The Nam Un dam in Sakon Nakhon is now holding 102% of its safe maximum capacity, necessitating continued discharge of water downstream with the dam is expected to take more inflow later this week.
Officials said about 4 million cubic metres of water flowed into the dam on Saturday following heavy rain, while the dam is discharging about 5 million cu/m of water per day.
It is necessary for the dam to release as much water as possible -- through all channels including the spillway and irrigation canals -- to take more inflow as several storms are expected to come before the end of the rainy season, they said.
Nam Un is among the country's four major dams now under close watch as they are holding water beyond 80% of their capacities. The other three are Srinagarindra and Vajiralongkorn dams in Kanchanaburi, and the Kaeng Krachan dam in Phetchaburi province.
For the Kaeng Krachan dam, flood draining is now under control and and flood impacts in Phetchaburi province had been controlled and curtailed after massive flood draining efforts early this week, as Prime Minister Prayut Chan-o-cha visited the province to inspect the area.
Srinagarindra and Vajiralongkorn dams are continuing to discharge 66 million cu/m daily combined after reaching 87% and 85% of their storage capacity respectively, according to the Royal Irrigation Department (RID).
Vaivij Sangpanitch, director of Vajiralongkorn dam, said the 43 million cu/m water has been drained daily, insisting the reservoir would have space to cope with rains expected to come the end of this month.
Prasert Inthab, director of Srinagarindra dam, said the draining of over 23 million cu/m daily provided capacity for taking more water by the end of this month.
He said dam officials gave prior notice to the village downstream about water draining and provided assistance for villages that might experience rising water.
Meanwhile, the Thai Meteorological Department (TMD) said about 60% of Sakon Nakhon province faces the threat of floods from tomorrow until Friday.
People have been warned of heavy rain, flash floods, overflows from streams and landslides.
Residents in the North and Northeast are also warned to expect flash floods and mudslides in the next few days, triggered by tropical depression Yagi hitting Vietnam Monday.
The depression, with a wind speed of 50 kilometres per hour, will move from the South China Sea to upper Vietnam Monday and Tuesday and will cause heavy rain across the northern and northeastern regions of Thailand, according to the TMD.
The weather bureau also said a southwest monsoon in the Andaman Sea and Gulf of Thailand could cause large waves of between two and four metres in some coastal areas.
Fishermen and boat owners are advised to exercise extreme caution while small boats should stay ashore.
Meanwhile, flash floods from a local mountain range have submerged agricultural areas in Phato and Lang Suan districts after Chumphon was battered by five consecutive days of heavy rain.
Locals have been forced to move their belongings to higher ground and evacuate their animals. The extent of damage to farmland is not yet known.
In Kanchanaburi, six families in Sangkhla Buri district urged state agencies on Sunday to speed up efforts to provide them assistance after their houses were damaged by a landslide caused by heavy rainfall last month.
All of them have been living in temporary accommodation since July 20.
The villagers earlier sought help from Tambon Wang Ka municipality which at the time sent authorities to examine their houses' condition. However, the municipality has yet to take any further action.
In an update on the general situation, Chayaphol Thitisak, chief of the Department of Disaster Prevention, said the flood situation caused by the tropical storm Son-Tinh has receded.
- Earlier: Nam Un dam full, discharging water
- Weather forecast: Storms, heavy rains in Northeast