7.                  LANDSCAPE AND VISUAL

 

7.1              Introduction

 

7.1.1        The EIA has recommended landscape and visual mitigation measures to be undertaken during construction and operation phases of the Project. This section defines the EM&A requirements to ensure the proposed landscape and visual impact mitigation measures are effectively implemented.

 

7.1.2        The construction phase EM&A of the landscape and visual environment and mitigation works shall be carried out as part of the site audit programme. Specific EM&A during operation phase of the Project is not required as long as the proposed mitigation measures in the EIA and as depicted in the Landscape Mitigation Plan are fully implemented.

 

7.2              Baseline Monitoring

 

7.2.1        Baseline changes with respect to the landscape and visual environments should be carried out in reference to the recorded baseline conditions of the site as described in the EIA. The monitoring should in particular record changes of each landscape resource, landscape character area and the view conditions of each visually sensitive receiver. Parameters used to describe changes in each of the above should be the same as in the EIA.

 

7.2.2        The baseline monitoring should be conducted as a one-off site survey prior to commencement of any construction works.

 

7.3              Monitoring and Audit

 

7.3.1        Monitoring and audit should be undertaken during the construction and operation phases of the Project to ensure and check that the implementation and maintenance of landscape and visual mitigation measures are carried out. Site inspections should be undertaken at least once every two weeks through the construction period.

 

7.3.2        A landscape auditor (as a member of the ET) shall be employed to review contractor’s submission and proposals and to monitor and audit the contractor’s landscape works in particular to ensure the existing trees retained on-site are being well preserved, tree transplanting and felling operations are being undertaken in accordance with the requirements, procedures and specifications as stipulated in the contract and the approvals granted by concerned authorities, and all the newly planted vegetations are being maintained properly during the establishment period.

 

7.3.3        In particular, the extent of the agreed works areas should be regularly checked during the construction phase. Any trespass by the contractor outside the limit of the works, including any damage to existing trees, woodland and vegetation should be noted.

 

7.3.4        The landscape auditor should also audit the proposed operation phase mitigation measures in the EIA to ensure they are fully implemented within the Project design and construction.

 

7.4              Event and Action Plan

 

7.4.1        Should non-compliance of the landscape and visual impacts occur, actions in accordance with the action plan stated in Table 7.1 should be carried out.

 

Table 7.1

Event and Action Plan for Landscape and Visual Impact - Construction Phase

 

Action Level

Environmental Team (ET) Leader

Independent Environmental Checker (IEC)

Engineer’s Representative (ER)

Contractor

Non-conformity on one occasion

1.   Identify source

2.   Inform the IEC and the ER

3.   Discuss remedial actions with the IEC, the ER and the Contractor

4.   Monitor remedial actions until rectification has been completed

1.    Check report

2.    Check the Contractor’s working method

3.    Discuss with the ER and the Contractor on possible remedial measures

4.    Advise the ER on effectiveness of proposed remedial measures

1.     Notify the Contractor

2.     Ensure remedial measures are properly implemented

1.     Amend working methods

2.     Rectify damage and undertake remedial measures or any necessary replacement

Repeated Non-conformity

1.        Identify source

2.        Inform the IEC and the ER

3.        Increase monitoring (site audit) frequency

4.        Discuss remedial actions with the IEC, the ER and the Contractor

5.        Monitor remedial actions until rectification has been completed

6.        If exceedance stops, cease additional monitoring (site audit)

1.    Check report

2.    Check the Contractor’s working method

3.    Discuss with the ER and the Contractor on possible remedial measures

4.    Advise the ER on effectiveness of proposed remedial measures

5.    Supervise implementation of remedial measures

1.        Notify the Contractor

2.        Ensure remedial measures are properly implemented

1.     Amend working methods

2.     Rectify damage and undertake remedial measures or any necessary replacement

 

7.5              Landscape and Visual Impact Mitigation Measures

 

