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32. The Wong-nei-chung and Mint Dam reservoirs have been utilized for the supply of water to the East Point and Bowrington Sugar Refineries.
33. During the winter of 1891-92, steps were taken to measure the minimum supply obtainable during the dry season from the Mint Dam works. From the measurements made it appears that a minimum supply of 100,000 gallons per diem can be relied on during an ordinary dry season.
34. Satisfactory arrangements have been made during the past year by which the long pending question as to the rights of Messrs. JARDINE, MATHESON & Co. over the Mint Dam Works has been settled, the Government undertaking, in consideration of Messrs. JARDINE, MATHESON foregoing all rights over these works, to supply free of cost, 100,000 gallons per diem to the East Point Works.
The
35. The Taitam and Pokfulam Filter Beds have been in constant use throughout the year. quantity of water filtered at the former being 843,010,474 gallons and at the latter 260,361,100 gallons, giving an average rate of filtration of 848 gallons per square yard per 24 hours in the case of Taitam and 708 gallons per square yard per 24 hours in the case of Pokfulam.
36. The total expenditure on the maintenance of the Water Works including those of the Hill District during the year 1892 has been $9,996.75 divided as follows:- ·
Maintaining Taitam Reservoir, Conduit and Filter Beds including supplying Sand and
cleaning Filters, $2,900.95.
Maintaining Pokfulam Reservoir, Conduit and Filter Beds including supplying Sand and
cleaning Filters, $1,038.48.
Maintaining the Distribution Works including cost of pumping water to the higher levels
of the City and the Hill District and inspection of House Services, $6,057.32.
37. The total quantity of water supplied to the City and Hill District was 1,183,647,574 gallons so that the cost per 1,000,000 gallons supplied has been $8.45.
38. The tabular statement in Appendix A shows the quantity of water abstracted from the Taitam, Pokfulam, Wong-nei-chung and Mint Dam Reservoirs during the past year.
39. In Appendices B and C will be found diagrams prepared from the annual report of the Director of the Government Observatory dated 15th April, 1892, shewing the monthly rainfall for the last 39 years and the rainfall for the months of September to May inclusive and for the months of October to April inclusive over the same period.
The portions coloured brown represent the actual rainfall and that coloured blue the average rainfall.
40. The ordinary dry season may be said to extend over the months of October to April inclusive or a period of 212 days, the average rainfall for that period being 18.74 inches.
41. When the rainfall for the months of September to May inclusive or over a period of 273 days falls much below the average as was the case in 1890 and 1891, and in 1885 and 1886, and 1886 and 1887, such period is one of exceptional drought, but their somewhat frequent occurrence points only too clearly to the necessity of exercising the utmost economy in the use of water and the most careful watchfulness against its misuse or waste.
42. A comparatively low rainfall or one much below the average during the months of September and October generally indicates an unusually lengthened period of drought.
43. As will be seen from the diagrams the rainfall during the dry season (October to April) of 1891 and 1892 was considerably above the average and the rainfall from September to May was also above it, consequently the scarcity of water experienced during the early part of 1891 and referred to in my last annual report was not again experienced during the early part of 1892.
44. In view of the mistaken idea that seems generally prevalent in the Colony that now that the big reservoir at Taitam" has been constructed there cannot possibly be any scarcity of water I make no apology for entering rather more fully into the most important question of the capabilities of the present sources of supply and storage reservoirs to meet the ordinary requirements of a population of some 146,000 persons.
45. To take the most favourable circumstances let us say that both the reservoirs at Taitam and Pokfulam are full on the 1st of September, that is to say we have a supply of 378,000,000 gallons, to this must be added the dry weather flow into these reservoirs which amounts approximately in the case of Taitam to 150,000 gallons per diem and in the case of Pokfulam to 100,000 gallons per diem, (I say approximately for it is only recently that means have been available for ascertaining the dry. weather flow at Pokfulam and in the case of Taitan no means are as yet available,) neglecting evapora tion we get a total supply available from these sources of 446,250,000 gallons during the period of 273 days or at the rate of 1,635,000 gallons per diem giving an average allowance of 11 gallons nearly per head per diem for a population of 146,000.
46. On examining the Table 42 annexed to my last report and Appendix A it will be seen that the consumption during the months of September to May inclusive was 763,645,000 gallons or at the rate of 194 gallons per head per diem.