The Land Transport Authority (LTA) said earlier today, according to an environmental impact assessment report, that its efforts to tunnel under the Central Catchment Nature Reserve could destroy the natural habitat for critically endangered wildlife.

The upcoming Cross Island MRT line would need 3ha of forests next to the reserve to be cleared.

However, the LTA explained that there are mitigating methods that could be put in place in order to reduce the impact on wildlife. These include re-planting trees in affected areas, and ‘wildlife-friendly’ security fences.

Some of the species of critically endangered wildlife include the Sunda pangolin and Raffles’ banded langur. The LTA added that construction works – though outside an estimated boundary – increase the likelihood of these animals being disturbed or injured by traffic during construction.

Despite the “major” impact that the construction and operation of the Cross Island Line could have on the ecology and biodiversity of the reserve, these could be reduced to “moderate” or even “negligible” depending on the worksite, provided that mitigation measures to reduce impact are carried out.

The LTA report also adds that diverting discharge outlets away from rare freshwater streams could also help to reduce pollution of the aquatic habitats.

In terms of reducing the impact of the tunnel operations, the report said that other than wildlife-friendly fences, roosts and nests identified during inspections could be removed with the aid of the National Parks Board.

The decision on whether to build through or around the reserve has not been finalised, with an environmental impact assessment of the line for both alignments done.

The report also pointed out, however, that there would be “major” residual impact for residents due to “visual” elements, such as activities at above-ground worksites and the presence of workers.

The LTA had earlier said that the alternative alignment could add about $2 billion to the rail project. This 9km-long skirting alignment will require longer tunnels and extra ventilation facilities, it said, compared with the 4km direct route, of which 2km will cut through Singapore’s largest nature reserve.

No figure was available for the total cost of adopting mitigation measures should the direct alignment be chosen. -/TISG