Shenzhen Western Corridor and Deep Bay Link
(ACE Paper 37/2001)
For discussion
Purpose
This paper presents the proposed alignments of the Shenzhen Western Corridor and Deep Bay Link. It also briefly highlights the main environmental issues that are being studied in detail under the environmental impact assessment (EIA) of the projects.
Background
2. Hong Kong has benefited from China's economic growth enabling herself to perform better than most of the neighbouring places, such as Singapore, Indonesia etc., during the recent economic recession that has occurred in Asia.
3. However, this economic advantage is not without worry since the three existing vehicular boundary crossings at Lok Ma Chau, Man Kam To and Sha Tau Kok are nearly saturated and it is expected that they will exceed their handling capacity within the next five years. In fact, the public has raised concerns on the frequent occurrence of traffic congestion and long waiting times at these crossings. (A map showing the location of these crossings and photographs showing their conditions are at Annex A.)
4. Both the governments of the HKSAR and Shenzhen City recognize the need to remove these potential bottlenecks to trade and traffic. However, there are difficulties in expanding the existing three crossings because they are located within the city centre of Shenzhen City. Over 80% of the cross-boundary traffic has to go through the main roads within the city centre causing serious traffic congestion and environmental impacts. On account of this, the Shenzhen Authority considers the fourth land boundary crossing - Shenzhen Western Corridor (SWC) should be built as soon as possible.
5. On Hong Kong's part, the 'Feasibility Study for Additional Cross-border Links' also confirmed the need for constructing SWC together with the connecting road, Deep Bay Link (DBL), within Hong Kong for the following reasons -
- to alleviate the nearly saturated existing land boundary crossings at Lok Ma Chau, Man Kam To and Sha Tau Kok; and
- to enhance trade between Hong Kong and South China, to facilitate Hong Kong's economic development and to enable Hong Kong to become a business hub of the Pearl River Delta area.
6. We have reached agreement with the Shenzhen authority that in accordance with the boundary of Guangdong and Hong Kong, each side will finance and manage its portion of the SWC, while the construction of the bridge will be a joint effort. Both sides have also agreed to implement the project as soon as possible.
7. At the 4th Plenary of the Hong Kong / Guangdong Cooperation Joint Conference held on 25 July 2001, further agreement has been reached on the principle of co-locating the boundary crossing facilities for immigration and customs clearance procedures on the Shenzhen side in planning SWC.
Proposal
Shenzhen Western Corridor
8. We propose to implement the Shenzhen Western Corridor, which is a dual 3-lane bridge crossing spanning Deep Bay. The length of the crossing is 5.1 km, 3.2 of which is within the HKSAR and 1.9 km within Shenzhen. It lands at Ngau Hom Shek in Hong Kong, and in Dong Jiao Tou in Shenzhen. (A map showing the proposed alignment is at Annex B.)
Deep Bay Link
9. We also propose to implement the Deep Bay Link, which links up the SWC and our local road network. DBL is proposed to be a dual 3-lane road of 5.4 km in length. (A map showing the proposed alignment is at Annex C.) The scope of works includes -
- slip roads linking DBL to the proposed Hung Shui Kiu New Development Area and the local road network in Yuen Long; and
- an interchange at Lam Tei linking Yuen Long Highway. The DBL will be linked to the Yuen Long Highway in its initial years of operation.
10. Our traffic forecasts indicate that the existing road network including Yuen Long Highway and Route 3 should be able to cater for the traffic of DBL in the initial stage. In the longer term, Route 10 between Yuen Long Highway and So Kwun Wat will be required. While our current planning is that this section of Route 10 would be completed after 2010, we will closely monitor the traffic situation and continue to review regularly its need and timing.
11. We propose to commence detailed design for the SWC and DBL in early 2002.
Environmental Issues
Shenzhen Western Corridor
12. The feasibility of the SWC project was established by the Feasibility Study for Additional Cross-border Links commissioned in 1995. No insurmountable environmental problem was identified but a further detailed assessment would be necessary to address all the issues thoroughly. The preliminary findings on some particular aspects based on a broad environmental assessment carried out under the above study during 1998/1999 are highlighted below.
Birds
13. Based on a bird survey carried out from January 1998 to February 1999 within the area concerned, 63 species of birds were recorded, two of which were Class II protected species in China. We did not identify the endangered species Black-faced Spoonbill in the above survey but a separate survey carried out by the World Wild Fund found the species on the mudflats within the area concerned. Possible mitigation measures include realigning the crossing to avoid areas of high ecological value, minimising the number and size of supporting piers, providing compensatory planting using native species, habitat creation and keeping construction activities confined.
