Some 45 villages in Singra and Naldanga upazilas were submerged by the floodwater on Sunday due to unusual rise of water levels of Atrai and Barnoi rivers.
At least 15 villages were flooded as Singra-Atrai regional flood control dam went under water last night.
The Atrai river was flowing 83cm above the danger mark, said sources at Water Development Board in Natore.
On the other hand, some 20,000 people of 30 villages under four unions in Naldanga upazila were marooned by floodwater following abnormal rise of water level of the Barnoi river.
Aman paddy, vegetables and other crops in the upazilas have been damaged by the floodwater..