Due to tidal bores, five of the 23 rivers in the Barisal division breached the danger mark on Monday night.
Ahsan Alam, a surveyor of the Barisal Water Development Board, said that the Surma and Meghna rivers flowed 3cm and 41cm, respectively, above the danger mark in Daulatkhan and Tajumuddin upazilas.
Similarly, the Tentulia river flowed 5cm above the danger level while Bishkhali river in Barguna and Biskhali river in Patharghata upazila flowed 7cm and 6cm above the red mark respectively.
Officials of the Water Development Board said they were concerned about riverbank erosion in the coastal areas of the division.
"We are trying to stop the erosion by placing geo bags,” said the surveyor.
Meanwhile, the low-lying areas of the division were also inundated, causing immense suffering to the residents.
Besides, heavy rains and the onrush of upstream hilly waters worsened the flood situation in Sunamganj and Sylhet districts, leaving thousands of villages inundated.
In Sylhet, the low-lying areas of the district have been flooded due to the onrush of water from the upstream, rendering nearly 100,000 people marooned, officials said.
In Sunamganj, all rivers of the district were flowing above the danger mark due to the onrush of hill water and torrential rains for the last couple of days.
Surma was flowing 7.7cm above its danger level at Nabinagar Point till 2pm on Monday, inundating the Boro paddy fields in the district.
