Hydro-Informatics Institute (HII), a state body under the Ministry of Higher Education, Science, Research and Innovation which analyses water-related data, is warning of a water shortage as it expects this year's rainy season to be shorter than usual.
"There will be less rain than last year, which will affect water reserves across the country," the director of HII, Sutat Veesakul, said yesterday.
Mr Sutat said the current rainy season -- which arrived later than in previous years -- is forecast to end in September, which means there might not be enough precipitation to replenish reservoirs across the country.
The effect of the shorter monsoon can already be seen, with 25 major dams and reservoirs across Thailand having less than 30% of their total water storage capacity.
Bhumibol, Sirikit, Pasak Jolasid and Kwae Noi Bamrung Daen dams -- four major dams in the Central Plains which supply water for rice production in the region -- only have about 700 million cubic metres (m³) of water remaining altogether, he said.
Mr Sutat said "water stress" is imminent as between November this year and May next year, about 12 billion m³ of water will be needed to meet demands from farms and households in the area.
He urged state agencies to do their best to conserve water in the remainder of the rainy season.
The institute said frequent and intense showers will last until the end of next month, which means the state's irrigation agencies only have about a month to save up enough water to last until next year.
While intense showers will bring relief to the nation's depleted dams, HII warned that they may harm farmers' earnings and livelihoods.
The late arrival of rain this year forced many farmers to postpone planting by a month, which means their crops will be ready for harvesting when the rain peaks, he said, while urging related agencies to prepare assistance.