Estuary Processes and Managment - River Dynamics and Integrated River Management - page 541

Painted Snipe which breeds in the summer in Long Valley. Both the active and inactive agriculture
creates an attractive habitat for birds. This is in spite of disturbance by human activity both in farming
and during extensive channelization work on both the River Beas and the River Sutlej. None of this has
had any measurable adverse effect upon the ecology, which seems to be resilient. It is estimated that its
ecological value depends upon the continuation of wetland agriculture; therefore, if this were abandoned
for economical or any other reason the present eco-system may disappear.
In the original proposal, KCRC designed 700 meters of viaduct through the central part of the Long
Valley Wetland to reduce adverse impacts on the wetland during operation (KCRC, 2000); some mitigation
measures during construction are also provided, including the provision of a temporary freshwater
wetland of 1.8 hectares as a roosting habitat (Fig. 8.85(a)). However, opponents pointed out that the
viaduct construction would badly damage the landscape and biodiversity of the Long Valley Wetland; the
environmentalists also questioned the effectiveness of the mitigation measures in making up for the possible
ecological damage, based on the low success rates of man-made ecological environments abroad.
In July 2000, the Environmental Protection Department (EPD) rejected the environmental impact
assessment (EIA) report of KCRC, and refused to issue an environmental permit for the construction
work. It was the first time that the EPD rejected a EIA report since the Environmental Impact Assessment
Ordinance came into effect in 1997. The reasons of rejection include: ķ the lengthy fragmentation
effect of the linear construction site; ĸ the mitigation proposed for fragmentation, silty run-off,
hydrological disruption, concrete washing and other pollutants is unlikely to be practical or effective
during construction, because of the poor drainage system in Long Valley, heavy rainfall, and flooding;
Ĺ the 1.8 hectares of proposed temporary wetland is unlikely to be effective to compensate for habitat
loss during construction.
The project sponsor lodged an appeal, on the grounds that the proposed rail link, which cuts through
the Long Valley wetland, is the most appropriate one in balancing the needs of the environment,
transportation and communities. After 27 days of hearing, the Environmental Impact Assessment Appeal
Board maintained the original decision against allowing the KCRC to build the Long Valley Spur Line.
Although the Appeal Board considered the viaduct to be a practicable solution, they considered that the
KCRC had not sufficiently demonstrated that the mitigation would be successful and it required further
studies to enable confidence to be given to this proposal.
Following the judgment, the KCRC developed an alternative scheme to construct a tunnel beneath
Long Valley without disturbing the sensitive habitat (Musgrave and Plumbridge, 2007). Although this entailed
an additional cost of around HK$ 2 billion, the tunnel scheme won the support of the environmentalists
and the public. Fig. 8.84(b) presents a plan view and a cross-sectional view of the rejected viaduct proposal
and the alternative tunnel scheme. The EIA report for the alternative scheme was approved by the EPD with
conditions on 11 March 2002, and the project was commissioned in August 2007. The Sheung Shui—Lok
Ma Chau Spurline case study serves as a good example of sustainable development, and a reminder that
economic benefits must be carefully balanced against environmental costs.
Review Questions
1. What are the key factors for delta development?
2. What are the causes of flooding of estuarine and coastal areas?
3. How to calculate flushing time for a semi-enclosed bay?
4. What causes algal bloom and how to mitigate algal bloom?
5. What are the methods of waste disposal?
6. State the coastal wetland evolution, degradation and restoration strategies?