Low-lying areas near three major dams in Nakhon Ratchasima were hit by flash floods on Tuesday after water levels in the reservoirs exceeded maximum capacity.
Lam Phra Phloeng dam on Tuesday recorded 165 million cubic metres of water, four times more than the amount recorded last year during the same period.
The Lam Takhong and Lam Phlaimat reservoirs were at 105% and 102% of their capacity.
Roads, villages and an industrial estate in the heart of Pak Thong Chai were inundated, affecting more than 5,000 households in 14 communities. The flood water was at least one metre deep in some places.
Residents along both banks of the Moon River were also warned to brace themselves for flooding. Rescue teams were sent in to help flood-hit residents, local officials said on Tuesday.
The Lam Phra Phloeng-Krathok intersection on Highway 2421 was flooded by around 10 centimetres of water while a section of the highway from Lam Phra Phloeng reservoir to Lam Phra Phloeng intersection was under 15cm of water. Small cars were warned against using the road, the officials said.
Route 304 from Nakhon Ratchasima to Kabin Buri district of Prachin Buri was made impassable due to flooding 50-60 cm deep. Ban Mueangpak Samakkhi School was also temporarily closed due to the flooding.
Nakhon Ratchasima Governor Wichian Chantharanothai issued a flood alert, warning residents in Si Khiu, Sung Noen, Kham Thale So, Muang and Chalerm Phrakiat districts, in the Lam Takhong river basin to be prepared evacuate.
The Phimai National Museum, meanwhile reinforced its flood barriers with 2,000 sandbags in an attempt to protect its antiquities.
In Sa Kaeo, water from Watthana Nakhon district quickly flooded Aranyaprathet municipality and 12 border villages. Aranyaprathet market suffered its worst floods in eight years.
In Kanchanaburi, the Talat Kao Kabin community was submerged in waist-high floodwaters.
Heavy rain in Phanom Thuan district affected more than 100 homes and rice fields, while strong currents also damaged bridges and check dams. Local people described the damage as the worst in 10 years.
More rain is expected later this week as Tropical Storm Saudel approaches.