2. DESCRIPTION OF THE PROJECT

2.1 Key Project Requirements

2.1.1 The purpose of the Spur Line is to serve passenger needs while achieving safety and operational requirements. The purpose of the project and its compatibility with planned developments dictate to a certain extent the alignment of the Spur Line. The Spur Line is therefore designed based on the key project requirements as set down below. Various other constraints and requirements including engineering and environmental which are detailed in Section 2.9, have been considered to fine tune the design. These include:

(i) to locate the Lok Ma Chau Station to provide a cross boundary rail linkage with the mainland at the Huanggang and Futian areas;

(ii) to provide a convenient connection at Sheung Shui Station for interchanging passengers to and from the Lo Wu Line; and

(iii) to serve the proposed Kwu Tung Strategic Growth Area (SGA).

2.2 Site Location and Site History

2.2.1 The Spur Line is an extension to the northern end of the existing East Rail system. Figure 2.1 shows the proposed horizontal alignment and the Study Area for the Environmental Impact Assessment (EIA) Study. The outline of the proposed Lok Ma Chau Station is also illustrated. Figure 2.2 presents the vertical alignment of the Spur Line.

2.2.2 The proposed vertical alignment will rise from the at grade level at the existing Sheung Shui Station and below the existing Po Shek Wu Road Bridge, onto viaduct across the existing East Rail. The up track towards Lok Ma Chau will rise from approximately +5.00 m PD to a level of +16.00 m PD over a distance of 566 m, supported by viaduct from Chainage (CH) 30+926 onwards. The down track has a much gentler slope, falling towards the Sheung Shui Station dropping 12 m in vertical level over a distance of 900 m.

2.2.3 The two single-track viaducts converge into one twin track viaduct at CH 31+300. The alignment will continue on a level of +18.00 m PD westward until CH 33+057. As the topography changes from the low-lying flood plain to hilly terrain, the alignment changes to at grade section and continues on embankment and cutting. The deck structure containing the track will change to ballasted track for the at grade section. From CH 34+657 onwards the railway will be constructed on viaduct until it reaches the Lok Ma Chau Station.

2.2.4 The location of the proposed Spur Line route runs through a series of different habitats, ranging from urban areas and container storage sites to some highly valuable ecological sites. In particular the Lok Ma Chau fishpond area, which is part of the Wetland Conservation Area (WCA) recommended by the Study on the Ecological Value of the Fish Ponds in the Deep Bay (Fish Pond Study) and adopted by the Town Planning Board (TPB PG-No 12B); and Long Valley, which supports a large number of avifauna species.

2.2.5 The Lok Ma Chau fishponds are of particular importance because of their proximity and ecological linkage to the Deep Bay Ramsar Site, which supports many globally threatened species, species with high proportions of their global or biogeographical population at the site and species that are of regional or local conservation importance.

2.2.6 Long Valley comprises a mosaic of active and inactive agricultural land, ponds and marsh, which support a diversity of bird species and other fauna. Long Valley is the largest remaining area of wetland agriculture in Hong Kong, and is a particularly important area for wetland bird species and one of only two remaining breeding sites for Greater Painted-snipe in the SAR. Details of these habitats and mitigation measures to minimize impacts on ecologically important areas are discussed in the Ecology Assessment in Chapter 4.

2.3 Nature, Scope and Benefits of the Project

2.3.1 The main elements of the Project include the construction and operation of a new railway that will connect from the existing East Rail to a rail accessed passenger boundary crossing at Lok Ma Chau.

2.3.2 Only a passenger train service will be operated on the Spur Line. Upon opening in 2004, the train frequency will be 6 trains per hour in each direction. This will gradually increase to the ultimate train frequency of 12 trains per hour in each direction in 2016. When the Spur Line is completed, trains to Lo Wu and Lok Ma Chau will be operated as split service direct from the existing Hung Hom station. The speed limit for the Spur Line is 100 km/h. In planning the train service of the Spur Line, it is essential that the Lok Ma Chau Boundary Crossing Point will open from 0630 to 2330 hours, as occurs at the existing Lo Wu Boundary Crossing Point. To accommodate the Boundary Crossing Point opening hours, the daily train service of the Spur Line will be provided between 0600 and one hour following the close of the Crossing Point.

2.3.3 Major benefits of the Project to the East Rail service include:

· Relieve congestion at East Rail Lo Wu Station,

· Increase the cross boundary rail capacity by establishing a second cross boundary point,

· Enhance linkage with the mainland at the Huanggang and Futian areas, where it is planned to base the future commercial centre of Shenzhen, and

· Facilitate future exchange with the proposed Shenzhen Metro System.

An additional benefit of significant importance is the maintenance of KCRC's high safety standards, which are currently under threat by the increasing pressure at Lo Wu Station.

2.4 Size, Scale, Shape and Design of the Project

2.4.1 The major components of the Project include the construction and operation of a railway station at Lok Ma Chau and the section of railway alignment from Sheung Shui Station to the future Lok Ma Chau station. They are as follows:

· Lok Ma Chau Station: Consists of an island platform, two tracks and two concourse levels, one for arriving and one for departing passengers, KCRC public facilities, staff facilities, and plant and support facilities.

· Immigration and Customs Facilities for Lok Ma Chau station : immigration halls for departing and arriving passengers, with facilitates for tidal flow, non-public immigration facilities, immigration and custom staff facilities, non-public custom facilities, security facilities, agricultural and quarantine facilities and Department of Health facilities.

