Dong Luang district chief Somsak Boonchan said the runoff from the Phuphan Noi mountain range was caused by several days of heavy rain.
The runoff developed into a large creek running down from the mountains that overflowed and flooded Khao Wong-Dong Luang Luang road in Ban Na Lak village of Tambon Phang Daeng.
The water level at the flooded section was so high that vehicles could not pass through.
The district chief said the authorities provided boats to provide a shuttle service for local residents, adding that officials were now stationed at the spot to facilitate the travel of the villagers around the clock.
The district chief said some 10,000 rai of farmland in the village were flooded and the water had now inundated nearby villages.
He said the Provincial Administration Department dispatched boats to provide immediate relief to local villagers, many of whom would be relocated from their flooded houses to a temporary shelter downtown.