Cross Island Line to take direct route under Central Catchment Nature Reserve

Cross Island Line to take direct route under Central Catchment Nature Reserve

The Cross Island Line (CRL) will take a direct route under the Central Catchment Nature Reserve (CCNR), the Ministry of Transport (MOT) announced on Wednesday (Dec 4). Deborah Wong reports.

SINGAPORE: The Cross Island Line (CRL) will take a direct route under the Central Catchment Nature Reserve (CCNR), the Ministry of Transport (MOT) announced on Wednesday (Dec 4).

This comes after years of debate and consultation over the routes Singapore’s longest MRT line would take.

Nature groups and environmentalists had previously raised concerns that the direct route - which will include a 2km tunnel under the CCNR - could have an impact on Singapore's wildlife and nature. 

The other route considered was a 9km stretch skirting the reserve and going under homes and businesses.

READ: Six years in the making - how the Cross Island Line's direct route was decided

Cross Island Line proposed alignments - map
Proposed alignment options for Singapore's Cross Island Line.

"After in-depth studies of the two underground alignment options for the stretch of the Cross Island Line in the vicinity of the Central Catchment Nature Reserve and extensive public consultations with various stakeholders, the Government has studied the trade-offs and selected on the direct alignment option which runs 70m under the CCNR," said MOT.


In explaining its decision, the ministry said the direct route offers shorter travelling time by about six minutes per commuter per trip, compared to the skirting alignment. 

For example, a commuter travelling from Ang Mo Kio to Clementi would need about 32 minutes with the direct route, instead of about 38 minutes with the skirting route.

The direct route will also lower public transport fares by about 15 per cent on average due to a shorter and more direct route, MOT said. It also presents a reduction in construction costs by about S$2 billion for taxpayers.

"In the longer term, it is a more environmentally-friendly option as the direct alignment has a lower energy consumption," MOT said.

READ: Cross Island Line environmental impact on nature reserve can be 'adequately managed': LTA study

READ: Wildlife seen in Cross Island Line site investigations

Since the CRL was first announced in 2013, the Land Transport Authority (LTA) has conducted Environmental Impact Assessment (EIA) studies on the two CRL routes and invited the members of the public to give their feedback.

It has also held engagement sessions with stakeholders, including nature and heritage groups, grassroots leaders and affected residents.

"LTA has been and is fully committed to implementing all practicable environmental mitigation measures recommended by the EIA," said MOT.

Cross Island Line direct alignment cross-section

Based on the sessions, LTA said the 2km tunnel under the CCNR will be about 70m deep, as opposed to the typical 20m to 30m, with no surface work sites in the nature reserve to ensure that flora and fauna will not be affected.

"Normally, MRT tunnels are about 30m deep under. With CRL, we decided to go much deeper, so that any impact on the flora and fauna in the nature reserve can be almost completely eliminated," said Minister for Transport Khaw Boon Wan in a Facebook post after MOT's announcement. 

"We also consulted international experts to make sure that our plan will work. 70m is equivalent to a 25-storey HDB block. This decision will increase the estimated project development cost by at least S$20 million."

Changi East Depot
The Changi East Depot, an above ground facility for CRL trains. (Image: LTA)  

LTA previously said it will be optimising the location and layout of the two surface work sites required for the direct route to minimise land use and reduce any potential disturbance to nearby plants and animals.

"LTA deeply appreciates the contributions and feedback from all stakeholders over the past six years. This includes nature groups, heritage groups, residents and grassroots leaders, whose participation has deeply enriched the planning process, and enlarged the common space for civic-minded debate," MOT said.

The CRL, Singapore’s eighth MRT line, will stretch from Jurong to Changi and is expected to save commuters up to 30 minutes to 45 minutes of travel time. The journey from Pasir Ris to Jurong is expected to take about 55 minutes.

The line is expected to have a daily ridership of more than 600,000 in the initial years, growing to more than 1 million in the longer term.

It will also connect existing radial MRT lines, with almost half of its stations being interchange stations, and is part of a plan to almost double Singapore's rail network by 2030 and help put eight out of 10 households within a 10-minute walk of a train station.

Ang Mo Kio Station
Artist impression of the CRL Ang Mo Kio MRT Station. (Image: LTA) 

"CRL is a critical transport infrastructure. It will vastly improve the quality of life for those commuters who need to cross the Island regularly," said Mr Khaw.

