85
LINES OF COMMUNICATION
Mainland.
59. Owing to the distribution areas in Kowloon being at such low levels com- pared with those of the City it has been found more practical to locate the filtration plants nearer to the sources of supply, the service reservoirs for distribution purposes being placed on points in Kowloon sufficiently high to ensure a good supply to the consumers. The lines of communication are therefore extended to the service reservoirs situated in the distribution areas.
60. The raw water supplied from the catchment areas of the Kowloon Waterworks is filtered by slow sand beds at a site adjacent to the last of a chain of three impounding reservoirs. The "line of communcation" of these resources consists of an 18" dia. pipe line to Kowloon Tong Service reservoir and a 15′′ dia pipe line to Pipers Hill Service reservoir.
61. Being in good condition and of sufficient capacity to deal with the re- sources of the Kowloon Waterworks no extension or improvement of the above mains is required.
62. The Kowloon Waterworks resources are augmented by those of the Shing Mun Valley whose "line of communication" consists of two sections. The upper section, which delivers raw water to the filters situated in the lower Shek Lai Pui Valley, consists of conduits and tunnels adequate in construction and capacity whilst the lower section, which supplies filtered water for both Kowloon and the City, is a 24" diameter pipe line. A second 24" dia. main is now being laid and these combined are estimated to be of sufficient capacity to provide for the requirements of Kowloon and the City for several years.
63. The existing "line of communication" from the Shing Mun Valley source, being of recent construction and designed for the existing and projected works is in no need of improvement.
Proposed Extensions.
64. New trunk mains of 21′′ and 18′′ dia. are proposed to supply water from the 24" dia. mains in Nathan Road to the proposed new service reservoirs at Kowloon Chai and Kowloon City (para. 90),
FILTERS
Island.
Existing Capacity.
"
65. The present normal capacity of the Island slow sand filters is 6.10 M.G./D. and that of the Rapid Gravity filters is 7.0 M.G./D. making a total of 13.10 M.G./D. Details of these, together with those of the Mainland, are shown in Appendix IV. Owing to an overlap however the whole of the filters cannot be used at the same time, the effective capacity being reduced to 12.05 M.G./D.
66. The very high consumption last summer necessitated the filters being run at rates far in excess of good engineering practice in order to provide the peak load of 16.35 M.G./D. actually passed through the filters. It is not possible to increase the filtration rate further nor can a greater amount of raw water be supplied to these filters. The maximum capacity of the Tytam tunnel being 10.0 M.G./D, this figure is the peak load which can be drawn from the Eastern Source of supply. The water is filtered at present at Eastern, Bowen Road, Albany and Elliot Eilters, the working capacities of which are 2.20, 3.00, 1.73 and 1.7 M.G./D. respectively, a total of 8.63 M.G./D. The amount of Tytam water filtered at Elliot is limited to the capacity of the Albany-Elliot main.