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This story features in Unearthed: The cities of the future

While others may dig for gold, oil or diamonds, it’s been said that Singapore has become expert at mining something just as precious – space. It’s spent decades reclaiming land from the sea, but that’s becoming increasingly difficult and fraught with long terms problems in the face of rising sea levels.

Now Singapore has its eye on becoming the world’s most advanced centre of urbanized underground development. The government has enacted legislation that enables it to buy land beneath privately-owned blocks. Meanwhile the Singapore Urban Redevelopment Authority (URA) is compiling a 3D master plan that will attempt to map the hugely complicated landscape of pipes, tunnels and other entombed assets.

And with good reason. As Arup’s East Asia Director of Infrastructure Mark Wallace said earlier this year, if you are going to build underground, “you should do it properly. Tall buildings are dead easy to take down. The underground? Not so easy.”

Arup’s benchmarking study also emphasizes the point that underground development “is associated with higher uncertainties and risks due to the lack of information on what lies beneath the surface.” So far Singapore has already invested $188 million in underground technology R&D. With a population expected to hit nearly 7 million by 2030, it’s not hard to see why the pressure is on.

Between now and that 2030 deadline, the URA is either building, planning or considering:

  • An underground bus park that will sit below a car park and a garden
  • A series of pneumatic waste transfer pipes and extensive air condition ducts
  • A deep tunnel sewerage system that uses gravity to draw sewage across the island to two central reclamation plants
  • A vast subterranean water reservoir at the very lowest level that will free up 3,700 hectares of surface space.

The first pilot areas of its Master Plan will be released to the public in 2019.

What you’ll find below Singapore

Behind the scenes
Singapore’s determination to drive its infrastructure underground also has a deeper backstory, spurred on by its determination to be more self-sufficient.

1) Water. For example, Singapore still receives 50% of its water from Malaysia – a situation it is keen to change. So, as well as moving sewer lines beneath the surface, the Deep Tunnel Sewerage System should also be able to produce 80% of Singapore’s clean water via recycling (the rest will come from forest collected reservoirs).

2) Construction materials. Singapore imports all its construction sand from Cambodia – expensively. The soil and rock extracted during this project will help offset that.

3) Energy. Harvesting gas from solid and food waste will make the most of all the waste created by 5.5million Singaporeans.

Can’t go up
Any higher than 90 storeys and buildings will start to disturb the flight paths of planes coming into Singapore.

Can’t go in
Spare land within Singapore is now so expensive that going underground, despite its complications, is actually cheaper. Eg, $900m for completing the Jurong Caverns whereas the land alone would have been $1bn+ on the surface, without construction.

Can’t go out
Singapore can’t reclaim any more land from the sea without affecting its ports and compromising sea lanes and space.

Can go down
Singapore’s geology offers top layers of Marine Clay which is soft and difficult to work with, so anything built on top must have deep piles. But further down you’ll find Granite and solid rock that can be securely dug through.