Chinese White Dolphins
14. A broad ecological assessment indicated that Chinese White Dolphins were seldom found in the locations of the proposed piers of the SWC. Nevertheless, submarine noise during construction of bridge piers might be potentially disturbing to the dolphins, depending on the piling method used and construction work could be appropriately scheduled to keep any possible impact to the minimum. Other possible mitigation measures include minimising the number and size of supporting piers, providing bubble curtains to mitigate impacts on dolphins, monitoring the area for the presence of dolphins before disturbing operations such as piling, and providing artificial reefs to create new habitats around the bridge piers.
Horseshoe Crabs
15. Horseshoe crabs are found in the coastal zones in Deep Bay. The nearest recorded site of horseshoe crabs from the leading point is at the site of special scientific interest (SSSI) in Pak Nai. However, the landing point is expected to be 500 to 1,500m away from the Pak Nai SSSI. Further investigation will be carried out to confirm the impact level and recommend necessary mitigation measures.
Oyster Bed
16. Part of an existing oyster bed would be affected by the project and a scheme to minimise the impact will be further looked into.
Water Quality
17. Deterioration in water quality could be a direct result of reduction in tidal flows under the bridge. This reduction in tidal flows can be restored by appropriate mitigation measures such that the water quality would also be restored to baseline or pre-development conditions. Possible mitigation measures include local dredging, appropriate realignment of bridge piers and widening of space between bridge piers. During the construction stage, mitigation measures such as the use of silt curtains at marine sites and at land-based sites, and standard site runoff control measures will be adopted. By incorporating suitable mitigation measures, the SWC project would not cause unacceptable adverse impact on water quality in Deep Bay.
Air Quality
18. The air quality in Hong Kong has a close relationship with the overall air quality within the Pearl River Delta Region. The new crossing could have localized impact on individual areas but, generally speaking, the additional traffic to be brought into Hong Kong would not result in any insurmountable adverse impact on the overall air quality.
Noise
19. Some direct mitigation measure in the region of the landing point would be necessary to reduce the noise impacts on the sensitive receivers.
20. We will take due care in choosing an environmentally acceptable alignment with appropriate structural form and construction methods. Also, we will fulfill the requirements under the EIA Ordinance and devise practical mitigation measures to minimize impact on the environment.
Deep Bay Link
21. According to an environmental assessment carried out under the Feasibility Study for Additional Cross-border Links, the DBL would unlikely cause insurmountable adverse impact on the ecological and water quality of the environment. The DBL might have localized impact on individual areas and the issues identified would be assessed in a detailed EIA. A thorough EIA is being carried out. The following main areas of concern, among others, are being assessed in detail.
Ecology
22. The proposed alignment has avoided existing wetlands and fishponds as far as possible. Field surveys have been carried out on flora, fauna and ecological habitats as part of an impact assessment to be made.
Air Quality
23. During construction, the contractors will be required to adopt effective dust reduction measures such as spraying onto works areas and covering up of stockpiles. The design will be carried out with a view to minimizing air quality impacts during the operation of DBL on existing and future air quality sensitive receivers.
Noise
24. Noise barriers of suitable heights and design will be erected where necessary to mitigate traffic noise. During construction, mitigation measures will be adopted to limit construction noise. The measures may include the use of quiet plant, quiet working methods and temporary/movable noise barriers.
Landscape and Visual Impact
25. The DBL, including elevated structures, will be designed to be visually acceptable. Chromatic treatment will be applied to noise barriers to ensure that they are aesthetically pleasing. Moreover, we will plant trees to compensate loss of trees resulting from the project, to soften visual intrusion of structures and to enhance greening along the route.
Cultural Heritage
26. The proposed alignment avoids burial grounds and significant graves to preserve traditional ways of life of indigenous villagers. The villagers will also be consulted on "Fung Shui" matters so that this issue can be considered in the design. Although there are numerous archaeological sites in the vicinity of the project, the design will avoid or preserve them as far as possible. Where it is not possible to avoid disturbing small localized areas of the sites, thorough archaeological rescue plans will be implemented prior to the commencement of works.
27. The proposed DBL alignment will be designed with consideration of existing and future sensitive receivers, ecologically sensitive areas, burial grounds, significant graves and archaeological sites etc.
The Way Forward
28. We will submit the EIA reports of the DBL and the Hong Kong portion of the SWC for the Director of Environmental Protection's approval under the EIA Ordinance and will follow the statutory procedures of making the EIA report available for comments by the public and the ACE. We will incorporate the recommended mitigation measures into the detailed design and shall apply for an environmental permit for the project prior to commencement of construction. As part of the EIA Studies, we will also identify environmental monitoring and audit requirements for adoption during construction and operation of the projects.
Advice Sought
29. Members are invited to provide comments on the projects. Members' comments will be given full regard in the EIA studies.
Transport Bureau
September 2001
