52 W. H. WARREN. 
can be irrigated from the Murray and the Murrumbidgee. The 
conditions are remarkably favourable to irrigation from both of 
these rivers. In the case of the proposed Lower Murrumbidgee 
Southern Canal, the head of which would be about a mile below 
Narrandera, no weir is required, but merely regulating gates to 
prevent excessive inflow of flood waters to the canal. Mr. 
McKinney estimates that the cost of the whole system of canals 
proposed in this case, for the irrigation of the districts bounded 
on the north by the Murrumbidgee River, and on the south by 
the Billabong Creek and Edwards River, and including work for 
fling Lake Urana would be £548,000. This is for a system of 
canals which would carry 2,000 cubic feet of water per second. 
It is worth while to consider what these figures mean. The 
capital outlay on a flow of one cubic foot per second is £274. 
Assuming that interest on the capital expended would be four per 
cent. and the cost of maintenance three per cent.—a very high 
rate—the cost of water per cubic foot per second for a year would 
be slightly over £19. This supply, on the evidence collected by 
Mr. McKinney, can be depended on throughout the spring months, 
and a diminished supply can be obtained throughout the greater 
part of the other seasons. When in Southern California, Mr. 
Deakin ascertained that the capitalized value of a cubic foot of 
water per second in perpetuity was reckoned at £8,000. Now 
there are many points of similarity between the conditions exist- 
ing in California and those in New South Wales, and there are 
some points of difference. Admitting all the latter, it may be 
asked whether if a cubic foot of water per second is worth £8,000 
in California, the same quantity should not be worth £274 or 
even double that sum in the western plains of this Colony ? 
The last river reported on by Mr. McKinney (in this case in 
conjunction with Mr. Ward), was the Darling. It proves that so 
far as regards the practicability of large irrigation schemes, the 
conditions of the Darling are much less favourable than those of 
the Murray or the Murrumbidgee ; but by combining the interests 
of irrigation and navigation, it is claimed that on the river Darling _ 
there is a great field for remunerative engineering work. 
