Why Kolkata Must Embrace Nature-Based Solutions to Tackle Urban Flooding

As Kolkata braces for another monsoon, scenes of waterlogged streets and overwhelmed drainage systems return with grim familiarity.

- Soumit Pandey, Ranjana Ray Chaudhuri and Sukanya Das

Urban flooding is now an annual ordeal, disrupting lives, damaging infrastructure, and straining public health systems. Once natural buffers, like canals, wetlands, and lakes that helped manage excess rainwater are now clogged, concretized, or encroached.

Amid growing climate threats, Kolkata must consider a sustainable alternative: Nature-Based Solutions (NBS).

NBS are interventions that work with natural systems, like restoring wetlands, planting native vegetation, or reviving water bodies to mitigate environmental hazards. Unlike conventional grey infrastructure (concrete embankments, pumps, stormwater tunnels), NBS provide multiple benefits. They absorb rainwater, recharge groundwater, improve biodiversity, and offer green public spaces. Critically, they are cost-effective and inclusive, especially when communities are involved in their design and upkeep.

Our recent study from TERI School of Advanced Studies (see Pandey, Chaudhuri, & Das, 2025) assessed the socio-economic viability of NBS in two contrasting areas: Maheshtala and Rabindra Sarovar Lake. Using household surveys and ex-ante cost-benefit analysis (CBA), we explored public awareness, perceived benefits, and the long-term financial feasibility of NBS interventions.