Kolkata Waterlogging Exposes Gaps In Urban Drainage
Repeated waterlogging across the Kolkata metropolitan region is once again highlighting a basic urban challenge: drainage systems must keep pace with heavier rainfall, expanding built-up areas and rising mobility needs. The latest disruption at the Katapol underpass in Serampore, Hooghly, where water can reportedly remain for days, offers a wider warning for Kolkata’s transport corridors and low-lying neighbourhoods.
The Katapol problem is particularly significant because an underpass is a mobility link designed to keep traffic moving safely. When drainage fails, however, the same infrastructure can become a barrier. Local accounts indicate that prolonged inundation has forced people to consider longer routes and, in some cases, crossing railway tracks to reach nearby areas. That turns a drainage failure into a direct public-safety and accessibility issue.The episode also exposes the limitations of relying mainly on emergency pumping after heavy rain. Kolkata’s municipal drainage department itself acknowledges that the city has an ageing network, including century-old brick sewers and pumping stations, while silt accumulation and reduced outfall capacity can restrict water movement. Rapid urbanisation and the loss of natural water-retention areas have also increased the volume of runoff reaching the drainage system.For Kolkata, the concern extends beyond individual flooded roads. Research on the metropolitan region shows that urbanisation, changes in land use and declining wetland buffers are increasing flood vulnerability. A recent flood-hazard study found that more than 65 sq km of Kolkata was affected across rainfall events examined between 2016 and 2023, with southeastern areas among the most exposed.
That makes drainage investment an economic as well as civic priority. Waterlogged roads delay workers, disrupt deliveries, increase vehicle operating costs and can restrict access to schools, hospitals and public transport. For lower-income households, the impact can be sharper because alternative transport and remote-working options are often limited.Kolkata is already moving towards larger investments in resilient urban services. In 2025, the Asian Development Bank approved a $200 million programme supporting climate- and disaster-resilient sewerage and drainage infrastructure in the city. The challenge is ensuring that such investment reaches the smaller links that determine whether people can actually move safely during extreme rainfall.Urban planners increasingly point towards a combination of upgraded drains, reliable pumping, restored canals, protected wetlands and better rainfall monitoring rather than isolated emergency measures. For Kolkata, urban drainage therefore needs to be treated as essential mobility infrastructure, with maintenance and local-level reliability receiving as much attention as major construction.
The next test will be whether drainage improvements can reduce the duration, frequency and social cost of waterlogging particularly at underpasses, railway crossings and other points where a flooded street can quickly become a safety hazard.
