Some 60km of new potable water pipelines, including one in Punggol, will be built underground over the next two years to meet demands from new developments, national water agency PUB said yesterday.
Ninety per cent of these projects will require the use of pipe-jacking for some sections of the pipelines, said the agency. The method involves tunnelling beneath existing infrastructure, such as MRT tunnels, power cables, and drains.
Environment and Water Resources Minister Masagos Zulkifli said yesterday: "We have to do this because our urban setting is more dense now. There is a lot of underground infrastructure that we have to bypass.The best way to do it is to go below (such structures), deep under them."
Mr Masagos was speaking during a visit to a pipe-jacking worksite in Tanglin Halt for the $365 million Murnane Pipeline - which is expected to be ready in 2019.
Pipe-jacking is about 21/2 times more expensive and slower than the open-cut method - where the ground is dug, pipes are laid and then covered back up. But it is also less disruptive to the daily lives of Singaporeans above areas where the tunnels are being built.
The 22km pipeline, which was first announced in 2014, with work starting in the second quarter last year, links the city to the Murnane Service Reservoir. It is named after Mr David Murnane, a pre-independence municipal water engineer. The pipeline is intended to meet future water demand, which is expected to double to about 115 million litres a day by 2060.
Mr Michael Toh, director of Water Supply Network at PUB, said: "Water pipes are laid to ensure that we are able to meet the growing needs of our customers."
Singapore's water network is planned and laid such that it is interconnected and able to provide alternative supplies if maintenance or repair is needed, he said.
Another pipeline in Punggol is also in the works to meet increased water demands there. It will serve future residential, commercial and industrial developments in the east, including Changi Airport and Tampines North New Town, said a PUB spokesman.
Over the past six years, the Punggol estate has doubled - from about 65,000 residents in 2011 to more than 130,000 last year - according to government data.
Aside from the Murnane and Punggol projects, new pipelines are slated for Tampines, Tuas and Tengah New Town.
PUB also announced that it will be renewing 75km of older pipelines over the next two years, as part of its routine maintenance and improvements. It has 5,500km of potable water pipelines under its charge.
On whether pipe-jacking has an impact on water prices, the Environment and Water Resources Ministry said in a statement: "Rising costs of asset maintenance and replacement, as well as of resources like chemicals, materials and manpower, have exerted upward pressures on the cost of water.
"A price increase is necessary now to ensure that PUB can continue to deliver a high quality and reliable water supply."