· A permanent way of a total route length of 7.4 km between Lok Ma Chau and Sheung Shui Stations, 5.0 km of which will be constructed on viaduct, and 1.6 km on cut and embankment. The remaining 0.8 km will be at grade. The project includes construction of the viaducts, rock cutting and earth embankment. The permanent way will be complete with traction power supply.

· A two level footbridge linking Lok Ma Chau and Huanggang Stations.

· Landscaping works and noise barriers where required. All other mitigation works as recommended in the EIA.

· The Dongjiang Raw Water Mains near the existing Sheung Shui Station have to be diverted. Works need to be carried out during the Dongjiang supply shut down in December 2001 and 2002 respectively.

2.5 Project Timetable

2.5.1 This project is being progressed on a “fast track” basis because of the safety concerns related to overcrowding at Lo Wu station. The programme therefore dictates that all the detailed design works should be completed by the end of year 2000. The construction works will commence in early 2001 for completion in early 2004.

2.6 Means of Implementation

2.6.1 The Spur Line will be constructed and operated by KCRC. The project will be implemented by means of detailed design contracts followed by construction contracts. The design of the project is underway and the work will be tendered out for construction following the completion of the detailed design works.

2.7 Related Projects

2.7.1 At the time of this Environmental Impact Assessment Report (EIA), two planning studies are in progress, one for North-West New Territories (NWNT), one for North-East New Territories (NENT). There will be a close interface between the Spur Line and the NENT Planning and Development Study. The proposed Kwu Tung SGA has recently been publicized under the NENT Planning Study, although the full details of the proposals (such as sensitive receivers etc.) are not yet available.

2.7.2 The Spur Line is being designed to maximise noise attenuation and therefore minimize constraints to developments along the alignment. In the absence of full details of the Kwu Tung SGA, the present assessment has indicated that development can take place with the SGA with no impact from the Spur Line.

2.7.3 The proposed Lok Ma Chau Station will be connected to the Shenzhen Metro’s Huanggang Station on the mainland side via a new footbridge for rail passengers. The Shenzhen Metro is expected to be completed by mid-2004. Close liaison with the Mainland Authorities to ensure proper co-ordination between the Spur Line and the Shenzhen Metro projects will be maintained.

2.8 Type, Scope, Scale, Frequency and Duration of the Construction and Operational Activities

2.8.1 Construction activities which will be carried out in the implementation of Spur Line include:

· Excavation and earth movement in ground preparation for at grade, embankment, cutting and viaduct sections.

· Installations of viaduct supports, and of viaduct sections that may be pre-cast off-site, or cast at the concrete casting yard in the temporary works area.

· Rock cutting or blasting within the Pak Shek Au area.

· Dredging and filling of ponds for temporary works (along alignment) or permanently (at Lok Ma Chau station).

· Foundation works and infrastructure works at Lok Ma Chau station.

· Landscaping, habitat creation works, and reinstatement works at the end of the construction period.

2.8.2 As mentioned in Section 2.3, only a passenger train service will be operated on the Spur Line. Train frequency will be 6 trains per hour in each direction. This will gradually increase to the ultimate train frequency of 12 trains per hour in each direction in 2016.

2.9 Background and History of the Spur Line

2.9.1 Introduction

This chapter describes the process of determining the vertical and horizontal alignment of the Spur Line. The project objectives, design criteria, constraints applicable and the assessment process to balance these requirements, leading to the identification of the optimum horizontal and vertical alignments are explained.

2.9.2 Background

2.9.2.1 Planning of the Spur Line has taken place over a long period of some 10 years, in order to identify the most suitable route and method of construction. In determining the route, consideration was given to a great many factors including: environmental issues, cultural heritage issues, railway engineering design requirements, land use and planning requirements and physical constraints. All of these issues were addressed to ensure the provision of a safe and reliable operating railway. The initial proposal for the development of the Spur Line was presented in the final report of the Railway Development Study in May 1993. In November 1998 a Preliminary Project Feasibility Study (PPFS), which evaluated the engineering and environmental feasibility of the potential routes was completed by KCRC and presented to government.

2.9.2.2 In September 1999 KCRC consulted the EIA sub-committee of ACE on the likely ecological impacts arising from the PPFS alignment and the proposed measures to mitigate against such impacts. All comments and suggestions from that meeting have been heeded by KCRC.

2.9.2.3 The factors that guided the determination of the alignment are described in section 2.9.3 and the process of balancing the various competing requirements of the Spur Line leading to the choice of the alignment is explained in sections 2.9.4 and 2.9.5.

2.9.3 Objectives, Criteria and Constraints

In planning and developing the alignment of the Spur Line the following were considered:

2.9.3.1 Environmental Objectives

· Minimization of impacts on ecologically sensitive wetland along the proposed route. Areas that could be impacted include the alluvial plane of the River Beas (Sheung Yue Ho) and River Sutlej (Shek Sheung Ho), Long Valley, fishponds at Lok Ma Chau and other wet agricultural land within the Study Area. These areas are shown on the general habitat map in Figure 4.1 of the Ecology Chapter.

· Avoidance of disruption to any ecological corridors and important habitats.

