Lower water in reservoirs might prevent off-season rice harvesting, according to Thaweesak Thanadachopol, deputy director-general of the Royal Irrigation Department (RID).
The overall water storage level in reservoirs across the country remains low which means the RID will not have enough water to feed the farm sector during the dry season.
"During the upcoming dry season, the RID needs to focus on managing water for household consumption and ecological preservation. We need to ask farmers for their cooperation by switching to growing plants that use less water," said Mr Thaweesak.
Provincial officials in Ayutthaya province and Ang Thong province are working with farmers who will be asked to abandon their off-season rice harvesting and find less-water-intensive crops in their place.
Off-season rice harvesting usually starts in January. It has been conducted in irrigated areas, mostly the Central region, and relies on the state's irrigation system.
Meanwhile, the drought situation has grown more severe in Nakhon Ratchasima in the northeastern region.
The situation in Phimai, Chakarat and Huay Thalaeng provinces has reached a critical level, as the Lam Chamuak reservoir, their main source of water, is drying up, according to media reports.
The reports said the water level in the reservoir at Moo 6 village in tambon Nikhom of Phimai district is now at only 25% of capacity of 32 million cubic metres.
The reservoir usually supplies water to the three districts, both for agriculture and tap water production.
Sirisak Raksiri, 35, a native of Phimai, said water in the Lam Chamuak reservoir is unusually low this year due to the widespread drought and lack of rain.
As a result, he said, officials at the reservoir have stopped supplying water for farming. The remaining water will be used only for the production of tap water feeding 20 villages in five tambons in Phimai, Chakrarat and Huay Thalaeng districts, he added.