3
1,000 gallons pumped, for coal only. The staff, including an European with an allowance for oil and waste, will cost about $25 per day, bringing the total nett cost of pumping to $0.05 per 1,000 gallons. When pumping from a full reservoir, or from one higher up the valley, the lift and consequently the coal consumption, would be reduced, but not in direct proportion, for there is a certain power at which the engine gives its best efficiency.
513
quantity of
obtainabie.
9. The quantity of water that can be obtained from the Taitam-tuk valley As to the will depend a good deal upon the capacity of the reservoirs, whether they be large water enough to carry forward a reserve, from one season to the next, as explained in the previous report. A rough approximation to the probable minimum, during a very dry year may be calculated. Taitam, with a gathering-ground of 1,093 acres, in- cluding catches and a storage-capacity of 406 millions, maintained, during the water year of 1901-1902, allowing for the broken portion of the current month, a total supply of about two millions per day, on the average of the whole rain-year. The new works will add about 852 acres of gathering-ground which contribute, direct, to the proposed low-level reservoir, and the water from a gathering-ground to the East of the Taitam-tuk Village, having an area of 245 acres, can be brought in, by constructing a sinall subsidiary reservoir, and a short length of conduit; thus giving a total additional area of 1,107 acres, and therefore practically equal, in point of area, to the present gathering-ground of the Taitam Reservoir. Therefore, one may safely assert that with a reservoir or reservoirs, equal in capacity, to the existing Taitam Reservoir, the proposed works will at least a Al as much water as Taitam now affords, or in other words double the supply which is now, during a drought, about two millions of gallons per diem. This is on the assumption that the additional storage only bears the same proportion to the added gathering-ground that the existing storage bears to the existing area of gathering-ground. `In all probability, by providing more storage, the supply could be materially increased. There is good reason to believe that the estimate of yield which I have given, will be materially exceeded in practice, for the following reasons. The proposed low-level reservoir will receive a larger proportion of its water, direct from its gathering-ground, than Taitam does, and will, moreover, collect any water that escapes from Taitam, or from the catches which feed it.
It will also receive any water percolating down through the soil, which now gets away, unperceived, to the
sea.
Lastly, by means of catch-water channels, water may be collected from the slopes of the hills, surrounding Taitam bay, from Cape D'Aguilar on the East to near Stanley Village on the West.
pro-
capacity of
plant.
10. The size of proposed engine was mainly determined, in the first instance, As to the with regard to the fact that the flow of Taitam in a very dry year, 1901-02, was for proposed a month on end at least, at the rate of one million gallons in 24 hours. The posed engine could raise this quantity without any appreciable storage, only a small collecting-pond, as proposed by Mr. COOPER. 1 feel certain that with adequate storage, a permanent additional supply of 2,000,000 gallons per day, could be main- tained, at the very least, in a dry water year. The proposed engine, therefore, will not be too large. If future experience shews that less, say for example only one million gallons a day can be obtained, then all that has to be done is to erect a second engine, of the same size, as a reserve. If, on the other hand, it is found that an additional supply of two millions or more can be maintained, then a second and third can be added, two to do the work, and with one in reserve. Or, on the other hand, if still more be obtainable, then even a fourth engine may be provided. I find that, during water-year 1901-02, an average daily supply was given from Taitam, from April to October inclusive, at the rate of 2,400,000 gallons a day, under constant supply, for the remainder of the year, the average rate of supply was 1,500,000 gallons a day, so that about one million of gall ›ns extra per day would have maintained the constant supply, for the whole year.