“It’s definitely flooding and it reflects that the Bangkok Metropolitan Administration [BMA] has failed to draw up efficient flood-prevention systems,” Assoc Prof Suwatthana Chittaladakorn said yesterday in his capacity as a member of the Engineering Institute of Thailand’s water-resources engineering subcommittee.

The EIT held a press conference to discuss the capital’s flooding problem and to present flood-prevention ideas in the wake of Bangkok’s recent inundation.

Many parts of the capital were under water last week, when rainfall was recorded at slightly over 60 millimetres per hour. “With that rainfall, all rainwater should have gone away within 10 to 15 minutes. If you can’t do that, you must admit that it’s flooding,” Suwatthana said.

The committee’s secretary, Asst Prof Sitang Pilailar, said the BMA had spent billions of baht on flood prevention every year since 2014 but to date had failed to deliver any impressive results.

“Clearly, the BMA lacks an holistic approach to flood problems. This is worrying,” Sitang said. “If the BMA does not change, Bangkok will continue to face flood risks.”

Suwatthana called last week’s floods a test the BMA failed. “Why was the Ratchadaphisek area flooded? Why didn’t water drain through the Lat Phrao Canal?” he said.

The expert said the BMA should know which parts of the capital were low-lying and flood prone but it still lacked efficient plans to prevent flooding.

“More [tropical] depressions will be coming along with more rain. Many storms may also come. But the BMA doesn’t seem to have any real plan, not even for the short term,” Suwatthana said.

The committee’s chairman, Prof Bancha Kwanyuen, identified the lack of an integrated water-drainage system, clogged drains, and flawed city planning as major causes of Bangkok’s floods. “In addition, the drainage system doesn’t reflect the actual rainfall intensity,” he added.

Surasak Klungsupavipat, a committee member, said the BMA needed to update its intensity rainfall figure, constantly dredge drains, punish those who throw garbage or dump stuff into public waterways, prevent encroachment onto channels, and promote integration among agencies responsible for flood prevention.

“Also, the BMA should improve drains and develop proper water-drainage tunnels,” he said.

Bangkok has one giant water-drainage tunnel with the capacity to drain 60 cubic metres of water per second but its real performance drops in the face of about 10 tonnes of garbage daily.

The construction of another tunnel is slated for completion this year, and the BMA plans to spend Bt5.9 billion constructing another water-drainage tunnel.

In a related development, the National Disaster Warning Centre had warned that flash floods and landslides may hit Chiang Mai, Tak, Chanthaburi, Ranong, and Phang Nga provinces yesterday. The same warning applies for today.

Meanwhile, a Myanmar man was found dead yesterday after run-off water from a nearby forest swept over a small village in Chiang Mai‘s Mae Wang district. “He might have fallen asleep when the flash flood came,” Mae Wang district chief Sutin Chan-ngarm said.