7.2 As discussed in Section 2, the revised scheme would avoid encroachment upon the Conservation Area (CA) by the originally proposed link bridge connecting the proposed VHA and existing VHA, and also avoid occupation of a large area within the Wetland Buffer Area (WBA) for the proposed VHA. Therefore, the recommended scheme would induce less ecological impact on comparing with the originally proposed scheme in the Study Brief.
7.4 The Country Parks Ordinance (Cap. 208) provides for the designation and management of country parks and special areas. Country parks are designated for the purpose of nature conservation, countryside recreation and outdoor education. Special Areas are created mainly for the purpose of nature conservation.
7.5 The Forests and Countryside Ordinance prohibits felling, cutting, burning or destroying of trees and growing plants in forests and plantations on Government land. Related subsidiary Regulations prohibit the selling or possession of listed restricted and protected plant species. The list of protected species in Hong Kong which comes under the Forestry Regulations was last amended on 11 June 1993 under the Forestry (Amendment) Regulation 1993 made under Section 3 of the Forests and Countryside Ordinance.
7.6 Under the Wild Animals Protection Ordinance, designated wild animals are protected from being hunted, whilst their nests and eggs are protected from injury, destruction and removal. All birds and most mammals are protected under this Ordinance. The Second Schedule of the Ordinance which lists all the animals protected was last revised in June 1992.
7.7 The amended Town Planning Ordinance provides for the designation of coastal protection areas, Sites of Special Scientific Interest (SSSIs), Conservation Area, Country Park, Green Belt or other specified uses that promote conservation or protection of the environment. The authority responsible for administering the Town Planning Ordinance is the Town Planning Board.
7.8 Town Planning Board Guidelines No. 12b provide a reference for consideration of developments in high ecological value Deep Bay wetlands and adjacent areas.
7.9 Chapter 10 of the HKPSG covers planning considerations relevant to conservation. This chapter details the principles of conservation, the conservation of natural landscape and habitats, historic buildings, archaeological sites and other antiquities. It also describes enforcement issues. The appendices list the legislation and administrative controls for conservation, other conservation related measures in Hong Kong and government departments involved in conservation.
7.10 Annex 16 of the EIAO TM sets out the general approach and methodology for assessment of ecological impacts arising from a project or proposal, to allow a complete and objective identification, prediction and evaluation of the potential ecological impacts. Annex 8 recommends the criteria that can be used for evaluating habitat and ecological impact.
7.11 EIAO Guidance Note No. 6/2002 clarifies the requirements of ecological assessments under the EIAO.
7.12 EIAO Guidance Note No. 7/2002 provides general guidelines for conducting ecological baseline surveys in order to fulfil requirements stipulated in the EIAO TM.
7.13 The Convention on Wetlands of International Importance Especially as Waterfowl Habitat (the Ramsar Convention) provides a definition of wetlands, and requires participating countries to conserve and make wise use of wetlands areas, particularly those supporting waterfowl population.
7.14 The extensive literature documenting the ecology of the San Tin area was reviewed. In particular, the following reports/data were referred to:
· Agreement No. CE 43/96 Main Drainage Channels and Poldered Village Protection Scheme for San Tin, NWNT: Environmental Impact Assessment Study, Final Assessment Report (1999);
· Sheung Shui to Lok Ma Chau Spur Line Environmental Impact Assessment, Tunnel/Viaduct Option: Final Report. (2002);
· Environmental Impact Assessment Study on Shenzhen River Regulation Project – Final Report (Peking University, 1995)
· Various fishpond and avifauna studies , e.g. Aspinwall (1997) and Young (1997 & 1998); and
· Winter Waterfowl Counts by the Hong Kong Bird Watching Society
7.15 To supplement and confirm the validity of existing data, terrestrial ecology surveys covering both the wet and dry seasons were conducted from September 2002 to February 2003. The surveys covered all areas within 500m of the original proposed works area. The surveys comprised:
7.16 Habitat surveys were conducted via a desktop review of aerial photographs and other relevant maps/plans followed by site visits to verify the review.
7.17 Previous vegetation surveys of the San Tin area and other sites in NWNT have shown the area to support few plant species of conservation interest. For this reason, detailed vegetation surveys were limited to the proposed works areas. Plant species, relative abundance and growth forms were recorded. Additional records were made of dominant and notable plant species in other habitats within the Assessment Area.
7.18 Identification of plant species and status in Hong Kong were made with reference to AFCD (2002) and Corlett et al. (2000).
7.19 The species and relative abundance of birds in different habitats in the Assessment Area were recorded. All locations within the Assessment Area were covered. Birds were recorded by direct observation using binoculars, and listening for calling birds. Avifaunal surveys were conducted on a monthly basis over a period of six months (Sept. 2002 – Feb. 2003), covering the wet and dry seasons (including the winter migratory period). An additional survey was conducted on 30th Oct. to record any nocturnal avifauna.
7.20 Surveys were conducted on 28th Sept. & 30th Oct 2002 (wet season); and 24th Feb. 2003 (dry season). Species present were recorded by direct observation, searching potential microhabitats (e.g., potential bat roosts), listening for calling animals, and searching for signs of mammal activity such as burrows, scats etc. The surveys were focussed on the proposed works area, and included both day and night surveys. The remainder of the Assessment Area was covered by more general surveys, focusing on habitats likely to support herpetofauna and mammals.
7.21 Surveys were conducted on 28th Sept. & 30th Oct 2002 (wet season); and 24th Feb. 2003 (dry season), and were focused on the proposed works area. The surveys comprised:
· Dragonfly survey: The species composition and relative abundance of odonates in different habitats in the Assessment Area were recorded by direct observation.
