Pallikaranai Marsh — A Ramsar-Listed Flood Buffer for South Chennai, Undermined by Continuing Encroachment

Pallikaranai Marsh is a freshwater marsh in south Chennai, Tamil Nadu, that historically covered an estimated 6,000 hectares and served as the natural floodplain for the surrounding area. It was declared a reserve forest by the Tamil Nadu government in 2007 and designated a Wetland of International Importance under the Ramsar Convention in April 2022 (Ramsar Site No. 2481), with 1,247.5 hectares formally notified.

The marsh is one of South India's most biodiverse urban wetlands: EBSCO Research Starters documents more than 120 recorded bird species — including flamingo, glossy ibis and purple swamphen — alongside reptiles, mammals, fish and molluscs. According to Madras Musings, it drains monsoon runoff from a network of interconnected waterbodies across neighbourhoods including Velachery, Injambakkam, Sembakkam, Nanganallur and Hasthinapuram, making it South Chennai's principal natural flood buffer and freshwater aquifer recharge zone.

The Tamil Nadu government began active restoration in 2018 using funds from the National Adaptation Fund for Climate Change, and in 2024 the National Green Tribunal ordered the removal of illegal encroachments — including apartment blocks and IT parks — built on notified wetland land, with a 2001-built 2.1-kilometre road segment across the marsh slated for replacement by an elevated bridge.

Despite these measures, urbanisation has cut the marsh from its historical extent of roughly 6,000 hectares to under 600 hectares today, and waste dumping from an adjacent landfill remains an active pressure — an honest illustration that formal protection and restoration funding have not yet resolved the encroachment driving the wetland's decline.

Read the full analysis: https://madrasmusings.com/vol-35-no-3/restoring-pallikaranai-marshland-a-critical-imperative-for-chennais-ecological-and-urban-resilience/