1.1.1
In the Policy Address 2015, the
Government set out the intention to adopt the concept of revitalising water bodies in
large-scale drainage improvement works and planning drainage networks for the
new development areas. The concept of revitalising water bodies is aimed at promoting greening,
biodiversity, beautification and water friendliness in addition to achieving
efficient drainage, with a view to building sustainable drainage facilities and
providing a better living environment.
1.1.2
Fo Tan Nullah (FTN) and Tai Wai Nullah (TWN) were
identified as one of the waterbodies of high revitalisation
potential and therefore were recommended for detailed investigation and
proposing revitalisation schemes for implementation,
taken into account its unique features and constraints in the feasibility study
on “Study on Revitalisation of Water Bodies” (“the
Study”) under Agreement No. CE 28/2015 (DS) commissioned by Drainage Services
Department (DSD) in December 2015.
1.1.3
In April 2020, AECOM Asia
Company Limited was commissioned by DSD to undertake Agreement
No. CE54/2019 (DS) – “Revitalisation of Tai
Wai Nullah and Fo Tan Nullah – Investigation” (hereafter referred to as
“the Assignment”) to revitalise the existing TWN and
FTN with an aim to enhance their ecological value, provide a greener
environment, promote water friendliness and improve the community environment.
The Assignment also includes provision of dry weather flow interceptors to
improve the water quality. As part of
the Assignment, an Environmental Impact Assessment (EIA) study under the
Environmental Impact Assessment Ordinance (EIAO) is required for the proposed
works to TWN and FTN, respectively.
1.1.4
This EIA Report covers the EIA
study for Revitalisation of FTN (hereafter referred
to as “the Project”).
1.1.5
The proposed revitalisation of FTN is classified as designated project
(DP) by virtue of Item I.1(b)(ii), Part I, Schedule 2 of the EIAO – “a drainage
channel or river training and diversion works which discharges or discharge
into an area which is less than 300 m from the nearest boundary of an existing
or planned site of cultural heritage”.
1.1.6
Project Profile for Revitalisation of FTN (No. PP-585/2019) was submitted to
the Environmental Protection Department (EPD) on 31 July 2019 for application
for an EIA Study Brief under section 5(1)(a) of the EIAO. The EIA Study Brief
for the Revitalisation of FTN (No. ESB-319/2019) was
issued on 11 September 2019 under the EIAO.
1.2.1
This Executive Summary (ES) summarises the key findings, recommendations and
conclusions of the EIA Report for the Project. The ES contains the
following information:
·
Section
2 presents purpose and nature of the Project, consideration of alternative
options and construction methods for the Project;
·
Section
3 presents the key findings of the environmental impact assessment;
·
Section
4 describes the proposed environmental monitoring and audit programme
for the Project; and
·
Section
5 presents the conclusions.
2.1
Purpose
and Scope of Project
2.1.1
The purposes and objectives of
the Project are to revitalise the existing FTN with the aim of enhancing the ecological value of
FTN, providing a greener environment, promoting water friendliness and
improving the community environment. The Project also includes provision of dry
weather flow interceptors to improve the water quality. Location
plan and general layout of the
Project are shown in Figure
2.1 and Figure 2.2 respectively.
2.1.2
The Project comprises the
following key components:
(a)
beautification of
the existing nullah (approximately 1.7 km long and 10 m to 35 m wide) by
re-surfacing, greening and modification of channel bed;
(b)
provision of dry
weather flow interceptor (DWFI) system;
(c)
provision of
features for ecological enhancement and installation of underground water
storage tank [approximately
10m (W) x 30m (L) x 2.5m (D)] under the existing Kwei Tei Street Garden equipped with two submersible water pumps
installed under the nullah bed at mid-stream of FTN and underground water pipes
for
associated water retention and supplement;
(d)
construction of
viewing decks and revamp of existing footbridges/bridges;
(e)
revamp/provision
of footpaths, railings, amenity areas and pavilions along the nullah banks;
(f)
improvement/modification
of existing planters; and
(g)
associated works
including landscaping, utility works, etc.
