Bangkok floods ease but six eastern districts remain on alert for overnight rain
Flooding in Bangkok has eased after two rain-free days, but 97 communities in six eastern districts remain affected as the city prepares for more rain overnight.
Flooding across Bangkok has eased significantly after two consecutive days without major rain, although water remains in 97 communities across six eastern districts, Bangkok Governor Chadchart Sittipunt said on Saturday (October 10).
The remaining affected districts are Min Buri, Nong Chok, Prawet, Saphan Sung, Lat Krabang and Bueng Kum, with many of the flooded communities located along canals where drainage remains constrained by large volumes of water surrounding the capital.
The Bangkok Metropolitan Administration (BMA) is preparing additional pumps ahead of another spell of rain forecast from Saturday afternoon into early Sunday.
Bangkok surrounded by water on three sides
Chadchart said Bangkok was currently facing water pressure from three directions: Pathum Thani and Nakhon Nayok to the north, Chachoengsao to the east and Samut Prakan to the south.
The situation means drainage from Bangkok depends not only on the city’s own infrastructure but also on coordination with neighbouring provinces and national water-management agencies.
Prime Minister Anutin Charnvirakul has instructed the Royal Irrigation Department to coordinate efforts to move water eastwards through Chachoengsao and southwards through Samut Prakan, alongside the BMA’s drainage operations.
More rain expected from 4pm to 4am
The Bangkok Command Centre is preparing for further rainfall expected between 4pm on October 10 and 4am on October 11.
The forecast indicates accumulated rainfall of around 40-50 millimetres.
Although that would be less severe than the rainfall recorded the previous week, Chadchart said the BMA would continue deploying pumps and closely monitoring drainage conditions in communities where water remains.
High canal levels slow eastern drainage
One of the main problems is that water levels remain high in north-south canals, particularly Khlong Lam Pla Thio, where levels are falling only slowly.
Water from Pathum Thani has continued to spill over flood barriers and enter Bangkok’s drainage system, while large volumes of water in Chachoengsao are making it more difficult to pump water eastwards.
The BMA has therefore deployed water-propelling boats in Prawet Burirom Canal and is coordinating with the Royal Irrigation Department to divert water towards Phra Ong Chao Chaiyanuchit Canal before draining it onwards to the Gulf of Thailand.
Samut Prakan’s relatively flat terrain is another constraint because water moves slowly through the area, Chadchart said. Coastal pumping facilities are also operating at only around 50% of capacity, increasing the urgency of pushing water out to sea and preventing it from flowing back towards Bangkok.
Chao Phraya remains within Bangkok’s capacity
On upstream water flows, Chadchart said discharge in the Chao Phraya River was around 2,300 cubic metres per second.
Bangkok could safely handle flows of up to about 3,000 cubic metres per second, he said, because the city’s flood barriers remained sufficiently high.
Most major reservoirs still had around 30% of their capacity available, although Pasak Jolasid Dam was relatively full.
Authorities therefore need to closely monitor any decision to divert water through Rangsit-area waterways, including canals feeding towards eastern Bangkok, as such releases could place additional pressure on already saturated communities.
Floods prompt review of development in low-lying areas
Chadchart said the latest flooding had exposed weaknesses in some low-lying parts of the city.
The prime minister had raised the issue of whether future housing-estate approvals should take greater account of local water levels and flood risk, particularly where development could make emergency access and rescue operations more difficult.
The BMA plans to incorporate lessons from the flooding into its databases and acquire additional drainage equipment, including high-capacity rapid-drainage systems, to strengthen longer-term preparedness.
Chadchart said major flood events could not be tackled by one agency alone and thanked government departments and other organisations for working together during the emergency.
Bangkok’s drainage monitoring system on Saturday showed most monitored roads returning to normal, although some locations in the eastern part of the city continued to report minor flooding.
