Winai Buapradit said the remaining water would flow to low-lying districts of Phimai and Chum Phuang as authorities were speeding up water drainage into the Moon River.
It should take a week before the situation in the province is back to normal, he said.
Kittikul Sepasiraporn, director of the Lamtakong drainage project, said waters from the Lamtakong reservoir flowed through the provincial town at a speed of 120 cubic metres/second and drained into Lam Boriboon, another major reservoir in the province, at 80 cubic metres/second.
The remaining flood water would continue to cover Nakhon Ratchasima for a few more days but Phimai would be the hardest-hit district, he said
More than 1,000 households in 24 communities in Nakhon Ratchasima municipality, including Assumption School on Mittraphap Road, have been flooded.