"It will interchange with almost all the other MRT lines and hence raise the network resilience. 

"The CRL will also support the development of new hubs such as the Jurong Lake District and the new BTO estates in Sengkang, Punggol and Hougang. CRL will meet the needs of a million commuters."

The first phase of the CRL, consisting of 12 stations, is expected to open by 2029.


Nature groups said they were mostly satisfied with the EIA studies and urged the Government to be cautious of any residual impact on the environment.

They said that even an “incremental impact can snowball over a period of time” to degrade the ecosystem of an area.

“While reaffirming our reservations concerning the methodology employed in assessing impact significance, we note that even the consultants have acknowledged that residual impacts of works underneath CCNR is still of ‘moderate’ significance, ie far from negligible,” the statement read.

“We would still urge the Government to take a precautionary approach and not to add more strains on the wildlife populations in a habitat that has already been stressed by so many perturbations.”

Defu Station
Artist impression of Defu MRT Station. (Image: LTA)  

Nature Society (Singapore) president Shawn Lum said that the impact of tunnelling and other works could be kept to a "moderate level" if mitigation measures were properly implemented.

He added the direct alignment of the CRL posed concerns to wildlife found in and around the proposed worksite on Island Club Road, noting that having the rail line skirt around the nature reserve would also have posed other nature and wildlife concerns. 

"Paramount among these is the critically endangered Raffles Banded Langur and its forest habitat," said Dr Lum. 

"We hope, together with the LTA and other agencies, that we can continue to refine detailed plans and mitigation measures and monitoring to ensure that this singular species will not be adversely impacted."

The LTA is commissioning an additional study by primatologist Dr Andie Ang to identify potential crossing locations for the langur around the work site area. 

Joseph Koh, who chairs the National Parks Board's nature reserves scientific advisory committee, said while he would have preferred to have the line go around the CCNR, the decision to run it under the CCNR was "not completely unexpected". 

workers at cross island line site
Site investigation works for the future Cross Island Line being carried out at the Central Catchment Nature Reserve. (Photo: TODAY)

Many of the concerns nature groups had have been addressed over the last six years, but there was still the possibility of unanticipated impact to flora and fauna, said Mr Koh, who is also the chairman of WWF Singapore. 

The protection of Singapore's biodiversity must be incorporated in future planning work, rather than be subjected to mitigation efforts, said Dr Lum. 

"Nature and the environment are not 'nice to have' for Singapore, but are vital for both tangible and intangible reasons," he said, noting the country is a signatory to the UN Convention on biodiversity. 


Senior Minister of State for Transport Lam Pin Min said authorities worked very closely with nature groups prior to making a decision on the route.

"I hope that this will not be the end of the journey working together, in fact it is only the beginning," he said.

Aviation Park Station MRT
Artist impression of Aviation Park MRT station. (Image: LTA) 

He hoped authorities would continue to be able to draw on the expertise of nature groups during the advanced engineering studies for the CRL - scheduled to begin by the second half of 2020 - to "co-create" further mitigating measures. 

Mr Khaw thanked the nature groups for their "advice, suggestions and understanding".

“We will continue to work with them as we move the project into the next phase of Advanced Engineering Study, design and construction," the minister said.

Residents in areas surrounding the CCNR were relieved that the construction of the CRL would not impact their homes. 

Bishan-Toa Payoh GRC MP Chong Kee Hiong noted that many residents of the area had previously expressed concerns that their property might be acquired, or that construction of the line might impact the structure of their houses. 

Lakeview Estate condominium resident Kelvin Tan said residents had experienced noise and inconvenience over the past five years as a result of construction of the Thomson-East Coast Line. 

Pasir Ris East MRT station
Artist impression of Pasir Ris East MRT Station. (Image: LTA) 

"While it's been a very long process, I think we're very grateful that (deciding on the CRL alignment) was a very well thought-out process where views from both sides - from the environmentalists as well as the residents - have been taken into consideration," said the 44-year-old civil servant. 

Daniel Yeo, who has lived in Yew Lian Park for 19 years, said many residents in the area were retirees. 

"My father-in-law has lived there for more than 50 years, from the very beginning," said the 46-year-old cardiologist. 

"The last thing you want to do is uproot them and have them move somewhere else."

Source: CNA/ec(mi)