Environment

The Cantonment Railway Colony was declared Bengaluru’s second Biodiversity Heritage Site in September 2025—a rare victory for citizens who had protested against large-scale tree felling for a proposed commercial development. Over 15,000 citizens stood tall against the tree felling, and following months of protests, the government declared the site a Biodiversity Heritage Site. However, just three months later, on December 6, the state government withdrew the notification. The reversal has once again put nearly 370 heritage trees in the colony at risk. A threat for citizen participation The colony houses around 370 mature and heritage trees belonging to around 50…

If Mumbaikars can gather for festivals, political rallies and celebrations, can they not rally for the right to breathe? That question and a sense of growing frustration and urgency were what led to the formation of the Human Chain for Clean Air — a citizen-driven movement demanding urgent government intervention. For weeks, the AQI in Mumbai has crossed hazardous levels, affecting children, senior citizens and working professionals alike. Each of us has been noticing that people around us are constantly coughing, children are falling sick frequently, and senior citizens are struggling to walk without breathlessness. I realised that instead of…

Chennai’s unregulated urbanisation has destroyed its water bodies and disrupted its natural drainage systems. This is true for the Kodungaiyur Canal System in North Chennai which includes the Ambattur, Korattur and Retteri lakes. This crucial waterway is designed to drain floodwaters into the Ennore Creek but is marred by encroachments and illegal sewage discharge. In fact, Kodungaiyur Lake, a part of Kosasthalaiyar and Cooum basin, is one of the lakes that has been eaten up and has been reduced to narrow canals because of human activity and government negligence. Flooding in encroached area, vulnerable groups affected During a datajam organised…

Saul Kere, a lake off Sarjapur Road, was once a thriving habitat for birds. “When I started birding regularly in  2019, I had observed nearly 180 species of birds here,” Bijoy Venugopal, a birder and environmentalist, recalls. “Even during our latest bird walk on December 7th, we recorded 67 species of birds, more than what you would see at some bird sanctuaries.” However, the number of birds has declined, mainly due to effluent inflow. E-bird, a public data forum, has a record of 213 bird species in Saul Kere. That is the richness of the biodiversity of the Saul Kere…

Walk through any city, and you'll encounter Nature-based solutions (NbS) everywhere: urban parks providing respite from hot streets, wetlands filtering stormwater, and trees along busy roads reducing air pollution, among others. This green infrastructure, however, is often viewed through a narrow lens—as mere providers of shade, picturesque spaces, or recreational spots.  This limited perspective has harmful consequences. When development pressures mount or budgets tighten, these natural assets become expendable and are often removed without proper analysis of their multidimensional benefits. This is where quantifying the benefits of NbS becomes essential. By measuring and monetising the value these solutions provide, we…

When the northeast monsoon hits Chennai, a foreseeable result of the heavy downpour is severe flooding in several areas, including Porur Lake. As residents living near this 200-acre water body battle inundation every year, our team set out to investigate the root causes of flooding using available data. Environmental issues have often been dealt with a one-size-fits-all approach, but our study aimed to provide specific solutions tailored to the Porur catchment area. For this, we mapped inundation patterns, land gradient, land use change and the outlay of stormwater drains (SWDs).   At a recent datajam organised by the Oorvani Foundation…

Mumbai’s L Ward, covering Kurla, Chandivali, Saki Naka, and Powai, has been quietly heating up, and not just metaphorically. It is a ward of extremes: dense slums on one side, luxury high-rises and malls on the other. But when the mercury rises, the contrasts fade, and everyone feels the burn. With urban heat on the rise across the city, L Ward is emerging as one of Mumbai’s hotspots where everyday life is increasingly being shaped by climate stress. The heat problem Spread across 15.6 sq km, L Ward is home to more than nine lakh people, packed into one of…

In 2015, when her infant daughter began wheezing, Subashini R purchased a machine she had only ever seen in hospitals. Daily trips from Kattukuppam in north Chennai to Tondiarpet Hospital were expensive, costing at least ₹500 then. Although the nebuliser cost four times her daily healthcare expenses, it reduced long-term costs in a region struggling with the lasting effects of pollution. “Every doctor tells locals to leave the region due to the chemicals here,” says the activist, part of the Save Ennore Creek Campaign. A decade later, nearly every household in Ennore has a nebuliser. Her younger daughter now suffers…

The Cooum River, once a sacred river that shaped the history of Madras, has now become a sad sign of urban degradation. For the millions of residents in Chennai, it has transformed into a malodorous, polluted, and stagnant channel, burdened with solid waste accumulation and extensive encroachments along its banks. During a recent datajam organised by Oorvani Foundation and OpenCity, we used Geographical Information System (GIS) datasets and population analytics to investigate the underlying causes contributing to this crisis. The results show that rapid urbanisation, inadequate provision of essential civic infrastructure, and the absence of coherent policy frameworks, along with…

The Pallikaranai Marshland, one of Chennai’s last remaining natural wetlands, has long been a site of ecological tension. Its designation as a Ramsar site brought national and international recognition, along with renewed expectations for strong conservation measures. Yet the marshland continues to face intense pressure from urban development, infrastructure projects and real estate expansion.  Recently, Arappor Iyakkam, an anti-corruption organisation, alleged that state agencies illegally cleared environmental and construction approvals for a large high-value housing project within the Ramsar boundary. As the matter unfolds, it reveals how regulatory gaps and political inaction make the marsh vulnerable. Meanwhile, residents of Tansi…