Coastal Flooding in India: Causes & Consequences

• The World Bank’s report Towards Resilient & Prosperous Cities in India warns that rising sea levels could severely impact Indian coastal cities by 2100, with areas in Mumbai identified as major coastal flood hotspots.

About Coastal Flooding

• Coastal flooding is the inundation of low-lying coastal areas caused by elevated water levels due to storm surges, high tides, or extreme waves.
• Recent Events in India:
  • Cyclone Tauktae, 2021: The West Coast was flooded, Kerala and Gujarat were severely affected.
  • Cyclone Ockhi, 2017: Coastal inundation in Kerala and Tamil Nadu.
  • Kerala Kallakkadal, 2012: Sudden swell-driven flooding along the southwest coast.
  • Mumbai Monsoon Floods, 2020: Heavy rainfall caused urban coastal flooding and waterlogging.

Driving Factors of Coastal Flooding in India

• Storm Surges: Tropical cyclones in the Bay of Bengal and Arabian Sea cause severe coastal flooding. E.g., Cyclone Hudhud (Andhra Pradesh) and Cyclone Tauktae (West Coast).
• Sea-Level Rise (SLR): Rising sea levels, caused by global warming, increase the frequency and intensity of floods. E.g., Indian Ocean GMSL projected >1 m by 2100 (IPCC).
• Swell-Induced Flooding: Long-period swells from distant oceans can inundate coasts without the need for storms. E.g., Kallakkadal events along Kerala’s coast.
• Extreme Weather: Seasonal monsoon waves and uneven rainfall intensify flooding.
• Human Activities: Unsustainable development and loss of coastal vegetation, increasing flood vulnerability, especially near ports and urban expansions.

Socio-Economic Impact of Coastal Flooding in India

• Loss of Life: Monsoon floods in Telangana and Andhra Pradesh caused 25 deaths and displaced thousands in 2025.
• Agricultural Damage: Cyclone Mocha in 2024 destroyed crops and fishing assets, causing ~$1.07 million in agricultural losses.
• Infrastructure Disruption: Flooding in Kerala, inundated homes and disrupted traffic, prompting emergency alerts.
• Economic Losses: Annual coastal flooding costs may rise from $2.4 billion in 2010 to $75 billion by 2050.
• Environmental Degradation: India lost 235 sq km of land to coastal erosion during 1990 to 2016, harming ecosystems and livelihoods.

Mitigation and Adaptation Strategies

• Natural Barriers: Mangroves along the coasts of Odisha and the Sundarbans act as natural buffers, reducing storm surge impacts by up to 50%.
• Integrated Coastal Zone Management (ICZM): Coordinate sustainable development, land-use planning, and disaster risk reduction along coasts.
• Cyclone-Resistant Infrastructure: Construct Sea walls, levees, dykes, groynes, and embankments to reduce inundation.
• Floodplain Zoning: Restrict settlements in Very High-Risk Zones (VHRZ), E.g., parts of the Odisha coast prone to 10–13 m storm surge.
• Early Warning & Monitoring: INCOIS alerts for cyclones and Kallakkadal swells prevented significant losses during Tauktae (2021).
• Community Preparedness: Promote awareness and conduct disaster drills for coastal communities to enhance preparedness.

Coastal flooding in India poses escalating socio-economic, agricultural, and infrastructural risks due to climate change, sea-level rise, and urbanization. Effective mitigation requires mangroves, ICZM, cyclone-resistant infrastructure, early warning systems, and community preparedness.

Reference: Hindustan Times

PMF IAS Pathfinder for Mains – Question 314

Q. Cyclone-induced storm surges are a major driver of coastal flooding in India. Critically examine their impact on vulnerable communities and suggest NDMA-prescribed flood mitigation measures. (250 Words) (15 Marks)

Approach

• Introduction: Write a brief introduction about the coastal flooding in India and mention an example.
• Body: Write major drivers of coastal flooding in India, impact on vulnerable communities and suggest NDMA-prescribed flood mitigation measures.
• Conclusion: Emphasis on a multi-pronged approach for the mitigation of coastal flooding.