210
information on the annual discharge down the Valley I have calculated the amount sent into Victoria and added to that the estimated amount which passed over the Waste weir during last year and find it to be 677,341,600 gals. This was with a rainfall of 62.92 inches but it must be remembered that the rainfall has within the last 6 years been as low as 56 inches per annum.
The amount discharged down the Ravine would vary considerably with the manner in which the rainfall occurs, whether heavily and continuously or with intervals and gently. Under any circumstances, much more water than is at present collected in this Valley might be stored for use in another Reservoir, such a Reservoir would be placed higher up the Valley and means should be adopted to take advantage of the improved head for a high service in the City if required.
The present supply main from Pokfolum would have to be taken up and, as was suggested by the late Surveyor General, it would probably be best to have the new main laid along a contour of the hill; the accompanying plan and section show roughly a trial line.
As it would appear that further supply would be required beyond that obtainable from Pokfolum, the question of source would have to be maturely considered. Without insisting upon any particular scheme, it might be pointed out (1) that probably the supplies referred to as 2 and 3 might be united to the Pokfolum main and the whole carried at an equal pressure.
(2) Regarding some of the smaller supplies, they may have to be abandoned on account of their liability to pollution as the City extends.
(3) I am of opinion that the idea of the high level formation...