Drainage Improvement in Northern Hong Kong Island, Hong Kong

• Client: Drainage Services Department, Hong Kong Government
• Components: Review of ecological baseline survey report, environmental impact assessment

Ecosystems is the ecological and fisheries consultant for a proposed improvement of the existing drainage systems in northern and western parts of Hong Kong Island. The consultant review results of ecological surveys and ecological and fisheries baseline conditions, conduct ecological and fisheries assessment, and recommend mitigation measures.

Yuen Long and Kam Tin Sewerage and Sewage Disposal Stage 2, Hong Kong

• Client: Drainage Service Department, Hong Kong Government
• Lead consultant: Ove Arup & Partners Hong Kong Limited
• Components: Ecological surveys, environmental impact assessment

Ecological study and impact assessment of a proposed sewerage and sewage disposal system for the North-West New Territories. The project covered a large area and is in the vicinity of Wetland Conservation Area and Wetland Buffer Area, which is the key ecological issue of the project. Surveys conducted include habitat mapping, vegetation, avifauna, and aquatic communities.

Aberdeen, Ap Lei Chau and Pok Fu Lam Sewerage, Hong Kong

• Client: Drainage Service Department, Hong Kong SAR
• Lead consultant: Atkins China Ltd.
• Components: Ecological survey, environmental impact assessment

Ecological assessment of a proposed renewal of the existing sewerage systems and construction of pumping stations in southern part of Hong Kong Island. It is part of the schemes recommended under the “Aberdeen, Ap Lei Chau and Pokfulam Sewerage Master Plan”. Ecosystems conducted ecological surveys, assess various options and potential impacts and advise on mitigation measures.

Mangrove Monitoring, Hong Kong

• Client: The Government of Hong Kong SAR
• Lead consultant: Ecosystems Ltd.
• Components: Ecological survey, mangrove management

Ecological monitoring of a mangrove management project in Inner Deep Bay to assess impacts and success of mangrove removal to enhance flood drainage. Surveys covered estuarine biota with focus on mangrove re-sprouting and bird distribution and abundance. A key issue is potential impacts upon Inner Deep Bay and Ramsar Site ecological resources.

San Wai Sewage Treatment Works and Sewerage EIA, Hong Kong

• Client: Drainage Services Department, Hong Kong Government
• Components: Ecological Monitoring

Ecological Monitoring for a trial mangrove cutting site at the river outlets of Tin Shui Wai Western Drainage and Shan Pui River Channel. Monitoring items includes benthos, bird use and mangrove regeneration at the two channel sections under management.

Yuen Long and Kam Tin Sewerage and Sewage Disposal Stage 1, Hong Kong

• Client: Drainage Services Department, Hong Kong Government
• Lead consultant: Environmental Resources Management Hong Kong
• Components: Ecological survey

The consultants conducted a four-season ecological study for a proposed sewerage and sewage disposal system for the north-west New Territories to identify ecological resources of importance for use in EIA. Surveys conducted include habitat mapping, vegetation, avifauna, and aquatic communities.

Strategic Sewage Disposal Scheme EIA, Hong Kong

• Clients: Drainage Services Department, Hong Kong Government
• Lead consultant: Montgomery Watson
• Components: Environmental impact assessment, ecological monitoring

Project to identify and conduct EIA of the preferred option for treatment and disposal of sewage from the majority of Hong Kong’s 6 million inhabitants. Project included a centralised treatment plant in Victoria Harbour and a long sea outfall. Ecosystems Ltd. participated in the ecological assessment of impacts of the preferred treatment and disposal system.

Construction-phase ecological monitoring of Stages 1 and 2 of the Project began in 1995 and continues to date. The objective of monitoring is to assess impacts of project construction upon birds using the river and surrounding habitats, particularly during migration and overwintering periods.

Shenzhen River Regulation Project, Hong Kong/China

• Clients:
  • Environmental Protection Department, Hong Kong Government
  • Shenzhen Water Resources Bureau, PRC
• Lead consultant: Peking University Department of Environmental Geography
• Components: Environmental impact assessment, ecological monitoring

Environmental Impact Assessment (EIA) of a major engineering project to improve flood control in the Shenzhen River, on the Hong Kong/PRC border. The EIA spanned 15 months and was co-ordinated by the lead consultant, Peking University Department of Environmental Geography. Primary Hong Kong consultants were AXIS Environmental Consultants and CES (Asia) Ltd. Ecosystems Ltd. served as a sub-consultant conducting ecological surveys and co-ordinating communications between the Hong Kong sub-consultants and the lead consultant in China.

