Chennai advances flood preparations but faces drainage limits

The Greater Chennai Corporation has accelerated flood-prevention work ahead of the Northeast monsoon, with the number of locations it considers vulnerable falling to 219 for 2026 from nearly 800 in 2015, according to The Hindu. The civic body said micro-level stormwater-drain works were 95% complete. It is also removing silt, mud, garbage and water hyacinth from canals, using machinery including a robotic excavator, and has hired diesel-powered pump tractors as a precaution.

GCC Commissioner G.S. Sameeran said the corporation was coordinating with the Railways, Chennai Metro Rail Limited and other agencies. Some major infrastructure projects would take longer, he said, so temporary pumping arrangements were being used to manage the monsoon.

Officials identified capacity constraints along the Buckingham Canal, the Adyar and Sholinganallur. They said the list of vulnerable sites was being reviewed using field assessments, rainfall patterns and the performance of completed mitigation works. Residents and elected representatives raised concerns about consultation and delays.

MDMK councillor S. Jeevan said representatives lacked information about inspections and warned of flood risks linked to delayed desilting of the Kodungaiyur Canal. A residents’ association leader said officials had not shared enough preparedness details.

Activist Haris Sulthan said many waterbodies remained largely dry and that the city’s five drinking-water reservoirs together held 4.5 TMC against a combined capacity of 11.7 TMC. He called for further desilting, deeper lakes and removal of water hyacinth. Experts linked Chennai’s flood risks to urbanisation, encroachments, polluted waterways and blocked natural drainage.

Climate researcher D. Raghunandan said the stormwater network should be redesigned for extreme rainfall of 100-200mm or more in a few hours. Other experts urged protection of wetlands and lakes, stronger zoning rules and greater water conservation.