Chennai’s first wetland sponge park comes up in Porur

Tamil Nadu Chief Minister M.K. Stalin has inaugurated Chennai’s first wetland sponge park in an OSR land off Mount Poonamallee High Road, Porur.

Officials said the wetland sponge park is the first of its kind in the city as visitors will be permitted inside a wetland, unlike Pallikaranai, and learn about the ecosystem and the species. The entry fee is expected to be finalised shortly. Until Chennai Metropolitan Development Authority (CMDA) identifies an agency for maintenance, residents and tourists will be permitted to visit the wetland sponge park without any entry fee. 

“The land was previously used as a parking lot. We have converted only the OSR land into a wetland sponge park. After work started in the 16.63 acres OSR land of Sri Ramachandra University in 2023, the biodiversity has improved during the eco-restoration and the number of species of birds has already increased in the wetland. The original area of the wetland was vast in areas such as Porur,” said Niveda Ramesh, design consultant, Sponge Collaborative.

Meanwhile, CMDA has started a GIS survey of such marshy areas to implement similar eco restoration projects across all the zones of Chennai Corporation and local bodies in the suburban areas of the metropolitan area. 

“As a number of residential areas of the city have been developed in marshy areas, CMDA is planning to convert existing open spaces in such clayey soil into wetland sponge parks based on the GIS survey and recommendations from MLAs and local councillors. Once we identify the land, we will verify the ownership and check the feasibility of converting it into a wetland sponge park. The survey will be completed shortly,” said an official of CMDA.

The wetland parks to be developed across the city are expected to improve the groundwater recharge, improve water storage and facilitate flood mitigation.

Pointing to the rise in Chennai’s built-up area over farmlands, forests, wetlands, and low-lying regions, an official of CMDA said the loss of wetlands and green cover has significantly diminished the city’s absorptive capacity, increasing vulnerability to risks such as urban flooding, drought, aquifer depletion, and urban heat islands.

As natural wetlands have declined because of urbanisation, constructed or restored wetlands in urban areas have become vital for mitigating climate change impacts, enhancing urban biodiversity, and fostering sustainable, resilient communities. The wetland sponge park has reclaimed a disappearing wetland that was once part of the expansive Porur lake, officials said.

Envisioned as an integrated public open space, the park restores essential hydro-ecological connections through carefully designed ecological landscapes, experienced via low-impact boardwalks and viewing decks.

Furthermore, the park will serve as vital natural infrastructure for the city, functioning as a ‘sponge park’ that mitigates flooding by capturing and infiltrating stormwater. It will also serve as a ‘constructed wetland’ that treats stormwater pollutants while acting as a carbon and heat sink, a ‘biodiversity hotspot’ supporting over 85 species of native flora and fauna, including migratory birds, officials say.

Visitors can relish the park’s natural experiences and recreational amenities while learning about the vital functions of wetlands as they explore the three themed zones highlighted on the map, said an official.