Irrigation dept defends closure of sluice gates

Even though the Bangkok Metropolitan Administration (BMA) has the capacity to dispose of 10 million cubic metres per day, it is currently operating at less than that because of the closure of two sluice gates under the RID’s control at Nong Chok and Prawet Burirom canals.

The two canals are Bangkok’s eastern floodways to detour runoff from the north into the sea via the Bang Pakong River in Chachoengsao.

The RID’s Hydrology and Water Management Office said the level of the Bang Pakong River was currently higher than the two canals. If the gates were lifted, water would rush into the capital, exacerbating the inundation, so the department was pumping the water from the Bangkok side across the two gates and into the Bang Pakong River.

In northern Bangkok, the department has mobilised 12 pumps to send water from the Bang Kanak and Nakhon Nuang Khet canals to the Bang Pakong River.

Pramote Maiklad, a former directorgeneral of the RID, said the BMA might be confused about how water flows and urged the Bangkok administration to work closely with the department, which knows which gates should be opened or closed. 

Chachoengsao’s elevation is higher than Bangkok and the ocean’s tide has risen higher than the canals linking to the sea, so the gates from the east to the west were shut.

“For Bangkok’s innercity canals, we use pumps to drain water out while the gates for canals linking to the sea will be closed. Water should be drained through the Saen Saeb, Prawet Burirom and Samrong canals before it is pumped out into the sea,” he said.

The Democrat Party’s shadow government urged the government to drain the runoff through eastern Bangkok more effectively within five to seven days. The claim that the Bang Pakong was higher so opening the gates would cause water to pour into Bangkok was doubtful, party leader Abhisit Vejjajiva said, citing the example that Canal 2’s level dropped after its sliding gate was opened. 

The imbalance in water evacuation could lead to the paralysis of the central administration, which would become a nationwide problem, the Democrats warned. They also questioned whether the government’s decision until recently not to open the eastern gates was because it wanted to protect a specific area. 

Seri Supparathit, director of the Sirindhorn International Environmental Park’s Energy for Environment Centre, said eastern Bangkok was equipped with many pumps to remove flood water quickly.

The government should send agencies to check each location and see whether the plan was actually implemented and if there was any obstruction.

Bangkok would be under only 2030 centimetres of flood water if the plan went well. There was still time to open all gates and use pumps to expel the water into the sea, Seri said.