ENG-1995 — Page 267

LAND, PUBLIC WORKS AND UTILITIES

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to undertake a series of environmental studies to examine the effects of the dredging and dumping activities, and to investigate possible ways to avoid or minimise adverse effects on the marine environment. Phase VI of the Fill Management Study began in July 1995 at an estimated cost of $74.2 million over the next two years.

Hydraulic Studies

Large reclamation projects can have significant effects on the flow of water, sediment transport and wave activity in the harbour. Any adverse effects could be very costly or difficult to remedy. To avoid these problems, the Civil Engineering Department employs sophisticated hydraulic models to analyse the likely effects of proposed schemes and check that they are within acceptable limits. The facilities used include computer-based mathematical models and a large physical model housed in the Harbour Hydraulics Laboratory at Tuen Mun.

The assessments provided by these models are used for planning reclamation layouts, the design of marine structures, navigation studies, and the planning of future maintenance dredging requirements. Recently, hydraulic model studies have been carried out for the Lantau Port Development project, the Central and Wan Chai Reclamation, the Green Island Reclamation, and the West Kowloon Reclamation. These analyses showed that the impact of these reclamations would be within acceptable limits. With an increasing awareness of environmental disturbance, the hydraulic models will continue to form an essential tool in the planning and design of future reclamation and marine projects.

Water Supplies

Water from China

China is the major single source of water supply for Hong Kong, and all future increases in demand will be met from this source. This arrangement dates from 1960, when a scheme was formulated for receiving a piped supply of 22.7 million cubic metres a year. The supply from China stipulated under the agreements was increased to 690 million cubic metres a year in 1995. This will continue to increase in stages to 840 million cubic metres per annum by the year 2000. Extra purchases may be made in years of low rainfall in Hong Kong.

Following the agreement reached with the Chinese authorities 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 demands beyond 1994 and into the early 2000s, a conceptual plan was developed for the necessary works to receive and distribute the additional supply. The works are being implemented in stages, with Stage I substantially completed and operating.

Water Storage and Consumption

Full supply was maintained throughout the year. At the end of 1995, there were 497 million cubic metres of water in storage, compared with 423 million cubic metres at the end of 1994. Hong Kong's two largest reservoirs, High Island and Plover Cove, held 436 million cubic metres. Rainfall for the year was 2 754 millimetres, compared with the average of 2 214 millimetres.

A peak daily consumption of 2.78 million cubic metres was recorded on June 26, compared with the 1994 peak of 2.73 million cubic metres. The average daily