HONG KONG 2004 - Land, Public Works and Utilities

The Civil Engineering and Development Department (CEDD) manages a comprehensive slope safety system, which has brought about a substantial improvement in the safety of slopes in Hong Kong. This has been achieved by improving slope safety standards and technology, ensuring the safety of new slopes, improving the safety of existing slopes, and providing public warnings, information, education and community advisory services on slope safety.

The department audits the adequacy of the design and standard of construction of all geotechnical works by the private sector, public authorities and government departments to ensure their long-term safety. In 2004, it audited 13 500 geotechnical design proposals and inspected 2 850 active construction sites.

The department maintains a continuing Landslip Preventive Measures (LPM) Programme to rectify the safety of existing slopes. In 2004, a total of about $770 million was spent on the LPM Programme. Upgrading works were completed on 250 government slopes, and all were landscaped to blend them with the surrounding environment. In addition, safety screening was completed on 312 private slopes.

The department inspects sub-standard slope to identify those particularly vulnerable to landslides, recommends clearance of the affected squatters and advises the occupants to seek safe shelter during heavy rain. In 2004, it inspected about 200 sub-standard slope and recommended clearance of the affected squatters.

With the availability of the Slope Maintenance Responsibility Information System on the Internet, the public can have ready access to information on slopes under their responsibility. Other slope-related information is also available in the Slope Information System. A bilingual version of the system has been uploaded to the Internet at the CEDD's Hong Kong Slope Safety website, an important source of reference for the public to obtain slope-related information.

The Catalogue of Slopes has been made more comprehensive by the department through systematically examining the latest topographic plans and using aerial photograph interpretation techniques to identify and register slopes which meet the registration criteria but have not been included in the catalogue. The number of registered slopes in the catalogue has subsequently increased from 54 000 to 57 000.

In sustaining public awareness of slope safety, the department continues to promote and disseminate slope safety and slope maintenance messages to the public. Apart from regular roving exhibitions and talks, a major exhibition on the landslide history of Hong Kong was held in the Central Library in April 2004 to draw the public's attention to slope safety through historical landslide incidents. As part of the slope maintenance campaign, a pamphlet on Maintenance of Buried Services Affecting Slopes has been prepared to remind slope owners to inspect and maintain underground water services. As part of the efforts to improve the living environment, an open competition for the Best Landscaped Slope Awards was held in February 2004 to encourage slope owners to maintain and beautify their slopes.

New initiatives of public education in slope safety are underway. A book on the landslide history of Hong Kong is being prepared for the public based on the information collected from the landslide history exhibition. The department, in collaboration with other relevant government departments and non-governmental organisations, is organising a joint publicity programme, Safer Living —Reducing Natural Disasters, to raise the community's preparedness for and resilience to natural disasters. The programme comprises a series of publicity events lasting for 12 months starting in March 2005, including exhibitions, public lectures, slogan and bookmark competition, a TV documentary and rescue drill demonstrations.

The department's Community Advisory Unit continues to provide useful advice to private slope owners to help them maintain and improve the condition and appearance of their slopes.

The department audits maintenance works of government departments to help in their slope maintenance work. Audits of government slope works indicate a continuous improvement in the overall state of maintenance.

The CEDD maintains a 24-hour year-round emergency service to provide geotechnical advice to government departments on actions to be taken to protect the public against landslide danger. The computerised information system and telecommunication facilities have been upgraded to enhance efficiency in handling landslide information and emergency calls.

The department conducts various studies to improve the knowledge and practice of dealing with natural terrain landslide hazards. It has applied the Geographic Information System and remote sensing techniques to identify historical natural terrain landslides, and quantify the landslide risk. Natural terrain hazard mitigation works are being arranged for six sites in developed areas, while studies are being carried out on four other sites.

During the year, the department continued to produce geotechnical guidance documents to disseminate new technological development findings and improved design and construction practices. In particular, Technical Guidance Notes giving enhanced geotechnical guidance on design and quality control of slope works were promulgated.

The Geotechnical Information Unit in the Civil Engineering Library, which houses the largest collection of geotechnical data in Hong Kong, served more than 26 000 public users during 2004.