7.5.1        The proposed works would unlikely be acceptable in landscape and visual terms if these mitigation measures are not incorporated. The landscape mitigation measures would need to be monitored as follows:

 

·                    LMM 1 (Landscape Mitigation Measure 1): Gabions / Gabion Mattress for Riparian Vegetation

            Gabion/ Gabion Mattress, a wire mesh cage filled with loose stone - provide flexible structure for bank & bed protection and with the gaps in between the loose stone, suitable plants can be introduced. A sufficient planting medium (compacted clay and topsoil) is needed to cover the gabion / gabion mattress to accommodate roots of the proposed plants. Since the water level for the channel will rise during wet season and drop during dry season, plants that are proposed should be able to adapt the alternate wet and dry condition and must have the ability to regenerate in the next season. These may include but not limited to the following species (which are also species present in the area): Alocais macrorrhiza, Alopecurus aequalis, Bacopa monniera, Colocasia esculenta, Commelina diffusa, Cyperus pilosus, Ludwigia adscendens, Polygonum barbatum, Polygonum chinense, and Ranunculus scleratus. Further suggested species are listed in DSD Practice Note No. 1/2005 “Guidelines on Environmental Considerations for River Channel Design, Section 9.2.2 - Proposed plant list in channel bed and toe-zone”. The areas to receive LMM1 – Gabions / Gabion Mattress for Riparian Vegetation are as follows:

 

            - MUP 03, 04A, 04B & 05     = approx. 4,170 m2

            - LMH01                                = approx. 705 m2

 

·                    LMM 2 (Landscape Mitigation Measure 2): Existing natural river bed to be retained or widened, using natural substrate (example rip-rap bedding) & Existing natural riverbank to be retained or reinforced using gabions/ gabion mattress for riparian vegetation (refer to different type of two-stage channel detail)

 

This measure has an emphasis on retaining or widening the existing natural riverbed and retaining or reinforcing the existing natural riverbank. Riprap bedding comprises of a layer of different sized, angular rocks or boulders to simulate the condition of natural pebble or stone stream/ riverbed. The space between the rocks provide good habitat for establishment of the ecosystem for flora and fauna.

 

            Similar to LMM 1 above, further suggested species of plants are those that can adapt to dry and wet conditions are listed in DSD’s “Guidelines on Environmental Considerations for River Channel Design, Section 9.2.2 - Proposed plant list for channel bed and toe-zone”. The areas to receive LMM2 are as follows:

 

            - MUP 03, 04A, 04B & 05     = approx. 14,390 m2

            - LMH01                                = N/A

 

·                    LMM 3 (Landscape Mitigation Measure 3): Compensatory tree planting along channel side

            The 1 meter wide verge at one side or both sides of the channel are proposed for compensatory tree planting. Compensatory tree planting is intended to replace trees that cannot be retained or transplanted and will serve dual purpose of landscape impact mitigation as well as mitigating the loss of riparian trees in terms of ecological impact. More species are listed in DSD’s “Guidelines on Environmental Considerations for River Channel Design, Section 9.2.3 Proposed plant list along channel side”.  Suggested percentage mixture of trees can be found in Table 8.8 of the EIA Report. Recommended plant species that are known to be of high value to wildlife as described in the Ecology chapter of the EIA should also be included.

 

            The areas to receive LMM3 – Compensatory Tree Planting (Heavy Standard Trees) are as follows:

 

            - MUP 03, 04A, 04B & 05     = 740 nos. of trees, approx. 1,100 m2

            - LMH01                                = 11 nos. of trees, approx. 16 m2

 

·                    LMM 4 (Landscape Mitigation Measure 4): Maintenance access ramps with grasscrete finish and planting with channel bed/ toe zone vegetation

 

Similar to LMM 1 & 2 above, plants species for LMM 4 should be plants that are able to adapt the alternate wet and dry conditions and have the ability to regenerate in the next season. Suggested species are listed in DSD’s “Guidelines on Environmental Considerations for River Channel Design, Section 9.2.2 - Proposed plant list in channel bed and toe-zone”.

