Intensity of Friday’s downpour in Penang a once-in-40-year occurrence, says state exco

Flood at Kimberley Street, George Town.

GEORGE TOWN: The high rainfall of 137mm, recorded during Friday’s storm, is a once-in-40-year occurrence, said State Local Government, Traffic Management and Flood Mitigation Committee chairman Chow Kon Yeow.

“The downpour last night was estimated to be a 40-year average recurrence interval (ARI) which means that it will occur once every 40 years or at a 2.5% chance of occurrence in any given year,” he told a press conference at the Town Hall here, Saturday.

Floods in Jalan Pasar, Pulau Tikus on Friday.

A rainfall between 30mm to 60mm is considered heavy and figures above 60mm are classified as very heavy.

“The capacity of the drains in Penang is between two-year and 10-year ARI and that was certainly not enough to withstand the heavy downpour.

Rescue team member ready bomba boat for flood at Jalan P. Ramlee, George Town.

“Our drainage system is not designed to cope with such rainfall intensity.

“It’s quite impossible to build a drain taking into account a high level of ARI in Penang. If we do, then the drains will be as wide as the roads here,” he said.