An overflowing Stamford Canal was the cause behind the flooding at Liat Towers two Fridays ago, said the Public Utilities Board (PUB).
Because the canal was full due to a three-hour heavy downpour, excess rainwater from the roof and back area of Liat Towers overflowed into the basement area and could not be drained off into the canal by the building's internal pumps. This led to ponding in the front of the building.
"When the canal in front of Liat Towers reached 100 per cent, the pumps were not able to discharge water accumulating in the basement into the Stamford Canal," said the PUB.
PUB said that the total recorded rainfall at Orchard Road on 23 December was 152.8mm after heavy rain hit the area over three hours.
This amount is about half the average monthly rainfall for December.
As a result of the heavy rain the Friday before Christmas, water ponded at the open area of Liat Towers while the underpass between Lucky Plaza and Ngee Ann City and the basement of Lucky Plaza were also affected.
Liat Towers’ building supervisor Chik Hai Lam told Yahoo! Singapore that “5 inches of water covered the walkway” in front of the mall and that the water came from the drain underneath Liat Towers.
This was the third time in two years that shops at Liat Towers -- Wendy's, Starbucks, Hermes and Massimo Dutti -- were badly affected by flash floods.
Other affected areas include Cuscaden Road, Newton Circus, Kampong Java, Lincoln Road, Wee Nam Road, Cambridge Road, the junction of Moulmein Road and Thomson Road in front of United Square, and the junction of Bukit Timah junction and Sixth Avenue.
Flood waters generally subsided in an hour, although Cambridge Road, Newton Circus and the junction of Moulmein Road and Thomson Road in front of United Square only saw waters subsiding at 6pm.
PUB advises the public to exercise caution as flash floods may occur in the event of heavy storms. The public can also call the PUB 24-hour Call Centre at 1800-284 6600 or go to PUB’s Facebook www.facebook.com/PUBSg or PUB iphone apps iPUBOne to report flash floods or to check on the flood situation.
SMS alert services on heavy rain warning and water level information are also open to public subscription at: www.pub.gov.sg/