· Butterfly survey: The species composition and relative abundance of butterflies in different habitats in the Assessment Area were recorded by direct observation.
7.22 Because of pollution, intensive management regimes and vegetation clearance, aquatic communities in the NWNT tend to be species poor. Preliminary site visits and literature review confirmed that no habitats of high value to aquatic communities are found in the Assessment Area. For this reason, detailed surveys of the limited freshwater and brackish water habitats in the Assessment Area were not required.
7.23 Potential ecological impacts arising from the Project were assessed following EIAO TM Annex 16 guidelines and the impacts evaluated based on criteria in EIAO TM Annex 8.
7.24 The Mai Po Marshes and Inner Deep Bay Ramsar site lies approximately 2km west of the proposed works area. The site was declared a Wetland of International Importance, or Ramsar Site, in 1995. Mai Po is recognised as an important feeding ground for migrant and winter visiting birds, particularly wetland-dependent species.
7.25 The high ecological value of wetlands adjacent to the Ramsar site in the Northwest and Northern New Territories was highlighted in a study and subsequent report on the Ecological Value of Fish Ponds in Deep Bay Area (The Fishpond Study. Aspinwall, 1997). The Fishpond Study recommended an area of fishponds and other wetlands in the North New Territories be designated as a Wetland Conservation Area (WCA). A buffer zone (the Wetland Buffer Area, WBA) of 500m was recommended to be established around the conservation area. These recommendations were incorporated into town planning board guidelines (TPB PG-N. 12B). The purpose of these two zones can be summarised as follows:
· Wetland Conservation Area: Aside from essential infrastructure works, no development detrimental to wetland habitats should be permitted within the WCA. Any essential works carried out in the WCA must comply with a “no net loss of wetland” policy. Any loss of wetland area or function will require compensatory habitat creation/enhancement.
· Wetland Buffer Area: Although development is allowed in the WBA, ecological impact assessments should be conducted for any proposal to demonstrate the development would not result in loss of ecological function of WCA (i.e., the development would not disturb avifauna and other wildlife utilising fishponds in WCA).
7.26 Figure 7.1 shows the boundaries of both the WCA and WBA in relation to the proposed development. About 500m of roads associated with the proposed development would encroach upon the WBA.
7.27 The San Tin Outline Zoning Plan (OZP) (S/YL-ST/5) was drafted to incorporate certain recommendations of the Fishpond Study.
7.28 In the current Assessment Area, wetlands north and west of the proposed works area are zoned as a Conservation Area (CA). The aim of the CA at San Tin is to conserve the ecological value of fishponds that form an integral part of the wetland ecosystem in the Deep Bay Area. Like the WCA, a ‘no net loss in wetland’ principle is adopted in the San Tin CA, which means no decline in wetland or ecological functions served by the existing fishponds should occur as a result of any change in use within this zone. New developments are not allowed unless the development is an essential infrastructure project with overriding public interest. Mitigation measures are required against any disturbance, and wetland compensation is required for projects involving fishpond filling.
7.29 The area to the west of the proposed development are zoned Other Use (comprehensive development and wetland enhancement area, WEA) in the San Tin OZP. Similar to the CA, a ‘no net loss in wetland’ principle applies in the WEA, where no decline in wetland or ecological functions served by the existing fishponds should occur. Additionally, a “precautionary approach” is adopted in the WEA, where the existing and continuous fishponds are to be protected and conserved.
7.30 Ngau Tam Mei CA is adjacent to the southeast boundary of the proposed works area. This CA is relatively free from development, and supports natural shrubland vegetation. The intention of the CA is to retain the natural characteristics of the area, and to buffer ecologically sensitive areas (particularly Lam Tsuen Country Park to the South: outside of the current Assessment Area) from the adverse effects of active developments.
7.31 Figure 7.1 shows the boundaries of the San Tin CA, Ngau Tam Mei CA and WEA in relation to the proposed development.
7.32 The San Tin East Main Drainage Channel (San Tin EMDC), currently under construction in the Assessment Area, would involve direct impacts to existing wetland habitats. To mitigate for these impacts, the Project will involve the creation of compensatory wetland habitats. The San Tin EMDC has committed the following ecological mitigation measures (locations refer to Figure 7.1):
· Grasscrete lining of EMDC.
· Constructed wetland along the eastern edge of the EMDC.
7.33 Once established, these features are expected to provide a moderate-high ecological value habitat, and attract fauna of conservation interest including several species of avifauna, herpetofauna and odonates.
7.34 The northern section of proposed development would run adjacent to both sides of the EMDC and the EMDC Constructed Wetlands. Under the EMDC constructed wetland design, allowance has been made for the construction of a link bridge close to the wetlands, with the area under the bridge being reserved to allow water circulation to the southern end of the wetlands. No direct impacts or indirect shading impacts to the wetland would therefore result from the link bridge construction and operation.
7.35 Additional compensatory wetland habitats under the San Tin Flood Protection Project include flood storage ponds at San Tin and Chau Tau, designed to be of moderate-high ecological value. Construction and planting of both ponds has been completed. The ponds have grasscrete-lined banks that supported a mix of herb and shrub species (e.g., Wedelia trilobata, Bougainvillea spectabilis). In addition, both ponds (particularly the Chau Tau pond) had been planted with emergent vegetation (e.g., Cyperus sp., Phragmites australis). The San Tin Flood Storage Pond falls outside the current 500m Assessment Area, and would not be affected by the proposed works. The Chau Tau Flood Storage Pond is within the current Assessment Area (refer to Figure 7.2).
