A combination of problems, from a power outage to the lack of maintenance of public drainage pipes under private property, contributed to widespread flooding in Bangkok on Wednesday evening, City Hall said.
Many city residents complained about flash floods which triggered traffic snarls in several key areas of Bangkok, prompting the Bangkok Metropolitan Administration (BMA) to hold a press briefing to explain the problem.
Heavy downpours battered 11 areas in the city with Din Daeng, Phaya Thai and Huai Khwang districts recording the highest rainfall at 100 millimetres, 99mm and 83mm respectively, said Narong Ruengsri, director of the BMA's Department of Drainage and Sewerage. Clouds had moved in from the north of Bangkok producing rainfall that submerged many roads. It took more than two hours to drain floodwater in Pracha Suk Road in Din Daeng district and Kamphaeng Phet 2 Road, around the Mor Chit area, in Chatuchak district.
In other less flooded spots of the city, the situation was brought under control in under two hours, Mr Narong said. The floods occurred despite an underground tunnel having been built in Makkasan to divert floodwater from Din Daeng, Huai Khwang and Ratchathewi districts. The Bang Sue water tunnel is also there to help expedite the water drainage but the floods continued.
Water pumps were put to work in smaller sois and streets, Mr Narong said, noting the rain fell over short periods but in large amounts.
He added the city's drainage operation was hampered by a blackout which shut off pumps at four major sumps. Metropolitan Waterworks Authority technicians were called to restore power.
The Meteorological Department said it rained heavily in many parts of the country from Wednesday night to Thursday morning.