OMR - Rajiv Gandhi Salai

Pallikaranai Ramsar site and zone of influence map

The Pallikaranai Marsh Reserve Forest is Ramsar site no. 2481, designated on 8 April 2022. The Ramsar Sites Information Service records it as 1,247.5 hectares, about 20 km south of Chennai city, with central coordinates 12°55'40"N, 80°13'13"E. It is the only Ramsar site within Chennai's city limits, and its western and southern edges run close to the middle stretch of OMR. Two lines matter on a Ramsar map, and only one is final. The first is the site boundary. In October 2025 the Tamil Nadu government told the Madras High Court that ground truthing was under way to fix the final boundary of the roughly 1,248-hectare site, and in February 2026 it said a demarcation report was being prepared under the Supreme Court's directions. The second is the zone of influence. On 24 September 2025 the National Green Tribunal (Southern Zone) barred approvals within the site and a 1 km zone of influence until a scientific study defines it, and asked CMDA, the Tamil Nadu State Wetlands Authority (TNSWA) and the Water Resources Department to prepare the map jointly.

Until the joint map is notified, there is no official CMDA Ramsar site and influence area map to download. View the marsh outline and the 1 km band on the 1acre map layer, and treat any plot inside that band as frozen.

How to check if your property is in the Ramsar zone

Searches for a Ramsar site check or a Ramsar survey number map come down to one question: is this survey number inside the marsh, inside the 1 km zone of influence, or outside both? No single official portal answers it yet, so check in this order.

If the parcel is within 1 km of the marsh, do not rely on an older CMDA approval or a broker's assurance that the freeze will lift. A plot that already has an approved layout may still need fresh permission for building work. If the survey number is poramboke or tank-bed land, it was never saleable in the first place, whatever its distance from the marsh.

Marsh Freezes, Patta Checks and the Documents Brokers Never Show You

Two issues quietly decide whether a plot on this corridor will hold value or turn into a frozen asset. One is proximity to Pallikaranai. The other is a thin land-records trail no one bothered to verify. The Pallikaranai Marsh, designated India's Ramsar site on 8 April 2022, covers 1,247 hectares and sits right alongside the IT corridor. The Chennai Second Master Plan 2026 already classifies the contiguous swamp area as conservation land where development is prohibited. The recent escalation matters more. On 24 September 2025, the National Green Tribunal Southern Bench ordered CMDA to stop issuing all new approvals inside the Ramsar boundary and its zone of influence, and signalled that even plots outside the marsh, but within a one-kilometre buffer, may be restricted until the Tamil Nadu State Wetland Authority completes a scientific delineation. As of October 2026 that delineation is still pending. CREDAI Chennai has challenged the order in the Madras High Court, and in October 2026 the State Wetlands Authority told the court it had identified survey numbers covering about 316 acres, excluding private patta land, as an interim zone of influence. The court asked for a report on that proposal; until it rules, the 1 km restriction stands. The table below shows the OMR localities where this Pallikaranai marsh NGT order directly bites, so you know which postcodes carry an active approval freeze.

Patta chitta verification Tamil Nadu is the second non-negotiable. Pull the patta and chitta directly from the Tamil Nadu eServices portal at eservices.tn.gov.in. For Chennai Corporation pockets, ask for the TSLR Extract; for periurban villages on the lower OMR, ask for the A-Register and the 1-B Register. Cross-check the survey number against the Field Measurement Book sketch and the encumbrance certificate. If the seller balks at any of these, treat it as a decision. The eServices portal also lets you verify whether the parcel is poramboke, which along OMR often means tank-bed or drainage land that was never legally saleable in the first place.

IT Corridor Pockets and the Sectors That Earn Their Premium

The OMR splits cleanly into three bands. The upper stretch from Madhya Kailash to Tidel Park is a built-out office-led market with limited fresh land. The middle band from Perungudi to Sholinganallur carries the densest job catchment and the highest end-user demand. The lower stretch from Navalur to Kelambakkam is the supply belt, where new layouts and group housing are still being sanctioned. The table below summarises how the master plan treats the corridor's principal localities and where the genuine investment depth sits.

Rajiv Gandhi Salai IT Corridor regulations allow a notably higher FSI than the general residential zones in the metropolitan area. Annexure XIII of the Second Master Plan permits IT development across the 500 m belt regardless of the underlying land use, subject to the corridor's own conditions. That single clause is what turned Sholinganallur and Navalur from peripheral villages into a 38% chunk of South Chennai's residential absorption in Q1 2026. Siruseri SIPCOT IT Park is the most misread node on the corridor. Brokers sell every adjacent village layout as "Siruseri-rate" land, but the 868-acre government-developed IT Park sits inside a defined SIPCOT boundary. Anything outside that boundary is village land governed by the surrounding panchayat layout rules, not the IT Park's premium pricing. The same scrutiny applies at Kelambakkam. Cross-check the SIPCOT plot map and the CMDA sanctioned layout before treating any "near IT Park" listing at face value.

Data Sources & Verification

This page is based on the Ramsar Sites Information Service record for Pallikaranai Marsh and on dated reports of the tribunal and court proceedings, read in October 2026. CMDA, the Tamil Nadu State Wetlands Authority and the National Green Tribunal websites could not be read for this update, so court and tribunal steps are taken from established news reports. Where a fact could not be confirmed, it was left out.

* Ramsar Sites Information Service, site 2481: name, designation date, area, location * DT Next (October 2026): CREDAI challenge, TNSWA interim zone of influence of about 316 acres * DT Next (November 2025): NGT order of 24 September 2025, 1 km zone of influence, joint mapping by CMDA, TNSWA and WRD, localities affected * DT Next (November 2025 and February 2026): ground truthing of the boundary, Supreme Court monitoring, demarcation report * DT Next (June 2024): CMDA's plan to mark the swamp survey numbers as a no-development zone in the Third Master Plan * DT Next (July 2026): Supreme Court order of 11 December 2024 on notifying wetlands