Harnessing nature : integrated management for urban flood mitigation using nature-based solutions in East Kolkata Wetlands, India.

Wetlands are crucial for ecosystem services, and the East Kolkata Wetlands (EKW) are particularly vital for Kolkata. The city's 4.5 million residents generate about 1.1 m³ of wastewater, which naturally flows to the EKW, recycling 50% of it. However, rapid urban expansion and increasing impervious surfaces are shrinking these wetlands, exacerbating urban flooding. Kolkata's urban growth, notably in Rajarhat with areas like Salt Lake and Newtown, has replaced valuable ecological services with concrete landscapes, increasing flood risks. Salt Lake was developed in the 1960s over saltwater lakes to accommodate the growing middle-class population, making the area prone to urban flooding. Global northern countries are adopting Nature-based Solutions (NbS) to address urban water issues, and similar approaches are proposed for mitigating floods around EKW. These include bioswales, rain gardens, and rainwater harvesting, tailored to specific areas' needs. This study emphasizes integrating NbS with traditional engineering solutions to reduce runoff and flood risks, promoting further research and administrative discussions on implementing NbS in urban planning.