· Avoidance of impacts on any existing communities, monuments, historical buildings, cultural heritage and archaeological resources. Known sites requiring conservation include:

¨ the historical village of Ho Sheung Heung;

¨ an important burial site at Kwu Tung;

¨ Chau Tau village;

¨ an important burial plot west of Chau Tau;

¨ San Tin village (which is one of the earliest inhabited villages in Hong Kong.

· Minimization of construction and operational noise arising from railway and station construction.

· Minimization of landscape and visual impacts on existing village zones by the careful location of the railway alignment.

2.9.3.2 Planning and Land Use Considerations

The chosen alignment took into account the following issues -

· The potential development of a Strategic Growth Area centred on a new railway station in the area of Kwu Tung:

· Minimization of land resumption (by making use of Government land rather than private land wherever possible):

· Minimization of impacts to existing public utilities

· Minimization of impacts on existing and planned development projects:

· Allowance for future connection with West Rail Phase II.

2.9.3.3 Safe Railway Operation

· The point at which the Spur Line branches off must be located on a straight section of the existing East Rail to ensure safe railway operation.

· The southbound track of the Spur Line must pass over the top of East Rail for safety reasons and so as not to adversely affect the line capacity of East Rail.

· Maximum gradient constraints require the viaduct crossing over East Rail to begin its ascent 500m south of the crossing point.

2.9.3.4 Operational Requirements

· Connection of the Spur Line to East Rail must be north of Sheung Shui Station.

· Spur Line must connect to Huanggang Station and the Shenzhen Metro.

· A double crossing must be located on the Spur Line at the nearest location possible to Sheung Shui station. This double crossing must be located on a straight section of track for safety reasons.

· Maximum gradient should not exceed 2.5%

· Minimum curve radius is 300 m.

2.9.3.5 Engineering Requirements

· Disruption of drainage paths must be avoided, particularly in the flood plain of the Beas and Sutlej Rivers to avoid flooding problems in the northern New Territories.

· Sufficient vertical clearance must be provided to allow for the local roads at Kwu Tung and Lok Ma Chau that the railway must cross.

· Sufficient clearance is required between the CLP 400kV overhead lines East of Chau Tau and the railway.

· Provision must be made for the planned expansion of boundaries of the Lok Ma Chau Vehicle Boundary Crossing and to minimize the uptake of fishpond area around Lok Ma Chau.

· Sufficient overhead clearance must be provided above the two 2.2 m diameter water pipes of Water Services Department at Pak Shek Au.

· Sufficient overhead clearance is required below the railway in crossing San Sham Road.

· Sufficient overhead clearance is required between the railway and the proposed pump house and maintenance access road ancillary to the Eastern Main Drainage Channel.

2.9.3.6 Social Considerations

· Private land resumption especially in built-up areas has to be avoided as far as practicable to minimize impact on occupants.

· The alignment should be located as remote as possible from village areas to minimize impact on residents.

2.9.4 Determination of Vertical Alignment

2.9.4.1 Development of the Spur Line vertical alignment has taken into consideration the various problems and benefits related to underground, elevated and at grade forms of construction. These were compared within the context of the environmental and engineering requirements of the Spur Line described. (Tables 2.1 and 2.2)

Table 2.1

Comparison of Environmental Impacts Related to Vertical Alignment Options

Environmental impact	Underground	At Grade	Elevated
Wetland Loss	Possible draw-down of water table may affect wetland. Significant Impacts if cut and cover method of tunneling used.	All wetland along the 32 m wide corridor of the alignment would be impacted.	Ground level impact limited to column foundations.
Ecological Impacts	Major disturbance during construction.	Fragmentation of existing ecological corridors, across Long Valley in particular.	Retains existing ecological corridors and minimize habitat loss. Minimal impact during construction.
Operational Noise	Minimal.	Extensive at source mitigation needed to minimize impact	Multi-plenum design adopted to successfully minimize impacts.
Construction Noise	Considerable noise associated with piling for cut and cover construction. Long construction period.	Extensive site formation throughout the alignment. Long construction period.	Viaduct decks manufactured off-site, shipped in by barge and transported by road. Impact limited and transient as only occurs during column construction.
Water Quality	Construction run-off minimal. Minimal operation phase impact.	Potential impacts on surrounding watercourses during the construction and operation.	Limited potential for impacts during viaduct column construction.
Visual And Landscape Impact	Minimal.	An at grade railway can be adequately landscaped to minimize impacts.	High visual impact in rural and predominately flat landscape of Long Valley and Lok Ma Chau.
Fugitive Dust During Construction	Potentially significant as cut and cover tunneling will require excavation of large quantities of spoil.	May be significant during site formation.	Minimal.
Construction Waste	Significant. Large quantify of soil is expected to be unsuitable for re-use on site. Suitable site for dewatering and disposal needs to be found.	Some soil may not be suitable for reuse on site and has to be disposed. Quantity not as significant as tunneling.	Minimal.
Cultural Heritage And Historical Buildings	Minimal, as long as the foundations of the buildings are unaffected.	May affect burial plots at Pak Shek Au and Chau Tau.	Minimal.

