Table 13.1 Summary
of Key Environmental Outcomes / Benefits
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Issue |
Environmental Outcomes / Benefits |
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Item A: Description
of the Project |
Requirements: General Development of the cruise terminal
at Kai Tak would require dredging at the existing seawall at the southern tip
of the former Phasing
of Development It is planned to implement the dredging works in two
stages. The Phase I Berth (South) of 450m long is scheduled for operation by
2012 and the associated dredging for manoeuvring of cruise vessels is scheduled
for completion by 2011. Phase II Berth
(additional 400m) for the longer term is scheduled for operation after 2015.
The programme for dredging in the manoeuvring basin for the Phase II Berth is unconfirmed at this
stage but its completion can be extended up to 2020 and the earliest possible
time for commencing the dredging for the Phase II Berth would be 2013 to
2014. The actual program for the
required dredging would also depend on the need for the Phase II Berth as driven by
the cruise market. The berth structure for
the Phase I Berth and the Phase II Berth will be built continuously for
completion by 2013. Manoeuvring
Area Provision is required for manoeuvring area of
adequate depth for cruise vessels manoeuvring onto and off the berths. The
layout and dimensions of the manoeuvring area are shown in Figure
2.4 and have been confirmed by detailed engineering assessment, to be
adequate for safe manoeuvring
of cruise vessels. Dredged
Depths For overall cost effectiveness,
initial navigation dredging for the operations of the Phase I Berth and the
Phase II Berth should allow for dredging to -12mCD. The area alongside of the
berth structure is to be dredged to provide a depth alongside of -13mCD to
allow for possible future deepening of the manoeuvring area if future new
vessels entail such water depth. Benefits: The Government aims to develop One of the key considerations for
locating the New Cruise Terminal at Kai Tak is that it is the only site
within the Upon completion of the New Cruise
Terminal, together with the existing cruise terminal in Tsim Sha Tsui, Potential consequences without the Project: The proposed dredging works are
essential for construction and operation of the proposed
cruise terminal at Kai Tak to provide the space needed for safe manoeuvring of cruise vessels
clear of the fairway and cruise berth. Without the proposed dredging works,
the safety of the cruise vessels’ manoeuvring will be in question. |
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Item B: ·
Consideration of Alternatives ·
Environmental Friendly Designs Recommended ·
Key Environmental Problem Avoided |
Site Location: Adequate water depth, turning basin
and landside developable space are the three key requirements in determining
the location of cruise terminal. The proposed location at the runway tip
would be best able to meet the above requirements when compared to the rest
of Kai Tak. The Preliminary Outline Development Plan (PODP) has proposed
two-alongside berths configuration comprising a continuous 850 m long berth
structure to cater for simultaneous berthing of one 360m and one 345m long
cruise vessel. This is expected to be able to accommodate the longest cruise
vessel commissioned to date. The
proposed location for the cruise terminal at the runway tip has the deepest
seabed along the former runway and larger manoeuvring space for receiving
mega cruise vessels. The access from and to the main fairway is also a very
direct one. Relocating the cruise
terminal to the middle part of the former runway will affect the operation of
the existing typhoon shelter, mooring buoys and submarine gas pipeline, which
in turn would affect the implementation programme of the cruise
terminal. Besides, more extensive
seabed dredging would be required as the water depth there is much shallower
(about 2-6m). This will not only
increase the technical difficulties but will also bring about more severe
environmental implications. An alternative location for the
cruise terminal at Dredging Extent: The proposed size and
configuration of the manoeuvring area is based on the minimum extent required
for safe manoeuvring of cruise vessels as determined by the real time vessel
simulation in order to minimize the associated waste generation as well as
the direct disturbance to marine ecological, fisheries and archaeological
resources. Dredging Programme: The programme for Stage 1 dredging
is governed by the required commissioning date of the Phase I Berth. Thus,
dredging required for operation of the Phase I Berth has to be carried out
during the period from later half of 2008 to 2011 as the first stage in order
to meet the commissioning programme for the Phase I Berth. Due to the site
constraints, dredging
for the Phase II Berth would need to be carried out at a later stage after
decommissioning of the existing submarine gas pipelines. The actual program for Stage 2
dredging would also depend on the future demand for the cruise terminal. The current tentative programme is to
commence the Stage 2 dredging in 2013 for completion in 2014 for the purpose
of this EIA. The selected time
horizon is the earliest possible timing for Stage 2 dredging. Our modelling assessment for Stage 2
dredging has included the impacts of all possible concurrent marine works
anticipated in or beyond 2012 and therefore is a worst-case scenario.
