The six pumps were redeployed to Bangkok by the Natural Resources and Environment Ministry after a request from Bangkok Governor Chadchart Sittipunt on Monday.
Five of the 30-inch-diameter pumps were being installed on Tuesday afternoon, four at the Phra Khanong pumping station and one in the Srinakharin-Bang Na area, Natural Resources and Environment Minister Varawut Silpa-archa said.
The five pumps will begin draining water on Wednesday.
The sixth pump was being transported to Bangkok, he added.
Varawut said the six pumps were loaned from regional offices and could drain floodwaters quickly when all operating together.
Last week, Chadchart was attacked by critics including losing governor candidate Suchatvee Suwansawat, who accused him of doing too little to prepare Bangkok’s flood defences ahead of heavy rain.
The capital has been hit by heavy downpours since Wednesday, leaving many parts of the city flooded, especially areas along canals.
Suchatvee said Bangkok Metropolitan Administration (BMA)’s failure to reduce the water level in Klong Prawet ahead of downpours had caused floods in his home district of Lat Krabang. The BMA should have sped up water pumping at the Phra Khanong station, he added.
Chadchart’s supporters cited his Facebook broadcasts from flooded areas as evidence the governor was working hard. On Monday evening, the governor appeared on Facebook Live leading a team of drainage chiefs to Phra Khanong pumping station.
The chiefs said the BMA Sewerage and Drainage Department was at full capacity but Bangkok had been hit by a series of downpours dumping over 100mm of rain.
Chadchart said during the broadcast that water pumps at Phra Khanong were too old to handle the situation but he was addressing the problem.
On Tuesday, Varawut said his ministry was coordinating with the BMA on several fronts to tackle the flooding.
The minister said he had set up a committee of officials from several ministry departments to coordinate with the BMA in tackling floods, pollution and garbage issues.
Varawut said he and Chadchart would discuss options for dealing with floodwater from upstream provinces. However, he dismissed any possibility that Bangkok could suffer flooding on the scale of the 2011 disaster. The 2011 disaster was caused by massive floodwaters from upstream provinces while the current floods came from heavy downpours, he explained.