TABLE OF CONTENT
List of Figures
1.1 The Sha Tin and Tai Po Drainage Master Plan (DMP) Study completed in October 1999 indicated that certain stormwater drains and natural rivers / streamcourses in the Sha Tin and Tai Po area did not have the required hydraulic capacity to meet the anticipated flow requirements. To alleviate the risks of flooding and to cope with future development as identified in the DMP Study, construction of river channels, upgrading of existing stormwater drains, construction of flood pumping stations in the low-lying areas and other minor drainage facilities were recommended.
1.2 Upon completion of the DMP Study, the Drainage Services Department (DSD) of Hong Kong SAR Government commissioned Maunsell Consultants Asia Ltd. to undertake Agreement No. CE50/2001 (DS) Drainage Improvement in Sha Tin and Tai Po – Design and Construction (hereinafter referred to as “the Assignment”), for implementing the drainage improvement works at various locations recommended in the DMP study.
1.3 The drainage improvement works in Shuen Wan recommended in the DMP Study has been reviewed under this Assignment. The following works items, which are collectively referred to as the “Drainage Improvement Works in Shuen Wan” (the Project), are proposed to alleviate the potential flooding problems in the Shuen Wan area in Tai Po:
Construction of a
§ Replacement of existing gates by automatic mechanical gates at the mouth of Wai Ha River
§ Construction of a drainage pipe of 280m long and 1200mm in diameter near Wai Ha Village
Construction of a flood relief drain of 260m long and 2100mm
in diameter along
§ Construction of a floodwater pumping station of about 10m high at Shuen Wan
1.4 Figure 1.1 shows the location of the Project.
In accordance with Category Q.1
of Part 1, Schedule 2 of the EIA Ordinance (Cap. 499), works partly or wholly
in an existing Conservation Area (CA) are classified as Designated Projects
(DP). Since a section of the proposed
1.6 This report provides a summary of the key findings of the EIA study, assessing potential environmental impacts from the construction and operation phases of the Project, and recommending mitigation measures to comply with the environmental legislation and standards.
1.7 Alternative design schemes and alignment options have been thoroughly considered and environmentally friendly design has been adopted to avoid / minimize impact to the CA, areas of ecological importance and species of conservation interest where possible.
Project Implementation and Interaction with Other Projects
1.8 The construction of the proposed Project is scheduled to commence in December 2007 for completion in June 2010.
1.9 A sewerage project, namely “Tolo Harbour Sewerage of Unsewered Areas Stage I Phase II” (hereinafter referred to as “the Sewerage Project”, would be carried out by Drainage Services Department in San Tau Kok Village. This Project was tentatively scheduled to start in November 2008 and complete in November 2010, and would likely be carried out concurrently with the Project.
2.1 Construction of the proposed drainage improvement works would, if unmitigated, generate noise levels exceeding 75 dB(A) Leq(30-min) at Noise Sensitive Receivers (NSRs) in close proximity to the proposed works.
2.2 Measures including the implementation of good site practices, use of quieter powered mechanical equipment (PME), temporary barriers, quieter alternative construction method (the Low Impact Method) and the use of noise enclosure were recommended to mitigate the potential construction noise impacts. With the implementation of these measures, no adverse impacts at the NSRs were predicted.
2.3 Potential air quality impacts arising from the construction of the proposed drainage works would mainly be related to dust nuisance from excavation, material handling and wind erosion from the site.
2.4 With the implementation of the dust suppression measures as stipulated in the Air Pollution Control (Construction Dust) Regulation, and good site practices, dust levels at air sensitive receivers would comply with the Hong Kong Air Quality Objectives (HKAQOs).
2.5 Potential sources of water quality impact associated with the construction of the proposed drainage improvement works include site runoff and drainage; debris, refuse and liquid spillages from general construction activities; and sewage from the construction workforce.
2.6 To minimize potential impacts on water quality, working method controls have been recommended. Excavation works within the affected length of the river channel should be carried out from October to April and in dry condition by use of containment measures within the channel. Sheet-piles would be installed around the works trench near the CA to serve as hoardings to isolate the works site. Control measures on the runoff and drainage are proposed to minimise construction run-off. Proper site management and good housekeeping practices would also be required to ensure that construction wastes and materials would not enter Wai Ha River or fish ponds at Shuen Wan. Sewage arising from the construction workforce would also require appropriate treatment through provision of portable toilets.
