D;— 7.

only a small portion of the power is utilised, which is sure to be the condition with the majority of the places examined.

Wairua Falls.—ln the AVairua River, in Whangarei County, about fourteen miles from Whangarei and eighty-four miles from Auckland. It has the great advantage of being the nearest to the great industrial centre of Auckland. Surveys were not complete, so that the total possibilities could not be passed on. The locality made a great impression regarding its possibilities, and is well worth a complete survey. I have used only a head of 150 ft. in the calculations, but if the surveys show it is possible—and I think it is—a dam 30 ft. to 50 ft. high can be built, giving the benefits of storage and increasing the possible development, if eighteen-hour service is sufficient, to more than 15,000-horse power, which would make it an excellent place to develop at once for the Auckland service. This depends somewhat on what can be done with the waters of the Mangakahia; if they can be diverted into this reservoir the figures given above are very conservative. The main disadvantage under which this locality labours is that it is somewhat remote, and that machinery and material will have to be rehandled several times. This, however, is not prohibitive. One great advantage is the presence of the cement-works near Whangarei, which can supply an excellent grade of cement, and also utilise a good deal of power when the plant is in operation. I would recommend that complete surveys be made here as soon as possible. There should be contours run every 10 ft. from the possible power-house locations, which it is thought should be on the north side of the river, up to the falls and to a level of 50 ft. above them. From the falls up the stream on both sides contours should be run every 10 ft. up to a level of 50 ft. above the falls.

8

Name. Drainagearea. Run-off per Square Mile of Drainagearea. Lakes' Area in Watershed. Flow per Second. Head. Horse-power. Wairua Mangakahia Okere Falls ... Huka Falls Aratiatia Eapids Orakei Korako Rainbow Falls... Atiamuri Rotoaira Rangitikei Manawatu Waikaremoana Wairoa Waimakariri ... Lake Coleridge Rakaia Lake Heron ... Rangitata Opihi Lake Tekapo ... Lake Ohau Ohau River Lake Pukaki ... Waitaki Clutha Manuherikia ... Lake Hawea ... Lake Wanaka ... Lake Wakatipu Shotover Lake Te Anau... Lake Manapouri Waiau Waiau Lake Monowai Otira Rolleston Lake Kanieri ... Inangahua Buller ■ ... Sq. in. 241-5 33-2 192 1,287 1,287 1,287 1,287 2,014 48 1,224 1,252 166-4 473 978 380 1,013 66 608 135 611 420 Ft. 1-1 1-12 2-61 3-91 3-91 3-91 3-91 2-48 1-748 1-753 0-800 4-16 1-098 2-42 4'42 494 4-55 4-92 0-89 8-35 13-8 Sq. in. None None 35 240 None None None 6 None None 23 None None 13 !3 2 34 24 Cub. ft. 275 375 500 5,000 5,000 5,000 5,000 5,000 84 2,144 1,000 692 520 2,000 1,675 5,000 300 3,000 120 5,100 5,800 5,800 6,800 17,700 22,000 500 5,500 18,000 12,000 1,000 2,400 3,000 3,790 4,390 600 160 240 62 Pc. 150 150 106 666 110 100 30 50 525 200 50 1,000 125 90 469 50 250 100 60 555 250 100 50 30 50 410 192 I 11,000 75,000 34,840 62,480 56,800 17,000 28,400 5,000 48,710 5,680 78,600 7,384 20,440 94,677 56,800 8,520 34,080 817 320,396 164,720 65,888 38,624 60,321 124,960 23,288 119,961 523 12-95 31 820 560 1,024 1,176 184 1,356 1,750 3,561 3,653 9,216 6-45 5-55 16 442 1,754 170 686 504 0-61 9-81 ' 17-58 10-2 5-44 1-77 1-72 1-06 1-23 6-5 24-8 43-4 3-88 None 42 69 110 None 142 50 182 194 12-8 None None 5-9 50 75 700 600 50 50 250 500 500 200 ' 68,160 8,520 190,848 204,480 21,520 24,935 17,040 9,088 13,632 704 1-14 4-42 14-5 1-9 None 28 8-96 2,000 7,500 10,000 1,000 100 400 25 50 22,720 34,080 28,400 5,680 Rotoroa Wairau Awatere None None