The Moon River burst its banks Wednesday, flooding parts of Chalerm Phrakiat and Phimai districts of Nakhon Ratchasima province.
Rising floodwater forced more than 20 households in riverside Ban Nong Bua community in Chalerm Phrakiat district to evacuate along with their possessions.
They sought shelter at a village pavilion while their houses were submerged by 1.5 metres of rising floodwater.
Ban Nong Bua was worst hit by flooding on Wednesday after two major reservoirs in nearby Khon Buri district _ the Lam Moon Bon and Lamsae reservoirs _ overflowed, causing the Moon River to rise rapidly. The river burst its banks, sending an enormous volume of water into the riverside community, a source said.
Lam Phraphloeng reservoir in Pak Thong Chai district and Lam Plai Mat reservoir in Soeng Sang district also exceeded capacity, so that a total of four out of five major reservoirs in the northeastern province overflowed.
Only Lam Takhong in Sikhiu district still had the capacity to hold more water, as the reservoir level currently stands at 90.8% of its capacity of 314 million cubic metres.
In Phimai district, vendors at flood-hit Muang Mai Phimai market set up temporary stalls along both sides of the Phimai-Chakkarat road on Wednesday.
Stalls lined the route, which covers almost one kilometre, disrupting traffic in the area.
The market was hit by the overflowing Moon River, with floodwater rising to 40cm.
Officials on Wednesday opened all 11 sluice gates of the Phimai dam to quickly discharge water as dam levels rose sharply. About 29 million cubic metres of water passes through the dam's sluice gates every day.