National water agency PUB plans to lay a new trunk water main under the southern half of the Rail Corridor to meet future water demand in the city area.
It announced the move yesterday and said it would preserve the lower half of the former railway line as an open green space for the foreseeable future.
About half of the 22km pipeline from Murnane Reservoir in Bukit Timah to Maxwell Road will be beneath the former Keretapi Tanah Melayu (KTM) railway line, which has been vacant since train service from Tanjong Pagar to Woodlands ceased three years ago.
The Murnane pipeline, a concrete-lined steel pipe 2.2m in diameter, will deliver potable water to the city area and complement an existing central pipeline that also does this.
The new pipeline will be 3m to 4m deep, or more where needed, depending on engineering studies.
It will sit above parts of the upcoming Deep Tunnel Sewerage System Phase 2 pipeline, which will link the downtown area with Tuas at depths of 20m to 50m.
The project is expected to cost roughly $300 million, depending on tender results. Construction will take place between 2016 and 2019, and some sections of the corridor will be closed temporarily. Before that, PUB will carry out soil investigation works, environmental impact studies and detailed engineering studies. The rail corridor will remain accessible to the public during all this.
The pipeline will also go under or around wildlife spots such as a bat roosting site and historic structures such as the former Bukit Timah Railway Station and a brick culvert along the Rail Corridor.
Typically, no permanent structures are permitted over such major water pipelines.
PUB spokesman George Madhavan said: "Once this pipe is laid, we don't envisage us coming in for the next 50 years or so." Water demand in the city is currently about 30 million gallons (136 million litres) a day - about 55 Olympic-size swimming pools - and this is expected to double by 2060, said PUB.
Nature and heritage interest groups have long pushed to save the Rail Corridor as a continuous green space for recreation. Last Saturday, they walked a stretch of it with Environment and Water Resources Minister Vivian Balakrishnan and PUB representatives.
Green corridor supporter Eugene Tay, an environmental consultant, said that while pipeline construction will pose a temporary inconvenience, "I hope this short-term disruption would eventually lead to the long-term conservation of the corridor over the next 50 to 100 years and beyond for future generations to enjoy".
Yesterday, Dr Balakrishnan posted on Facebook: "I agreed to this plan because it not only enhances water resilience, but it is also one way of guaranteeing uninterrupted public access along this corridor for hopefully a century and beyond."
This article was first published on July 01, 2014.
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