The department provides specialist geotechnical services to government departments, including the provision of ad hoc geotechnical advice and the conduct of feasibility studies, detailed investigations, design and construction supervision for a wide range of public works projects. The projects handled by the department during the year included site formation works at Kong Sin Wan Tsuen, Pok Fu Lam, North Point Salt Water Service Reservoir, Quarry Bay Salt Water Service Reservoir, Yau Tong No. 2 Freshwater Service Reservoir and Magazine Gap Road No. 3 Freshwater Service Reservoir Extension; and geotechnical works for the drainage project at San Tin and Stage III of the Shenzhen River Regulation Project. In addition, the department provides construction material testing and ground investigation services to support public works projects. The testing service is provided by the Public Works Laboratories. During the year, some 910 000 tests were carried out and 12 500 metres of soil and rock drilled.

The department enforces legislation relating to mining, quarrying and explosives, and administers quarrying contracts. It processes applications for the manufacture, storage, conveyance and use of explosives, and inspects stone quarries, blasting sites and explosives stores.

Hong Kong consumed 13.5 million tonnes of aggregates and other rock products in 2004. About 50 per cent of its demand for aggregates and rock products was met locally, with the balance imported from the Mainland.

One quarrying contract and two quarry rehabilitation contracts were in force during the year. The rehabilitation contracts require the operators to rehabilitate the quarries within a specified period, in return for the granting of rights to process and sell surplus rock excavated during the course of the works. The rehabilitation works involve recontouring and extensive planting to blend the quarries with the surrounding hillsides.

The department manages two government explosives depots (one at Kau Shat Wan on Lantau Island and the other at Piper's Hill, Sha Tin) which provide bulk storage facilities for imported explosives. It also undertakes the delivery of explosives from the depots to blasting sites and issues shot-firer certificates. About 2 200 tonnes of explosives were consumed in 2004, used mostly for quarrying and site formation works.

The department also provides technical support to the Home Affairs Bureau and the Marine Department in assessing applications for fireworks displays.

The Marine Fill Committee (MFC) is responsible for identifying and managing the supply of marine fill resources for development projects, and for managing disposal facilities for dredged and excavated sediment. The Public Fill Committee (PFC) has the duty to manage construction and demolition (C&D) materials and utilisation of land-based fill reserves. Both committees are responsible to the Secretary for the Environment, Transport and Works.

About 20.5 million tonnes of C&D materials were generated by local construction activities in 2004. Of this, about 18.1 million tonnes of inert materials were re-used as fill in projects such as Penny's Bay and Tai O developments, or stockpiled at the fill banks in Tuen Mun Area 38 and Tseung Kwan O Area 137.

The PFC explores ways to minimise the generation of C&D materials and reduce their disposal at landfills. Public construction works are required to adopt waste management plans that reduce the generation of C&D materials at source. The temporary recycling facility at Tuen Mun Area 38 recycles suitable C&D materials into aggregates for re-use. In 2004, the recycling facility produced about 210 000 tonnes of recycled aggregates for use in government projects.

The MFC maintains a Fill Management Database on fill requirements, mud disposal and surplus excavated materials from major public and private projects. Its purpose is to help the construction industry coordinate sources of fill materials and make the best use of surplus materials. All project data is available at the CEDD's home page.

The department manages mud disposal facilities. In 2004, about 2.97 million cubic metres of uncontaminated mud and 1.55 million cubic metres of contaminated mud were generated from various works projects and maintenance works on navigational channels in the harbour. Uncontaminated mud was disposed of at open sea floor disposal grounds or exhausted marine sand borrow pits. Contaminated mud was placed in specially selected and closely monitored exhausted sand borrow pits, which were then capped with clean mud on completion of filling to isolate the contaminants from the environment. The use of exhausted sand borrow pits for mud disposal is preferred as it has the dual benefits of providing much needed disposal capacity and restoring the seabed to its natural profile and state.

In connection with the management of Hong Kong's fill resources and mud disposal capacity, the department, on behalf of the MFC, continues 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 the impact on the marine environment.