Royal Irrigation Department spokesman and director of the Water Management and Hydrology Office Mr Thongplaew Kongchan said if rain dies not fall, water in the irrigation system will be adequate only until early August this year.
He urged all the people to use water economically, notably during the Songkran festival.
If possible, he suggested that water playing days should be reduced and water volumes should be cut.
He said the people should not celebrate the water festival same as they used to be in the past but to celebrate appropriately or just splashing water at each other slightly to uphold as tradition so that there will be water left to survive the worst situation.
Meanwhile the Department of Disaster Prevention and Mitigation director-general Mr Chatchai Promlert said a total of 12 provinces comprising 46 districts have been declared emergent drought-stricken disaster areas where immediate assistance is needed.
He said authorities have been despatched to inspect water sources and remaining water so that efficient water management will be implemented to enable water utilisation, particularly water for consumption will not be short.
He named areas where authorities will keep special monitoring as near Ubonrat dam in Khon Kaen where there are large rice cultivation and fish farms.
National Disaster Prevention and Mitigation Commission secretary-general Dr Seri Suprathit said Thsiland will face the worst drought in 20 years and water crisis is inevitable.
He said that the 120-day critical period from March to June will be closely watched as seasonal rain will come late.
He said if there is no rain during the period, rice grown in over four million rai of farmland worth 12 billion baht will be all damaged.
The damage is estimated from just the cost of each farmer per a rai of rice farming, he said.
Besides, there might have a need to also shut water supply for household consumption periodically so as to ensure the people will have enough water for consumption throughout the critical period, he added.