State irrigation department has identified at least 65 vulnerable earthen dykes in the Sunderbans delta, spanning North and South 24-Parganas districts, ahead of the anticipated landfall of cyclone Dana on October 24.

Emergency repair work of these dykes has been initiated by the irrigation department, although officials remain uncertain about their durability against the strong river waves that could be triggered by gusty winds expected to reach up to 110kmph.

A senior bureaucrat in Nabanna said chief minister Mamata Banerjee, personally overseeing the repair efforts, had sent senior IAS officer Manish Jain to South 24-Parganas and minister Manas Bhunia to East and West Midnapore for monitoring.

According to sources in the irrigation department, 17 of these dykes, primarily located in South 24-Parganas, were critical as they had suffered breaches, sparking fear of flooding.

State irrigation minister Manas Bhunia acknowledged the serious threat Cyclone Dana posed.

Speaking to The Telegraph, Bhunia said: “Not just in the Sunderbans, but in many areas, earthen dykes are in a vulnerable state. We are concerned and are addressing the issue on a war footing by identifying and fortifying these dykes.”

In most cases, emergency measures are being done such as earth filling under bamboo frameworks, sandbag piling, and covering stretches with geosynthetic sheets. However, persistent rainfall over the past two weeks has significantly weakened the soil, creating challenges for the department.

An irrigation department engineer warned: “If a high tide coincides with the cyclone, the dykes are unlikely to hold. Breaches are likely, which could lead to saline water inundating the nearby areas, potentially causing floods and damaging farmlands.”

Bhunia, when asked about the condition of the soil impacting the fragility of the dykes, said: “We have limited options... we cannot bring soil from another planet.”

He attributed the issue to the natural geomorphology of the region, which often results in dyke breaches.

Officials have also raised concerns about the vulnerability of dykes in areas such as Sagar Island, which is expected to be one of the hardest-hit locations when Dana makes its landfall.

On Wednesday, irrigation officials implemented emergency repair work on dykes in Shibpur and Tapoban (Dhablat gram panchayat), Mahishmari (Ganga Sagar gram panchayat), Bankimnagar (Sumatinagar gram panchayat), Pastala (Muriganga-I gram panchayat) and Chakfuldubi (Muriganga-II gram panchayat).

Sagar block development officer Kanhaiya Kumar Roy said: "These dykes are in a critical state, but no breaches have occurred yet. We are taking all possible measures to mitigate the threat posed by Dana."

Bhunia added that the dykes in areas such as Namkhana, Gosaba of South 24-Parganas and Sandeshkhali, Swarupnagar, and Gaighata in North 24-Parganas were being closely monitored by dedicated teams, with repairs going on in those where breaches were detected.

Repair efforts are on in dykes in Swarupkathi and Shibbari (Hingalganj-Dulduli) as well as Sardarpara (Jogeshganj).

The administration in both districts has begun evacuating residents living near vulnerable dykes.

The North 24-Parganas administration has also set up a central control room for the cyclone, providing dedicated helplines (9073940039, 9073940058, 9073940038) for emergency assistance.