Table 2.2

Comparison of Vertical Alignment Selection within

Engineering Constraints

Engineering Constraint	Underground	At Grade	Elevated
Drainage	Tunneling cannot be safely carried out in floodplain areas of Long Valley and Lok Ma Chau because of risk of inundation during construction.	Potential restriction of drainage in low-lying areas. Potential flooding problems, posing a safety and operational risk.	Minimal disruption of drainage.
Impact on existing railway operation	Tunneling cannot be carried out beneath the existing operating East Rail line at Sheung Shui.	The railway cannot be at grade as it crosses the existing East Rail line.	A viaduct must be used to cross the existing East Rail line.
Clearance requirements	Bored tunneling requires a minimum soffit to ground surface of 2 tunnel diameters.	At grade is required to clear Po Shek Wu Bridge at Sheung Shui.	Viaduct must provide adequate clearance to Lok Ma Chau Boundary Crossing, and the Eastern Main Drainage Channel pump house.
Gradient limitation	Tunneling would only be possible for a short section given the requirement for viaduct across the existing East Rail and at Lok Ma Chau to minimize wetland loss.	Cutting is required at Pak Shek Au to maintain consistent vertical alignment.	Where viaduct is required, the length is dictated by the gradient, before the rail can change to at grade or tunnel.
Safety issues	Tunneling requires ventilation and emergency accesses..	Safety access can be readily achieved.	Safety access can be relatively easily achieved.

2.9.4.2. Tables 2.1 and 2.2 illustrate that the environmental perspective is outweighed by the constraints posed by engineering, and in particular, safety and operational issues.

2.9.4.3 Constraints placed by the crossing of an operational railway at Sheung Shui, minimization of loss of wetland in the ecologically important Long Valley and the fishpond areas of Lok Ma Chau, are addressed by the viaduct as the preferred construction option along the majority of the alignment.

2.9.4.4 An at grade section must be constructed west of Tong Kok because of the topography but this section occurs where ecological resources are minimal.

2.9.4.5 The Spur Line vertical alignment was determined, through comprehensive assessment of engineering and environmental constraints. The preferred alignment resulted in the major length of the railway being on viaduct, while sections in non-ecologically valuable areas are at grade.

2.9.5 Determination of Horizontal Alignment

The horizontal alignment of the Spur Line was defined after thorough consideration of all the requirements described in section 2.9.3. Careful evaluation of various route options was made to ensure the choice of an optimum alignment.

2.9.5.1 Alternatives Considered - Eastern Part

Recognizing the ecological importance of Long Valley, an area of about 34 ha, five alternative route options as shown in Figures 2.3, 2.4a and 2.4b were evaluated. The results are summarized in the following sections.

2.9.5.1.1 CentralKCRC Alignment

For this alignment the Spur Line begins immediately north of Sheung Shui Station and branches off from East Rail at a point 500 metres north of Po Shek Wu Road where it turns west to traverse Long Valley on viaduct. It follows a straight alignment towards Tong Kok in order to avoid the most northerly farms and village houses that predominate in the southern 12 ha of the valley. The alignment footprint takes up about 0.85 ha of agricultural land, all of which is in private ownership. Agricultural land in Long Valley is subject to the crop growing preferences of the various farmers, and the ecological importance of the area can therefore change on a temporal basis. With the railway the wetland created under the viaduct and its ecological value will become secure, even in the very long term.

The Central~~KCRC~~ aAlignment fully meets the planning, land use, railway safety and operations and general engineering requirements set down in sections 2.9.3.2 to 2.9.3.6. In particular the Central~~KCRC~~ aAlignment begins at a straight section of East Rail, it also avoids the constraints arising from Shek Wu Hui Sewage Treatment Works and the Sheung Shui Slaughter House which block other routes. It does have an impact on the ecology as outlined in Section 4, but constructing the railway on viaduct enables the creation of 2.4 ha of wetland along its alignment, additional to the enhancement to permanent wetland status of 1.4 ha of the River Beas meanders, all of which will provide long term secure wetland. In total 3.8 ha of permanent wetland is created to mitigate ecological impacts on Long Valley. During operation of the railway, adoption of the multi-pleunum floating slab track for the viaduct means that airborne noise and vibration at ground level is minimized and long term impacts are considered to be acceptable.

Ecological impacts during the construction phase will be compensated through the provision of 3.2 ha of compensatory wetland habitat, which will be completed prior to construction works commencing in the particularly sensitive present marsh area. Access to the Long Valley by contractors will be severely limited, including the use of precasting, including viaduct deck segments, to minimize temporary works and the need to work from ground level.

2.9.5.1.2 Northern Route

For this route the Spur Line branches off from East Rail at a point further north, near to the Sheung Shui Sewage Treatment Works. Immediately after branching off it traverses a westward curve and eventually turns southwest to join the ~~KCRC~~ Central Alignment west of Tong Kok.

The proposed branching off point of this alignment is located on an existing 800 metre radius eastward curve on East Rail that is unacceptable on safety grounds. The curve has to be straightened to overcome the operational safety issue described in section 2.9.3.3. Figure 2.5 shows that to achieve this the existing East Rail tracks must be realigned such that they encroach into a substantial part of the Shek Wu Hui sewage treatment works and the recently completed Sheung Shui slaughterhouse.

Discussions with the Drainage Services Department with regard to the effects of this alignment on the sewage treatment works have indicated that the impacts would seriously compromise the operations of the facility. The Shek Wu Hui sewage treatment works is operating at its full capacity of 60,000 cubic metres of sewage per day. The sewage treatment works totally occupies its existing site.

If the treatment process is to be maintained, taking sections of the works out of commission is not feasible unless they can be re-provided in advance. Advance re-provisioning cannot be achieved, as there is no available land, the site being fully occupied with existing essential facilities.