2.1.1
Subsequent to the issue of
the EIA Study Brief (No. ESB-319/2019), due to
the pressing needs to alleviate flood risks near Kwei
Tei Street, the improvement/modification of drainage
channel connecting Kwei Tei
Street, which does not constitute material change to an exempted DP under the
EIAO, has been excluded from the Project scope for implementation under another
public works contract so as to expedite its implementation programme. Furthermore, an underground water storage
tank under existing Kwei Tei
Street Garden equipped with submersible water pumps installed under the nullah
bed at mid-stream of FTN and underground ground water pipes has been proposed
to support the provision of ecological enhancement features in the nullah. In accordance with Clause 6.2 of the EIA
Study Brief, confirmations have been sought from the Director of Environmental
Protection in writing that these two changes would not fundamentally alter the
key scope of the EIA Study Brief and it is still valid for the preparation of
the EIA Report.
2.1.2
During operational phase, similar to the existing practices, regular maintenance works for
the drainage and sewerage systems along FTN, including desilting along the nullah and minor maintenance to the
DWFI system, would be carried out by the DSD to
remove excessive silts, debris and any obstructions to safeguard the hydraulic
capacity of the nullah. The
maintenance practices and frequency would be similar to the existing maintenance works undertaken by the DSD.
Water Quality
Improvement and Water Friendliness
2.2.1
Due to ageing drainage systems
and possible expedient connection made in the past, polluted discharges from
the existing drainage outlets along FTN are observed at present. Complaints and concerns from the public,
including Sha Tin District Council (STDC) and local stakeholders, on the
long-standing water quality and odour nuisance of FTN
were received. With the implementation
of the proposed DWFI system of the Project, the dry weather flows from the
drainage outlets along FTN will be intercepted and discharged to the existing
sewerage system via gravity mains (i.e. no DWFI pumping
station required) for conveying to Shatin Sewage Treatment Works for
treatment. With the interception of the
polluted discharges, the water quality would be improved and odour nuisance to the resident nearby would be alleviated.
2.2.2
While FTN is not suitable to be
opened up for public access due to safety reasons, the improvement of water
quality and riverside environment of the nullah due to the Project would
enhance user experience and hence promoting water friendliness culture. In view of the existing fragmentated,
inconsistent and underutilised public open spaces
along FTN, installation of viewing decks along the nullah as well as
improvement and landscaping works to existing walkways and public open spaces (e.g. installation of thematic
pavilions, decked walkway and open spaces) are proposed to allow public to
engage with and enjoy the revitalised waterscape.
Greening Enhancement
2.2.3
The existing concrete nullah
bed from the section south to Kwei Tei Street down to the section with tidal influence near Fo Tan MTR Station and embankment down to the confluence
with Shing Mun River will be resurfaced with layer of vegetation, which will
enhance both the aesthetic and ecological values of FTN. Greening along the nullah bed and banksides,
such as provision of emergent wetland planting (e.g. reed and other aquatic
herbs), mangroves, climbing plants, tree and / or grasscrete
etc, will be provided. The existing mature trees growing along the
nullah banks will be retained, and additional tree planting will be
provided. The existing planters will
also be modified to beautify the footpath along FTN.
Ecological Enhancement
·
Reprofiling of the low flow channel (from the
section south to Kwei Tei
Street down to the section with tidal influence near Fo
Tan MTR Station) and construction of in-stream weirs to create a meandering
alignment along the nullah to mimic natural stream pattern where practicable,
providing a series of microhabitats for wildlife in surrounding areas;
·
Provision of DWFI system to improve water quality
and to support ecological enhancement;
·
Introduction of general constructed wetland
systems (artificial wetland created to mimic processes
in natural wetland ecosystems involving vegetation, soils, and their associated
microbes through engineering design) to the channel bed, which can serve as
greening and ecological enhancement measures whilst achieving some degree of
pollution removal;
·
Greening along the channel bed and banksides,
such as provision of emergent wetland planting (e.g.
reed and other aquatic herbs), mangroves, climbing plants, tree and / or grasscrete to the banksides;
·
Incorporation of planting designed to attract
wildlife species (e.g. birds and butterflies) during revamp of public open
space along FTN;
·
Provision of nest boxes / hunting perch for
wildlife (e.g. birds) along FTN;
·
Installation of oyster baskets along the bottom
of channel bank at the small portion of Shing Mun Main Channel within the
Project site to provide habitats for intertidal species and ardeids; and
·
Modification of channel bank at downstream
section of FTN to enhance foraging habitats for waterbirds.
2.3.1
Environmental implications of
various options in regard to the extent of DWFI system, water retention and replenish
methods, and ecological enhancement designs have been considered with a view to
optimising the revitalisation
design of FTN in order to enhance the ecological value
of the nullah, provide a greener environment, promote water friendliness and
improve the community environment whilst avoiding,
minimising and mitigating any potential adverse
environmental impacts of the Project.
