The water levels in all the major dams are normal and the monsoons in the East and Northeast are weakening, water expert Royon Jitdon said on Monday.
Mr Royon, director of the Hydro and Agro Informatics Institute (HAII) and member of the government's Water and Flood Resources Management Committee, said Sirikit dam still has room for about three billion cubic metres of additional water.
Vajiralongkorn and Pasak dams were also still below capacity, he said.
"After Oct 10, we'll assess the water situation again.
"Now, we're just concerned about flooding, but we'll have to also consider storing water for use during the dry season.
"We have to create a balance for people nationwide, not just the people in Bangkok," Mr Royon said.
Storm Gaemi, downgraded from a tropical depression to a low pressure cell, could continue to cause heavy rain in Ratchaburi, Petchaburi, Prachuap Khiri Khan, Uthai Thani, Kanchanaburi and Bangkok on Tuesday.
It would further weaken and then disperse, he said.