The 7.4km, $7 billion rail link cutting through the heart of Long Valley is the only viable option among seven possible routes, the KCRC claims.
Six other routes avoided the valley, a wetland habitat for 210 bird species, but the rail company said they were either too expensive, failed to meet safety standards or were too time-consuming.
These routes would add $1.3 billion to $3.3 billion to the project's budget because of extra private land resumption, and new provisions for roads and other public facilities. Some of them also present immense technical difficulties, such as requiring a rail bridge spanning 250 metres or involving a sharp turn to avoid the valley. These would compromise safety and extend construction time by four to five years, the company alleges.
Despite the KCRC studies, Robert Law, Director of Environmental Protection, refused to issue an environmental permit, partly on the grounds that the developer had failed to fully consider the alternatives. Mr Law also said the proposed mitigation measures would fail to compensate for damage to the area.
The spur line is to run from Sheung Shui to Lok Ma Chau, where a new border-crossing checkpoint will be built to ease border congestion at Lowu.
The KCRC has warned that if the project fails to start on time, the line may not be completed by 2004 as scheduled when daily passenger flow at the Lowu border crossing is predicted to reach 300,000 a day, a 50 per cent increase on 1997.