D.—No. 8.

20

PAPERS RELATING TO THE

I have pleasure in being able to report that such a race is practicable, and that the cost will be moderate, taking into consideration its great elevation, the large area of ground it will command throughout, and the immense power derivable from it at the lower levels. The race is purposed to commence at upper gorge of Mikonui, about 17 miles from the sea, with an eievation of 980 feet above high water mark. The fall will be at the rate of 30 feet per mile for the first 6 miles, and afterwards at the rate of 8 feet per mile. The terminating level on ridge near Ross will be 680 feet above sea, and the total distance 22 miles. The cost of this trunk to carry 40 Government sluice heads of water, will be about £17,500. Starting from Trunk Race about 7\ miles along its course, a branch race to supply the Totara Valley and terraces on north side of Greenland Range will be practicable; it would have a fall of eight feet per mile throughout, ending on terrace north of Donnelly's Creek, at an elevation of 666 feet above the sea; distance, 15 J miles."' The steep nature of sidling on north face of Greenland Range would render this an expensive work as compared with the race on south side, and, at present, the country it would traverse does not give promise of as good returns, but in case of its becoming desirable to provide a water supply for the Totara Valley, it could be derived from the Mikonui Trunk Race at a less cost, and a higher elevation, than from the Totara or any other source I am aware of. The cost of this branch, including the increased expenditure on main race to provide for its supply would be about £15,600. Total estimate, £33,100. The levels of principal points ascertained during the progress of the survey are as follows, the figures where the asterisk is used being deduced from barometer readings, and the remainder from absolute levelling :— Malpoy's Race, near cemetery at Ross ... ... 310* feet above sea level. Ross Flat ... ... ' ... 105 to 170 „ „ Donoghue's Flat ... ... ... ... 44* „ „ Energetic Company's Race ... ... ... 76* ~ „ Redmond's Gully wliim claims ... ... ... 130* „ „ Race crossing Redmond's Gully at junction with Black's 192* „ „ Level of water west end of Lower Gorge, Mikonui ... 98 „ „ Level of water east end of Lower Gorge, Mikonui ... 264 ~ „ Lowest point on dividing ridge between Mikonui and Totara... ... ... ... ... 710* „ „ Level of water in Mikonui at Forks ... ... 417 „ „ Level of water in first town to north ... ... 584 ~ ~ Level of water in flat west end of Upper Gorge ... 933* ~ „ Level of water in junction of Totara and Smythe's Creek ... ... ... 001* „ „ Level of water in junction of Beaufill's Creek ... 443* ~ „ Level of water in j unction of Disappointment Creek 333* ~ „ Level of water in junction of Duffer's Creek ... 277* ~ „ Level of water in junction of Constitution Creek ... 221* ~ „ Level of water in junction of Hatter's and Cameron's Creeks... ' ... ... ... ... 370* Level of water in junction of Cameron's Gully at crossing of upper track ... ... ... 648* „ ~ Level of water in iunction of Frenchman's and Fox's Creeks ... ... ... ... 487* Top of ridge head of Harvey's Creek ... ... 1,377* „ ~ Saddle, main branch of Harvey's Creek ... ... 803* „ „ Woolhouse's accommodation-house on the Totara ... 156* „ ~ Highest point Greenland Hill ••* ... ... 2,959 „ ~ Starting point of Calder's Race (supply two Government heads to Cameron's Gully) ... ... 1,483* „ „ I have taken the opportunity, while exploring the country, to run a line of levels, with beach marks, Ac, along the Mikonui River, as a base of reference in laying out the work, should this race be undertaken. I have, Ac, C. Y. O'Connor, C.E., Malcolm Fraser, Esq., Chief Surveyor. Mining Engineer.

MIKONUI WATER SUPPLY. The detail survey for this race was commenced on 24th June, 1869, under the superintendence of Mining Engineer and Surveyors, whose salaries and expenses were paid by a company inaugurated at Ross. The cost of the survey and plans amounted to £38 per mile of contour line. The plans were completed in October same year, and an estimate made at that time for a race nine miles in length, with cuttings and fluming constructed for 10 heads, and with tunnels of sufficient size for 40 heads, amounted to £12,800. This race would have terminated in German Gully, above Ross, and would have been dependent for supply on artificial reservoirs and the creeks which it crossed. It was proposed as a temporary expedient, in order to assist in carrying out the main undertaking, and it most probably would have done so, as water 620 feet above the sea at German Gully was worth about £16 per head per week. The scheme, however, fell through, in consequence of want of funds on the part of the promoters.