7.36 A number of small wetland areas have been created to compensate habitat loss associated with the expansion of the Lok Ma Chau Border Crossing Kiosk (Figure 7.1). The wetlands are approximately 400m north of the proposed development.
7.37 The Assessment Area comprised a patchwork of eleven major habitat types, with disturbed habitats (developed areas and village/orchard) accounting for over 60% of the Assessment Area. Habitat maps are given in Figure 7.2. Representative photographs of habitats are given in Appendix 7.1. Plant species recorded in the Assessment Area are listed in Appendix 7.2. Table 7.1 below provides a breakdown of the approximate coverage of each habitat type within the Assessment Area. A description of habitats recorded in the Assessment Area is given in the following sections.
Table 7.1 Breakdown of Habitat Coverage within the Assessment Area
|
Habitat Type |
Coverage within Assessment Area (ha) |
% of Total Assessment Area |
|
Active Fishpond |
2.1 |
0.9 |
|
Abandoned Area |
5.0 |
2.0 |
|
Active Agriculture |
6.1 |
2.6 |
|
Abandoned Agriculture |
5.7 |
2.4 |
|
Plantation |
8.2 |
3.4 |
|
Developed Area |
101.6 |
42.5 |
|
Village/Orchard |
49.1 |
20.5 |
|
Shrubland/Grassland Mosaic |
38.9 |
16.3 |
|
Nullah/drainage channels |
5.2 |
2.2 |
|
Fung Shui Woodland |
7.4 |
3.1 |
|
Secondary Woodland |
10.2 |
4.3 |
|
Total |
239.2ha |
100%* |
*Total does not add up to 100% exactly due to rounding up of figures
7.38 Actively managed fishponds within the WCA were recorded just inside the Assessment Area boundary, approximately 450m to the west of the proposed development. Typically, the fishponds supported little aquatic or emergent vegetation. Fishpond bunds were found to support grasses (e.g., Eleusine indica, Paspalum conjugatum)and weeds(e.g., Mikania micrantha), along with stands of fruiting plants (e.g., Psidium guajava, Carica papaya, Musa paradisiaca).
7.39 A number of fishponds within the Assessment Area have recently been filled, although no development has taken place on the reformed land. The vegetation in these areas consisted mainly of grasses (e.g. Elephantopus tomentosa, Imperata cylindrica) and common weed species (e.g., Mikania micrantha).
7.40 Two areas of wet agricultural land were located southwest of Chau Tau village. The vegetation was dominated by common crop species (particularly water spinach; Ipomoea aquatica and water cress; Nasturtium officinale), and weed species (e.g., Polygonum perfoliatum) along field bunds and in fallow areas.
7.41 The area south west of Pun Uk Tsuen comprises abandoned wet agricultural land. The area probably once supported similar crops to nearby actively farmed land. The abandoned agricultural land was marshy in places, and supported numerous grass and weed species (e.g., Wedelia trilobata, Bidens pilosa, Miscanthus sinensis).
7.42 Small areas of roadside plantation were recorded along Castle Peak Road, San Tin Highway, and other roads/paths in the Assessment Area. Plantations consisted of stands of exotic tree species including Casuarina equisetifolia, Melaleuca quinquenervia and Acacia confusa, along with occasional native species (e.g., Ficus microcarpa, Macaranga tanarius).
7.43 Mature plantation stands were recorded from San Tin and Shek Wu Wai villages. Dominant species included Eucalyptus sp. and Melaleuca quinquenervia.
7.44 Much of the Assessment Area (particularly the Lok Ma Chau border crossing and adjacent areas, and areas south of San Tin Highway) consisted of highly disturbed habitats including roads, car parks, open storage areas, industrial areas and construction sites. Plant diversity in these areas was low, and limited to common weed (e.g., Ageratum conyzoides) grass (e.g. Elephantopus tomentosa) and tree (e.g., Macaranga tanarius) species.
7.45 Several villages were recorded in the Assessment Area, including San Tin, Chau Tau and Pak Shek Au. Notable plant species recorded in this habitat included ornamental species and fruit trees (e.g., Araucaria heterophylla, Averrhoa carambola, Citrus maxima, Hydrangea macrophylla).
7.46 Shrubland/grassland mosaic habitat was recorded on hillsides on the northeastern boundary of the Assessment Area, and south of the San Tin Highway. The latter area included Ngau Tam Mei Conservation Area. Shrubland/grassland mosaic is typical of upland areas in Hong Kong, and is maintained by frequent hillfires. Typical species recorded included Bridelia tomentosa, Litsea rotundifolia, Rhus chinensis and Dicranopteris linearis.
7.47 Numerous ditches, drainage channels and nullahs were recorded in the Assessment Area. The physical characteristics of this habitat type varied considerably. Some channels were wholly lined with concrete, whereas other had natural substrates and vegetated banks. Water quality was found to be very bad in most of these channels, resulting from untreated domestic and agricultural wastes, as well as run-off from open storage and industrial areas.
7.48 Vegetation recorded along the banks of channels was limited to common grass and weed species (e.g., Panicum maximum) and occasional trees/shrubs (e.g., Leucaena leucocephala). The nullah north of San Tin Village was covered by an extensive growth of the exotic Eichhornia crassipes.
7.49 Fung shui woodlands were recorded close to Lok Ma Chau, Chau Tau and Pak Shek Au. Fung Shui woodlands can be identified by their close proximity to villages, presence of graves, and characteristic plant species composition. Plant species diversity in these woodlands was considered moderate, with common species including Miscanthus sinensis, Cinnamomum camphora, Dicranopteris pedata and Psychotria asiatica.
