Pongsakorn urges Bangkok Metropolitan Administration to be honest: the drainage system is operating at only 50%, possibly due to malfunctions, raising fears it cannot handle new water inflows without repairs.
On 1 Oct 2026 GMT+7 at the Democrat Party headquarters, Pongsakorn Khwanmuang, party spokesperson, expressed observations and questions to Bangkok Metropolitan Administration (BMA) and the Drainage Department regarding prolonged flooding lasting 2–3 days in areas such as Khlong Chan and Romklao housing estate. Although flooding has begun to subside in some locations, he noted that while heavy rain naturally causes flooding, it is concerning that drainage systems in key areas—like Khlong Saen Saep, Lat Phrao, Khlong Tan, Phra Khanong, and Prawet Burirom canals—have not efficiently drained water despite existing infrastructure. Investigations found abnormalities at two critical points:
1. The Khlong Saen Saep drainage tunnel has a maximum capacity of 60 cubic meters per second, but during the event, actual drainage dropped to as low as 29 cubic meters per second, averaging just 60% of full capacity.
2. The Phra Khanong pumping station has a drainage capacity of 173 cubic meters per second but operated between 87 and 100 cubic meters per second, averaging only 50% of its potential.
Pongsakorn continued that these figures indicate drainage equipment is not being used to full capacity. If fully operational, water would be drained more quickly. This raises questions whether many pumps—four in the Khlong Saen Saep tunnel and 20–30 at Phra Khanong station—are damaged or malfunctioning. He dismissed claims that water from main canals did not reach drainage points by citing Rama 9 Pond, which feeds the Khlong Saen Saep tunnel. At that time, the pond overflowed to road level, yet the system only used about 38 cubic meters per second, roughly 50% capacity. He urged honesty about why pumps and machinery are underperforming and called for urgent repairs. The problem remains unresolved; without fixing these issues, massive incoming water will soon flood Bangkok again.