Littering not the sole culprit for flooding

I REFER to last Tuesday's report ("Past flood assumptions might not hold water"). While I agree that people should refrain from littering, I do not think littering alone can clog our large drainage and canal systems.

The report did not address the crux of the flood problem - drainage clogging. I believe our drainage and canal system can cope with most heavy rains, and flooding is caused only by chokes.

The PUB has done an excellent job of keeping the island practically flood-free for many low-lying areas. It was very unfortunate that it was caught off guard by the Orchard Road flood.

Fast-flowing rainwater usually flushes drains and carries away floating material along its path. In torrential rainfall, a greater volume of water rushes through the drains and canals, creating a more powerful flush at a higher speed to carry away small floating litter to the sea.

When large items like logs, leaves and branches get caught at certain spots in the drains, clogging takes place and this chokes water flow. The PUB has taken effective measures to screen large floating debris to facilitate the free flow of rainwater. More such screening and constant clearing should be implemented at flood-prone drainage systems around the island.

Since we live in a tropical city, we may face the prospect of flash floods occasionally. It does not help to re-examine data and update models and parameters. Only physical measures, like increasing the gradient or deepening drains and canals, as well as vigilant clearing of debris, will minimise the chances of flooding.

Paul Chan

the Bear

6 Jul 10, 13:36

i wonder.. suddenly he becomes an expert in floods?

Clivebenss

6 Jul 10, 16:57

The sea level rising?

Arapahoe

6 Jul 10, 17:35

Singapore beaver

Clivebenss

6 Jul 10, 17:36

Originally posted by Arapahoe:

Singapore beaver

longkang beaver?