The Lawsuit That Saved Kolkata's Living Sewage Works

East of Kolkata lies a 12,500-hectare mosaic of shallow sewage-fed fishponds, known as bheris, that fisherfolk shaped over generations into what is effectively the world's largest natural wastewater treatment system. City sewage flows in, sunlight and algae break it down, and carp grown on the resulting bloom come out the other end: roughly 550 million litres of wastewater a day handled without a treatment plant, and around 10,000 tonnes of fish a year. In 1992, with 227 acres about to be handed over for a World Trade Centre development, the citizens' group PUBLIC — founded in 1990 by Bonani Kakkar — filed a public interest litigation in the Calcutta High Court, and Justice Umesh Chandra Banerjee's judgment barred land-use change across the wetlands. That ruling underpinned Ramsar designation in 2002 and the East Kolkata Wetlands (Conservation and Management) Act of 2006, though encroachment and filling continue to eat at the edges.