Extent of DWFI System
2.3.2
Drainage outlets with polluted
discharges were identified between Sections 2 to 5 of FTN (see Figure 2.2 on division of channel sections), i.e. from the section south to Kwei Tei Street down to the
section near Fo Tan MTR Station, through pollution
source identification survey. For the
preferred extent of DWFI system, a full-scale DWFI system that
intercepts the dry weather flows from all the drainage outlets identified with
polluted discharges along the nullah within Sections 2 (part) to 5 of FTN is
considered to be able to fully eliminate the existing polluted discharges to
FTN and would improve the water quality and resolve the odour
problem of FTN which favours the revitalisation, hence
it is selected as the preferred option. Section 6 of is connected to natural catchments whilst Section
1 is surrounded by private housing estates / institutional uses which
have well-established sewerage and stormwater drainage
systems that expedient connection/misconnection from industrial area or
significant polluted surface runoff due to the nature of the catchment area would be unlikely for these two
sections. Likewise, Sections 1 and 2 (part) of the nullah are also subject to tidal influence with the outlets being submerged mostly in
water that the discharges cannot be intercepted by the instream DWFI system. DWFI system is hence not
considered necessary for Sections 1, 2 (part)
and 6 of the nullah.
Water
Retention and Replenish Methods and Ecological Enhancement Designs
2.3.3
In view of the limited baseflow of FTN, water retention and replenish methods have also been considered to
retain and supplement water to the nullah in order to provide sufficient water
flow to support a healthy aquatic habitat in the channel.
2.3.4
In-stream fixed weirs, which would not be washed away in case of flood
discharge, would be incorporated in the nullah bed to retain water depth for
aquatic habitats. By impounding floodwater or environmental flows, weirs are
particularly useful in the dry channels to retain water for a longer period,
which could promote plant growth and aquatic species survival in such an
otherwise dry environment.
2.4.1
The Project site will be
divided into six sections to be constructed in sequence starting from
downstream FTN (Figure 2.2 refers). The construction
works along the nullah within each section would last for approximately 1 year
and will not be undertaken at the entire section at the same time to avoid
multiple construction activities overlapping / concentrating in a certain area
over any period.
2.4.2
The proposed revitalisation works would be constructed by traditional open-cut and in-situ
concreting method that mainly involve site clearance, soil excavation,
sheet-piling, bore piling, formwork, concreting, backfilling, and
reinstatement. Desilting works at
downstream tidal zone would be carried out at the commencement and prior to the
completion of the construction works to remove the silt accumulated at the nullah,
in addition to the routine maintenance desilting works undertaken by DSD along
FTN and by CEDD along Shing Mun River under existing arrangement.
2.4.3
For each section, the
construction works within the nullah, including nullah bed modification,
construction of DWFI system along the nullah, mid-stream submersible water
pumps and water pipes along the nullah and desilting works at downstream tidal
zone will only be undertaken during dry season to reduce the potential water
quality impacts due to surface run-off.
To further reduce the water quality impacts, the excavation in the
nullah will be carried out in an enclosed area surrounded by concrete blocks,
sandbag barriers or other appropriate physical barriers.
2.4.4
The major parts of the DWFI
system are u-channel and pipe system cast-in with the concrete block at nullah
wall for stabilisation. Taking the inconsistent
shapes and sizes of nullah wall / drainage outlets and limited accessibility to
the nullah bank into consideration, the more flexible construction method of
in-situ construction of DWFI system is considered more suitable and practical
than the off-site pre-cast construction.
Hence, it is adopted to avoid prolonged construction duration and
repeated construction activities and to reduce potential disturbance/nuisance
to the environment and local public from trial installations or on-site
adjustment of pre-cast concrete mass.
2.4.5
The proposed underground water
storage tank with an area of approximately 300 m2 and 2.5m deep will
be installed at shallow depth to match the downstream invert level of the
nullah. Conventional bottom-up open-cut
construction method is considered the most suitable and practical for such
shallow excavation and small-scale substructure and hence and is adopted.
2.5.1
The construction works are
tentatively scheduled to commence in Q1 2024 for completion in Q4 2029.
