LAND, PUBLIC WORKS AND UTILITIES
of marine fill resources for development projects, and for the provision and management of disposal capacity of dredged sediments. The PFC is responsible for construction and demolition materials management and land-based fill reserve utilisation. The Civil Engineering Department (CED) provides administrative and technical support to both committees.
From 1990 to 2000, about 285 million cubic metres of marine fill were used for reclamation projects, of which about 40 million cubic metres of marine sand were imported from the nearby regions in the Mainland. It is expected that a further 350 million cubic metres of fill would be required for land formation to meet the need for housing and infrastructure developments in Hong Kong during the decade. Currently, the reclamation projects for the development of the Hong Kong Disneyland at Penny's Bay and the Container Terminal 9 will extract over 50 million cubic metres of marine sand from the marine borrow areas within Hong Kong waters. The CED manages mud disposal facilities. In 2000, about 36 million cubic metres of uncontaminated mud generated from various projects were disposed of, some at open sea floor disposal grounds and some in exhausted marine sand borrow pits. The increasing use of exhausted sand borrow pits for disposal has the dual benefit of providing much needed disposal capacity while at the same time restoring the seabed to its natural profile and state. About eight million cubic metres of contaminated mud were placed in an empty marine sand borrow pit at East Sha Chau. These intensively monitored disposal pits are capped with uncontaminated mud to isolate the contaminants from the environment.
In connection with the management of Hong Kong's fill resources and mud disposal capacity, the CED, on behalf of the MFC, continued to undertake a series of geotechnical, environmental and ecological studies and monitoring to examine the effect of the dredging and disposal activities, and to investigate possible ways to avoid or minimise adverse effects on the marine environment.
The MFC also maintains a Fill Management Database on fill requirements, mud disposal and surplus excavated materials from major public and private projects. The database is aimed at assisting the construction industry to co-ordinate sources of fill materials and make the best use of the surplus materials. All project data is publicly available on the Internet (http://www.info.gov.hk/ced/fm.htm).
Hydraulic Studies
Coastal engineering projects may affect the flow of water, sediment transport and wave activity in the harbour. To minimise any adverse effects, the Civil Engineering Department employs sophisticated computer hydraulic models to analyse the likely effects of proposed schemes, both during and after the construction phases, to ensure that they are within acceptable limits. The models are used for reclamation layout planning, design of marine structures, waterway studies and assessment of future maintenance dredging requirements.
A number of hydraulic studies had been carried out to investigate the impact of major coastal engineering projects. These major projects included the Green Island Reclamation; Tonggu Waterway; Siu Lam Typhoon Shelter and Tang Lung Chau Dangerous Goods Anchorage. A trial section of wave absorbing seawall is being built at the new waterfront of the West Kowloon Reclamation. It is anticipated that this
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