7.50 Several small patches of largely natural secondary woodland were recorded close to San Tin Highway. Due to their small size, plant species diversity in these habitats was relatively low. Typical species encountered included Celtis sinensis, Macaranga tanarius and Psychotria asiatica.
7.51 Terrestrial fauna recorded in the Assessment Area during recent surveys is listed in Appendix 7.3.
7.52 Recent field surveys recorded 58 avifauna species in the Assessment Area. Of these, 11 can be considered species of conservation interest (Table 7.2).
7.53 No species of conservation interest were recorded in areas potentially directly affected by the proposed development.
7.54 Five herpetofauna species were observed in the Assessment Area during recent field surveys. No species of conservation interest were recorded.
7.55 No mammal species were directly observed during recent surveys of the Assessment Area, although civet scats were recorded from Fung Shui woodland close to Chau Tau.
7.56 Twenty-one butterfly and six odonate species were recorded in the Assessment Area during recent field surveys. No species of conservation interest were recorded.
7.57 In accordance with the EIAO TM Annex 8 criteria, the ecological importance of recorded habitats has been evaluated in Tables 7.2a-7.2f below.
Table 7.2a Ecological Value of Active Fishponds in the Assessment Area
|
Criteria |
Active Fishponds |
|
Naturalness |
Created habitat |
|
Size |
2.1ha |
|
Diversity |
The habitat supports a high diversity of avifauna |
|
Rarity |
Five avifauna species of conservation interest (Cormorant, Phalacrocorax carbo; Grey Heron, Ardea cinerea; Chinese Pond Heron, Ardeola bacchus; Great Egret, Casmerodius albus; Little Egret, Egretta garzetta) recorded from fishpond habitats during recent field surveys |
|
Recreatability |
Habitat is easily recreated on suitable low-lying areas of land |
|
Fragmentation |
Not fragmented |
|
Ecological linkage |
The habitats form part of a larger wetland area in the NWNT, and are functionally and structurally linked to the Deep Bay Ramsar site. Fishponds to the west of the proposed development fall within the WCA. |
|
Potential value |
Ecological value could be increased with appropriate management. |
|
Breeding/Nursery ground |
No significant records |
|
Age |
No information available |
|
Abundance/Richness of Wildlife |
High abundance of avifauna |
|
Ecological value |
High |
|
Criteria |
Abandoned Area, Plantation, Developed Area, and Village/Orchard |
|
Naturalness |
Created habitats. |
|
Size |
Created and highly disturbed habitats cover almost 70% of the Assessment Area (163.6ha). |
|
Diversity |
Species diversity is low. |
|
Rarity |
Zitting Cisticola (Cisticola juncidis), a locally restricted species, recorded from abandoned area |
|
Re-creatability |
Habitat can be re-created easily. |
|
Fragmentation |
Habitat is not fragmented. |
|
Ecological linkage |
Abandoned Area west of proposed development lies within the WCA |
|
Potential value |
Some areas (e.g., open storage areas, abandoned areas) formed by in-filling of fishponds. If ponds were to be re-instated, potential ecological value is moderate-high. |
|
Nursery ground |
No record of significant nursery or breeding ground was found in the survey. |
|
Age |
Not applicable. |
|
Abundance/Richness of Wildlife |
Low. |
|
Ecological value |
Low |
|
Criteria |
Fung Shui Woodland |
Secondary Woodland |
|
Naturalness |
Largely natural habitat |
The secondary woodlands have been modified and subjected to human disturbance. |
|
Size |
3.1ha |
Small patches found close to San Tin Highway total 4.3ha |
|
Diversity |
Moderate species diversity |
The species diversity is low-moderate. |
|
Rarity |
No species of conservation interest recorded from the habitat |
No species of conservation interest recorded from the habitat |
|
Re-creatability |
Habitat can be re-created, but would take 40-50yrs to mature. |
Habitat will regenerate in 10-40 yrs. |
|
Fragmentation |
Small patches of woodland separated by other habitats. |
Small patches of woodland separated by other habitats. |
|
Ecological linkage |
Habitat not linked to any ecologically important areas in any significant way |
Habitat not linked to any ecologically important areas in any significant way |
|
Potential value |
The potential value is considered moderate. |
The potential value is considered moderate. |
|
Nursery ground |
No record of significant nursery or breeding ground was found in the survey. |
No record of significant nursery or breeding ground was found in the survey. |
|
Age |
The habitat is relatively mature. |
The habitat is relatively mature. |
|
Abundance/Richness of Wildlife |
Moderate |
Low-Moderate. |
|
Ecological value |
Moderate |
Low-Moderate |
|
Criteria |
Active & Abandoned Agriculture |
Shrubland/Grassland Mosaic |
|
Naturalness |
Created habitat |
Habitat maintained by frequent hill fires. |
|
Size |
11.8ha |
38.9ha |
|
Diversity |
The species diversity is low. |
Low to moderate. |
|
Rarity |
Red-throated Pipit(Anthus cervinus), White-cheeked Starling(Sturnus cineraceus) and Red-Billed Starling(Sturnus sericeus) recorded from active agricultural land during recent surveys. |
No species of conservation interest recorded. |
|
Re-creatability |
Habitat is easily recreated on suitable low-lying areas of land. |
Habitat regenerates naturally after fire disturbance. |
|
Fragmentation |
The habitats are not fragmented. |
The grassland/shrubland mosaic is not fragmented. |
|
Ecological linkage |
Habitat not linked to any ecologically important areas in any significant way. |