2.6
Concurrent Projects
2.6.1
The
potential cumulative environmental impacts during
construction and / or operational phase from the below interfacing projects
within 500 m from the Project or ones that involve construction works within or
in close proximity to Shing Mun River and its tributaries have been reviewed.
·
Proposed floodwall along Shing Mun River under
Drainage Improvement Works in Sha Tin and Sai Kung;
·
Rising main for connecting Sha Tin Main Sewage
Pumping Station to the planned Intermediate Sewage Pumping Station along Shing
Mun River proposed under the Relocation of Sha Tin Sewage Treatment Works to
Caverns – Upstream Sewerage and Pumping Stations;
·
Sewerage Works near Kwei
Tei Street;
·
Widening of Tai Po Road (Sha Tin Section);
·
Revitalisation of Tai Wai Nullah;
·
Revised Trunk Road T4 in Sha Tin;
·
Redevelopment of Housing Authority’s (HA) Sui
Fai Factory Estate for Residential Use; and
·
New Facilities Building of the Hong Kong Sports
Institute (HKSI)
2.6.2
No adverse cumulative
environmental impacts from the above potentially interfacing projects were
predicted during the construction and operational phases of the Project. Nonetheless, it is recommended that during the
detailed design stage, the contractor of this Project should be requested to
closely liaise with the contractors of these potential concurrent projects in
planning the interfacing works properly to avoid / minimise
repeated and concurrent construction works as far as practicable to further minimise any potential cumulative impacts and to enhance
overall environmental performance of the Project.
2.7
Public Consultation
2.7.1
Consultation exercise carried
out include:
·
Meeting with Sha Tin District Council in June
and July 2018, March 2021
·
Meeting with Sha Tin District Council Health and
Environmental Committee in March 2019
·
Meeting with Green Groups in July 2020
·
A series of public engagement exercises (e.g.
interviews, workshops and surveys) through the use of Design Thinking Approach
between December 2020 to August 2021.
2.7.2
During the public inspection
period of the Project Profile submitted for the Application of EIA Study Brief
(No. PP-585/2019) in 2019, comments received were largely in favour of the Project, in particular, the proposed
DWFI system and ecological enhancement are considered to be beneficial to the
community. Members of the Sha Tin
District Council, general public and green groups are supportive of the
Project. Their key concerns and comments
on avoidance and minimisation of impacts on existing
natural watercourses / habitats and associated wildlife, water quality issues
and odour nuisance, promotion of water friendliness,
insufficient baseflow to support proposed ecological enhancement and
improvement on walkability along the nullah and enhancement of public open
spaces have been incorporated into the design of the Project.
3
Key
Findings of the environmental impact Assessment
3.1
Air
Quality Impact
3.1.1
Potential air quality impacts
associated with the construction and operational phases of the Project have
been assessed in accordance with the criteria and guidelines as stated in the
requirements given in Section 3.4.4 and Appendix B of the EIA Study Brief, as
well as Annexes 4 and 12 of EIAO-TM. The assessment area for air quality impact assessment
is within 500m from the boundary of the Project area.
3.1.2
The potential air quality
impacts arising from the construction of the Project would be related to
fugitive dust emissions from construction works and gaseous emissions from the
use of powered mechanical equipment (PME), and odour
nuisance from the desilted/excavated materials generated
during desilting works at downstream tidal zone / excavation works in the
nullah. Since the construction works of
the Project would be divided into sections which are in small scale, the air
quality impacts would be localised and minor, and
would be well controlled through the implementation of good site practices and
dust suppression measures stipulated in the Air Pollution Control (Construction
Dust) Regulation as well as the proposed good site
practices to minimise the exhaust emissions from non-road
mobile machinery (NRMMs) and odour nuisance from handling of desilting/excavated materials. No adverse air quality impact due to the
construction of the Project would therefore be anticipated.
3.1.3
With the implementation of DWFI
system under the Project to intercept and divert the polluted discharges from
drainage outlets along the nullah to the existing sewerage system for
treatment, the odour nuisance of FTN would be
alleviated as a result of the operation of the Project. Any odour emission generated from exposed desilted
materials during the routine maintenance works would be temporary and confined
to the areas of maintenance works that it would be well-controlled through good
site practices. No adverse air quality
impact due to the operation of the Project would be anticipated.
3.2.1
Potential noise impacts associated with the construction and operational phases of
the project have been assessed in accordance with the criteria and guidelines
as stated in the requirements given in Section 3.4.5 and Appendix C
of the EIA Study Brief, as well as Annexes 5
and 13 of the EIAO-TM. The assessment area for noise impact assessment
is defined by a distance of 300m from the site boundary of the Project.