2.7 With the implementation of these recommended mitigation measures, unacceptable impacts on water quality would not be anticipated. Regular site inspection should be undertaken to check against the proper implementation of the mitigation measures.
Waste Management Implications
2.8 The types of wastes associated with the construction activities of the Project would include construction and demolition (C&D) materials, chemical waste and general refuse from the workforce.
2.9 Waste reduction measures and good site practices are recommended to minimize the potential impacts associated with the generation of wastes. It is also recommended that the excavated C&D materials with suitable characteristics/sizes should be reused on-site as fill material as far as practicable. Appropriate waste handling, transportation and disposal methods for all waste generated during the construction works should be implemented.
2.10 Provided that the waste arisings are to be handled, transported and disposed of using the recommended methods and that good site practices are to be strictly followed, adverse residual impacts are not anticipated during the construction works.
The alignment of the twin-cell
box culvert has been carefully designed such that impacts on key ecological
resources are avoided / minimzed. The
main impact on habitats resulting from the proposed works would be minimised to
A low ecological value recreational fishpond area,
2.13 With the implementation of the recommended mitigation measures, the ecological impacts resulting from the proposed works during construction and operation phases are considered to be acceptable.
2.14 No direct loss of fishing ground would arise from the Project with recommendations to protect water quality implemented, specific mitigation measures to protect fisheries resources are not necessary.
2.15 To alleviate the landscape and visual impacts arising from the Project, various mitigation measures such as landscape planting have been recommended. Measures during construction phase would be implemented from the commencement of the works and should be applied for the whole duration of the construction period. Management and maintenance for the mitigation measures should follow ETWB TCW No. 2/2004.
2.16 During construction phase, the Project would induce moderate landscape impacts at two identified landscape resources, while there would be one visual sensitive receiver subject to moderate residual impact after mitigation. After completion of the construction, the impact to the sensitive receivers will be reduced. The anticipated adverse residual landscape and visual impact would be low and generally acceptable.
2.17 Upon completion of the proposed works and after mitigation, there would only be limited landscape and visual impacts during operation phase. Therefore, with reference to criteria defined in Annex 10 of the EIAO TM, landscape and visual impacts in the construction and operational phases would be acceptable with mitigation measures.
3.1 An environmental monitoring and audit (EM&A) programme has been recommended for implementation during the construction and operation of the Project, to check on compliance with environmental legislation and standards during Project implementation.
4.1 The main objective of the Project is to alleviate the potential flooding problems in the Shuen Wan area in Tai Po.
4.2 The EIA study has identified and assessed potential environmental impacts of the Project. All direct and indirect, as well as cumulative impacts likely to arise during the construction and operation phases of the Project have been evaluated. With the implementation of the recommended mitigation measures, the Project would be environmentally acceptable and no adverse residual impacts would be expected.
1.2 渠務署完成以上研究後，批出工程顧問合約編號 CE 50/2001 - 沙田及大埔雨水排放系統改善計劃 - 設計及建造予茂盛（亞洲）工程顧問有限公司，實施研究所建議之雨水排放改善措施。
§ 沿洞梓路建造一道長約1,000米，3米（闊）及 2.5米（高）雙管箱形暗渠
1.9 渠務處於本工程項目施工期間，於䃟頭角村會有另一項名為「吐露港內未有污水設施而興建的污水收集系統第一階段第二期」工程進行。 該工程預計會在2008年11月動工，並在2010年11月竣工，預計會與本工程項目同期進行。
4.1 本工程項目的目的，主要是改善大埔船灣區的雨水排放系統，以減輕該區的水浸危機，並配合該區之未來發展 。
4.2 是次環評研究已指出擬建工程項目對環境可能造成的影響，並予以評估。擬建工程項目在施工和運作階段可能造成的所有直接、間接和累積影響，都已採用適當和被認可的評估方法作出評估。 在實施研究報告所建議的緩解措施後，本工程項目在環保方面會屬可接受，而且不會造成不良的剩餘影響。