Mumbai’s outdated drainage and mangrove loss worsen flooding amid earliest monsoon since 1950

Mumbai is grappling with severe flooding as the earliest monsoon since 1950 arrived 16 days ahead of schedule, according to the India Meteorological Department (IMD). The city’s outdated drainage infrastructure, originally designed during the British era to handle just 25 mm of rain per hour, is ill-equipped to manage the intense downpours.

Adding to the crisis is the loss of over 40 percent of Mumbai’s mangroves in recent decades, often cleared illegally for urban development. These mangroves historically acted as natural buffers, absorbing excess water and reducing flood risks.

"The outdated infrastructure, vanishing wetlands, and climate change together have made monsoons in Mumbai worse with every passing year," experts say. Climate scientists note that intense rainstorms have tripled since the 1950s and are expected to become more frequent.

The IMD has issued a yellow alert for Mumbai, forecasting heavy to very heavy rainfall over the west coast through June 1. Recent data shows Mumbai recorded an average rainfall of 106 mm in 24 hours, with Nariman Point receiving 252 mm between May 25 and 26.

Urban development has also blocked natural drainage routes, further exacerbating flooding during the monsoon season. The combination of early, heavy rains and compromised natural and man-made drainage systems poses a significant challenge for the city’s flood management.

As Mumbai faces these mounting pressures, experts emphasize the urgent need to upgrade drainage infrastructure and protect remaining mangrove ecosystems to mitigate future flood risks.

Mumbai faces worsening floods amid the earliest monsoon since 1950, with the southwest monsoon arriving 16 days early. Outdated drainage systems, designed for 25 mm/hour rainfall, and a 40% loss of mangroves exacerbate flooding risks, while climate change intensifies heavy rainstorms, officials and scientists warn.