Rivers in several northeastern provinces face the risk of overflowing as water levels have risen by up to a metre a day, flooding plantations and raising the spectre of communicable diseases spreading, officials said on Friday.
Somchai Vitdumrong, the governor of Nakhon Phanom province, has ordered residents living along the Mekong River to brace for possible flooding as water levels in the province rose by 50 centimetres to one metre on several days last week.
"The water level is now around 10 metres, just three metres short of critical level," he said.
He said 1,000 rai of rice plantations have already been affected. Heavy rainfall last week resulted in not enough runoff being released to control the situation, causing many areas to become inundated.
"We've instructed local authorities to communicate with residents and farmers to move their belongings to higher ground, take care of their pets and be careful of communicable diseases that the water can spread," Mr Somchai said.
Districts in the province that are vulnerable to flooding include Na Kae, That Phanom, Muang, Tha Uthen, Si Songkhram and Ban Phaeng, he said.
Ormsin Chivapruck, a minister attached to the Prime Minister's Office, examined the water levels on Friday in Ubon Ratchathani, where the Chi and Mun rivers converge before flowing into the Mekong.
He said he had told provincial governors to monitor the situation as levels have risen 64cm in the past seven days.
"I have told the governor and related agencies to be vigilant and warn people of the risk of floods if rainfall continues," he said.
In Kalasin, 18 districts saw heavy rainfall last week, causing the Chi River to rise 29cm.
Officials said runoff from Khon Kaen and Maha Sarakham has pushed water levels in the province to a critical stage, particularly in the districts of Kamalasai, Rong Kham and Khong Chai. Swift currents and brown water were reported.
Local authorities must remain vigilant and monitor the situation around the clock, said Wichan Tanhin, an officer in Kalasin who is in charge of natural disaster prevention.
The situation is expected to worsen as more rainfall is forecast for the coming days.