Guwahati drainage capacity questioned amid urban flooding

Guwahati is facing significant urban flooding challenges as rapid infrastructure growth outpaces the capacity of its drainage systems. Major water channels, including the Bharalu, Bahini, and Lakhimijaan, no longer function as natural rivers but serve as the city’s primary storm-water drainage network.

While the Guwahati Metropolitan Development Authority (GMDA) has conducted re-sectioning to improve carrying capacity, officials note that effective capacity varies due to siltation, earth, and debris brought in by runoff. The design discharge for the Bharalu is approximately 83 cubic metres per second, while the Bahini is around 48 cubic metres per second, but current effective capacities remain uncertain.

Critics argue that the city’s expansion—including flyovers, widened roads, and dense construction—has occurred without integrated assessments of natural water-flow patterns. In response to recurring waterlogging, the Assam Government has directed consultants to revise the Comprehensive Drainage Master Plan and the Detailed Project Report for the Bahini-Bharalu Basin to address these planning gaps.