in order to combat regular flash flooding in kuala lumpur (sometimes twice yearly) caused by two overflowing rivers in the north of the city, engineers decided to construct a huge stormwater tunnel to drain the water from it’s source to a reservoir, underground. they then thought, ‘why not kill two birds with one stone?’, went back to the drawing board and managed to alleviate another of the city’s problems: major traffic congestion.
in a circular nutshell, here’s the amazing solution…
the whole tunnel system is 9.7km long - only the 4km of tunnel that runs under the heavily congested roads of the city is split into the three sections you can see above.
this system has three modes of operation.
mode 1: no storms - the tunnel is used purely as an underground motorway on the top two levels.
mode 2: moderate storms - traffic is still permitted to use the top levels and any flood water is channeled through the lower level.
mode 3: major storms - all traffic is cleared from the tunnel and water surges through all 3 levels.
the pic below illustrates these modes… (click for bigger)
i’m guessing they have a foolproof system in place to ensure that the watertight gates can never be opened until every last vehicle has left the tunnel. the project cost a whopping £335million to design and build, another perfect reason to open a toll-road in the middle of it, and the motorway section was opened 14 may this year. the opening of the stormwater system followed in june. scarily, the tunnel began to leak shortly after opening to the public. watch the clip below of some mentalists who decided that the best thing to do after spotting a potentially life threatening situation is to get out of the car and press record…
you can watch the beginning of a discovery channel documentary on the smart tunnel below…
and finally, here’s a news report from the opening day…
links:
- the smart tunnel website
- tunnelling experts mott macdonald’s smart page
