Pramote Maiklad, former director-general of the Royal Irrigation Department, said the timeframe was tight but that officials in five sub-committees under the water management committee of the National Council for Peace and Order would have to finish the plan on time.
Mr Pramote said the first requirement was a nationwide water management overview, followed by management plans suited to each river basin.
Thailand has never had a real water management plan, only policies pished by politicians aimed at attracting votes, he said.
Suwatthana Jittaladakorn, a water resources engineering adviser at the Engineering Institute of Thailand, said the three-month timeframe might be too tight, because water management had to be studied in various dimensions.
The biggest concern rested with the Chao Phraya river basin because it was large and needed clear management ideas.
He recommended that existing water retention areas should be used, and that the bottleneck in the Bang Ban and Bang Sai areas of Ayutthaya province should be widened. People affected by the plan should have their say in the development and receive fair compensation, he added.
Both Mr Pramote and Mr Suwatthana are advisers to the NCPO water management committee headed by assistant army chief Gen Chatchai Sarikalya.