The Government has backed plans for a rail tunnel under Long Valley, costing $2 billion more and taking up to two years longer than the defeated plan to build a spur line across the ecologically sensitive wetlands.
The proposal, which has been endorsed by the Executive Council but needs further environmental impact assessment, was drawn up after an appeal board in July ruled out the previous scheme for a viaduct over Long Valley, home to 210 bird species.
Under the new plan, the 7.3km spur line will go underground 4.3km from the existing Sheung Shui station and then rise to the surface at Chau Tau, where it will climb on a 3km viaduct to connect to the Lok Ma Chau terminal.
The whole of Long Valley would be spared, in line with the mandate of the appeal board, Kowloon-Canton Railway Corp (KCRC) director of East Rail extensions Lee Kang-kuen said yesterday.
In San Tin, where the spur line would rise on the viaduct, nine hectares of fish ponds would be removed but up to 28 hectares of fish ponds would be upgraded nearby in compensation, Mr Lee said.
He also pointed to stringent measures to avoid underground water leaking from drilling of the tunnel, leading to settlement.
But the construction would be complicated in the Sheung Shui section, where existing rail line would have to be moved sideways to create space for the spur line tunnelling work. The whole project is estimated to cost $10 billion and will be finished by late 2006 or early 2007, compared to a cost of $8 billion and a completion date of 2005 under the previous viaduct proposal.