ENG-1960 — Page 29

16

REVIEW

Apart from helping many of the smaller villages in these ways, Government has also carried out since the war a considerable programme of extensions and improvements to the supplies of the larger townships, some of which have been equipped with roughing filters as well. The Yuen Long area, for example, bene- fited in 1952 from the construction of a small impounding reservoir which feeds water to the town through a six-inch main, and in 1958 work began on a fully treated supply from the Tai Lam reservoir. Before 1955 the thriving fishing community on Cheung Chau Island had no supply other than local wells and rain-water collected in roof-top tanks, supplemented by water boats at times of severe shortage, and the rapid increase in population made it essential to augment the island's resources from outside. A small impounding reservoir was therefore constructed on Lantau, the water being delivered across a narrow neck of sea by submarine pipeline. A service reservoir and distribution system were also installed. The supply is still not enough for Cheung Chau's needs, but improvements are being made. No other town in the New Territories was supplied from a reservoir until the completion of the Tai Lam scheme enabled Tsuen Wan and the Castle Peak area to enjoy a filtered supply from that source.

The problem of water distribution in the New Territories is not only one of procuring domestic supplies, but also of providing irrigation for agriculture. Traditionally the countryside has de- pended on rice which is a crop excellently suited to the climate with its heavy summer rainfall. Direct rainfall gives enough water, on the average, over the growing period of the two rice crops. But it does not rain every day, even in the summer, and genera- tions of farmers have therefore installed irrigation systems which rely on diverting the flow from streams into channels running to the fields. The diversion dams were mostly quite small, only three or four feet high and twenty feet or so across. Their function was not to conserve water but to raise the level of the stream high enough to allow the water to flow away along the supply channel. Until a few years ago they were made of rocks and earth, and the channels were dug out of the earth, unlined and protected from damage only by the growth of vegetation along their banks. Con- sidering that they were planned and built by uneducated farmers with no surveying instruments other than a good eye for ground,