4.                       ECOLOGICAL IMPACT ASSESSMENT

 

4.1                   Introduction

 

4.1.1             The aim of this Ecological Impact Assessment Report (EcoIA) with respect to ecological impacts of the construction and operation of the Spur Line is to:

 

•           Review the ecological resources within the area affected by the project and identify Valuable Ecological Components (VECs), including habitats and Species of Conservation Importance.

 

•           Identify the potential impacts from the construction and operation of the Spur Line.

 

•           Identify potential mitigation measures that may be used to reduce or overcome the potential impacts of the construction and operation of the Spur Line.

 

•           Provide an assessment of the predicted residual impacts of the construction and operation of the Spur Line taking into account the proposed mitigation measures.

 

4.1.2             This assessment is based on guidelines given in Annex 8 (“Criteria for evaluating an ecological impact”) and Annex 16 (“Guidelines for ecological assessment”) of the Technical Memorandum on Environmental Impact Assessment Process (EPD), together with the general and specific key issues identified in the Study Brief for the EIA issued by DEP on 15 October 2001.

 

4.1.3             As discussed in Chapter 2 of this Report, a considerable amount of work has been done on the selection of an alignment for Spur Line which minimizes impacts on the environment, particularly on the ecological resources of the area, while meeting engineering, operational and safety requirements. Routing the Spur Line across Long Valley was necessary for reasons outlined in Chapter 2 and Appendix A2.1.

 

4.1.4             An EIA previously submitted for a viaduct option across Long Valley was rejected by the Director of Environmental Protection on 16 October 2000. This decision was upheld by the Appeal Board in its judgement that was handed down on 30 July 2001. Due to time constraints and requirements for further study on ecological interactions in Long Valley, without assurance of acceptance of proposed ecological mitigation measures, a decision was taken to redefine the alignment by placing it in tunnel from Sheung Shui to Chau Tau. The changes in ecological impacts resulting from this new alignment have been incorporated into this EIA. In addition, this EcoIA covers those issues that have arisen during the previous EIA Report evaluation and appeal process, both through the process itself and as a consequence of external factors (such as changes in habitats and animal distribution).

 

4.1.5             Placing the Spur Line in tunnel has eliminated any direct impacts on Long Valley and thus removes the need for compensation. This is a major benefit of the tunnel option. Avoidance of impacts at Lok Ma Chau, however, was not possible because of the need to connect to Huanggang Station in Shenzhen. The configuration of this connection requires an above ground station within the Wetland Conservation Area (WCA) together with a footbridge across Shenzhen River. The Spur Line project is a major infrastructure project with overriding public interest. Nevertheless, impacts from the project on wetland resources within the WCA must be addressed and mitigated as described in this Eco1A.

 

4.2                   Methodology

 

4.2.1             Baseline information for this EcoIA is derived from the sum of the following sources and studies:

 

•           A Preliminary Project Feasibility Study (PPFS) of the proposed Sheung Shui to Lok Ma Chau Spur Line prepared in 1998 (Binnie 1998).

 

•           An ecological review of the Spur Line corridor (ERM 1999b), which provided much of the baseline data presented in the previous EIA.

 

•           A twelve month baseline ecological study of the Spur Line corridor conducted from April 2000 to May 2001 (see Appendix A4.1 of this EIA Report).

 

•           Within this Baseline Report, sectoral studies of key habitats and species: a four season study of Greater Painted-snipe Rostulata benghalensis in Long Valley undertaken from April 2000 to January 2001 and a study of Greater Spotted Eagle Aquila clanga and Imperial Eagle Aquila helica distribution and habitat preferences in Deep Bay conducted from November 2000 to March 2001. In addition, a study of response of waterbirds, in particular ardeids and Black-faced Spoonbills Platalea minor to the draining down of fish ponds was undertaken at Lok Ma Chau during November 2000 to March 2001.

 

•           Additional field surveys conducted in the Chau Tau and Lok Ma Chau Village areas during October 2001 covering mammals, birds, herpetofauna, butterflies and dragonflies in order to identify any habitats and species of conservation importance which might not have been fully covered in the other surveys detailed above (see Appendix 4.1 to this Report). In addition a bat roost at Chau Tau was surveyed periodically during September 2000 to November 2001 (see paragraph 4.3.20) .

 

•           A survey of the entire Spur Line corridor conducted in September to October 2001 to update the habitat map for the corridor.

 

4.2.2             As is required under Annex 16 of the Technical Memorandum to the EIA Ordinance, the defined Study Area consisted of a one-kilometre corridor (500 m on either side of the proposed alignment), except where, as is described above, sectoral studies required a narrower or broader focus. A corridor of 100 m either side of the alignment was subjected to more detailed survey; this 200 m corridor was considered to represent the area that is most likely to be subject to impacts from the construction and operation of the railway.

