In a move that could ease worries for property owners near Chennai's Pallikaranai marshland, the Tamil Nadu State Wetlands Authority (TNSWA) told the Madras High Court on August 20, 2026, that construction can be managed, not outright banned, around the 'zone of influence' (ZoI) area.
Chief Justice Sushrut Arvind Dharmadhikari and Justice G. Arul Murugan reviewed a report from the National Centre for Sustainable Coastal Management (NCSCM) suggesting an interim ZoI. This will be in place until detailed studies determine a permanent boundary based on hydrological and land use traits.
The interim ZoI proposes varying widths. For about 30.14 kilometers of the 77.85-kilometer boundary, a zero-meter width is suggested from the marshland boundary. Another 16.16 kilometers could range from zero to 20 meters, while 3.20 kilometers might extend between 20 to 50 meters. Widths of 50 to 100 meters and over 100 meters are suggested for 3.80 kilometers and 24.55 kilometers, respectively.
Approximately 46.30 kilometers, or 59.5%, of the boundary falls within the 0-20 meter interim ZoI width. Meanwhile, around 24.55 kilometers, or 31.5%, would exceed 100 meters. This variety in the wetland-urban interface supports a flexible, specific approach rather than a one-size-fits-all rule.
The TNSWA's update responds to several writ petitions from the Confederation of Real Estate Developers Association of India (CREDAI) - Chennai chapter and others. These petitions challenge a blanket ban by the National Green Tribunal (NGT) on new construction within 1 kilometer of the marshland.
During court, advocate P. Veena Suresh, representing the NCSCM, noted that the interim ZoI map was created at the state's request. It follows the Wetlands (Conservation and Management) Rules, 2017, by the Union Ministry of Environment, Forest and Climate Change, defining the ZoI as areas where development could harm the wetland's ecological structure and function.
However, the advocate pointed out that Pallikaranai marshland lies in a highly urbanized area with dispersed drainage and significant built-up regions. The NCSCM chose guidelines suited for wetlands with diffused drainage instead of well-defined systems.
The Additional Advocate General (AAG) highlighted that existing drainage paths, low-lying areas, and natural features maintaining hydrological connections to the marsh were included in the interim ZoI. Satellite wetlands linked ecologically to Pallikaranai marsh were also considered.
After reviewing the AAG's presentation, the judges allowed a two-week period for Senior Counsel P. S. Raman, representing CREDAI-Chennai, and others to examine the report and prepare their arguments. The next court hearing is set for September 7, 2026.
