Changing weather patterns causing more flash floods

Civil defence staff taking measures to pump out flood water. Every project, including road projects, should be required to incorporate a storage tank for rainwater. TODAY file photo
The flash floods last Friday led to the unprecedented closure of a stretch of the Ayer Rajah Expressway. TODAY file photo
Work to tackle problem under way, but will take a few years to bear fruit: PUB
Published: 4:03 AM, September 13, 2013
Updated: 12:40 AM, September 14, 2013
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SINGAPORE — Changing weather patterns and rapid development have resulted in more flash floods here over the last few years, and though work is under way to tackle the situation, it could take a decade or more before results become apparent, national water agency PUB has said.

Responding to questions from TODAY, the National Environment Agency (NEA) said the amount of rain falling on the island has crept up in recent times — and so have the instances of flash floods, which had initially been described as the result of freak weather.

In 2010, there were 15 days when flash floods occurred. In 2011 and last year, the number was 23 days for each of the two years. So far this year, there have been 14 days.

The NEA said the trend towards heavier rainfall began in the ’80s. “Rapid development and urbanisation, as well as global warming, are likely to be significant factors which may explain this trend,” it added.

The PUB said it has been noting this trend and has put in place a series of drainage projects to control the flash flooding. However, the scale of these projects is such that they will require several years to be built, and results will only be seen down the road.

The most recent incident last Friday led to the unprecedented closure of a stretch of a major highway, the Ayer Rajah Expressway.

In a briefing for this newspaper, PUB Chief Executive Chew Men Leong reiterated that the drainage improvement work is “going to take years”. “It’s not going to happen tomorrow — that’s the difficulty we face here,” he said, citing land constraints.

“We do not have sufficient land to cater to the most extreme storms ... so we cannot eliminate flash floods completely. It is simply not possible but we mitigate. We are confident of increasing resilience and reducing the occurrence of flash floods.”

Since the ’70s and ’80s, when there was widespread flooding, the Government has spent S$2 billion on the drainage infrastructure,

Last year, an expert panel on drainage design and flood prevention measures unveiled a raft of recommendations. Since then, another S$750 million has been set aside to increase drainage capacity.

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