Therefore, no alternative programme has been considered for the capital
dredging. Based on the water
quality model predictions provided in the EIA report, no unacceptable water
quality impacts are expected under the assumed programme for capital dredging
with implementation of all the recommended mitigation measures. The duration of maintenance
dredging would be less than 6 months for each berth. Alternative programme for the
maintenance dredging to be carried out in either dry or wet seasons has been
considered under the water quality impact assessment. Based on the model
predictions, maintenance dredging in wet season would contribute larger water
quality impact and is therefore not preferred. It is recommended in this EIA
that the maintenance dredging should not be programmed in wet seasons (April
to September) to avoid the potential water quality impacts. Dredging Method, Dredging Rates and Staged Dredging
Requirements: Dredging from seabed required for
safe manoeuvring of cruise vessels would be carried out at a maximum
production rate of 4,000 m3 per day during both the Stage 1 and
Stage 2 dredging period at construction stage and 2,000 m3 per day
during maintenance dredging period at operational phase. The
total volume of capital dredging is estimated as 700,000 m3 for
Stage 1 and 680,000m3 for Stage 2. The total volume of maintenance
dredging is estimated as 350,000m3 once every 5 to 10 years. Closed grab dredgers are
considered as the most suitable dredgers for relatively small volumes and
contaminated mud. It is feasible to use small trailer suction dredgers
although these will give less control over handling of contaminated mud and
produce more marine sediment by volume (due to high water content) when
compared with grab dredging. Whilst larger equipment has been adopted for
major reclamation projects such as the Penny’s Bay reclamation and Container
Terminals in Kwai Chung, in this case, given that dredging is not on the
critical programme path, it is assumed that the most cost effective
construction method with the least environmental impact will be adopted for
the cruise terminal i.e. closed grab dredgers. The dredging rate of 4,000 m3
per day for Stage 1 and Stage 2 assumes that the area will only be big enough
to sustain 2 grab dredgers operating simultaneously. Barges serving each grab
dredger are assumed to have a capacity of 1,000m3 and can complete
up to two trips to the marine dumping area per day. Based on the production rate of 2,000
m3 per day, only 1 closed grab dredger would be required for
maintenance dredging. Dredging from the existing seawall
of the former The
water quality modelling assessment has included the assumption that there may
be a number of concurrent dredging projects nearby to the cruise terminal. These
assumptions are conservative in order to allow all potential projects to
proceed without severe constraints.The dredging locations, rates, timing and phased implementation have
been analyzed and confirmed by the technical assessments performed under this
EIA to be environmentally acceptable. In particular, modelling assessment has
been carried out under this EIA to assess the water quality impacts of
undertaking the dredging in either the dry or wet season and concluded that
the proposed dredging rates, locations and timing would not cause any
unacceptable water quality and marine ecological impact, provided that all
the mitigation measures recommended under this EIA are properly implemented. Berth Structure: Dredging
of existing seawall would be required for berth construction. The cruise terminal berth structure will need to be
constructed within the land limits as a measure to protect and preserve the Harbour. Preliminary
schemes for six types of berth structures have been developed and reviewed
including: ·
Option 1 – Piled Quay Deck; ·
Option 2 – Precast Reinforced Concrete
Caisson; ·
Option 3 – Precast Concrete Blockwork Seawall; ·
Option 4 – Bored Pile Retaining Wall with
Anchor; ·
Option 5 – Precast Reinforced Concrete ·
Option 6 – Sheet Pile Cofferdam Wall. After
reviewing all the factors, Options 4, 5 and 6 are not recommended based on
engineering considerations. Amongst the three short listed options, the piled
quay deck (Option 1) would require the least amount of dredging at the existing
seawall during construction and is the preferred option based on
environmental consideration. The piled quay deck is also considered the
preferred option in terms of cost, programme and engineering requirements.
