PUBLIC WORKS AND UTILITIES
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Chinese authorities began to supply water on October 1 in accord- ance with the terms of the 1960 agreement, and a 24-hour supply was introduced once more. To insure against restrictions in the winter months it was, however, necessary to make use of saline water from the Plover Cove Reservoir. By mixing this with normal supplies the salinity of the water in many areas in Hong Kong was gradually raised, first to a sodium chloride content of 600 parts per million and later to 900 parts per million. Supplies of normal low salinity were maintained to certain industrial areas.
Systematic waste detection had to be curtailed during periods of restricted supply, but the clear benefits which follow from this practice demand that it be reintroduced whenever possible. Water consumption for the year totalled 39,795 million gallons, compared with 43,760 million gallons in the previous year. These figures include industrial and domestic supplies, but largely exclude flush- ing demand for sanitary purposes, generally met from independent wells or from a separate government seawater flushing system, which supplied 9,769 million gallons of water during the year.
Work on major supply schemes continued. At Plover Cove the new reservoir took shape. In January the dam was raised above sea level and the three mile sea inlet which makes up the reservoir, was successfully sealed. Plover Cove, which will have a useful storage capacity of 30,000 million gallons, is due to be completed in late 1968, when the permanent pumping station comes into operation. Water is now being drawn out by temporary pumping installations. In February pumping out of seawater began; the excitement which was felt as the water level inside the reservoir was seen to fall, turned to triumph when, in April, the level of -27 feet below principal datum (about 31 feet below mean sea level) was reached.
The original plan was to allow rainfall to dilute the seawater in the reservoir and to hold the contents at -27 PD by pumping out to sea. The water remaining in the reservoir at that level would act as a buffer to prevent disturbance by incoming flood waters of the saline mud on the floor of the reservoir. When there was little rainfall in May this plan was abandoned. The reservoir was pumped almost dry in early June and allowed to collect rainwater without
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