Residents in seven lower Central Plains provinces have been warned to brace for overflow from the Chao Phraya River as more water has been discharged from the Chao Phraya dam in Chai Nat.
Suchart Chareonsri, director of Regional Irrigation Office 12, said he has sent letters warning of possible floods to the governors of Chai Nat, Uthai Thani, Sing Buri, Lop Buri, Ang Thong, Suphan Buri and Ayutthaya.
The volume discharged from the Chao Phraya dam will rise from 790 cubic metres (cu/m) per second as the office had to release water to the sea to prevent inundation upstream where there has been heavy rain and flash floods.
As a result, the Chao Phraya River water level will rise to 60-80 centimetres in the seven provinces, particularly in Chai Nat's Sapphaya district and Sing Buri, Ang Thong and Ayutthaya, Mr Suchart said.
According to the office, water volume flowing into the dam is at 976 cu/m per second, up by 528 cu/m per second, compared to last week, while the water level upstream stood is 16.75 metres above sea level, rising by 25cm.
"The dam has to continue discharging about 800-850 cu/m per second of water volume for a while. This will affect the lower plains downstream," he said.
Mr Suchart also warned residents to move their belongings to higher ground and keep themselves updated on water situation announcements.
In Ayutthaya's Sena district, irrigation authorities were sent to rescue villagers from more than 80 riverside households which were inundated by overflow from the Noi River as a result of the increased water volume discharged by the dam.
The flood water stood at 50cm while some areas were submerged under almost one metre of water, said Saksiri Yoosuk, director of Regional Irrigation Office 10.
However, only riverside communities were flooded by the overflow while farmland has not been affected, he said.
In the Northeast, rice paddy fields and a road have been damaged by overflow from local watercourses in Sakon Nakhon's Khok Si Suphan district.
District chief Ekkaphab Sophon said the flooding was caused by an increase in the water level in Nong Han, the largest local freshwater lake in the Northeast.