Chavalit Chookajorn, permanent secretary, said the El Nino weather phenomenon delayed and reduced rainfall in the country and that reserved water was low in reservoirs.
He said that usable water in the Sirikit and Bhumibol dam reservoirs reached only 10 per cent of their combined capacity.
The Meteorological Department expected the monsoon to increase water in reservoirs late this month and there should consequently be enough water for agriculture and household consumption.
Meanwhile, the Ministry of Agriculture and Cooperatives ordered more rainmaking operations to support plantations for the time being.
Under the current weather conditions, Thai farm products should fall in volume this year.
Chavalit said the amount of rice produced this year is expected to drop from the targeted 28 million tons to only 26 million tons.