Discussions with the operators of the slaughterhouse have indicated that this alignment would directly impact the unloading sidings to the west of the abattoir to where all the arriving animals are delivered. This area is essential for the normal operations of the slaughterhouse and cannot be made available to facilitate the construction of the viaduct that is needed for this route.

Construction of the railway viaduct in this location would effectively close down the slaughterhouse operations. This facility has only recently been opened at a cost of $2.0 Billion after a construction period of 4 years and a planning period of over 10 years. Given the long lead-time to develop such a facility, there is no possibility of it being re-located.

To overcome the conflict with the slaughter house and sewage treatment works the alternative of elevating East Rail to pass over the Spur Line was considered. It is concluded that this alternative is not feasible on both railway safety and operational grounds. The principal reason is that as East Rail carries freight traffic and therefore the maximum allowable gradient is 1.0%. This differs from the Spur Line gradient criterion of 2.5% because Electric Multiple Units (EMU)’s can accommodate more severe gradients than freight trains.

If the Spur Line were to join East Rail at grade, by extending the straight section of East Rail northwards, there is insufficient distance, from the Po Shek Wu Road bridge to the point at which the East Rail up-track viaduct would cross the at-grade Spur Line, to gain the required headroom. There is also insufficient distance to the north of the crossing point for the upline to get down to the level of the Lo Wu Goodsyard. In addition, it is not possible for an at-grade railway to cross the five Dongjiang water mains and maintain the minimum clearance required to ensure the pipes are not subjected to excessive loading. This is because the crowns of the pipes are at approximately the same level as the existing rails.

~~This route~~The Northern Route will necessitate substantially more private land resumption and will require the demolition of approximately 20 village houses as it traverses through the new village of Tsung Yuen. This social impact is considered to be unacceptable.

The route also requires extensive cutting of the hills to the rear of Ho Sheung Heung which will create a severe visual impact, affect a large number of graves and generate a large quantity of surplus spoil.

Operationally journey time will be longer but more importantly, the requirement for a double cross-over close to Sheung Shui station will be impossible to achieve. The nearest location a straight section of track where it is safe to install the double cross-over could be located is over 2.3 km from Sheung Shui station. This deficiency renders this alignment unacceptable on operational grounds.

In summary, the Northern Route is not available for the railway, given the severe social impact on Tsung Yuen, and the blockages from existing essential infrastructure facilities. The latter arises from severe railway operational and safety constraints, associated with the need to re-lay 0.6 km of existing East Rail.

2.9.5.1.3 River Beas Route

For this route the Spur Line branches off from East Rail at a point between that of the Central~~KCRC~~ Alignment and the Northern Route and traverses through the northern section of Long Valley. The route utilizes a continuous reverse curve to join to the ~~KCRC~~ ~~Alignment~~Central Alignment east of Tong Kok, passing close to the village of Ho Sheung Heung and the Hung Shing Pui Fung Temple.

As with the Northern Route, there is no possibility of introducing the necessary length of straight track into this alignment near to Sheung Shui station, to permit the insertion of the double cross-over. The nearest location is some 1.7 km away, which is a serious departure from the fundamental operational requirements of the railway as stated in Section 2.9.3.

As illustrated in Figure 2.6. this River Beas route locates the down track viaduct (where it connects to East Rail) in between the existing railway and the sewage treatment works. Within this corridor, which is approximately 10 metres wide, are located two 1.8 metre diameter trunk sewer inlet pipes to the sewage treatment works together with a 250millimetre diameter leachate pipe from the North East New Territories Landfill.

There is a critical location on this corridor where the sewer inlet pipes pass under the River Sutlej tributary in a box culvert. At this location the delivery sidings to the Sheung Shui Slaughterhouse connect to East Rail. The combination of the underground pipelines and the siding turnout from East Rail effectively sterilizes the available space between the railway and the sewage treatment works making it impossible to construct the viaduct support column foundations. There is no potential to move the sewer inlet pipes as any alternative route would impact other essential sewage treatment works facilities.

If these major engineering constraints were solvable, there is a further major constraint associated with this route. Because of the obtuse angle at which this route crosses East Rail and the slaughterhouse delivery sidings, a bridge with a clear span of approximately 250 metres would be needed, as there is no room between the East Rail tracks to locate intervening support columns. The construction of such a bridge over the existing operating railway may well be impractical, as well as imposing unacceptable risk to the operating railway. The impact on the project programme, given the complexity and severity of the construction problems, as well as railway safety considerations, makes this route unacceptable. In contrast, the Central~~KCRC~~ Alignment is designed to cross East Rail at a more acute angle utilizing conventional viaduct construction techniques. The River Beas Route is therefore not feasible due to the these engineering constraints.

Although the River Beas route poses major engineering constraints, the route has been reviewed in respect of the key environmental issues of noise, ecology, visual impact and cultural heritage. The main environmental impacts arising from the Central~~KCRC~~ Alignment and the River Beas Route, are summarized in Table 2.34.

The detailed noise assessment on the nearest sensitive receiver in the village of Ho Sheung Heung (contained in Appendix 1) indicates that by adopting the same railway viaduct approach as for the Central~~KCRC~~ Alignment neither construction nor operational noise will present problems. As with the railway as a whole, adequate mitigation can be provided to contain potential noise impacts.

