In land-strapped Singapore, underground space has been named a strategic resource by the high-level Economic Strategies Committee.
A masterplan is in the works to map out possible uses and the Ministry of National Development said details will be released this year.
Underneath the bustling Chinatown lies a vast labyrinth of interconnected tunnels snaking across Singapore.
The Downtown railway line, which is being built entirely underground, is part of a decades-long push to go down under in search of space.
The result is a subterranean world teeming with activity.
At the basement level, there’s a complex network of utility pipes, electrical grids and pedestrian linkways.
The Common Services Tunnel, which is located five to 10 metres deep, is a system of tunnels designed to house utility services in the Marina Bay area. Built in 2006, the facility allows for the maintenance and repair of utility, sewage and electrical pipes through specially-constructed access points, without having to disrupt traffic above ground.
And 15 to 20 metres deep are the MRT lines and the Marina Coastal Expressway.
Just below that, at the 20 metre to 60 metre level, the Deep Tunnel Sewerage System delivers waste water to an underground treatment plant in Changi.
Over at Jurong Island, the Jurong Rock Cavern is being built at about 150 metres below the island.
And somewhere in the deeper, darker depths, is the Ministry of Defence’s ammunition facility located under Mandai quarry.
But not all of Singapore has rock that is solid enough for cavern developments.
Most of it is in the west and central parts of the island lying about 100 metres deep.
In the west, there is sedimentary rock while hard granite is found in the central Bukit Timah region.
Thus, the first step is to create a geology office to know where the good rock is located in Singapore.
The Singapore Geology Office, which is located within the Building and Construction Authority, was set up in April 2010. Its aim is to create a database of information on Singapore’s geology, to facilitate future underground developments.
Most information on Singapore’s geology derives from a national survey done in 1976 although the information was updated in 2009. Government agencies and developers looking to build underground either referred to these sources, or commissioned their own studies.
Building and Construction Authority’s Geological Office assistant director, Kiefer Chiam, said: “The existing information is quite shallow because it’s mainly targeted at infrastructure works like MRT, services or building basements. There isn’t much information at deeper levels like 100 metres or more.
“In order to support the underground masterplan, we need to know where the good rocks are.”
In the immediate term, the focus is on adding more basement-level services like shopping malls and linkways.
But as underground construction incurs huge costs, a masterplan is needed to coordinate future uses and integrate them with structures above ground.
Adele Tan, Deputy Director of Planning Policies at Urban Redevelopment Authority (URA), said: “Those are things we have to sort out amongst the agencies. We work closely with each other on it. And where there are conflicts, we have to talk it through and see what are the most optimal alignment and the most cost-effective alignment.
“As we build more things underground, there will be more competing uses and more conflicts of space. Some of these uses that come later may find that they have to go even deeper to avoid some of the uses that are already there in the shallower surfaces.”
The challenge of building undergound is not just a technical one. There is also the issue of land rights to consider. In cities like Helsinki for example, private ownership of subterranean land is limited to a certain depth. But in Singapore, the law gives private owners rights to the land stretching all the way down.
It is not a problem currently because the Rapid Transit Systems Act gives rail authorities the right to go through private land. But this may have to be reassessed along with other regulations such as safety codes and utility plans.
Ms Tan said URA is studying other cities for models it can adapt.
URA is also studying how other cities pay for underground developments. In Japan for instance, the government shares the cost with private developers. Unlike places like Hong Kong, Norway and Japan, Singapore’s good rock is buried deep underground, and are much more expensive to access.
Ms Tan said: “As we have a better understanding of our space underground, we can then develop this underground space plan progressively. We can identify suitable uses to put underground and put them in the right places as well, so that we can save land.”
Singapore’s subterranean expansion is still in its early stages.
Urban planners are laying the ground for future development, a process that will take years.
And if they succeed, it will open up many more possibilities on how Singaporeans use the space above to live, work and play.
Source : Channel NewsAsia – 1 Jan 2012