Option 1 is therefore recommended to be used as the basis for the Scheme
Design of the quay structure for the cruise terminal development. |
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Item C: Air Quality Impact |
Environmental
benefits of environmental protection measures recommended: No adverse air quality impact is expected from
the Project. However as a precautionary measure to minimize the potential
odour emissions, if any, the dredged sediment placed on barge should be
properly covered as far as practicable to minimise the exposed area and hence
the potential odour emissions during the transportation of the dredged
sediment. Compensation areas
included: Not required (no adverse air quality impact is expected from the
Project). Population and
environmental sensitive receivers protected: Planned developments on the former airport
runway including: ·
Residential Developments ·
Planned Hotel ·
Landscape Deck at Cruise Terminal ·
Planned |
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Item D: Noise Impact |
Environmental
benefits of environmental protection measures recommended: No adverse noise quality impact is predicted
from the Project, However, good site
practices as listed below have been recommended in order to further
ameliorate the construction noise impacts. ·
Only well-maintained plant should be operated
on-site and plant should be serviced regularly during the construction
program. ·
Mobile plant, if any, should be sited as far
away from nearby noise sensitive receivers (NSRs) as possible. ·
Machines and plant (such as trucks) that may
be in intermittent use should be shut down between works periods or should be
throttled down to a minimum. ·
Plant known to emit noise strongly in one
direction should, wherever possible, be orientated so that the noise is
directed away from nearby NSRs. ·
Material stockpiles and other structures should
be effectively utilised, wherever practicable, in screening noise from
on-site construction activities. Compensation areas
included: Not required (no adverse noise impact is expected from the Project). Population and environmental
sensitive receivers protected: Planned residential developments on the former airport runway. |
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Item E: Water Quality
Impact |
Environmental
benefits of environmental protection measures recommended: Implementation of the proposed mitigation
measures including use of closed grab dredging, the deployment of silt
curtains at appropriate dredging areas, and installation of silt screens at
selected seawater intakes along the water front of Victoria Harbour (refer to
Figure 5.6 to Figure 5.8) would reduce the predicted
water quality impact to an acceptable level.. Compensation areas
included: Not required (no adverse water quality impact is predicted from the
Project after implementation of the mitigation measure). Population and
environmental sensitive receivers protected: Seawater intakes along the waterfront of |
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Item F: Waste Management
Implications |
Environmental
benefits of environmental protection measures recommended: Implementation of the proposed waste control
and mitigation measures (refer to Section 6.7 for details) would avoid the
potential water quality, dust, odour, and noise impacts associated with
handling, transportation and disposal of the identified wastes arising from
the Project. Compensation areas
included: Not required (no adverse waste impact is predicted after implementation
of the mitigation measure). Population and
environmental sensitive receivers protected: Water quality, air, and noise sensitive
receivers at or near the Project site, the waste transportation routes and
the waste disposal site. |
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Item G: Impact
on Cultural Heritage |
Environmental benefits
of environmental protection measures recommended: It is recommended that the dredging
contractor should monitor the dredge spoils. A procedure for briefing the
dredging contractors about the possible presence of marine archaeological
resources during dredging and a procedure for handling them have been
developed in consultation with the AMO, to ensure compliance with the AMO
standards and protection of any archaeological resources at the proposed
dredging site. Compensation areas
included: Not required (no adverse impact on cultural heritage is predicted). Population and
environmental sensitive receivers protected: Potential archaeological resources within the
proposed dredging site. |
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Item H: Marine
Ecological Impact |
Environmental
benefits of environmental protection measures recommended: All the marine habitats and associated flora
and fauna that would be directly impacted due to this Project are all of
generally very low ecological values. Coral colonies that would be directly
affected would be translocated, as far as practicable, to the nearby suitable
habitats. Water quality control measures (as described in Item E above) would
minimise indirect impact on marine habitats and associated life due to change
of water quality. Compensation areas
included: Temporary loss of artificial seawall habitats
would be recovered by the re-construction of new seawalls. Population and
environmental sensitive receivers protected: Ecological resources at and near
the Project site. |
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Item I: Fisheries Impact |
Environmental
benefits of environmental protection measures recommended: In view of the small size of affected area,
temporary and insignificant loss of fisheries production and low impact on
fishing activities, fisheries impacts due to direct loss of fishing area
within the dredging area is considered as minor and acceptable. Water quality
control measures (as described in Item E above) would minimise indirect
impact on fisheries due to change of water quality. Compensation areas
included: Not required (no significant adverse fisheries impact is predicted). Population and
environmental sensitive receivers protected: Fisheries resources at and near the Project
site. |