Habitat not linked to any ecologically important areas in any significant way |
|
Potential value |
The potential value is moderate. |
The potential value is low-moderate. |
|
Nursery ground |
No record of significant nursery or breeding ground was found in the survey. |
No record of significant nursery or breeding ground was found in the survey. |
|
Age |
Not applicable. |
The habitats are frequently disturbed and therefore are secondary in nature. |
|
Abundance/Richness of Wildlife |
Low. |
Low. |
|
Ecological value |
Low-Moderate |
Low |
Table 7.2e Ecological Value of Nullah/Drainage ditches habitat in the Assessment Area
|
Criteria |
Nullah/Drainage Ditches |
|
Naturalness |
Habitat extensively modified through channelisation. Very bad water quality |
|
Size |
5.2ha |
|
Diversity |
The species diversity is low. |
|
Rarity |
Grey Heron(Ardea cinerea), Chinese Pond Heron(Ardeola bacchus), Coot(Fulica atra) and Wood Sandpiper(Tringa glareola) recorded from this habitat type. |
|
Re-creatability |
Moderate. |
|
Fragmentation |
Not applicable |
|
Ecological linkage |
Nullahs and ditches are structurally and functionally linked to high ecological value fishponds, and fall partially within the WCA. |
|
Potential value |
The potential value is moderate. |
|
Nursery ground |
No record of significant nursery or breeding ground was found in the survey. |
|
Age |
Not applicable. |
|
Abundance/Richness of Wildlife |
Low. |
|
Ecological value |
Low |
|
Criteria |
San Tin EMDC wetlands |
Chau Tau Flood Storage Pond |
|
Naturalness |
Habitats will be artificially created and maintained |
Habitat is artificially created and maintained |
|
Size |
Small-moderate |
0.47ha |
|
Diversity |
Habitats expected to attract a moderate-high diversity of wetland dependent species |
Habitat supports low-moderate diversity of wetland dependent species |
|
Rarity |
Habitats designed to attract avifauna, amphibians and insects of conservation interest |
No rare species recorded from the habitat |
|
Re-creatability |
Habitat can be re-created easily. |
Habitat can be re-created easily. |
|
Fragmentation |
Habitat is not fragmented. |
Habitat is not fragmented. |
|
Ecological linkage |
The habitats would form part of a larger wetland area in the NWNT, and would be functionally and structurally linked to the Deep Bay Ramsar site. EMDC and compensatory wetlands lie partially within WCA and San Tin CA. |
The habitat forms part of a larger wetland area in the NWNT. |
|
Potential value |
On-going management of habitats would ensure moderate-high ecological value will be maintained, although value would be limited by disturbance from adjacent Lok Ma Chau Border Crossing. |
Low |
|
Nursery ground |
Habitats expected to provide breeding habitats for avifauna, amphibians and insects of conservation interest |
No record of significant nursery or breeding ground was found in the survey. |
|
Age |
Habitats currently undergoing formation |
Recently formed. |
|
Abundance/Richness of Wildlife |
Abundance/richness of wildlife expected to be moderate-high |
Low-moderate. |
|
Ecological value |
Moderate-High* |
Low-Moderate |
*Assessment based on potential future ecological value following establishment of suitable habitats.
7.58 Active fishponds to the west of the proposed development were considered of high ecological value. The ponds form part of a larger wetland habitat that includes the Deep Bay Ramsar site, and were found to provide important feeding grounds for numerous wetland dependent birds species, including several species of conservation interest.
7.59 The ecological value of habitats covering almost 70% of the Assessment Area was found to be low. Abandoned areas, plantations, developed areas, and village/orchard were all found to be highly disturbed, and had low floral and faunal diversity.
7.60 Both fung shui and secondary woodland habitats in the Assessment Area were small in area, and had relatively low floral diversity. These habitats are therefore considered of low-moderate to moderate ecological value.
7.61 Active and abandoned agricultural land was found to have low floral and faunal diversity, although three avifaunal species of conservation interest were recorded from actively farmed land. These habitats were considered to be of low-moderate ecological value.
7.62 The ecological value of shrubland/grassland mosaic in the Assessment was considered to be low: no species of conservation interest were recorded from the habitat type, and floral and faunal diversity was low.
7.63 Most nullahs and drainage ditches in the Assessment Area were heavily impacted by organic wastes and other pollutants, limiting their value to aquatic communities. These habitats were considered to be of low ecological value.
7.64 Areas set-aside for the San Tin EMDC committed compensatory wetland habitats are considered to be of moderate-high ecological value. The areas are currently highly disturbed and of low ecological value, but once established, the wetlands are expected to support some species of conservation interest. However, their value will be limited to some extent due to disturbance from the adjacent Lok Ma Chau Border Crossing and other nearby developments.
7.65 No species of conservation interest were recorded at the flood storage pond at Chau Tau. This habitat is considered of low-moderate ecological value.
7.66 With reference to EIAOTM Annex 8, the conservation value of species recorded in the Assessment Area has been evaluated. A summary of species of conservation interest is provided in Table 7.3 below.
