Pairote Kopol, Disaster Prevention and Mitigation official in Nakhon Phanom, said all districts and local administrations were instructed to be prepared for flooding and overflowing riverbanks.
Rains hit Nakhon Phanom beginning Monday and water pumps were installed in the municipality area to immediately drain waters into the Mekong River - currently at seven meters high.
He said the Mekong River could receive much more water as it was six meters below its critical level.
Somporn Damnui, director of the Udon Thani irrigation project, said waters in the major reservoir in the provincial seat and nearby areas were drained out at the rate of 300,000 cubic meters per day to the reservoir at Ban Chan several days ago, while waters from Nong Samrong reservoir were also discharged at 300,000 cubic meters per day.
Two other major reservoirs, Huay Luang and Kud Ling Ngor, could receive much more water, he said.
After the major floods in Udon Thani in 2000-2001, the Irrigation Department had constructed a sluice gate near a dyke to help speed up water release into the Mekong River.