Account for the huge flooding of million cities in India including the smart ones like Hyderabad and Pune. Suggest lasting remedial measures.

Hyderabad's October 2020 deluge and Pune's repeated flash floods show that India's million-plus cities — including designated smart cities — now flood almost annually, repeating the script of Mumbai 2005 and Chennai 2015. Urban flooding is less a natural disaster than a man-made one.

Why million cities flood

• Encroachment of lakes, tanks and floodplains: Hyderabad's cascading tank system has shrunk drastically, and construction chokes Pune's natural streams (nullahs) like Ambil Odha.
• Concretisation makes surfaces impervious, cutting infiltration and sharply reducing the lag between rainfall and runoff.
• Storm-water drains designed decades ago for far lower rainfall intensities are further clogged by unmanaged solid waste and encroachments.
• Climate change is intensifying short-duration cloudburst-type rainfall over urban heat islands.
• Smart-city investments prioritised visible infrastructure over drainage, wetlands and hazard zoning; multiple agencies dilute accountability.

Lasting remedial measures

• Blue-green infrastructure on the sponge-city principle: restore lakes, wetlands and natural channels as flood buffers, with mapped and enforced buffer zones under the Wetland Rules, 2017.
• Map the city's natural drainage with high-resolution surveys before sanctioning new layouts, so construction follows hydrology rather than defying it.
• Redesign storm-water systems using current rainfall intensity-duration-frequency data, not colonial-era assumptions, and keep them functional through scientific solid-waste management.
• Enforce floodplain zoning and drainage-aware building permissions in master plans; make rainwater harvesting and permeable surfaces mandatory.
• Implement NDMA's urban flooding guidelines: dedicated municipal flood cells, real-time rainfall telemetry and IMD's impact-based flash-flood warnings.
• Institutional fix: a single empowered drainage authority per city with hydrological expertise.

Cities must stop treating water as an enemy to be expelled and start making room for it. Only when drainage, wetlands and zoning enter the core of urban planning will 'smart' cities stop drowning in ordinary monsoons.