Major cities of India are becoming vulnerable to flood conditions. Discuss.

Hydro-climatic pressure

• Many large cities sit on coasts, deltas, or river terraces: Mumbai, Chennai, Kolkata, Kochi, and parts of Surat are exposed to the sea, the tide, and cyclone rain.
• Monsoon bursts and cloudbursts now often dump a large share of monthly rain in a day, which older storm drains were not sized to carry.
• Climate change raises the chance of extreme rain and, on the coast, of higher sea levels and storm surge that hold river water back.
• Himalayan and foothill cities such as Srinagar and parts of Guwahati face river floods plus slope debris that chokes channels.

Urban form that creates the flood

• Lakes, tanks, wetlands, and floodplains have been filled for housing and IT parks; Chennai’s Pallikaranai marsh and Bengaluru’s tank chain are textbook losses of storage.
• Natural drains (nullahs, nalas) are narrowed, covered, or used as sewer lines, so peak flow has nowhere to go.
• Paved catchments and high-rise plots raise runoff coefficient; rain that once soaked laterite or alluvium now hits the road in minutes.
• Solid waste and construction debris sit in drains; a blocked grill turns a 50 mm shower into a street river.
• Informal housing on riverbanks and nala edges puts the poorest in the deepest water and also squeezes the channel.

Governance and infrastructure gaps

• Storm water and sewage are mixed in many wards, so a flood is also a health event.
• Municipal maps of micro-drains are incomplete; pumping stations fail when power or maintenance fails, as Mumbai’s Mithi story after 2005 showed.
• Upstream dams and barrages, if operated without city warning, can worsen a downstream urban flood.
• Insurance, early warning, and last-mile alerts still miss slum pockets even when the IMD issues a red warning.

Why ‘major cities’ in particular

• High population density means the same water depth harms more lives and more GDP in a few hours.
• Underground metros, flyovers, and basements add new traps for water that old towns did not have.
• Peri-urban sprawl beyond municipal limits grows faster than drainage plans, so the flood starts in the suburb and enters the core.

What discussion should recommend

• Restore tanks and wetlands as infrastructure, desilt and widen primary drains, and separate storm water from sewage.
• Enforce floodplain and tank-bed zoning; stop regularisation of marsh fill.
• Design roads as temporary channels with safe ponding parks, and keep pumping and power backup for the lowest wards.
• Link IMD nowcasts to ward-level sirens and to the urban poor, not only to television.

Way forward for the answer

• Argue that vulnerability is extreme rain plus a sealed, encroached city, illustrated by Mumbai, Chennai, Srinagar, and Bengaluru.