A primary concern of the EIA was potential adverse impacts to wetland conservation areas in Deep Bay at the mouth of the river–Mai Po Marshes in Hong Kong and Futian Nature Reserve in Shenzhen. Deep Bay wetlands are internationally recognised as important bird conservation areas for the East Asian region; Mai Po was declared a Ramsar site in late 1995.

Construction-phase ecological monitoring of Stages 1 and 2 of the Project began in 1995 and continues to date. The objective of monitoring is to assess impacts of project construction upon birds using the river and surrounding habitats, particularly during migration and overwintering periods.

Territorial Land Drainage & Flood Control Strategy Study – Phase III – Sedimentation Study, Hong Kong

• Client: Drainage Services Department, Hong Kong Government
• Lead consultant: AXIS Environmental Consultants Ltd.
• Components: Ecological survey, environmental impact assessment

Assessment of 13 river channels in Hong Kong under consideration for flood control measures and maintenance dredging. Study sites ranged from intensively urbanised areas with considerable industrial and domestic sewage outflows to rural watercourses in which the main impact on ecology was livestock waste inputs. Ecosystems Ltd. provided ecological input to the study.

Each channel was ranked in terms of value of existing ecological resources. Potential ecological impacts of dredging were assessed, and mitigation measures were developed to deal with unavoidable impacts. Four seasons of ecological monitoring were conducted on channels identified as containing ecological resources of conservation importance and at risk under a regimen of dredging. To support the decision making process, a conceptual ecological model was developed for each channel requiring dredging on flood-control grounds.

Main Drainage Channels for Ngau Tam Mei, Kam Tin and Yuen Long, Hong Kong

• Client: Territory Development Department, Hong Kong Government
• Lead consultant: ERM-Hong Kong, Ltd.
• Duration: 1994 – 1995 (EIA); 1997 – 2001 (ecological monitoring)
• Components: Ecological baseline survey, environmental impact assessment, ecological monitoring

Environmental Impact Assessment (EIA) of a drainage channel scheme to ease flooding pressures in the Deep Bay catchment in the North-West New Territories of Hong Kong. Ecosystems Ltd. provided ecological consulting services. The site lies near the Mai Po Marshes Nature Reserve, a waterfowl habitat of international significance and recently declared Ramsar site. The channel system drains to Deep Bay, a site of regional and international conservation importance for mangroves and other wetland habitats and for wetland-dependent migratory birds.

The assessment included comprehensive review of prior regional studies, flora and fauna surveys, prediction of impacts and development of mitigation measures. Evaluation of project design revealed that some wetland areas to be lost did not require inclusion in the project for engineering or flood-control reasons. These areas were of considerable value for mangrove stands and as feeding habitat for waterbirds. It proved possible by making minor changes to the project design to save these areas. This avoidance of loss was particularly important in that habitat of this type is decreasing in extent in the Deep Bay area. To offset unavoidable losses of wetland, alternative mitigation measures were proposed, including restoration of cutoff river meanders as wetland habitat useful to waterbirds, and replanting of mangroves in tidal portions of the new channels.

Ecosystems Ltd. is also conducting monitoring of colonial bird breeding sites, mangroves and intertidal fauna on and near the project site. The monitoring programme will cover the construction and initial operation phases of the project. Monitoring is designed to detect impacts of channel construction and operation upon numbers and species of breeding birds, and upon mangrove survival in the drainage, in order to allow early and effective response to such impacts. Monitoring will also compare bird use of newly constructed channels to bird use of channels cut off or abandoned by the new drainage scheme.

Main Drainage Channels and Poldered Village Protection Schemes for San Tin, Hong Kong

• Client: Territory Development Department, Hong Kong Government
• Lead consultant: ERM-Hong Kong, Ltd.
• Components: Ecological baseline survey, environmental impact assessment

Environmental Impact Assessment (EIA) of flood protection scheme for a low-lying village site in the northern New Territories near the Shenzhen River. The project includes a large drainage channel and pumping systems to protect village areas. The site is adjacent to recently declared wetland buffer and conservation areas and lies not far from the Mai Po Marshes Nature Reserve, a waterfowl habitat of international significance and part of Hong Kong’s first Ramsar wetland.