3.2.2
Construction noise is expected
from the use of powered mechanical
equipment (PME) during various construction
activities. No marine transportation of
construction materials and waste is required.
Noise impact arising from construction activities of the Project has been assessed. With proper implementation of the proposed mitigation measures, including
adoption of good site practices, use of quality
PME / quieter construction method including silent piling by
press-in method, adoption of movable noise barriers, and proper
scheduling of noisy construction activities, the mitigated cumulative
construction noise levels from the Project and nearby concurrent project at all
representative noise sensitive receivers (NSRs) in the vicinity of the Project
work site would range from 59 to 75 dB(A), complying with the noise criteria set out in
the EIAO-TM. Potential cumulative construction noise on
representative NSR NAP2 (Yuk Wo Court), NAP3 (51 Fo
Tan Village), NAP4 (57 Fo Tan Village) and NAP6
(Jockey Club TI-I College) is also anticipated to be insignificant. Subject to the detailed design and
construction programme, as an enhancement measure to
further improve the environmental performance of the construction of the
Project, other quieter construction methods, such as use of road ripper instead
of breaker for concrete breaking during excavation works, would also be
considered where viable. Noise
monitoring is recommended as part of the environmental monitoring and audit
(EM&A) programme for the construction phase of
the Project to check compliance with the daytime construction noise
criteria. Weekly site audit is also
recommended to audit the proper implementation of the recommended mitigation
measures for daytime construction activities as part of the EM&A programme.
3.4.1
The waste impact assessment was conducted in
accordance with the criteria and guidelines as stated in the requirements given
in Section 3.4.7 and Appendix E of the EIA
Study Brief, as well as Annexes 7 and 15
of the EIAO-TM.
3.4.2
Construction and Demolition
(C&D) materials will be generated from channel bed modification, improvement
of existing walkways, landscaping and miscellaneous works, construction of DWFI
system and underground water storage tank construction. Based on the latest layout, it is estimated
that approximately 41,400 m3 of inert C&D material and 3,000 m3
of non-inert C&D materials would be generated.
3.4.3
Inert C&D materials from
the above construction works will be sorted and reused as filling material as
much as possible. It is estimated that
that approximately 36,600 m³ of inert C&D materials (mainly soil) could be
reused on-site as backfill materials whilst approximately 4,800 m³ of surplus
inert C&D materials would be delivered to public fill reception facility
(PFRF) for beneficial reuse in other project.
Non-inert waste will be recycled as far as possible before disposed to
landfill. Opportunities in minimisation of generation and maximisation
of reuse of C&D waste would be continually investigated during the detailed
design and construction phases. With the
implementation of the recommended good site practices and mitigation measures
for the handling, transportation and disposal of the identified waste arising,
no adverse environmental impacts would be anticipated.
3.4.5
The main waste types generated
from the operation of the Project would be silt, debris, screening and limit
amount of chemical waste from the routine maintenance of the DWFI system and
underground water storage tank, as well as desilted materials from maintenance
desilting works. With implementation of
the relevant legislative requirements and the recommended best waste management
practices, adverse environmental impacts (including potential hazard, air and odour emissions, noise and wastewater discharges) and
public transport impact would not be anticipated during operational phase. Provided that sufficient
number of trash bins and recycling bins would
be provided / retained for the collection of
general refuse generated by pedestrians / users along the revitalized
FTN, no unacceptable environmental impact and public transport impact would be
anticipated.
3.5.1
The land contamination assessment is conducted in accordance with the criteria and guidelines as stated in the
requirements given in Section 3.4.8
and Appendix F of the EIA Study Brief, as well as Sections 3.1 and 3.2 of Annex
19 of the EIAO-TM.
3.5.2
Based on the site appraisal,
the Project area has been occupied by non-contaminating land uses and no
potentially contaminating activities were observed. No adverse land contamination impact arising
from the Project is therefore anticipated and mitigation measures are
considered not necessary. No further
site investigation works at the Project area is required.
3.6.1
The assessment on potential sewerage and
sewage treatment impacts on the downstream public sewerage, sewage treatment
and disposal facilities arising from the Project has been conducted in accordance with the criteria and guidelines as stated in the
requirements given in Section 3.4.9 and Appendix G of the EIA Study Brief, as
well as Section 6.5 of Annex 14 of the EIAO-TM.
