“Freak” Rain Every 50 Years?

At lunch yesterday, a colleague of mine told me about the previous day’s rain that had caused flooding in the Bukit Timah area. The damage, he told me, was quite substantial, with some of the major casualties being the cars caught in a basement carpark (with water levels up to waist-height). He was surprised that I hadn’t known about it as it was all over the news (after which I told him I did now, and I still hadn’t watched the news).

So it was with interest that I noticed a column on this flood in the Straits Times. It quoted Singapore’s Minister for the Environment and Water Resources Yaacob Ibrahim as saying that “Thursday’s deluge which submerged parts of Bukit Timah was a “freak” event that comes once in 50 years”. The article also added that “[Yaacob Ibrahim] said his ministry knew that the canal was not up to the task of draining away all the rain that fell that day”.

Two questions immediately came to mind after I read that short column: (1) how did the ministry determine that this type of rain occurred once every 50 years? and (2) if they knew that it occurred every 50 years, and that the canal couldn’t deal with that amount of rain, if approximately 50 years had gone by why hadn’t they done anything before this?

I’m not faulting the ministry for not predicting this amount of rain — nobody could have predicted it. But if it’s unpredictable, do not say it occurs once every 50 years; say that the weather’s unpredictable, apologise for not taking action earlier (for PR’s sake) and then take steps to rectify the problem (as they have). Saying it occurs only once every 50 years will only make those most vulnerable complacent, and that’s definitely not a good thing.