14
Public Works and Utilities
PUBLIC WORKS
Waterworks. The history of the Hong Kong Waterworks has been marked by a succession of crises caused by demand outstripping supply. Water restrictions have been necessary in the dry months of almost every year and on one occasion the supply was reduced to 24 hours every other day. The increase in demand is illustrated by the fact that over a period of four years, on a 10-hour a day supply, consumption has risen by more than 62 per cent. This is a compound increase of 13 per cent a year and underlines the need for the large capital works now being carried out. This need was even more strongly stressed this year by an extremely dry winter and the continuation of drought conditions into the usually wet summer season. By 1st October each year no further heavy rains can normally be expected and all storage reservoirs must be substantially full if reasonable hours of supply are to be maintained throughout the dry season. The rainfall between 1st October 1961, and 1st October 1962, was nearly 19 inches below average and even after receiving 8,679 million gallons from the Chinese reservoir at Sham Chun the hours of supply were 31 per cent less than in the previous year.
Delivery of water from a 5,400 million gallon storage reservoir being built at Shek Pik on Lantau Island should begin toward the end of next year. The natural catchment of 1,917 acres at Shek Pik is being increased to 8,017 acres by catchwater channels which will carry water to the reservoir from distant valleys. In some places tunnels have been blasted through hill spurs and mountains to carry the water. The dam itself is almost at sea level and a valve tower will control the flow from various draw-off levels. Five and a half miles of supply tunnels will carry the water to a pumping unit at Pui O and thence to a treatment works overlooking Silver Mine Bay. Both the pumping unit and the treat- ment works will have a capacity of 35 million gallons a day.