 

4.2.3             Ecological investigations were supported by an extensive literature review, both in respect of supplementary data regarding habitats and species present and in the research necessary to identify and quantify potential impacts. The following principal sources were consulted during the preparation of the previous EIA (Binnie 2000a) and the present EIA study:

 

Environmental Impact Assessment Study on Shenzhen River Regulation Project – Final Report (Peking University 1995);

Main Drainage Channels for Fanling, Sheung Shui and Hinterland – Final EIA Report (CES 1997);

Main Drainage Channels for Fanling, Sheung Shui and Hinterland Environmental Impact Assessment – Supplementary Paper on Ecological Mitigation Utilising Abandoned Meanders (TTD 1998);

Main Drainage Channels for Fanling, Sheung Shui and Hinterlands Environmental Monitoring and Audit Manual – Final Report (CES 1998);

KCRC West Rail (Northern Section) – Initial Environmental Assessment Report (ERM 1998a);

Sheung Shui to Lok Ma Chau Spur Line Preliminary Project Feasibility Study (Binnie 1998);

Main Drainage Channels and Poldered Village Protection Scheme for San Tin, NWNT: Environmental Impact Assessment Study – Final Assessment Report (ERM 1999a);

KCRC East Rail Extensions – Sheung Shui to Lok Ma Chau Spur Line Project: Ecological Study (ERM 1999b)

Expansion of Kiosks and Other Facilities at Lok Ma Chau Boundary Crossing: Final Environmental Study Report (Binnie 1999);

Shenzhen River Regulation Project Stage III Environmental Impact Assessment – Final Assessment Report (Binnie 2000b);

Planning and Development Study on North East New Territories Development Study – In progress (Maunsell Consultants Asia Ltd)

Design of Ecological Mitigation and Landscaping Works and Assessment of Land Contamination for Eastern Drainage Channel for San Tin (Maunsell Consultants Asia Ltd 2001)

San Tin West Drainage Channel Project Profile (DSD 2001)

San Tin West Drainage Channel Study Brief (EPD 2001)

Comprehensive Conservation Strategy and Management Plan for the Deep Bay Ramsar Site; (Aspinwall Clouston and Wetlands International - Asia Pacific (1997);

various fishpond, ardeid and spoonbill studies, e.g. Aspinwall (1997), Young (1997 & 1998), Zhuang and Lau (1997) and Leader 1998; and

other sources of information (such as the Annual Reports of the Hong Kong Bird Watching Society and Reports on Waterfowl and Egretry Monitoring in the Mai Po Inner Deep Bay Ramsar Site).

 

 

4.2.4             The habitat map is based on that included in the previous EIA (Binnie 2000a). This was updated from aerial photographs dated 15 February 2001, followed by ground-truthing undertaken during October 2001.

 

4.2.5             In the previous EIA, the ecological importance of habitats with respect to the occurrence of mammals, birds, reptiles, amphibians, fish, dragonflies, and butterflies was determined based on the investigation of existing literature sources undertaken in ERM (1999b). In the present EIA, this review has been complemented by observations made during the comprehensive field surveys described above. All of these taxa groups have been relatively well studied in Hong Kong, allowing the significance of observations to be placed in context in terms of (at least) their local abundance and habitat requirements. The identification of Species of Conservation Importance (in accordance with the EIA Ordinance Technical Memorandum) was therefore restricted in this EIA report to these groups.

 

4.2.6             Whilst it would clearly be desirable to extend both survey and analysis to other invertebrate groups, the data required to assess the ecological significance of individually observed specimens within the Study Area (i.e. species lists, spatial distribution, habitat requirements, relative abundance, etc.) are not available. However, as is discussed by ERM (1999b), the abundance and diversity of butterflies and dragonflies can, at least, be used as an indicator of the importance of habitats to a wider suite of invertebrate taxa. Thus, whilst the habitat requirements of the two groups does not reflect the specific needs of all invertebrate groups, the presence of the range of habitats required to support their larval and adult stages and overall species diversity is likely to reflect to some degree the relative 'health' of the populations of other, less well studied, groups. The use of butterflies as sensitive indicators of habitat diversity and of the impacts of anthropogenic changes to habitats is supported by Erhardt (1985), whilst Wilson (1995) cites dragonfly larvae as good indicators of both water quality and habitat diversity.

 

4.2.7             The principal direct loss of habitats of ecological importance arising as a consequence of the Spur Line comprise the loss of land where the line emerges from the tunnel at Chau Tau and goes on to an embankment, the footprint of the columns of the viaduct section between Chau Tau and Lok Ma Chau and footprint of the station complex at Lok Ma Chau. In addition there are small areas of land taken up by ventilation buildings and emergency access points along the tunnel section. The area of each habitat to be lost was measured by overlaying maps of the alignment onto the revised (October 2001) habitat map. Habitat area calculations were made using GIS software. Non-ecologically valuable habitats (such as urban/residential areas and container storage areas) and areas where works are being carried out under other projects (such as the Fanling and Sheung Shui Main Drainage Channels (CES 1997) and the Lok Ma Chau Border Crossing Expansion (Binnie 1999)) were removed from the area evaluation equation.

 

Continue