|
Common Name |
Scientific Name |
Status* |
Distribution/Rarity |
Recorded Habitat |
|
Cormorant |
Phalacrocorax carbo |
PRC |
Regionally important population in Hong Kong |
Fishponds |
|
Grey Heron |
Ardea cinerea |
PRC |
Regionally important population in Hong Kong |
Fishponds and nullah |
|
Chinese Pond Heron |
Ardeola bacchus |
PRC |
Declining but regionally important population in Hong Kong |
Fishponds and nullahs |
|
Great Egret |
Casmerodius albus |
PRC |
Regionally important population in Hong Kong |
Fishponds |
|
Little Egret |
Egretta garzetta |
PRC |
Regionally important population in Hong Kong |
Fishponds |
|
Coot |
Fulica atra |
RC |
Regional and local population in decline |
Nullahs |
|
Wood Sandpiper |
Tringa glareola |
LC |
Restricted Range in Hong Kong |
Nullah |
|
Red-throated Pipit |
Anthus cervinus |
LC |
Restricted Range in Hong Kong |
Active agricultural land |
|
Zitting Cisticola |
Cisticola juncidis |
LC |
Restricted range in Hong Kong |
Abandoned area |
|
White-cheeked Starling |
Sturnus cineraceus |
PRC |
Regional population restricted distribution (probably under-recorded) |
Active agricultural land |
|
Red-Billed Starling |
Sturnus sericeus |
GC |
Regionally important population in Hong Kong |
Active agricultural land |
*LC – Local Concern (Habitat loss/damage in Hong Kong would pose significant threat to local survival); PRC – Potential Regional Concern (Large, secure populations in Hong Kong are of regional significance); RC – Regional Concern (Habitat loss in Hong Kong would have implications for the survival of the species in South China); GC – Global Concern (Further habitat loss or damage in Hong Kong may have implications for the global survival of the species). Refer to Fellowes et al. (2002) for further explanation of status.
7.67 Ecological impacts resulting from the construction and operation of the development are expected to be minor. Potential impacts are described in the following paragraphs.
7.68 The footprint of the proposed development would be largely limited to low ecological value habitats including open storage areas, car parks and roadside plantations.
7.69 Potential indirect impacts during the construction phase would include:
· Noisy construction phase activities could disturb wildlife utilising moderate-high and high ecological value habitats close to the works areas. In particular, avifauna of conservation interest feeding in fishponds west of the works area, and moderate-high value committed compensatory wetland habitats could be disturbed;
· Increased human activity associated with construction works could disturb wildlife in adjacent habitats;
· Soil exposed during site formation works could be washed into nearby watercourses, leading to elevated suspended sediment levels. Spills of construction materials, fuels and solvents could also be washed from the works area to nearby waterbodies. An increase in suspended sediments and other pollutants could impact aquatic communities in fishponds/watercourses close to the proposed works area; and
· Uncontrolled dumping or stockpiling of materials could disturb habitats adjacent to the proposed works area.
7.70 Watercourses close to the proposed works area drain into the Shenzen River, which discharges into the high ecological value Inner Deep Bay Area. The EIA Study Brief specifies that potential ecological impacts to both the Shenzen River and Inner Deep Bay Area are assessed in the EIA report. However, given their distance from the works areas (approximately 1.6km and 4.2km respectively), and the anticipated low levels of sediments and pollutants entering watercourses as a result of construction/operation phase activities, site run-off is unlikely to have a noticeable effect on Shenzen River or Inner Deep Bay. Furthermore, water quality control measures would be implemented to minimise any disturbance (refer to Section 5). Potential impacts to communities in these habitats will therefore not be addressed further in this report.
7.71 No operation phase direct ecological impacts are anticipated.
7.72 Potential indirect impacts during the operation phase would include:
· Traffic utilizing the development could disturb wildlife using moderate-high value committed compensatory wetland habitats and high value fishponds in the Assessment Area;
· Elevated sections of the new roads and bridges would shade vegetation growing beneath the roads.
· The impermeable surface of new roads associated with the Project could increase surface run-off into nearby waterbodies. The run-off could contain pollutants (e.g., oil) and elevated sediment levels that could adversely affect aquatic communities, if uncontrolled.
7.73 Potential ecological impacts to habitats in the Assessment Area resulting from the current Project have been evaluated according to Table 1 of Annex 8 of the EIAO TM, and are summarised in Tables 7.4a-7.4f below.
Table 7.4a Overall Impact Evaluation of Active Fishponds
|
Evaluation Criteria |
Active Fishponds |
|
Habitat quality |
High |
|
Species |
Five avifauna species of conservation interest recorded from fishpond habitats during recent field surveys |
|
Size/Abundance |
No habitat loss. |
|
Duration |
No impact |
|
Reversibility |
N/a |
|
Magnitude |
N/a |
|
Overall impact conclusion |
No impact |
|
Evaluation Criteria |
Abandoned Area, Plantation, Developed Area, and Village/Orchard |
|
Habitat quality |
Low. |
|
Species |
Zitting Cisticola (Cisticola juncidis), a locally restricted species, recorded from abandoned area would be subject to minor indirect disturbance. |
|
Size/Abundance |
Direct loss of small areas of plantation and developed areas. Shading of vegetation growing in plantation and developed areas. |
|
Duration |
Loss of habitat would be permanent. |
|
Reversibility |
Loss of habitat would be permanent. |
|
Magnitude |
The scale of the impact is considered low. |
|
Overall impact conclusion |
Very Low
|
|
Evaluation Criteria |
Fung Shui Woodland |
Secondary Woodland |
|
Habitat quality |
Moderate. |
Low-moderate. |
|
Species |
No direct impact to species of conservation interest, although there may be potential indirect impact to the wildlife. |
No direct impact to species of conservation interest, although there may be potential indirect impact to the wildlife. |
|
Size/Abundance |
No habitat loss. |
No habitat loss. |
|
Duration |
Minor, temporary increase in disturbance during construction phase.
Negligible operational phase impact. |
Minor, temporary increase in disturbance during construction phase.
