The Highway Department reported that at least two parts of the Map Ta Phud-Rayong Highway were under water up to 80 centimetres high.
The Rayong By-pass Highway was under some 80-centimetre-high water, the department added.
And the Ban Chang-Map Ta Phud Highway was also under 80-cm-high water.
Several communities on the banks of rivers and canals were hit by floods, including the Krung Thai housing estate in Tambon Thabma in Mueang district.