SINGAPORE: The Land Transport Authority has announced that it will put out a tender on Wednesday (Jun 8) to appoint a specialist for site investigation works for the direct alignment option of the Cross Island Line (CRL).
Works will commence in the fourth quarter of this year, and this will be on top of the site investigation works for the skirting alignment option, which started last month.
"Both alignment options are being studied and site investigations are essential to help LTA assess their engineering feasibility," said LTA.
The findings of the site investigation works will provide LTA with information on the underground soil conditions, as well as provide input for phase two of the Environmental Impact Assessment (EIA), which will assess the impact of construction and operations for the two options.
The alignment of the CRL has created some controversy, with the direct alignment option cutting through the Central Catchment Nature Reserve. Environmentalists and nature groups have been calling for the protection of the forest area and are concerned about the possibility of the Cross Island Line being built through it.
The direct alignment will run for 2km below the Central Catchment Nature Reserve at a depth of approximately 40m with no physical structures on the surface, while the skirting alignment will run for 9km under homes and businesses, with the need for supporting ventilation facilities on the surface.
A decision will be made on the alignment after the site investigations and phase two of the EIA.
The LTA said that the tender follows discussions with nature groups, residents and other stakeholders, and also takes into account the petition by the Love Our Macritchie Forest movement.
"The National Parks Board (NParks) gave approval for the SI works within the Central Catchment Nature Reserve (CCNR) to proceed after these extensive public consultations and discussions on the mitigating measures with LTA and the nature groups," it added.
ADDITIONAL MEASURES TO REDUCE ENVIRONMENTAL IMPACT
The authority said that it is introducing additional mitigating measures to reduce the environmental impact of the site investigation works on the Central Catchment Nature Reserve.
This includes scheduling geophysical surveys with one to two rest days in between, engaging a certified arborist to ensure that trees are not damaged during the works, involving nature groups as observers and having NParks officers issue stop-work orders should there be any breach or deviation of agreed mitigating measures or when pollution is detected.
The 50-kilometre Cross Island Line was announced in January 2013 and is slated for completion in 2030.
ENVIRONMENTAL CONCERNS ADDRESSED BY MITIGATING MEASURES: NPARKS
In a statement on Wednesday, NParks said that after a "stringent process of review and study" with LTA, it was satisfied that the nature community's concerns had been addressed with additional mitigating measures listed in the EIA.
Among these, NParks said site investigations will take place in existing trails or clearings, avoiding the most ecologically sensitive parts of the CCNR; the magnitude of residual impact will be mostly restricted to small areas; more elaborate safeguards have been put in place to limit the impact of site investigation work; and compliance of the conditions will be closely monitored by a team of NParks ecologists, supported by trained representatives from the nature community.
Full compliance of all the mitigation measures will ensure that any potential residual impact of site investigation work remains limited and short-term," the authority said.
However, it noted that any site investigation work, even with stringent mitigation measures, can add on to the cumulative impact of the many other ongoing activities within the nature reserves, such as jogging and hiking and NParks' own regular maintenance works, leading to the deterioration of the nature reserves over time.
"All such activities can be highly intrusive and potentially damaging to the nature reserves if they are not properly regulated," it said.
Besides stringent regulation of activities, additional efforts to improve ecological connectivity, implement species recovery programmes, and restore and rehabilitate degraded habitat within the reserves are necessary to protect Singapore's national heritage, NParks said.
The agency is exerting a "concerted effort" to strengthen the ecological resilience of the nature reserves, such as by establishing nature parks such as the newly opened Chestnut Nature Park and the upcoming Windsor and Thomson Nature Parks, which relieve the demands of recreational activities within the nature reserves, it added.