Vast portions of Sunderbans riverine belt were inundated and large stretches of agricultural land and fisheries damaged after earthen dams in North 24-Parganas and South 24-Parganas districts were breached since the early hours of Friday.

Heavy rainfall, triggered by low pressure and accompanied by spring tide, over the past few days has triggered the breach.

Stretches of earthen dams along the Roymangal, Bidyadhari, Kalindi and Goureshwar rivers in several blocks of North 24-Parganas, including Haroa, Minakha, Sandeshkhali, and Hingalganj, have been washed away by tidal waves.

Saline water has entered the areas damaging agricultural land and fisheries, while flooding residential areas and markets.

According to preliminary estimates, at least 20 gram panchayats in the two districts have suffered fresh damage in the inundation. The situation has turned so serious that both the district administrations have been preparing to evacuate a large number of people from the affected zones apprehending increase in the water levels in the rivers.

Hingal resident Azahar Mandal said: “We are apprehending bad days again after Amphan. The water level in the river is increasing at an alarming rate. If it continues to rain, the area will be flooded damaging houses and properties.”

In South 24-Parganas, water level has been increased in several rivers, including Muriganga, Gangasagar, and Moni. This has led to damages to thatched dams at many places.

On the Ghoramara island of Gangasagar, vast stretches of agricultural land has been inundated by saline water after a thatched dam was washed away.

Officials of the irrigation department visited several affected places on Friday, but repairs could not be taken up because of high water level and incessant rain.

“The water level is rising and nothing can be done at the moment,” an irrigation official said.

Trinamul MLA Bankim Hazra, who is also the chairman of the Sunderbans Development Board, said: “Irrigation officials will undertake the job on an emergency basis to address the damage caused to the dams.”

In East Burdwan’s Kalna, people put up bamboo railings for a 1km stretch along Bhagirathi to avoid accidents. The embankment has eroded following heavy rainfall.

The villagers took the decision as a portion of mud road at Chak-Kamalpur village in Kalna’s Purbasthali 2 block was washed away.

Soumik Bagchi, the block development officer of Purbasthali 2, said: “We have already sent a proposal to the state government for the repair of the embankment.”