2. Project Description
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Consultancy Agreement No. CE 63/2008 Providing Sufficient Water Depth for Kwai Tsing Container Basin and its Approach Channel Environmental Impact Assessment Report 2. Project Description 2.1 The Project Requirements and Programme The southern portion of the Rambler Channel between Tsing Yi and Kwai Chung has been developed into Hong Kong’s primary container shipment port. Nine container terminals, comprising a total of 24 berths which line the east and west sides of the channel, are collectively referred to as the Kwai Tsing Container Port (KTCP), and the waterway within the KTCP is referred to as the Kwai Tsing Container Basin (KTCB). Access for ocean-going container vessels between the KTCB and the main shipping lanes is along the section of the Northern Fairway to the south of Tsing Yi, the Western Fairway and the East Lamma Traffic Separation Scheme (ELTSS). Developments within the container shipping industry have seen the introduction of ultra-large container ships (ULCS) to the main intercontinental shipping routes. These vessels have a maximum draft of 15.5m. The current average seabed level within the KTCB is approximately -15.6mCD, while depths in parts of the approaches to the KTCB are shallower. Therefore, it is proposed under this Project to deepen the seabed level of the KTCB and its marine access route to provide adequate depth of water to enable the new generation of ULCS to call at the KTCP. The Project layout is shown in Figure 2.1 . The Project’s objective is to lower the seabed in the KTCB and its access fairways and channels so as to maintain an adequate clearance for ULCS at all times. For the purpose of determining the functional least depth of dredging, the maximum draft of an ULCS is taken to be 15.5m. It is recommended in Marine Department’s “The Complete Berthing Guidelines for Port of Hong Kong” that an under-keel clearance of 10% of the maximum draft is provided within manoeuvring basins, sheltered fairways and approaches to berths. Marine Department has confirmed the applicability of this criterion to the Kwai Tsing Container Basin and its approaches in the Northern and Western Fairways as well as the East Lamma Traffic Separation Scheme, and has advised that the minimum depth to be provided is 17.0m below lowest astronomical tide, corresponding to a sea bed level of -17.0mCD. In order to determine the appropriate maintained seabed level, an assessment of the sedimentation rates within the Project area since 1990 has been carried out. The assessment concludes that the potential for sedimentation within the Project area is low. However, it is not known with certainty that the conditions which existed in the period covered by the assessment will prevail for the service life of the KTCP. In order to account for possible increases in the sediment load in the Pearl River Estuary, yet still achieving a sensible balance between capital and maintenance dredging works, a target seabed level of -17.5mCD has been adopted. In Section 2.2.1 of Port Works Design Manual Part 1, the Chart Datum (CD) is 0.146m below the Principal Datum (PD). Therefore, the target seabed level is -17.646mPD. For construction tolerance, the final seabed level should not be shallower than the targeted level, nor should it be 0.3m deeper than the targeted level. In addition to the foregoing, modification of the Tsing Yi Submarine Sewage Outfall and demolition of the Kwai Chung Submarine Sewage Outfall are included as part of the scope of works for this Project. For the Tsing Yi Submarine Sewage Outfall modification works, this will involve removal of the rock armour, replacement of the existing riser pipes and non-return valves, and followed by the re-application of rock armour. Demolition of the Kwai Chung Submarine Sewage Outfall will only involve the dismantling of the pipe section that is above the dredge level. The dredged volume quoted in the Study Brief was 5.5Mm 3; 259053/TNI/ENL/23/E July 2010 P:\Hong Kong\MRT\259053 KTCB\01 Project Management\71 Deliverables\07 Environmental Impact Assessment Report\FINAL_PE\EIA_Rpt_Jul 10_Ch 2.doc 2-1 Consultancy Agreement No. CE 63/2008 Providing Sufficient Water Depth for Kwai Tsing Container Basin and its Approach Channel Environmental Impact Assessment Report however, as the engineering design has progressed in parallel with this EIA, the dredged volume has been refined to be at 4.4Mm 3. This provides environmental benefit through the reduction in the volume of material to be dredged and disposed of as well as reducing the extent of potential impacts on the receiving water column. According to the latest estimate, the Project is tentatively scheduled to commence works in the second half of 2011, to be substantially completed within 2 years except for a small area near Container Terminal no. 1 and 5. 