Many low-lying areas in the country’s northern Rangpur and north-eastern Sylhet regions were flooded on Sunday with major trans-boundary rivers, including the Teesta, Dharla, Surma, and Kusiyara, swelling due to the onrush of waters from hills and heavy rainfalls upstream India.

India has opened all 54 gates of the Gazaldoba barrage on the common river Teesta, forcing Bangladesh Water Development Board authorities to open 44 gates of the Teesta barrage, causing floods in the low-lying areas of the northern districts in Rangpur.

The situation was rapidly deteriorating in both Rangpur and Sylhet, and more areas were going under flood water in the regions, BWDB officials said.

Over 100,000 people in at least 63 villages in 12 upazilas of the five northern districts of Rangpur, Lalmonirhat, Kurigram, Gaibandha, and Nilphamari have been marooned due to a sudden onrush of water.

BWDB northern region chief engineer Mahabub Alam said that 113 houses were destroyed in the past 36 hours in Rangpur, Kurigram, Lalmonirhat, Nilphamari, and Gaibandha. Geobags are being thrown to prevent damage to river banks, he said.

The Brahmaputra, Teesta, Dharla, and Dudhkumar rivers swelled further on Sunday with the onrush of water and incessant rain, said officials.

Asafuddullah, an executive of the BWDB, said that the gates of the Teesta barrage were opened to cope with the flow of water after the Indian side informed them of the opening of the Gazaldoba barrage in the face of a huge onrush of waters amid heavy rain in Shiliguri and Darjeeling.

The water level of the Teesta was flowing 38cm below its danger mark at Dalia Point around 3:00pm on Sunday, according to the BWDB Flood Forecasting Warning Centre.

The water of all the main rivers, including the Surma and Kusiyara in Sylhet and the Jadukata and Baulai in Sunamganj, was swelling until the evening, BWDB officials said on Sunday.

BWDB executive engineer in Sylhet Asif Ahmed told New Age that the water  of the Surma was flowing 11cm above the danger mark at Kanaighat upazila in the district at 6:00pm, inundating most of the low-lying areas of the upazila.

He said that the water of the two main rivers, Surma and Kusiyara, also closed in on danger levels at other points, including Fenchuganj and Sherpur at Osmani Nagar upazila in the district, due to heavy rain and an onrush of water from the upstream for four days.

In the Rangpur region, low-lying areas of 12 upazilas, including Gangachara, Kaunia, Pirgachha, Sundarganj, Fulchhari, Rajarhat, Ulipur, Hatibandha, Kaliganj, Aditmari, and Lalmonirhat Sadar, were affected by the flooding.

Deputy commissioner of the Lalmonirhat, Mohammad Ullah, said that they had taken all necessary measures to ensure the safety and health of the people. ‘The local administration is ready to tackle the situation,’ he said.

Meanwhile, BWDB officials have warned residents of the low-lying areas on the banks of the Teesta and Dharla to remain alert about the latest flood situation.

Sunamganj WDB executive engineer Shamsuddoha said that the Surma had crossed the danger level at Chhatak upazila in the district on Sunday and was flowing 41cm above the danger mark around noon.

‘The water levels of two other rivers—Jadukata and Baulai—are also close to the danger marks. If the rivers’ water continued to rise further, it might cross the danger marks, causing floods in most of the upazilas in Sunamganj,’ he said.

The road communication between Tahirpur upazila and Sunamganj district headquarters was snapped in the morning as a part of the Tahirpur-Sunamganj road had gone under water, the upazila nirbahi officer Asaduzzaman Rony said.

The authorities recorded a rainfall of 200mm in Sunamganj between 6:00am on Saturday and 6:00am on Sunday, while 81mm, 82 mm, and 72mm rainfall were recorded in the city, Kanaighat, and Sherpur points in Sylhet, respectively, during the same period.

District administrators in Sunamganj and Sylhet said that they had already asked the upazila administrations concerned to take every necessary measure to face the situation and also to keep the shelter centres prepared.