PUBLIC WORKS AND UTILITIES
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Drainage. Nearly all built-up areas, including the larger towns in the New Territories, have waterborne sewerage systems. How- ever, as large new blocks of flats take the place of older and much smaller buildings the flow to the sewers is steadily increasing. Many of the older sewers are becoming laden beyond their designed capacity and an accelerated programme to replace them with larger mains is vital. The nuisance from seawall sewer outfalls has grown and there are extensive plans to build intercepting sewers which will carry the sewage to selected sites where it will be treated and discharged into deep water through submarine outfalls. Of five schemes for the Kowloon peninsula the Yau Ma Tei scheme is in operation while the other four are in an advanced stage. Work on three of five schemes on Hong Kong Island was started during the year and one of these, the Wan Chai scheme, is in partial operation.
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Surface water draining down from the hills through built-up areas was formerly led to the sea through large open channels, known as nullahs. These nullahs were frequently 10 feet wide or more and were normally located in the centre of the road. With the tremendous increase in both vehicle and foot traffic such obstructions had to be removed, and during the last 10 years many nullahs have been decked over. Extensive systems of culverts have also been constructed at several resettlement estates, and in new towns such as Tsuen Wan, Kwai Chung and Shek Wu Hui, to divert stream-courses and facilitate drainage.
Investigations into the cause of disastrous floods at Yuen Long in May, 1960, have resulted in a plan to reduce the risk of future flooding. It provides for the construction of new culverts and the realignment of existing stream-courses over a period of five years. Construction of the first stage was nearly complete at the end of the year and work had started on some of the other stages. Similar plans for flood control in other vulnerable areas of the New Territories, in particular the Indus River basin, were also being prepared. Improvements to the drainage and sewerage systems of such small outlying communities as Sai Kung, Peng Chau, Cheung Chau and Sha Tau Kok were also undertaken during the year.
Port Works. The most important work in progress during the year was the central reclamation scheme, which will eventually link the reclamation already carried out for the Star Ferry piers