A few steps away from the chaos of Mount Poonamallee Road traffic, Porur in Chennai now hosts the city’s first sponge park Dr MS Swaminathan Wetland Eco Park. Once a marshland turned dumping ground and parking lot, the 16.63-acre site has been transformed into a thriving eco-space that not only reduces urban flooding but reconnects residents with nature.
Developed by the Chennai Metropolitan Development Authority (CMDA) in collaboration with Sponge Collaborative, the sponge park slows down, filters, and stores stormwater instead of draining it away quickly like conventional flood-control systems. This nature-based solution is designed to recharge groundwater, create a safe flood buffer, and act as a community green space.
“When we came here initially, the land was degraded, with garbage piles and broken asphalt. Our aim was to restore its wetland function,” said Manushi Ashok Jain, Co-Founder of Sponge Collaborative.
Today visitors walk along elevated boardwalks above restored ponds, play in the children’s zones, and gather in sports areas all while the park quietly performs its environmental duties. Over 1,000 people visit the park on weekends.
“We deepened the retention pond by five feet it can now hold up to 30 million litres of water during monsoon,” says Niveda Ramesh, Associate Urban Designer with Sponge Collaborative.
The water journey is carefully designed: stormwater is first guided into a bioswale, then cleaned through a sedimentation pond, aeration basin, and a phytoremediation pond using native wetland plants. Only treated water from the nearby Sri Ramachandra University campus enters the system.
But not everything is smooth. Long-term maintenance remains a challenge, and any inflow of untreated sewage could reverse the gains.
“We don’t allow raw sewage here. Microplastics and untreated contaminants could not only damage the water filtration process but also pollute groundwater. Worse, research shows microplastics can enter our food and water supply, impacting human health causing inflammation, hormone disruption, and even crossing into organs like the liver and brain,” warns Niveda.
Sponge parks offer more than just flood mitigation. They represent a sustainable response to Chennai’s twin crises of water scarcity and flooding, offering a new blueprint for urban development. But experts say one sponge park isn’t enough.
“What we need is a city-wide sponge network wetlands, holding ponds, green spaces all connected and carefully placed,” says Dr S Janakarajan, water expert and President of the South Asia Consortium for Interdisciplinary Water Resources Studies.
Sponge Collaborative is already working on this vision by mapping potential sponge sites, training municipal engineers, and developing a master plan for green infrastructure in Chennai.
Porus wetland is not just a pilot it’s a starting point for a greener, flood-resilient Chennai. And a reminder that with the right vision, even a garbage dump can turn into a life-giving ecosystem.