14
REVIEW
Colony's financial position allowed the full scheme to go ahead as a charge to general revenues rather than to the Development Fund. Apart from a few miles of catchwaters, the work is now complete.
The reservoir has a capacity of approximately 4,500 million gallons and has been formed by a main dam across the Tai Lam valley and three subsidiary dams across adjacent cols. The main dam is in two parts, with a maximum height of 200 feet above foundations and a maximum width of 143 feet at the base; its total length is 2,300 feet. There are about 240,000 cubic yards of concrete in the dam.
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The main dam has an ordinary spillway 452 feet long which allows flood water to flow over the face. The water is drawn from the dam through a valve tower with valves at four different levels. It is then conveyed to a pumping station at Tsuen Wan through a system of tunnels approximately 5 miles long and by about 8,000 feet of 48" diameter steel pipeline. The water travels from the pumping station to a filtration plant capable of dealing with 40 million gallons a day, and from there it is fed into the distribution system through two service reservoirs.
The Tai Lam valley has a direct catchment of approximately 4,000 acres, but catchwaters of various sizes will intercept water from a further 7,000 acres and bring it into the new reservoir. Approximately 23 miles of catchwater channel are required of which about 17 miles have been completed, and the remaining 6 miles are under construction. The complete scheme will have cost about $134 million.
Forest plantations were sadly neglected during the occupation of the Colony and many were denuded of trees to provide fuel for the population that remained. Some of the scars are still visible in deeply eroded hillsides. Since the war there has been a steady programme of re-afforestation, particularly on the catch- ment areas feeding the main reservoirs, with the purpose of reducing erosion and encouraging the maximum penetration of rainfall, so as to spread the delivery of water into the reservoirs over a longer period. Since 1953, when the Tai Lam scheme was already under way and the forestry programme was accelerated, the Agriculture and Forestry Department has planted about 10,000