Construction Near Pallikaranai Marshland Can Be Regulated Rather Than Banned, TNSWA Informs Madras High Court

The Tamil Nadu State Wetlands Authority (TNSWA) has informed the Madras High Court that construction activities in the designated zone of influence surrounding the Pallikaranai marshland in Chennai can be regulated rather than placed under a complete ban.

What Happened

During proceedings before the First Division Bench comprising Chief Justice Sushrut Arvind Dharmadhikari and Justice G. Arul Murugan, the court examined an interim proposal for the 1,247.54-hectare wetland. The submission came in response to writ petitions filed by the Confederation of Real Estate Developers Association of India (CREDAI) Chennai chapter and other parties. These petitions challenged a National Green Tribunal (NGT) ruling that had placed a blanket ban on new building construction within a uniform one-kilometre radius around the wetland boundary.

Appearing on behalf of the state authority, Additional Advocate General (AAG) P.V. Balasubramaniam, assisted by advocate P. Veena Suresh, submitted an interim Zone of Influence (ZoI) map. The map was formulated by the National Centre for Sustainable Coastal Management (NCSCM) based on the Union Ministry of Environment, Forest and Climate Change Guidelines for Implementing the Wetlands (Conservation and Management) Rules, 2017.

Key Highlights

• Site-Specific Boundary: The NCSCM report recommended a variable-width boundary rather than a uniform distance across the 77.85-kilometre total boundary length of the marshland.
• Breakdown of Proposed Buffer: Out of the total perimeter, a zero-metre width was suggested for 30.14 km, and a width between zero and 20 metres was proposed for 16.16 km. Together, approximately 46.30 km (59.5%) of the boundary falls within a 0 to 20-metre range.
• Wider Zones: The proposed width is between 20 and 50 metres for 3.20 km, 50 to 100 metres for 3.80 km, and above 100 metres for 24.55 km (31.5% of the perimeter).
• Urban Landscape Factors: The AAG noted that Pallikaranai marsh is set within a dense, urbanised setting with gentle slopes, diffused drainage, and built-up structures directly adjacent to the boundary wall in multiple sections.
• Ecological Inclusion: Low-lying areas, existing drainage channels retaining hydrological connectivity, and connected satellite wetlands have been factored into the interim ZoI.

Why This Matters

The state authority’s stance highlights a move away from uniform distance-based restrictions in favour of site-specific management. Because 59.5% of the examined boundary has an interim zone width under 20 metres, adopting a tailored framework accounts for the existing urban interface adjacent to the marshland while scientific studies determine the final zone of influence.

What to Watch Next

The Madras High Court has granted a two-week period for Senior Counsel P.S. Raman, representing CREDAI-Chennai, and counsel for other petitioners to review the NCSCM status report and file their responses. The First Division Bench directed the High Court Registry to list the matter for its next hearing on September 7, 2026.

Frequently Asked Questions

What is the Zone of Influence (ZoI) for a wetland?

According to the Union Ministry’s 2017 wetland implementation guidelines cited in court, the ZoI is defined as the area where developmental activities could potentially trigger adverse effects on the structure and ecological functioning of the wetland ecosystem.

Why was a variable width proposed instead of a uniform buffer?

The NCSCM report noted that the significant variation in suggested buffer widths reflects the mixed, heterogeneous urban-wetland boundary, supporting a tailored, site-specific approach over a blanket setback distance.

What earlier order led to this court matter?

The case arises from challenges against an order by the National Green Tribunal that had imposed a blanket prohibition on new construction within a uniform one-kilometre distance from the Pallikaranai marshland boundary.

Source: Madras High Court proceedings and status report submissions reported by The Hindu.