2.2 The Study Area and Surrounding Environment The Kwai Tsing Container Port (KTCP), located in the north-western part of the harbour in the reclamation along Rambler Channel between Kwai Chung and Tsing Yi Island, comprises nine container terminals with 24 berths of 7,804 m of deep sea frontage and is operated by five companies, each responsible for maintaining a strip of seabed of approximately 50 m wide along the terminals. In addition to KTCP, the study area also includes a portion of Northern Fairway south of Tsing Yi Island and a section of Western Fairway west of Hong Kong Island. Additionally, to the northwest side of the container basin, there are also two submarine outfalls namely Tsing Yi Submarine Sewage Outfall and Kwai Chung Submarine Sewage Outfall which are part of the project. Collectively, the study area occupies an area of approximately 446 ha in size. 2.3 Need for the Project and Consequences of not Proceeding with the Project Hong Kong’s container port is the third busiest in the world after Singapore and Shanghai, followed by Shenzhen. It is renowned for its efficient cargo-handling operations making it a preferred shipping hub in the region. With the global trend of increasing size of container ships, the ULCS to be generated in the near future will have a maximum draft of 15.5m. However the KTCB and its approach channel are being maintained at the depth of about -15.5 mCD with some parts being only at -15.2 mCD, while the water depth for the Yantian Container Port in Shenzhen is at -16.0m. In the short term, with the trend of the increasing size of container vessels, current container ships occasionally have to wait for high tide to depart from Kwai Tsing Container Port due to insufficient depth of the KTCB. Such limitations reduce the efficiency in cargo-handling operations, potentially harm the reputation of Kwai Tsing Container Port and conceivably could encourage vessels to make alternative arrangements including the diversion of traffic to Shenzhen and other regional ports. The execution of this Project is therefore necessary to keep the container basin deep enough to maintain current efficiencies and to facilitate the growing size of container ships in the short term. In addition, it is also needed to meet the draft requirement of ULCS and to maintain the competitiveness of the Kwai Tsing Container Port and Hong Kong as a regional hub port in the long term. Benefits from this Project are the considerable increase in import and export capacity and the associated economic and social gains for Hong Kong as a whole. In the absence of this Project, the insufficient depth of KTCB and its approach channel will cause Kwai Tsing Container Port to become less efficient given the increased vessel sizes, including the inability to physically berth and accommodate the ULCS. The long-term development potential of the Kwai Tsing Container Port will inevitably be constrained by the depth of KTCB and its approach channel. International shipping lines will no longer continue to call into the Hong Kong port but turn to Yantian Port or other ports, 259053/TNI/ENL/23/E July 2010 P:\Hong Kong\MRT\259053 KTCB\01 Project Management\71 Deliverables\07 Environmental Impact Assessment Report\FINAL_PE\EIA_Rpt_Jul 10_Ch 2.doc 2-2 Consultancy Agreement No. CE 63/2008 Providing Sufficient Water Depth for Kwai Tsing Container Basin and its Approach Channel Environmental Impact Assessment Report resulting in the long term, in a critical loss of shipping trade and declining competitiveness of Hong Kong in the world port economy. 2.4 Consideration of Alternative Construction Methods and Sequence of Work 2.4.1 “Do Nothing” Scenario The “do nothing” scenario is described in the preceding section 2.3. The current depth of the KTCB limits the efficiency of KTCP and threatens the long term position of Hong Kong as a regional hub and world class port. The new generation of ULCS is expected to have a draft of 15.5m. This means that in order for these ULCS to access the container terminals at KTCP, a minimum water depth of about 17m would be required. Current seabed levels thus constrain access by ULCS to tides higher than +1.5mCD. Such restrictions on the permissible access time for ULCS would severely hinder the operational flexibility and efficiency of these container ships, and would be an impractical option for both shipping lines and terminal operators. Consequently, a “do nothing” option is not considered viable for the long term economy of Hong Kong. 2.4.2 Alternative Locations KTCP is currently the only port in Hong Kong that contains the facilities which can handle the volumes of cargo associated with the ULCS.