 

            Mitigation measures involve the establishing of plant communities from wild grass/flower seed mixes instead of turf. This would require a reduction in regular cutting. The areas to receive LMM 4 – Maintenance Access Ramps with Grasscrete Finish and Planting are as follows:

 

            - MUP 05                                = approx. 2,180 m2

            - MUP 03, 04A&B, LMH01 = N/A

 

·                    LMM 5 (Landscape Mitigation Measure 5): Mitigation planting along embankments

            Proposed plants that are adapted to the area between the average high water level and top of the embankment. As this area is close to water table, the moisture content in soil is relative high during the wet season. These may include but not limited to the following species (some of which are also species present in the area): Ficus hispida, Ficus viriolosa, Ilex pubescens, Ligustrum sinense, Rhododendron simsii, and Schefflera heptaphylla. Suggested species are listed in DSD’s “Guidelines on Environmental Considerations for River Channel Design, Section 9.2.3 Proposed plant list for planting at embankment”. The areas to receive LMM 5 – Mitigation Planting along Embankments are as follows:

 

            - MUP 05                                = approx. 590 m2

            - MUP 03, 04A&B, LMH01 = N/A

 

Tree Preservation

 

7.5.2        The tree vegetation in MUP05 area is dominated by the roadside planting (nearly 300 trees) of mainly exotic tree species along Sha Tau Kok Road. Most trees within the site limit are retained but some in some condition it is necessary to fell or transplant the trees. A few large species, such as Chinese Hackberry Tree (Celtis sinensis) (tree nos. T884, T973, T1001, T1028: 4 trees) including one with a climber, Derris trifoliate growing on it at Loi Tong village, Chinese Banyan (Ficus microcarpa) (tree no. T905: 1 tree) and Chinese Tallow Tree (Sapium sebiferum) (tree no. T1002: 1 tree) located within the channel, are native, in good to fair health condition and medium in amenity value, will be retained (preserved) with special treatment using gabion mattress. An indicative sketch showing the special treatment to preserve these existing trees within the channel is shown in Figure 8.7i of the EIA Report.

 

Measures for Preservation and Protection of Trees

 

7.5.3        To ensure the preserved trees are not adversely affected during construction, the Contractor should submit a Tree Preservation and Protection Plan to the ET for review and Engineer for approval before commencing any works on site.

 

7.5.4        In addition, the Contractor should exercise the greatest care to avoid any damage to the preserved trees and should comply with the following in respect of all the preserved trees:

 

(i)                  No nails or other fixings shall be driven into the trees.

 

(ii)                No fencing, services, or signs other than the identification labels or markings shall be attached to any part of the trees.

 

(iii)               No trees shall be used as anchorages for ropes or chains used in guying or pulling or for equipment used for removing stumps, roots or other trees, or for any other purposes.

 

(iv)              No soil, materials, equipment or machinery shall be stockpiled or stored within the tree protection zones[1].

 

(v)                No site offices, workshops, canteens, containers or similar structures shall be installed within the tree protection zones.

 

(vi)              Excessive water shall be drained away from the tree protection zones to prevent damage to tree roots by asphyxiation.

 

(vii)             No passage or parking of vehicles and no operation of equipment or machinery shall take place within the tree protection zones unless otherwise agreed by the Engineer.

 

(viii)           No stripping of surface vegetation or top layer of soil shall be carried out within the tree protection zones unless otherwise agreed by the Engineer.

 

7.5.5        The Contractor should erect, secure and maintain in good condition temporary protective fencing to protect the preserved trees before commencement of any works within the site. The temporary protective fencing should be erected along or beyond the perimeter of the tree protection zone of each individual tree. If erection of temporary protective fencing is not practicable, temporary hessian armouring (or hessian and plank armouring) should be provided around tree trunks to protect the preserved trees. The Contractor should submit method statements including proposed design details of the temporary protective fencing or armouring to the ET for review and to the Engineer for approval.