The detailed ecological assessment (contained in Appendix 1) concludes that the 1.85 ha of Long Valley (of which 0.45 ha is due to direct habitat loss and 1.4 ha due to indirect habitat loss between the viaducts) affected by the River Beas Route has its own ecological problems. The Greater Painted-snipe can be found in this wetland affected by the ~~GazettedKCRC~~ Alignment, whilst the Chinese Pond Herons from the Ho Sheung Heung Egretry are found along the River Beas Route. On balance it is considered that the impact on the Greater Painted-snipe will be easier to mitigate by the pre-construction creation of the 1.4 ha of marsh in the River Beas meanders. In contrast the River Beas Route directly impacts these meanders making their enhancement for Spur Line construction impact mitigation impossible. In the long term the permanent 3.8 ha of wetland/marsh provided by the ~~GazettedKCRC~~ ~~Alignment makes this alignment preferable to the River Beas Route on ecological grounds.~~

The detailed ecological assessment contained in Appendix 1 is summarised in Table 2.3 below. AsIn summary, the ecological impacts of the ~~Gazetted~~ Central Alignment and the River Beas Route are almost the same. However, as this table states, ~~whilst~~ both alignments have some adverse ecological impacts. , the key concern in the comparison is an assessment of how the routes differ with respect to residual impacts during the construction and, especially, the operational period. In this regard the smaller residual impacts for the Gazetted Alignment (particularly with respect to the provision of off-site mitigation areas) render this route slightly preferable.Whilst the River Beas Route causes less fragmentation and impact on species, on the other hand, the Central Alignment provides better opportunity for off-site mitigation, therefore both alignments are equal after considering all ecological aspects.

Table 2.3 Ecological Impact summary table (Key Impacts)

	Central~~Gazetted~~ Alignment	River Beas route	Comments	Preferred Option in respect of impact reviewed
Construction period
Impact on habitats of ecological importance	Major: freshwater marsh severely affected, wetland agriculture areas affected	Minor: some wetland agriculture areas affected, but much of alignment already impacted by River Beas channelisation, longer period of construction activity in area of River Beas not considered critical (since no advance compensatory habitat provision was required in respect of River Beas channelisation project temporary loss of this habitat has already been judged not to be of critical importance)		River Beas alignment less destructive in short term
Impacts on Bird Species of Conservation Importance if no mitigation	Major: freshwater marsh is principal refuge habitat for Greater Painted-snipe and several other bird species; construction activities will create general disturbance in Long Valley	Medium: principal impact predicted to be on flightline between Ho Sheung Heung egretry and Long Valley; construction activities will create general disturbance in Long Valley	Disturbance effects in Long Valley as a whole similar between options	River Beas alignment has less impact
Mitigation potential	Major: temporary wetland provision will create alternative marsh area for Greater Painted-snipe and other species doing construction period	Minor: no scope for temporary habitat provision; limited scope for control of working practices to minimise disturbance		Impacts of Central~~Gazetted~~ Alignment easier to mitigate (but impacts greater to begin with)
Residual impacts	Minor: temporary habitat provision will mitigate for short term impacts on habitat	Minor/Medium: residual disturbance to egretry flightlines cannot be mitigated	Response to disturbance by egrets unpredictable	Potential for residual impacts greater for River Beas alignment
Operational Period
Impact on habitats of ecological importance if no mitigation	Major: significant fragmentation of Long Valley as route passes through core area; direct loss of wetland habitat; impact on key marsh area; indirect loss due to disturbance	Major: some fragmentation of Long Valley (though route avoids core area and there is relatively little linkage between main area of Long Valley and portion north of River Beas), direct loss of wetland habitat; indirect loss due to disturbance	~~Gazetted~~Central Alignment has more impact on marsh, River Beas alignment creates more overall habitat loss due to wider disturbance footprint of twin viaducts	Both alignments have major adverse ecological effects if no mitigation but River Beas alignment preferable due to less fragmentation of wetland
Impacts on Bird Species of Conservation Importance if no mitigation	Major: potential threat to Greater Painted-snipe population and significant adverse effects on populations of many other wetland bird species including freshwater specialists such as Pheasant-tailed Jacana and Watercock	Major: significant adverse effects on populations of many wetland bird species especially Chinese Pond Heron but also some (albeit lesser than for ~~Gazetted~~Central Alignment) effects on a suite of freshwater specialists including Greater Painted-snipe, Pheasant-tailed Jacana and Watercock	Both alignments have major adverse effects	River Beas alignment preferable because of lower impact on Greater Painted-snipe
Mitigation potential	Area under viaducts and River Beas meanders offer scope to mitigate for all habitat loss (both direct and indirect) for all species	Area under viaducts (which includes River Beas meanders) offers scope to mitigate for direct habitat loss for all species. No scope to mitigate for indirect habitat loss as all mitigation areas will be subject to avoidance of viaduct structure and noise impacts from railway operations	No scope to provide off-site mitigation for River Beas route	~~Gazetted~~Central Alignment much preferred because of opportunity to provide off-site mitigation
Cumulative impacts including cumulative effect of River Beas channelisation, Spur Line and new road to north of River Beas	Conversion of River Beas meanders to permanent wetland will have a net overall benefit on ecological function of these areas. Long term fragmentation effects for core area of Long Valley greater than for River Beas alignment as largest part of Long Valley will be situated in a triangle bounded by road and railways. However the northern part of Long Valley will be undisturbed once river channelisation is completed	Conversion of River Beas meanders to permanent wetland will have some benefit but this will be partially negated by their being affected by disturbance impacts. No scope for off-site mitigation of cumulative disturbance impacts to River Beas available. Cumulative fragmentation effects of road and railway smaller for core area of Long Valley, but a large area of northern Long Valley on either side of the River Beas will be impacted	River channelisation not expected have significant long term fragmentation effects whilst effects of road will be much greater than those of the railway	Whilst fragmentation effects of River Beas route are less this is achieved at the price of sterilising a swathe of land on both sides of the River Beas. ~~KCRC route~~Central Alignment is clearly preferable with respect to cumulative impacts on River Beas and the channelisation mitigation.
Residual impacts	Significant habitat fragmentation unavoidable, but all habitat loss and impacts on species fully mitigated; significant long-term increase in permanent freshwater wetland area managed for conservation purposes, part of this area free from disturbance impacts	Some habitat fragmentation unavoidable, direct habitat loss fully mitigated but significant indirect habitat loss for disturbance sensitive species; significant long-term increase in permanent freshwater wetland area managed for conservation purposes, but entire area (including mitigation areas previously proposed for River Beas channelisation) affected by disturbance impacts	Key factors to be evaluated are relative importance of permanent fragmentation impacts vis-à-vis permanent indirect habitat loss for disturbance sensitive species	As both alignments have some adverse ecological impacts, they are equal after considering all ecological aspects.Gazetted Alignment preferable as full mitigation for habitat loss for all species of conservation importance considered to be slightly greater weight in a Hong Kong context than fragmentation effects