3.6.2
A DWFI system is proposed to
improve the water quality in the Fo Tan Nullah with
intercepted dry weather flow estimated to be at 2,700 m3/day. The
sewerage impact assessment indicated that existing sewerage system has
sufficient capacity to take up the additional dry weather flow intercepted by
the DWFI system. Thus, no mitigation
measures are required.
3.7.2
A literature review and
ecological field surveys covering both dry and wet seasons between May 2020 and
November 2020 have been conducted. A total of seven habitat types were recorded
within the 500m assessment area from recent surveys, including developed area /
wasteland, village / orchard, plantation, shrubland, woodland, natural
watercourse and modified watercourse. Dominant habitat types recorded within
the Project area were developed area / wasteland and modified watercourse,
which are of low ecological value. Short section of natural
watercourse directly upstream of the concrete nullah of FTN, which is of low to
moderate ecological value, was also located within the
Project area and has been avoided under the revitalisation
design that no works would be conducted within the natural watercourse.
3.7.3
For habitats outside the
Project area, woodland is considered of moderate to high ecological value,
shrubland and natural watercourse of low to moderate ecological value, while
remaining habitats (developed area / wasteland, village / orchard, plantation
and modified watercourse) are of low and very low ecological value. Species of
conservation importance recorded within the assessment area included 11 flora,
16 avifauna, one odonate, five herpetofauna, 14
mammal and three freshwater species. Among these species, only four avifauna,
one mammal and two freshwater species of conservation importance were recorded
within the Project area.
3.7.4
Marine habitats within the
assessment area included subtidal hard substrata, soft bottom, and intertidal
habitats, which are all of low ecological value. As the Project area is located
far from marine habitats (>2.6 km), no direct impacts to marine habitats are
anticipated, and indirect impacts are considered negligible.
3.7.5
No direct impacts to natural
habitats within the assessment area are anticipated for the Project. Although
natural watercourse was identified within the Project area, direct impact on
the natural habitat has been avoided through confinement of construction works
within boundary of the highly disturbed habitats of developed area and modified
watercourse only. Direct impacts arising from the proposed works would be
limited to the temporary loss (about 7.17 ha) of some modified watercourse and
developed area. Given the relatively low
to moderate ecological values of affected habitats, the small area affected,
and the temporary nature of the impact, direct impacts are expected to be Minor.
All affected areas will be reinstated and enhanced in terms of
ecological value as part of the project. Avoidance measures (e.g. protection of
mature trees along the nullah and avoidance of encroachment onto natural
watercourse) would be implemented to preserve the day roosting habitats for
bats and ardeids.
3.7.6
Indirect impacts during the
construction phase would comprise of human disturbance, construction noise,
dust, lighting/glare and site run-off. With proper implementation of the
recommended mitigation measures and good site practices, no significant adverse
ecological impact is anticipated. With
ecological enhancement measures incorporated into revitalisation
design of FTN, nature of disturbance during operation phase would be minimal
compared to existing baseline condition.
Net positive ecological outcome would be resulted from the created and
enhanced wetland habitats. No
unacceptable adverse residual impacts would therefore be expected during both
construction and operation phase.
3.7.7
Monthly site audit should be
carried out throughout the construction phase to ensure recommended measures
are properly implemented. No EM&A programme is required during
operational phase.
3.7.8
Ecological enhancement designs
have been incorporated into the revitalisation plan
to promote ecological value of the Project, as well as enhancement measures and
good site practices to further minimise any potential
environmental impacts. The proposed revitalisation plan for FTN should seek to find a balance
between design for local communities’ requirements (e.g. aesthetics,
recreation/leisure and access) and ecological enhancement. Ecological enhancement could be achieved by
incorporating habitat creation within and along the FTN to improve the overall
ecological value of the Project area. The design should not result in
disturbance impacts to surrounding habitats and fauna utilising
the nullah. Upon completion of revitalisation for FTN, ecological value of the Project
area should be improved by ecological enhancement measures incorporated into
the design. A post-enhancement
ecological monitoring programme will be developed and
implemented by the DSD to review effectiveness of these enhancement measures
(e.g. creation of wetland habitats, vegetation planting and specific
enhancement measures for identified species).
The programme should aim to record the overall
ecological condition of the Project area, including but not limited to the
followings: quality of the created habitats and enhancement elements, usage by
targeted fauna species and vegetation conditions. Maintenance and management
requirements for FTN should be adjusted accordingly based on the monitoring
results.
