The Royal Irrigation Department (RID) is concerned about the possibility of a water shortage as the off-season planting of rice has begun across the country.
The department noted that around 46% of farmland which relies on state irrigation channels for water has been planted since November, with the rice almost ready to be harvested.
RID director-general Prapit Chanma said a survey on Dec 26 found that rice has been planted on 3.01 million of the 6.41 million rai of irrigated, agricultural plots nationwide.
The majority of the off-season rice was planted around the Chao Phraya River basin, where 2.08 million rai of irrigated farmland has been planted with rice, followed by the East with 420,000 rai, and the North with 410,000 rai.
Authorities are concerned because while almost half of all irrigated farmland has been planted with off-season rice, Thailand's four major dams are only about 42% full, Mr Prapit said.
As of yesterday, the Bhumibol, Sirikit, Pasak Jolasid and Kwae Noi Bamrung Daen dams held about 7.785 billion m³ of water.
The RID has been working to improve its water management to ensure there is enough water to last until the end of the dry season. Since November, the department said, authorities have saved about 5.7 billion cubic metres of water, of which 1.425 billion m³ have been used.
The department said 40% of the water saved will be used for agricultural purposes, while 35% will be used to maintain the ecosystem, 20% for household consumption and 2% for industries.