Executive engineer Arifuzzaman Bhuiyan of the flood forecasting and warning center told Prothom Alo that the water level of two main river basins-- the Brahmaputra and Ganges—are increasing simultaneously. The water in the Teesta river has also crossed the danger level. As a result, 30 to 40 per cent of the country might get inundated for the next 7 to 10 days.

According to the flood forecasting centre, the water of the Brahmaputra has entered through Kurigram and is likely to inundate Gaibandha, Jamalpur, Bogura, Tangail, Sirajganj, Manikganj and Pabna. Kurigram, Lalmonirhat and Rangpur in the Teesta basin might also get flooded.

Record-breaking floods in Sylhet

Incessant rain coupled with onrush of water from the upstream has broken all the previous records in Sylhet. 80 per cent of the division has already gone underwater while 90 per cent of area in Sunamganj district has been flooded. Water level may surge in the next two days.

According to the flood forecasting centre, Sylhet saw such floods in June 1998. The floods following that were mostly limited to haor areas and low-lying areas of Sunamganj. Sylhet and Sunamganj experienced a sudden flood in 2019 but a flood ravaging almost the whole of the division has not been seen in the recent past.

Arifuzzaman Bhuiyan said no floods in the past submerged 80 per cent of a division. The floods in Sylhet in the past were mainly confined to haors and adjoining areas. But this time even the highlands were affected.

The water may not recede before Monday as heavy rains are forecast upstream, he added.

According to the European Centre for Medium-Range Weather Forecasts (ECMWF), Meghalaya’s Cherapunjee in upstream Bangladesh would see rainfall of 500 to 600 millimetres on Saturday. Earlier in the last 24 hours, 972 millimetre of rain was recorded in the area, the third-highest in the last 122 years. In the last three years, about 2500 millimetres of rainfall was recorded in the bordering area of Sylhet.

River experts said many regions of Sylhet division’s Surma, Kushiara, Gowain and a number of other rivers have been filled with silt. As a result, the rivers cannot hold the onrush of waters in the rainy season. Also, the water capacity of haor areas has decreased due to an increase in various activities including agriculture.