Pallikaranai marsh has been a Ramsar wetland of international importance since 8 April 2022, and the protected site covers about 1,247.5 hectares on Chennai’s southern edge, according to the Ramsar Sites Information Service. It is one of 20 Ramsar sites in Tamil Nadu listed by the Tamil Nadu State Wetland Authority (TNSWA), and the only one inside the Chennai city region.
With the northeast monsoon setting in over Tamil Nadu on 15 October, the marsh is doing what it has always done: soaking up stormwater from Velachery, Medavakkam, Sholinganallur and the OMR belt. Here is what the Ramsar tag means, why the marsh matters every time it rains, how to visit, and the disputes that are still running over its boundary.
What the Ramsar listing covers
The site is formally named Pallikaranai Marsh Reserve Forest, and it is managed by the Tamil Nadu Forest Department through a conservation authority for the marsh, with TNSWA as the state wetland regulator. The Ramsar Information Sheet filed by the state lists Forest Department land parcels handed over in stages from 2007 to 2014, including a 2012 transfer from the Chennai Corporation. Land outside the boundary sits with municipal bodies, other departments and private owners, which is where most of the conflict arises.
The biodiversity count submitted to Ramsar is substantial for an urban wetland: about 115 bird species, 46 fish, 21 reptiles, 10 mammals and 10 amphibians, along with molluscs, crustaceans and butterflies. Glossy ibis and pheasant-tailed jacana are among the birds regular watchers look for in the cooler months.
Ramsar status alone does not ban construction. Restrictions come from the Wetlands (Conservation and Management) Rules, 2017, Master Plan land use and court orders. CMDA told the National Green Tribunal in a status report that its Second Master Plan marks the Pallikaranai swamp as ecologically sensitive and that it had issued no planning permission inside the earmarked swamp area.
Why the marsh matters for flooding
The Ramsar record describes the marsh as an aquatic buffer for flood-prone Chennai and Chengalpattu districts. It collects runoff in the wet months and releases it slowly, and it recharges the groundwater that many south Chennai borewells rely on. The state’s information sheet says about 54 smaller waterbodies spill their surplus into the marsh during the monsoon.
Water leaves the marsh mainly through the Okkiyam Madavu channel into the Buckingham Canal and on to the sea near Kovalam. That outflow is the weak point. The information sheet notes that roads built across natural drainage routes have cut the capacity of channels around the marsh and raised flood risk. When the outlets are choked, water backs up into the colonies that were built on the marsh’s former edges.
The shrinkage is the core problem. A Citizen Matters report citing a differential GPS survey said 38% of the marsh had been legally or illegally occupied, including large areas used by the Corporation and other public bodies.
The boundary and buffer zone dispute
Three linked disputes are open as of mid-October 2026.
- The 1-km planning freeze. Acting on an NGT order in a case that began with a June 2023 report about a road being laid across the Perumbakkam marsh, CMDA issued an office order in September 2025 halting planning permission within about a kilometre of the marsh. Eleven revenue villages are covered, among them Madipakkam, Pallikaranai, Perumbakkam, Sholinganallur, Karapakkam, Perungudi and Velachery. Residents protested on 31 January 2026, saying even repairs needed approval.
- The zone of influence. The NGT has asked TNSWA to define the marsh’s zone of influence, the area around it where activity needs to be regulated, DT Next reported. How that zone is drawn will decide how many of the frozen plots are freed. We found no revised CMDA order lifting or narrowing the freeze as of 18 October 2026.
- The Perumbakkam housing case. On 31 October 2025 the Madras High Court restrained work on a 14.7-acre high-rise project next to the marsh, The Federal reported. The State Environment Impact Assessment Authority later revoked the project’s environmental clearance, The South First reported; the CMDA planning permission was a separate question.
Property owners in these villages should check their survey number with CMDA and consult a lawyer before building or buying.
Visiting the marsh
The Forest Department runs a learning and interpretation centre, observation decks, an elevated walkway and watchtowers fitted with binoculars, according to the information sheet.
- Go early in the morning, when bird activity is highest and the heat is lower.
- Carry binoculars and water, wear closed shoes, and stay on marked paths.
- During heavy rain alerts, trails and low roads around the marsh can flood; check with the Forest Department before heading out.
- Do not feed birds, play music or leave plastic behind.
The threats that remain
The Ramsar listing rates urban development, roads, sewage, industrial effluent, garbage and invasive species as high-impact threats. Leachate from the neighbouring Perungudi dump yard is a named concern, as are invasive fish that compete with native species. Groundwater decline from urbanisation is another. The next things to watch are TNSWA’s zone-of-influence submission to the tribunal and any revised CMDA order that follows it.
Quick answers
When did Pallikaranai become a Ramsar site?
On 8 April 2022, covering about 1,247.5 hectares.
Can I build within 1 km of the marsh?
CMDA’s planning freeze from September 2025 still applies until a revised order is issued. Check your survey number with CMDA.
Who manages the marsh?
The Tamil Nadu Forest Department manages the reserve forest, and TNSWA regulates it as a wetland.
How many bird species live there?
About 115, according to the Ramsar record.
Information checked against official sources on 18 October 2026. Fees, dates and rules can change; confirm on the linked official pages before acting.
Sources
- Pallikaranai Marsh Reserve Forest, Ramsar Sites Information Service (Ramsar Convention)
- Ramsar Information Sheet: Pallikaranai Marsh Reserve Forest (Tamil Nadu State Wetland Authority)
- Ramsar sites of Tamil Nadu (Tamil Nadu State Wetland Authority)
- O.A. 91 of 2023 (SZ), Additional Status Report by CMDA (National Green Tribunal)
- Pallikaranai’s 1-km buffer zone sparks debate on housing rights, encroachment and ecology (Citizen Matters, Feb 2026)
- Madras HC halts housing project near Pallikaranai Ramsar wetland (The Federal, 31 Oct 2025)
- Tamil Nadu SEIAA revokes environmental clearance for housing project in Pallikaranai Ramsar marshland (The South First)
- TNSWA told to submit zone of influence around Pallikaranai marshland (DT Next)
