The northeastern region is expected to see another round of flooding next month as two more weakened storms are forecast to swipe the country.
At least two typhoons are expected to develop in the Indian Ocean next month, according to Sucharit Koontanakulvong, head of the Water Resources Engineering Department at Chulalongkorn University.
However by the time they strike Thailand both will have weakened to depressions, causing heavy rain in the North and Northeast, he said yesterday.
More flooding is likely as a number of provinces are still inundated from Storm Sonca with resources to contain rising water levels already fully stretched, he added.
"I'm concerned the impact of these depressions will last longer than usual," Mr Sucharit said.
He was speaking at a seminar on flooding and preventative measures organised by the Thailand Research Fund.
"Residents in the Northeast should not lower their guard against possible flooding and keep monitoring the situation closely," he said.
Some media have speculated that as many as 10 storms could be heading Thailand's way in the next couple of months but Pramote Onnom, director of the Thai Meteorological Department's (TMD) Chai Nat office, dismissed such rumours as groundless.
Mr Sucharit said the last time the country saw this much rainfall was in 2011 when massive floods struck. He said both episodes recorded similar levels of precipitation but this year's floods displayed a "different pattern".
In 2011 the rains struck more areas housing dams, causing them to overflow, he said. But during this monsoon season dams nationwide were less affected, with Bhumibol Dam in Tak now at 50% capacity and Sirikit Dam in Uttaradit at 62%, he added.
One of the results of this is that the country is more likely to experience a drought when the rainy season ends, Mr Sucharit said.
"The challenge is how can we manage an effective early warning system to lessen the damage," he said, expressing concern about future economic losses.
In 2011, flood-related damage cost approximately 1.1 trillion baht, 70% from the industrial sector.
About 70% of the country's gross domestic product (GDP) is generated by the economic activity of just 10 of Thailand's 77 provinces including Bangkok and rain-ravaged Nakhon Pathom, he said.
As such, special measures must be put in place to flood-proof them including Nonthaburi, Pathum Thani, Ayutthaya, Samut Sakhon, Samut Prakan, Rayong, Chacheongsao and Chon Buri, he added.
Vichien Kerdsuk at the Research for Social Development Institute of Khon Kaen University, said climate change is making floods harder to predict and more severe.
In Sakhon Nakhon the amount of rainfall triggered by Sonca reached 796.6mm, devastating the province in hours. The level was roughly three times the 30-year average of 288.7mm.
The TMD issued a nationwide warning yesterday to brace for torrential rain until Sunday.
Bangkok governor Aswin Kwanmuang said the capital is ready to deal with the heaviest rainfall of the year forecast for next month.
Pol Gen Aswin said precipitation hits its peak in September with 340mm recorded on average.