The Land Transport Authority (LTA) has completed Site Investigations (SI) for two alignment options that are being studied for the underground Cross Island Line (CRL) in the vicinity of the Central Catchment Nature Reserve (CCNR). These investigations took place between May 2016 and September 2017, and are the first steps in assessing the feasibility of the two CRL alignment options, directly underneath or skirting round the CCNR.
2. Monitoring results from cameras and transect surveys from the SI works for the direct alignment suggested that fauna are present in the area (see Annex A), following the completion of SI works within the CCNR. These findings follow from about a year of observations in the CCNR post-SI works. A flora management procedure, developed with inputs from the National Parks Board (NParks) and nature groups, was also adhered to throughout the period to minimise the ecological impact.
3. “Our camera traps picked up presence of animals like the Sunda Pangolin and Lesser Mousedeer after the completion of SI works. The findings were encouraging and validated the mitigation measures developed,” said Dr Goh Kok Hun, LTA’s Director of Civil Design & Land.
4. In conducting the SI for the skirting alignment option, all boreholes were located outside the CCNR. Apart from drilling new boreholes along the alignment, LTA had also made use of existing boreholes from other projects along the skirting alignment as far as possible.
5. Planning and construction of a new MRT line is a multi-year endeavour and includes feasibility studies for the different possible alignments, soil investigations to assess soil conditions along the potential alignments, as well as an Environment Impact Assessment (EIA). Given that the CCNR and its vicinity are ecologically sensitive areas, a robust two-phase EIA process has been adopted for studying the two alignment options of the CRL:
a. Phase 1 evaluates the existing ecosystem and the physical conditions of the CCNR, and the environmental impact of SI (e.g. the drilling of boreholes). The Phase 1 EIA report was gazetted on 5 February 2016. In response to the potential environmental risks identified, LTA, with inputs from NParks and nature groups, developed and implemented a comprehensive suite of mitigation measures (see Annex B) as part of the Environmental Management and Monitoring Plan, which guided the SI works process. The impact of SI was closely monitored from its completion in September 2017 until end-2017.
b. Phase 2, which incorporates findings from the earlier SI, assesses the potential environmental impact of the future construction (e.g. tunnelling) and daily operation of the CRL in the longer term. Phase 2 is ongoing and is expected to be completed later this year.
6. LTA has been in close consultation with nature groups on the studies, and will continue to engage them on the CRL.
7. The Government is committed to taking into consideration all relevant factors, before making a considered decision on the final CRL alignment. These factors will include transport connectivity, technical feasibility, environmental impact, financial viability, land use compatibility impact on surrounding developments, and stakeholder feedback. We will finalise the CRL alignment in the vicinity of CCNR after results from the Phase 2 EIA have been studied and discussed with stakeholders.
Annex A: Photographs of fauna captured using camera traps
Annex B: Mitigating measures to protect the CCNR during the SI works
Annex C: About the Cross Island Line