What are the environmental implications of the reclamation of water bodies into urban land use? Explain with examples.

Rapid urbanisation has converted lakes, tanks, marshes and floodplains into real estate, airports and roads. Reclaiming these water bodies removes ecological services that cities then pay for in floods, scarcity and heat.

Environmental implications

• Urban flooding: wetlands are natural sponges and detention basins; their loss channels runoff into streets. Chennai’s 2015 flood was worsened by construction over the shrunken Pallikaranai marsh, Mumbai’s 2005 deluge by encroachment of the Mithi river floodplain, and Bengaluru’s 2022 inundation by building over lake beds and channels.
• Groundwater depletion: paved-over tanks stop aquifer recharge — a key reason Chennai faced its ‘Day Zero’ water crisis in 2019 and Bengaluru rationed water in 2024.
• Loss of biodiversity and livelihoods: reclamation destroys fish and bird habitat; the East Kolkata Wetlands, a Ramsar site that treats the city’s sewage and supports thousands of fishers, faces real-estate pressure.
• Water-quality collapse in surviving fragments: shrunken, sewage-loaded lakes turn eutrophic — Bengaluru’s Bellandur lake infamously froths and catches fire.
• Microclimate damage: losing water bodies intensifies the urban heat island effect.
• Higher disaster vulnerability for the poor, who often settle on reclaimed low-lying land most exposed to waterlogging.

The way forward: notify urban wetlands under the Wetlands (Conservation and Management) Rules 2017, enforce no-construction buffers, revive tank cascades, and mainstream blue-green, sponge-city planning — treating water bodies as civic assets, not vacant plots.