"Chennai's recurrent floods are as much a failure of urban planning as of meteorology." Critically examine this with reference to 2015 and 2023.

The CAG's audit of the 2015 Chennai floods called them "man-made" under Central Water Commission norms [1]. In December 2023, Cyclone Michaung flooded the city again. Taken together, these years support the statement: extreme weather is the hazard, and poor planning turns it into a disaster.

Meteorology: the hazard is real

• Cloudburst-level rain: radar recorded 100–200 mm/hour over Chennai in 2015 [2]. No city drainage can carry this without damage.
• Forecasting limits: IMD counts the northeast monsoon as "normal" anywhere within 88–112% of its long period average (LPA) [3]. A seasonal outlook cannot warn of a single extreme day.
• 2023: Michaung brought about 36 hours of heavy rain from 3 December [4]. This was a cyclone-driven event that no planner could prevent.

Urban planning: the disaster is man-made

• Reservoir management: on 1 Dec 2015, Chembarambakkam held 3.481 of 3.645 TMC, and outflow exceeded inflow for 13 hours. The tank had no scientific inflow-forecast system [1].
• Encroachment: the CAG blamed weak enforcement of Master Plans for construction on tanks, lakes and riverbeds [1].
• Drainage gaps: storm-water drains covered too little of the city, used the wrong design rainfall intensity and had missing links [1].
• Flood, then scarcity: 8.7 TMC went to the sea in 2015, over 75% of the capacity of the city's four reservoirs [1].
• 2023 repeat: reverse flow in the Buckingham Canal carried refinery oil into the city [4]. This exposed hazardous land use along waterways.

Assessment

• The statement largely holds. Weather sets the scale of a flood, but planning decides how far the water spreads and how fast.
• It also has limits. Even perfect planning cannot fully absorb cloudburst rain [2]. In 2023, a different weather system caused much the same damage, which shows that the lessons of 2015 were only partly learnt.

Chennai's floods come from both natural and man-made causes, and both need fixing. The way forward has three parts:

• Build on the ₹561.29 crore Chennai Basin flood mitigation project [5] and the Fifteenth Finance Commission's allocation for the city [6].
• Apply the NDMA Urban Flooding Guidelines [6].
• Run reservoirs by forecast, restore wetlands and enforce no-build zones along waterways.

This would make Chennai resilient, in line with SDG 11.