This route places the railway 100 metres nearer to the village of Ho Sheung Heung and the heritage site of the Hung Shing Pui Fung Temple. The assessments (detailed in Appendix 1) indicate that the impacts will be greater than those predicted for the Central~~KCRC~~ Alignment. Exploratory discussions with the villagers of Ho Sheung Heung have indicated that they would raise very strong objections to any proposal that would locate the railway nearer to the village.

Overall the River Beas Route is inferior to the Central~~KCRC~~ Alignment, given the ecological dis-benefits, coupled with serious social and environmental consequences.

Table 2.34 summarizes the main environmental impacts for the Central~~KCRC~~ Alignment and the River Beas Route. This summary represents a synthesis of the detailed comparisons for each environmental discipline presented in Tables ~~A1.1 to A1.4~~A1 to A5b in Volume 23, Appendix 1.

From an overall environmental perspective, the Central~~KCRC~~ Alignment has a lesser impact and is preferable.

Table 2.34

Summary of Environmental Impacts Comparison between Central~~KCRC~~ Alignment and River Beas Route

	Central~~KCRC~~ Alignment	River Beas Route	Comments	Preferred Option
Ecology	~~Without mitigation~~ ~~GazettedKCRC~~ ~~Alignment would lead to the loss of better quality habitat and slightly more disturbance of most of the Species of Conservation Concern that occur in Long Valley.~~ ~~All impacts related to habitat and disturbance can be mitigated through on-site and off-site compensation areas.~~ Significant fragmentation of wetland habitat unavoidable as route bisects core area of Long Valley (c.f. Appendix 1, Table A1).	River Beas Route affects slightly lower quality habitats and results in lower disturbance to Species of Conservation Concern. However, River Beas meander mitigation will be adversely impacted by this alignment. ~~Full compensation of disturbance impacts would not be possible because no off-site compensation areas are known to be available.~~ Some fragmentation of wetland habitat unavoidable, route avoids core area of Long Valley but leaves small isolated area to the north of River Beas with little linkage to other wetland areas (c.f. Appendix 1, Table A1).	~~Some fragmentation of habitats will occur under both options.~~ Area impacted by River Beas route already adversely impacted by River Beas channelisation	~~Impacts from River Beas Route are marginally lower than from~~ ~~GazettedKCRC~~ ~~Alignment. However, because~~ ~~GazettedKCRC~~ ~~Alignment has the potential for full permanent mitigation, this is preferred overall.~~ River Beas route preferable with respect to fragmentation impacts as it is, on balance, preferable to retain a large unfragmented wetland area
	Significant construction impact on freshwater marsh	No construction impact on freshwater marsh	Freshwater marsh habitat very important but is not protected and can be re-created	The Beas River Route is preferred
	Significant impact on key habitat for Greater Painted-snipe and other wetland species	Significant impact on habitat available to wetland dependant species especially those more sensitive to disturbance such as Ardeids	Mitigation for loss of marsh habitat for Greater Painted-snipe feasible, mitigation for disturbance impacts requires off-site areas	River Beas route preferable with respect to impact on freshwater marsh ~~KCRC Route preferable since this permits~~ ~~mitigation for both direct impact on marsh habitat and disturbance impacts~~
	All direct and indirect impacts on wetland habitats and species of conservation importance can be mitigated by temporary and permanent on-site and off-site compensation areas	Direct impacts to wetland habitats and species of conservation importance can be mitigated by permanent on-site compensation areas. No off-site compensation areas available to mitigate for disturbance impacts	~~KCRC route~~Central Alignment allows River Beas meanders to be used for off-site mitigation. These meanders will be on-site mitigation areas for River Beas route	~~KCRC Route~~Central Alignment preferable because all impacts on wetland habitats and species of conservation importance can be mitigated
	Residual impacts can be limited to fragmentation effect on Long Valley ecosystem. These cannot be entirely eliminated but can be reduced in the long term by appropriate habitat management of the Long Valley ecosystem; off-site compensation areas (River Beas meanders) permit elimination of residual impacts with respect to habitat loss for disturbance-sensitive species	Residual impacts can be limited to some fragmentation and habitat loss for disturbance-sensitive species. The small remaining wetland area north of the River Beas will be of little value once linkage with the larger Long Valley area is broken, whilst habitat loss for disturbance-sensitive species cannot be made good by off-site mitigation since the only available areas for compensation are impacted by this route	Final assessment of ecological merits of options hinges on evaluation of relative importance of residual impacts	Whilst fragmentation and loss of linkage with the small area north of the River Beas consequent on selecting the River Beas route is of less significance than the fragmentation of the core Long Valley area caused by the ~~KCRC Route~~Central Alignment~~, the KCRC route is marginally preferable overall since this route permits full mitigation off-site of habitat loss for disturbance-sensitive species~~. As both alignments have some adverse ecological impacts, they are equal after considering all ecological aspects.