Negligible operational phase impact. |
|
Reversibility |
Disturbance will be limited to duration of construction phase. |
Disturbance will be limited to duration of construction phase. |
|
Magnitude |
The scale of the impacts is considered low. |
The scale of the impacts is considered low. |
|
Overall impact conclusion |
Very Low. |
Very Low. |
|
Evaluation Criteria |
Active & Abandoned Agriculture |
Shrubland/Grassland Mosaic |
|
Habitat quality |
Low-moderate. |
Low. |
|
Species |
No direct or indirect impact to species of conservation interest. |
No direct or indirect impact to species of conservation interest. |
|
Size/Abundance |
No habitat loss. |
No habitat loss. |
|
Duration |
No direct/indirect impact. |
Minor, temporary increase in disturbance during construction phase.
Negligible operational phase impact. |
|
Reversibility |
N.A. |
Disturbance will be limited to duration of construction phase. |
|
Magnitude |
N.A |
The scale of the impacts is considered low. |
|
Overall impact conclusion |
No Impact. |
Very Low |
Table 7.4e Overall Impact Evaluation of Nullah/Drainage ditches habitat in the Assessment Area
|
Evaluation Criteria |
Nullah/Drainage Ditches |
|
Habitat quality |
Low. |
|
Species |
No direct impact to species of conservation interest, although there may be potential indirect impact to the wildlife, including several avifaunal species of conservation interest.
Aquatic communities potentially affected by sedimentation/pollution from construction and operation phase site run-off. |
|
Size/Abundance |
No habitat loss. |
|
Duration |
Minor, temporary increase in disturbance during construction phase.
Negligible operational phase impact. |
|
Reversibility |
Disturbance will be limited to duration of construction phase. |
|
Magnitude |
The scale of the impacts is considered low. |
|
Overall impact conclusion |
Low. |
|
Evaluation Criteria |
San Tin EMDC wetlands |
Chau Tau Flood Storage Pond |
|
Habitat quality |
Moderate-High*. |
Low-Moderate. |
|
Species |
Habitats designed to attract avifauna, amphibians and insects of conservation interest. |
No direct or indirect impact to species of conservation interest. |
|
Size/Abundance |
Link bridge over the EMDC would cause minor shading impact to grasscrete channel lining
Traffic utilizing new development would cause minor operation phase disturbance.
|
No habitat loss. |
|
Duration |
Use of development would lead to occasional periods of increased disturbance during the operational phase.
Shading impact to EMDC would be permanent |
No direct/indirect impact. |
|
Reversibility |
Minor increase in disturbance during operational phase will be permanent.
Shading impact to EMDC would be permanent |
N.A. |
|
Magnitude |
The scale of the impacts is considered low. |
N.A |
|
Overall impact conclusion |
Very Low. |
No Impact. |
*Assessment based on potential future ecological value following establishment of suitable habitats.
7.74 Potential direct impacts to terrestrial habitats and species resulting from the Project are considered minor. Areas directly affected by the proposed works generally support low ecological value habitats (developed areas, plantations) where no species of conservation interest were recorded. No direct impacts to moderate-high value ecological habitats (active fishponds, Fung Shui Woodland, San Tin EMDC Wetlands) are anticipated.
7.75 Potential indirect impacts to wildlife and habitats are of greater concern than direct loss of habitats resulting from the proposed works. Wetland habitats within the Assessment Area (e.g., active fishponds) provide feeding grounds for wetland-dependent birds and other wildlife. The following paragraphs provide a more detailed evaluation of potential indirect impacts to habitats and wildlife in the Assessment Area.
7.76 No construction or operation phase disturbance to birds utilising the extensive area of fishponds west of the proposed development is predicted. The closest ponds are located about 175 m from the proposed works boundary and occur to the north of the Lok Ma Chau Kiosk and the existing VHA. Therefore noise disturbance resulting from construction phase activities and human activity, and operation phase traffic are expected to have a negligible effect, particularly given the existing high level of disturbance at the works area.
7.77 Construction phase impacts to the EMDC and associated compensatory wetlands would be largely avoided due to the respective programmes of the present Project and the EMDC. The EMDC and associated compensatory wetland site formation would be completed by the end of 2005, and it is expected that vegetation in the EMDC wetlands would take a further 12-15 months (i.e., until the end 2006/early 2007) to establish after site formation works are completed. Construction works for the Interchange would be completed around the same time (late 2006/early 2007).
7.78 Operation phase disturbance resulting from traffic on the interchange would be extremely limited. The Assessment Area as a whole, particularly close to the San Tin Highway and Lok Ma Chau Border Crossing, is already highly disturbed by heavy road traffic, and no substantial increases in general disturbance levels are expected to result from use of the new roads . Furthermore, a roadside barrier wall (2m high), and a 2m-wide screen planting buffer zone will be constructed between the slip road and adjacent areas of the San Tin EMDC Wetlands to minimize noise and visual disturbance (Figure 7.3 refers).
7.79 Shading impacts to vegetation growing on the EMDC grasscrete lining are considered minor, given the small size of the affected area.
7.80 Construction and operation phase site run-off is expected to have a negligible impact on the EMDC committed compensatory wetlands. Standard good site practice would limit the sediment levels in the run-off and minimise the levels of other potential pollutants. During the operation phase, the slip road will be supported on a retaining wall, and all surface run-off will be collected by standard road gullies. No road surface run-off would therefore flow into the EMDC committed compensatory wetlands.
7.81 The flood storage pond at Chau Tau is almost 400m from the proposed works area; no impacts to this habitat are anticipated.
7.82 Impacts to watercourses other than the San Tin EMDC in the Assessment Area are expected to be minor. Standard good site practice would limit the sediment levels in the run-off and minimise the levels of other potential pollutants.
