LAND, PUBLIC WORKS AND UTILITIES
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China. The bulk of internal production came from seven contract quarries supervised by the Geotechnical Control Office.
The Public Works Central Laboratory was relocated to its new premises in Kowloon Bay in July, and a new 2 000 KN Universal Testing Machine was installed in September. The seven Public Works Laboratories carried out some 336 000 tests on construction materials, including soil and rock, concrete, reinforcing steel, timber, aggregates and bit- uminous products.
Water Supplies
Water from China
The supply of water from China is now the major single source of supply for Hong Kong and it is from this source that all future increases in demand will be met. This dates back to 1960 when a scheme was first formulated for receiving a piped supply of 22.7 million cubic metres a year. Today, the annual supply from China has increased to over 500 million cubic metres and this will continue to increase in stages to 660 million cubic metres by 1994-5. The concept of seeking a supply from China and steps taken by the Water Supplies Department of Hong Kong to realise such a goal have brought about radical changes to the history of water supplies in Hong Kong.
Following agreement reached with the Chinese Authority in December 1989 to increase the China water supply up to a maximum of 1 100 million cubic metres per year to cope with anticipated water demands of Hong Kong beyond 1994, a conceptual plan was finalised for the works to be constructed in stages to receive and distribute the additional supply, and consulting engineers were engaged to carry out detailed planning and design with a view to completing the Stage I works by end-1994. The Stage I works include some 22 kilometres of large-diameter transmission pipelines, new pumping stations at Muk Wu, Tai Po Tau, Au Tau and Sai O and uprating of an existing pumping station at Tai Mei Tuk.
Water Works
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Full supply was maintained throughout the year. At the beginning of 1990, there were 243 million cubic metres of water in storage, compared with 230 million cubic metres at the start of 1989. The combined storage of Hong Kong's largest reservoirs, High Island and Plover Cove, was 200 million cubic metres. Rainfall for the year was 2047 millimetres compared with the average of 2 225 millimetres. Water piped from China during the year totalled 590 million cubic metres. The salinity of water at High Island remained at about 20 milligrams per litre while at Plover Cove it varied from 51 milligrams per litre at the beginning of the year to 54 milligrams per litre at the end of the year.
A peak consumption of 2.66 million cubic metres per day was experienced, compared with the 1989 peak of 2.63 million cubic metres. The average daily consumption through- out the year was 2.39 million cubic metres, an increase of three per cent over the 1989 average of 2.32 million cubic metres. The consumption of potable water totalled 873 million cubic metres compared with 845 million cubic metres in 1989. In addition, 119 million cubic metres of salt water for flushing was supplied, compared with 112 million cubic metres in 1989.
With reliable supplies available from China, it was decided by the Executive Council in July 1989 to dispose of the Lok On Pai Desalting Plant. Tender for the disposal of the