3.8.1
Potential impacts on fisheries
have been assessed in accordance with Section 3.4.11 and Appendix I of the EIA
Study Brief as well as Annexes 9 and 17 of the EIAO-TM.
3.8.2
The Project would only involve
construction works within the Project area (existing FTN and developed area
alongside). No loss of fishing grounds and mariculture areas are anticipated
within the assessment area. With the implementation of the recommended water
pollution control measures, the Project would not cause any unacceptable
indirect impacts to fishing grounds and mariculture areas within the assessment
area during both construction and operational phases. Thus, no further
mitigation measures and environmental monitoring and audit programme
specific to fisheries impact are required.
3.9.1
Cultural heritage impact
assessment (CHIA) has been conducted in accordance with the relevant
requirements as specified in Section 3.4.13 and Appendix K of the EIA Study
Brief, as well as Annexes 10 and 19 of the EIAO-TM.
3.9.2
A Declared Monument, Old House,
Wong Uk Village, is located within 300m of the
discharge area from the revitalised FTN, and located at about 900m from the nearest site boundary. As the proposed works are mostly situated
within the FTN and there is substantial separation distance between the Old
House and the proposed works, no direct and indirect impacts on the Old House
would be anticipated during the construction and operation phases of the
Project.
3.10.1
A landscape and visual impacts
assessment has been carried out in accordance with Section 3.4.12 and Appendix
J of the EIA Study Brief, Annexes 10 and 18 of the EIAO-TM, and EIAO Guidance
Note No.8/2010.
3.10.2
During construction phase, the
proposed channel modification and construction of DWFI system and mid-stream water pumps
for ecological enhancement associated water supplement will be
constructed inside the existing Fo Tan Nullah, while
certain proposed architectural structures will be constructed at the roadside
which may impose visual impact to adjacent VSRs. Amongst the 173 nos. of surveyed trees, 133
nos. are proposed to be retained, including all
existing mature trees growing along the nullah banks. A total of 25 nos. of trees are proposed to
be removed, all of which are common species including Acacia confusa, Bauhinia variegata, Bischofia javanica, Ficus virens, Melia
azedarach and Morus alba, and including 15 nos. of undesirable
species, Leucaena leucocephala; and a total of
15 nos. of Magnolia grandiflora are proposed to be transplanted. As
stipulated in DEVB TC(W) No. 4/2020, “…the number of compensatory trees onsite
and offsite shall not be lower than that of number of trees removed including
dead trees, but excluding trees of undesirable species...”, therefore, To
compensate the loss of existing trees, approximately 10 nos. of heavy standard
compensatory trees are proposed in available planting area to enhance the
amenity value to vicinity of site. With the implementation of mitigation measures including
preservation of trees, compensatory tree planting, tree transplantation,
control of night-time lighting glare, erection of decorative screening
hoarding, careful management of construction activities and facilities, as well
as reinstatement of temporarily disturbed landscape areas and watercourses, no
unacceptable residual landscape and visual impacts from the construction of the
Project would be anticipated.
3.10.3
Fo Tan Nullah will be revitalised
with architectural and landscape features aimed at promoting water friendliness
and providing an enhanced green and ecological environment. The proposed
architectural and landscape features, and modified channel bed would
be the key sources of visual / landscape changes during operation. With the proposed greening enhancement along
channel bed and embankment, provision of recreational opportunity along nullah,
sensitive and aesthetically pleasing design, re-provision of affected open
space, the overall impacts are considered as acceptable in
accordance to Annexes 10 and 18 of the EIAO-TM and the Project would be beneficial to
the landscape and visual aspects.
4
Environmental
monitoring and audit
5.1.2
The findings of the EIA
provided information on the nature and extent of the environmental impacts
likely to arise from the construction and operation of revitalised
Fo Tan Nullah. The EIA has, where appropriate,
identified mitigation measures to ensure compliance with the relevant
environmental legislation and standards.
5.1.3
Overall, the EIA concluded that
the Project would comply with the requirements of the EIA Study Brief and
EIAO-TM with the implementation of the proposed measures during the
construction and operational phases of revitalisation of Fo Tan Nullah. The schedule of
implementation of the proposed measures has been provided in the EIA
Report. An EM&A programme
has also been recommended to ensure the effectiveness of the proposed measures.