Kolkata Metro Tunnel Wall Damaged by Civic Pipeline Work
An underground retaining wall of the North-South Metro corridor was damaged during civic pipe-laying activity on SP Mukherjee Road, prompting safety concerns for the city’s busiest mass transit line. Metro Railway engineers confirmed that a section of the diaphragm wall—critical for structural stability and flood prevention—was compromised during ongoing installation of a 1,400mm water pipeline by city authorities. In response, the Metro administration has requested immediate repairs and a shift in pipeline alignment to safeguard tunnel integrity.
The incident occurred near Mudiali, where workers laying the steel water line unintentionally breached a 3-metre stretch of the diaphragm wall, about one metre below ground level. Constructed to support tunnel structures and prevent water ingress, the diaphragm wall is essential to the Metro’s underground infrastructure. Officials warned that welding joints used in laying the pipe could cause future leakages, risking tunnel flooding. Metro Railway has formally urged the municipal water supply department to reroute the pipe to the eastern flank of the road to minimise proximity to the Blue Line corridor. City officials acknowledged receipt of the request and stated that they would independently inspect the site before proceeding with corrective measures. The North-South Metro, spanning 31 kilometres from Kavi Subhas to Dakshineswar, serves over 600,000 daily commuters and forms a crucial component of Kolkata’s urban mobility network.
This is not the first time structural vulnerabilities have threatened smooth operations—services were recently disrupted between Central and Chandni Chowk due to tunnel flooding after heavy rainfall. Recurring incidents have led to ongoing assessments by infrastructure experts to recommend long-term remedies for the ageing transit system. Engineers caution that while pipeline upgrades are essential to improve civic infrastructure, they must be executed with utmost coordination when close to sensitive transport corridors. Unregulated construction near metro infrastructure, especially involving heavy-duty equipment and welding work, increases the likelihood of structural compromise. In densely populated cities like Kolkata, where road space is limited and multiple utilities share underground corridors, collaborative planning between urban development bodies and transport departments becomes imperative for safe and sustainable infrastructure development.
As urban infrastructure grows denser and more interconnected, the Kolkata incident serves as a warning for other metros to prioritise cross-agency coordination. The need for comprehensive urban planning that aligns civic utilities with transport safety cannot be overstated. Ensuring the resilience of public transit systems must remain a top priority—not only to protect daily commuters but also to uphold the long-term sustainability of city-wide infrastructure investments.
