Green tribunal orders Bengal to carry out coastal protection plan for eroding Sagar Island

The National Green Tribunal has directed the West Bengal government and the state Coastal Zone Management Authority to carry out a full coastal protection plan for Sagar Island, the low-lying island at the mouth of the Hooghly that hosts the Gangasagar Mela every January, Millennium Post reported on Tuesday.

The tribunal's Eastern Zone Bench, made up of judicial member Justice Arun Kumar Tyagi and expert members A. Senthil Vel and Ishwar Singh, ruled on Friday in a case it had taken up on its own on rising sea levels and their impact on the mela. It closed the case with directions: the state must implement the recommendations of the National Centre for Sustainable Coastal Management (NCSCM) and the Integrated Coastal Zone Management plan for the island, and the Coastal Zone Management Authority must file a comprehensive action-taken report within six months, according to the report.

What the study found

The NCSCM assessment placed before the tribunal found that 63% of the area inside the island's identified hazard line is at high risk and another 18% at very high risk, Millennium Post reported. A satellite-based study cited in the case found long-term erosion along 44.55% of Sagar's coastline, rising to 54.67% when only recent years are measured, suggesting the problem is spreading.

The measures the tribunal wants carried out include "living shorelines" at Sibpur, a stretch identified as erosion-prone, which use plants and natural materials rather than concrete to hold the coast; more mangrove planting to trap sediment; and regular beach replenishment with dredged sand near the Kapil Muni temple, the centre of the mela.

The state told the bench that five coastal protection projects covering 4.68 km of shoreline were under way at an estimated cost of Rs 61.84 crore. It also pointed to a proposed Rs 4,100-crore Lower Sundarban programme that would cover 39 vulnerable islands, including Sagar, the report said. The order, as reported, does not set out who will fund that larger programme or when it will start.

Background

Erosion at Sagar has been visible for years. In December 2024, Down To Earth reported that the Bay of Bengal had advanced to within about 450 metres of the Kapil Muni temple; the magazine has separately reported that several of the bathing ghats used by pilgrims have been swallowed by the sea. The December 2024 report cited data showing the sea at Diamond Harbour, upstream on the Hooghly, rising by about 5.16 mm a year, against a national estimate of about 1.3 mm a year, and a World Meteorological Organization finding that sea levels in the Bay of Bengal had risen almost 30% faster than the global average over three decades.

Scientists quoted in that report, including Sugata Hazra of Jadavpur University, also blamed construction on the beach that destroyed protective sand dunes. Fieldwork by other researchers found that embankments had held back coastal flooding and erosion "only with limited success".

The stakes are high for the state. A senior official told Down To Earth that about 1.2 crore pilgrims had attended the 2024 mela and that the state expected similar or higher numbers in 2025.

What happens next

The Coastal Zone Management Authority has six months to show the tribunal what it has done. The next Gangasagar Mela, in mid-January 2027, will be the first since the order.