15,315 to the depreciation fund, £23,783 to the sinking fund, and £44,388 to general reserve. This scheme has now paid off all arrears of depreciation and sinking fund, and for the first time established a general reserve fund. It now has a credit of £188,294 in depreciation funds, £144,557 in sinking fund, and £44,388 in general reserve accounts. There has not been a great deal of construction work on this scheme, the main items being on lines and substation extensions in anticipation of interconnection with the Waitaki power plant.

Lake Coleridge System.

This graph has no particular points of interest, except that it shows the very low percentage earned in the earlier years, and also that, although there have been very considerable increases in total capital in recent years, these increases have only tended to reduce the percentage earned for a brief period. It is regretted, however, that owing to the phenomenally low rainfall experienced in the watershed supplying the Lake Coleridge station, there is at the moment of writing a shortage of power in the area served. The Department is doing everything possible to minimize the inconvenience caused thereby. The scheme relies on heavy rains and melting snow in the spring months to replenish the storage used up during the summer and winter months. These rains, which in the main come from