At least six subway stations are on the floodway, authorities said.
Residents have threatened to open the defenses to drain water from their flooded neighborhoods, the Bangkok Metropolitan Administration said.
"The main problem of solving flood is no longer technical but people," Prime Minister Yingluck Shinawatra said during the weekly radio address.
The flooding has killed 442 people, the Interior Ministry said. Of Thailand's 64 provinces, 25 have been affected.
Bangkok's central business district is still dry but other parts of the bustling metropolis of 12 million people are inundated. Read More