 

7.5.6        Notwithstanding the above measures, the Contractor should also follow all the requirements listed in the General Specification for Civil Engineering Works: Section 26 – Preservation and Protection of Trees.

 

7.5.7        To enhance the health and the appearance of the preserved trees, advance tree surgery or pruning works may be necessary. The Contractor should provide detailed proposals and method statements to the ET for review and to the Engineer for approval before commencement of any tree surgery or pruning works. Pruning should be conducted in accordance with good arboriculture and horticultural practices.

 

7.5.8        The Contractor should assign a competent member of the site supervisory staff to oversee and supervise tree works related to horticultural operations and preservation of trees within the site, including, but without limitation to, planting, transplanting, tree surgery work, pruning and control of pest and disease affecting trees on the site.

 

Tree Transplanting

 

7.5.9              Selection criteria for determining tree suitable for transplanting are summarized below:

 

1. Health - determine if the tree is healthy, free of disease, infestation, is undamaged in any way.

 

2. Species - is the tree of a species worth retaining in some way - if really rare then a more sensible approach would be to revise the alignment. However, no registered tree or tree of conservation importance or rare/protected species was found in the Project area. A good specimen even if not rare then it could be a good candidate for transplanting. Invasive species, introduced species of no amenity value or very common, quick growing species and species that tend not to respond well to transplanting (e.g. many conifers) would be best avoided as candidates for transplanting also.

 

3. Size - Large trees, 500mm girth or larger (measured at 1m above ground level), which require specialized methods to transplant, have a lower survival rate than that of smaller trees and are also likely to be considerably damaged to their form using conventional transplanting techniques. Budget constraints may be a consideration in assessing the possibility of very large trees as only in the case of significant trees (or old or valuable trees) are the costs likely to be an acceptable proposition. The transplanting of large trees is therefore likely to be considered only when all other factors justify the attempt. 

 

4. Form - Trees of poor shape (even though they may be healthy) and multi-stem trees which are difficult to transplant.

 

5. Location - Certain trees may be situated in positions that are difficult to transplant from due to their location next to surfaces, utilities, structures etc that makes careful excavation and protection of the root difficult or impossible.

 

 

Compensatory Tree Planting (LMM3)

 

7.5.10          Where trees cannot be retained or transplanted and have to be felled, compensatory tree planting (LMM3) is proposed as shown in Figures 8.6A I-V to 8.6B I-III (of the EIA). In addition, existing retained and new slopes should be planted with suitable tree planting mixes for screening to mitigate views and other purposes. Based on the current available information, the approximate numbers of trees to be felled and compensated are summarized below.

 

 

Felled

Compensated

Ratio

MUPs

117 nos.

740 nos.

1 : 6.3

LMH01

1 no.

11 nos.

1 : 11

 

Landscape Plan

 

7.5.11          As details of the proposed planting cannot be ascertain at the EIA stage, the preliminary design stage of the Project, it is recommended that a detailed Landscape Plan be submitted before commencement of the planting or landscape works of the Project. The Landscape Plan should include the locations, size, number and species of plantings, design details, implementation programme, maintenance and management schedules, and drawings in scale of 1:1000 showing the landscape and visual mitigation measures. The Landscape Plan should also take into account the plant species recommended in the Ecology chapter. The Landscape Plan should be certified by the ET Leader and verified by the IEC as conforming to the information, requirements and recommendations set out in the approved EIA Report before submission to the relevant authorities.

 

7.5.12          The implementation schedule for the recommended mitigation measures is presented in Appendix A.

 

7.5.13          If the above measures are not sufficient to restore the impacts to acceptable levels upon the advice of ET Leader, the Contractor shall liaise with the ET Leader on some other mitigation measures, endorsed by IEC and propose to ER for approval, and implement the mitigation measures.

 

 

 


[1]               “Tree protection zone” means an area the perimeter of which is defined by the dripline of the tree. “Dripline” of a tree means the imaginary vertical plumb line that extends downward from the tips of the outer most tree branches and intersects the ground.