Friday, October 24, 2008

Hill-cutting blamed for flash floods

Population is the root cause. Hill-cutting is to support the increasing population. Very interesting idea in the news below by former PBA engineer Kam U-Tee.
BTW, who shall we blame? Man for hill-cutting or God for population explosion?What is your comment?
Friday October 24, 2008

GEORGE TOWN: Hill-cutting and development of valleys on the island are the main cause of the recent flash floods in Ayer Itam and its surrounding areas.

Water resources expert Datuk Kam U-Tee said the floods were caused by conversion of the Paya Terubong and Bayan Baru valleys into “concrete aprons that do not retain water.”

“The water immediately flows into the streams causing flash floods even with moderate rainfall.

“Because of hill-cutting activities, the flowing water causes erosion of the slopes which carries mud and silt into the river beds,” said Kam, who was Penang Water Authority general manager for 17 years until he retired in 1990.

Dredging the river is not a permanent solution, he said, adding that the floods could not have been caused by water released from the nearby Air Itam Dam.

“In some countries, developers are required to include retention ponds and underground water tanks to allow release of water more evenly.

“Developers encroaching onto river flood plains, which are natural flood retention features, cause a faster flow but with reduced cross sections,” he said.

Last week, Sungai Air Itam overflowed its banks causing floods in surrounding areas including Air Putih, Hye Keat Estate and Taman Lumba Kuda.

It was described as among the worst floods in 20 years.

Kam said many did not realise that the dam comprised of less than one quarter of the total Sungai Air Itam catchment area.

Penang plans to introduce several flood-mitigation methods including retention ponds, bunds and higher dam walls.

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