Thinking outside the box

"For Singapore, one of the major ways to prevent flooding is to try and reduce the 'speed' of the rainfall," said Tan Ying Hao, senior manager at the Catchment &Waterways Department of the Public Utilities Board, under the Singaporean Government. "This means extending the time it takes for a raindrop to fall from the sky to the ground. The key words here are 'interception' and 'infiltration'."

Singapore is famous for its varied plant life, but especially rain trees, South American imports with giant canopies that retain water. "The trees have certainly done their part in catching rain in the middle of downpours, but that's far from enough," Tan said.

"For the past few years, the government has been championing the construction of rooftop gardens and water tanks, both on rooftops and below ground.