RUNNING the planned Cross Island MRT Line along Lornie Road instead of through Singapore's largest nature reserve would add just 2km and four minutes to travel time.
That would help reduce the damage to the reserve's ecosystem, the Nature Society (Singapore) suggested in a 40-page paper giving its take on the new line.
The position paper, released yesterday, also described the environmental damage that may be caused by the soil investigations and tunnelling needed for the 50km MRT project, which is expected to be ready in 2030.
The line, first announced in January as part of the Government's Land Use Plan, runs from Jurong to Tampines. It appears to pass through densely built-up areas like Sin Ming, Hougang and Clementi.
But is also seems to cut through primary and secondary forest in the Central Catchment Nature Reserve near MacRitchie Reservoir.
The forest, home to birds such as the critically endangered white-rumped shama and uncommon animals including the pangolin and clouded monitor lizard, will be affected by the land clearing needed for soil investigation works, the paper said.
The soil works, which involves boring 70m-deep holes every 15m to 20m to determine soil strength, would also muddy and choke delicate freshwater streams containing rare native fish like the malayan pygmy rasbora, the NSS added.
While water agency PUB has rules to control erosion during construction, "mitigation does not equate to no impact", said NSS spokesman Tony O'Dempsey.
And tunnelling through granite also carries the risk of rock collapse and soil subsidence, the paper added, pointing out that the MacRitchie forest is part of a gazetted nature reserve under the Parks and Trees Act.
The National Parks Board said in its statement yesterday it "would be concerned about the impact that any development may have on the Central Catchment Nature Reserve, which is gazetted for the conservation of our flora and fauna".
NSS suggested the use of alternative routes, such as building the line along Lornie Road.
It may be expensive to acquire the land, the paper suggested, but the price of lost and damaged ecosystems should also be factored into project costs.
A Land Transport Authority spokesman said it had received NSS' paper and will study it in detail, adding that the path the line will take has not been decided.
She said: "No decision will be made until after an environmental impact assessment has been conducted. We remain committed to ensuring that any decision taken will seek to safeguard our nature reserves even as we seek to meet the infrastructure development needs of Singaporeans."
Last Friday, Minister of State for Transport Josephine Teo visited the forest with several nature groups and wrote about her trip on Facebook.
"A new MRT line will impact many different stakeholders, all of whom have views we need to consider," she wrote.
"They include commuters concerned about distance and home owners whose families may have to relocate... It goes without saying that whatever we do, we will take into account the impact on our nature reserves."