7.83 Indirect impacts to other habitats in the Assessment Area would be negligible. Abandoned areas, secondary woodland, plantations, developed areas, village/orchards and grassland/shrubland mosaic are of low or low-moderate ecological value, and are not particularly suitable habitats for species of conservation interest recorded elsewhere in the area. Other habitats (Fung Shui woodlands, active/abandoned agricultural land) are relatively distant from the proposed works areas, therefore negligible or very low construction or operation phase disturbance is anticipated.
7.84 The shading effects of elevated sections of the proposed development would only affect vegetation growing in low ecological value habitats (developed areas, plantation). This impact is therefore considered relatively minor.
7.85 Other current or planned projects that have potential for direct and/or indirect ecological impacts in the San Tin area include:
· San Tin EMDC and compensatory wetland creation
· Lok Ma Chau Border Crossing Kiosk Extension
· Sheung Shui to Lok Ma Chau Spur Line
7.86 Interactions between the current Project and the San Tin EMDC have been discussed in earlier sections of this chapter. In summary, construction phase disturbance to the EMDC committed compensatory wetland habitats would largely be avoided. The wetland habitats would only become established in late 2006/early 2007; after the proposed development is completed (late 2006/early 2007). Operation phase disturbance would be minor, as the area is already heavily disturbed and subject to noise disturbance from the current Lok Ma Chau Border Crossing and adjacent open storage facilities. Shading impacts to vegetation growing on the EMDC grasscrete lining are considered minor, given the small size of the affected area.
7.87 To provide compensation for wetland habitat loss resulting from the Border Crossing Extension, several small areas adjacent to the Crossing have been set aside for the creation of reedbeds (Figure 7.1 refers). At the time of writing, these areas are at various stages of development, with some reedbeds having recently been planted with stands of Phragmites sp. and other riparian/emergent vegetation. The Interchange construction/operation is not expected to impact these habitats, which lie over 400m from the works area.
7.88 Ecological impacts associated with Sheung Shui to Lok Ma Chau Spur Line were addressed in EIA report for the Project (Binnie & Partners, 2002). Cumulative ecological impacts resulting from the Spur Line Project and the current Project are not anticipated for the following reasons:
a) The main area of ecological importance directly and indirectly impacted by the Spur Line Project are fishponds around the station complex at San Tin/Lok Ma Chau (currently under construction). These ponds are approximately 1.5km from the proposed works area for the current Project, and therefore would not be affected by the construction or operation of the proposed development.
b) Construction and operation phase ecological impacts resulting from the Spur Line Project would be mitigated through wetland enhancement and re-creation close to station complex site. Areas of wetland enhancement/re-creation are over 1km from the works area for the current Project, and therefore would not be affected by the construction or operation of the proposed development.
7.89 In conclusion, cumulative ecological impacts resulting from this and other projects in the Assessment Area would be comprehensively addressed through mitigation measures. Cumulative impacts are therefore expected to be minor and acceptable.
7.90 Despite relatively minor predicted impacts resulting from the Project, mitigation measures should be adopted to avoid, minimise and compensate for identified ecological impacts, particularly those with the potential to affect San Tin EMDC committed compensatory wetlands.
7.91 Where the slip road runs adjacent to the San Tin EMDC wetlands, a roadside barrier wall (2m high) will be constructed to minimize operation phase noise disturbance to the wetlands. Furthermore, a 2m buffer strip will be planted with trees and other dense vegetation to provide a visual screen between the slip road and the wetlands.
7.92 Where practicable, potentially noisy construction phase activities should be scheduled to avoid the peak bird migratory period (November-March).
7.93 Landscaping works (refer to Figure 5.1 for proposed landscaping areas) should maximize use of native plant species of high conservation value to birds and other wildlife. Examples of species of known conservation value are given in Table 7.5 below, although other suitable species could be considered for planting works subject to commercial availability.
Table 7.5 – Examples of Plant Species of Conservation Value to Wildlife for Landscaping Works
|
Common Name |
Species Name |
Growth Form |
|
Chinese Hackberry |
Celtis sinensis |
Tree |
|
Camphor Tree |
Cinnamomum camphora |
Tree |
|
Chinese Eurya |
Eurya chinensis |
Shrub |
|
Evodia |
Evodia lepta |
Small Tree |
|
Round-leaved Litsea |
Litsea rotundifolia |
Shrub |
|
Blood-red Melastoma |
Melastoma sanguineum |
Shrub |
|
Rose-myrtle |
Rhodomyrtus tomentosa |
Shrub |
|
Mountain Tallow |
Sapium discolor |
Tree |
|
Ivy Tree |
Schefflera octophylla |
Tree |
|
Scarlet Sterculia |
Sterculia lanceolata |
Tree |
7.94 Good site practice measures should be implemented through the construction phase. The measures should include:
· Placement of equipment or stockpile in designated works areas and access routes selected on existing disturbed land to minimise disturbance to natural habitats.
· Construction activities should be restricted to work areas that should be clearly demarcated.
· The work areas should be reinstated immediately after completion of the works.
· Waste skips should be provided to collect general refuse and construction wastes. The wastes should be disposed of timely and properly off-site.
· Drainage arrangements should include sediment and oil traps to collect and control construction site run-off. Water quality mitigation measures recommended in Section 5 of the report should be implemented.
· Open burning on works sites is illegal, and should be strictly prohibited.
7.95 Residual impacts resulting from this Project would be limited to the direct loss of small areas of low ecological value, disturbed habitats, increased disturbance in the Assessment Area resulting from traffic utilizing the new development, and shading of the EMDC grasscrete lining following link bridge construction. As described in s7.74-s7.89, these impacts are considered minor. Overall, residual ecological impacts are considered minor and acceptable.
7.96 Aside from auditing the implementation of mitigation measures recommended in s7.90-s7.94, no specific ecological EM&A programme would be required.
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