ENG-1961 — Page 272

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PUBLIC WORKS AND UTILITIES

will enable the target of housing 20,000 persons per year to be reached within the next two years.

Drainage. Nearly all built-up areas, including a few of the larger towns in the New Territories, have water-borne sewage systems. However, as large new blocks of flats take the place of very old and much smaller buildings, the flow to the sewers is steadily increasing and many of the older sewers are becoming laden beyond their designed capacity. This has meant continual replace- ment of existing systems by larger mains. The nuisance from seawall sewer outfalls has grown and extensive plans to build intercepting sewers in the place of the many seawall sewer outfalls will soon bring the sewage to selected sites where it will be treated and discharged into deep water through submarine outfalls. Pump houses have been installed in many cases to raise the sewage in the intercepting sewers where the fall is not sufficient for gravity flow. Of the five schemes for the Kowloon Peninsula, the Yau Ma Tei scheme is in complete operation and work was begun on the remaining four. Work on three of the five schemes on the Island was started 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, used to be led to the sea through large open-trained channels, known locally 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 vehicular and foot traffic, such obstructions had to be removed, and during the last nine years many nullahs have been decked or culverted. Extensive systems of culverts have been constructed at the resettlement estates at Wong Tai Sin, Wang Tau Hom, Kwun Tong, Jordan Valley and Chai Wan, and in new towns such as Tsuen Wan and Shek Wu Hui, to divert stream-courses and facilitate drainage.

Investigations into the cause of the 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. Work on the initial stage of the plan started towards the end of the year. Similar plans for flood control in other vulnerable areas of the New Territories are also being prepared.