PUBLIC WORKS AND UTILITIES
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Cove in a reservoir constructed by the damming of an almost land-locked bay to form a fresh water lagoon. Messrs Binnie, Deacon & Gourley and Messrs Scott & Wilson, Kirkpatrick & Partners, Consulting Engineers for the Integrated Scheme, were asked, while continuing with their investigations into the practi- cability of the Scheme as a whole, to prepare designs and draw up contracts for the tunnels, treatment works at Sha Tin and other associated works in stage one. Several of these contracts have now been let. A bold gamble is being taken to construct the tunnels to such a size as to take the Plover Cove yield, though it is not known for certain whether the construction of the Plover Cove dam is in fact a practical proposition. This action is a measure of the Colony's urgent need for additional water resources.
When completed the Shek Pik Reservoir will bring the Colony's total storage resources to 15,900 million gallons. The dam itself is almost at sea level and now stands an average of 50 feet above the valley floor and is becoming a landscape feature. From what will be the largest of the Colony's reservoirs, the raw or untreated water will flow through supply tunnels by gravity to a pumping station at Pui O, which will lift the water at an average rate of 27 million gallons a day to the treatment works overlooking the bathing beach of Silver Mine Bay.
The treated water will descend below sea level carried by either or both of two 30" diameter submarine pipelines. The steel pipes are made by Hume Pipe Industries Ltd of Singapore. They are protectively lined inside and out, and further protected on the outside by concrete which also serves as ballast so that the pipes sink even when empty. The welding of the pipes into one con- tinuous length and the outer protection of wrapped fibre-glass and concrete is being done in Hong Kong. The 27 foot lengths are made up into pipes 81 feet long which are successively jointed on a 'lay barge' to form a continuous pipeline. As the 'lay barge' is pulled from under the latest 81-foot length to be connected up, that section of pipe follows those already laid to the bottom of a sea- bed trench later to be covered with sand. The only pipes that will be seen are the short lengths contained in a water-tight concrete box off the northern shore of Chau Kung or Sunshine Island where the two 30" pipes will be cross-connected and a small branch sub- marine pipeline laid to serve the island of Peng Chau. The pipes