Ecosystems Ltd. provided ecological input to the study. Ecological concerns included the alteration of existing hydrology, elimination of streams and other wetlands, and consequent effects upon wildlife, particularly waterfowl and migratory birds for which the area is regionally important. The consultants predicted impacts of the project and developed mitigation measures including restoration of vegetation within channels to promote wildlife use, design of flood storage ponds to provide wetland habitat, and creation of a compensatory wetland area adjacent to the site.

Main Drainage Channels for Fanling, Sheung Shui and Hinterlands, Hong Kong

• Client: Territory Development Department, Hong Kong Government
• Lead consultant: CES (Asia) Ltd.
• Components: Ecological impact assessment, impact mitigation proposals

Environmental Impact Assessment (EIA) of a drainage channel system to provide flood control for a frequently inundated rural area in Central New Territories. Potential ecological impacts of concern included changes to the ecology of river systems due to dredging and channelisation, loss of streamside vegetation and habitats due to channel modification, and impacts on plant and animal communities dependent on river systems. The consultants developed impact mitigation measures including minimisation of alteration to existing channels where flood risks were low, sympathetic design of new channel profiles, and use of cut-off river meanders as wetland compensation sites.

Lamma Power Station Jetty and Navigation Channel Modification Works, Hong Kong

• Client: Hongkong Electric Co. Ltd.
• Lead consultant: AXIS Environmental Consultants Ltd.
• Components: Ecological baseline survey, environmental impact assessment

Environmental Impact Assessment (EIA) of impacts of maintenance dredging of a channel for passage of ships carrying fuel ash away from a coal-fired power station on Lamma Island in southern Hong Kong. The southern portion of the Island is a Site of Special Scientific Interest and the area to be dredged is close to a proposed Marine Park site. Species of special concern included intertidal biota, Green Turtles and Aleutian Terns.

Bird surveys were conducted along the coastline of the island to identify species sensitive to impacts of increased sedimentation and turbidity from dredging. Intertidal habitats were characterised and intertidal communities were quantitatively assessed through transect surveys. Potential impacts to birds and intertidal communities from the dredging were predicted.

Eastern Waters Marine Borrow, Hong Kong

• Client: Civil Engineering Department, Hong Kong Government
• Lead consultant: AXIS Environmental Consultants Ltd.
• Components: Ecological impact assessment

Study to establish the feasibility of dredging marine sand from the seabed at sites in eastern Hong Kong waters. Reviewed information available on the marine ecology of the area to assess ecological issues to be addressed. Coral communities were among the major ecological constraints considered in valuing the site.

Outlying Islands Sewerage, Stage 1, Phase I, Hong Kong

• Client: Hongkong Electric Co. Ltd.
• Lead consultant: CES (Asia) Ltd. / Maunsell Environmental Management Consultants Ltd.
• Components: Environmental impact assessment(Packages A-E); (Package J)

Packages A-E: Environmental Impact Assessment (EIA) of proposed sewerage systems and sea outfalls for several outlying island communities in Hong Kong. Ecological survey covered land-based sites and marine outfall zones. Key issues include potential impacts of sewage effluent discharge upon Indo-Pacific Hump-backed Dolphin Sousa chinensis , the local population of which is threatened by human activities including pollution and reclamation. Predicted impacts of the project and proposed impact mitigation measures.

Package J: EIA of sewerage system, treatment plant and submarine outfall at Sok Kwu Wan, Lamma Island, a small outlying island community. Surveys covered land-based and marine sites. Key issues include potential impacts of effluent upon local fisheries and cetacean populations.

Tolo Harbour Sewerage of Unsewered Areas Stage I, Phase II, Hong Kong

• Client: Drainage Services Department, Hong Kong Government
• Lead consultant: Mouchel Asia Ltd.
• Components: Environmental impact assessment

Environmental Impact Assessment (EIA) of project to provide sewerage systems to over 47 unsewered villages in the Tolo Harbour catchment. The project was of high priority due to the enclosed nature and poor tidal flushing capacity of Tolo Harbour which makes it particularly sensitive to the environmental burden of high levels of sewage discharge. Sites were assessed and ranked in terms of ecological sensitivity, potential impacts to local ecology were predicted and impact avoidance or mitigation measures were proposed. Key issues of ecological concern were potential negative impacts to stream channels and mature woodlands in areas where new sewerage systems were to be installed.