Noise	Noise levels due to Central~~KCRC~~ Alignment at sensitive receivers in Long Valley are below the ANL.	Noise levels at selected NSRs in Ho Sheung Heung are greater than the ANL due to the presence of points and crossings on River Beas Route alignment at this location. Mitigation in the form of a barrier or enclosure will be required.	Noise impacts from both alignments can be adequately mitigated	~~KCRC~~ Central Alignment
Cultural	Minimal impacts on historical buildings (primarily in Ho Sheung Heung) arise due to the Central~~KCRC~~ Alignment.	The River Beas Route lies very close to selected historical sites in Ho Sheung Heung. Woodland that is affected by the alignment must be replaced and a buffer woodland planted to provide a visual barrier between the railway and the sites of cultural heritage.	The alignment must maintain a minimum distance of 50m from any cultural or historical sites in Ho Sheung Heung. River Beas Route may need to be slightly realigned to achieve this requirement.	~~KCRC~~ Central Alignment
Landscape and Visual	The impact of the ~~Gazetted~~Central Alignment on the landscape character of Long Valley is greater than that predicted for the River Beas Route. However, visual impacts on Ho Sheung Heung village would be less significant than those which would accrue as a result of the River Beas route. The ~~Gazetted~~Central Alignment would be open to a large number of Visually Sensitive Receivers both to the south in areas such as Yin Kong and Tsung Pak Long, and in the north with Ho Sheung Heung. However these views would be largely long distance in nature.~~The impact of~~ ~~GazettedKCRC~~ Alignment on the landscape character of Long Valley is greater than River Beas Route. However, visual impacts on Ho Sheung Heung village would be lower with this option and no tree removal is required in Long Valley.	Impacts on the Long Valley landscape character area would be less significant than those predicted for the ~~Gazetted~~Central Alignment. However the landscape character of the village environs would be subject to more adverse impacts due to the proximity of the alignment. Visual impacts would be more severe for this option despite being partially screened by the existing woodland. This is largely due to the requirement for noise barriers or enclosures which would increase the visual mass of the viaduct structure and reduce the effectiveness of landscape mitigation measures such as woodland planting. However for visually sensitive receivers situated in the south of the study area such as those in Yin Kong and Tsung Pak Long the visual impacts arising from the River Beas Route would be less significant. ~~Impacts on Long Valley landscape character are lower than for~~ ~~GazettedKCRC~~ Alignment. However, landscape character will be degraded due to removal of trees around Ho Sheung Heung and visual impacts will be more significant from Ho Sheung Heung, in particular from several historical sites.	The ~~Gazetted~~Central Alignment would have the most significant impact on the landscape character of the Long Valley area although the River Beas alignment would have an additional adverse impact on the Ho Sheung Heung village environs. In terms of visual impact both alignments would be open to a large number of visually sensitive receivers however the requirement for noise barriers on the River Beas alignment would result in a more significant level of visual impacts. ~~The significance of impacts for each Option depends largely on the location of the viewpoint.~~	The River Beas Route would be preferable in terms of the significance of adverse impacts on the landscape character of Long Valley. The ~~Gazetted~~Central Alignment would be preferable in terms of the visual impact on visually sensitive receivers although both options are open to a large number of potential receivers. Overall considering the significance of the predicted landscape and visual impacts there would be negligible difference between the two options. ~~Landscape impacts are slightly greater for~~ ~~GazettedKCRC~~ ~~alignment than River Beas Route. Visual impacts are greater for River Beas Alignment, making~~ ~~GazettedKCRC~~ ~~Alignment the preferred option.~~
Other Issues	Potential impacts on water quality may occur where the viaduct crosses River Beas. As the distance across the channels is short (relative to the distances for River Beas Route), the viaduct may be constructed to span the channels.	The alignment will cross a longer stretch of the Rivers Beas and Sutlej than Central~~KCRC~~ Alignment, creating the potential for greater water quality impacts. Drainage impacts are likely to be greater than Central ~~KCRC~~ Alignment. Spoil heaps to the south of Ho Sheung Heung may create more waste than Central~~KCRC~~ Alignment.	Differences between the options are minimal in terms of air quality impacts.	Central~~KCRC~~ Alignment.