Urban water infrastructure in India often comes at the cost of wetland ecosystems. Examine with reference to coastal backwaters and migratory bird habitats.

Coastal backwaters and their intertidal mudflats are feeding stops for birds on the Central Asian Flyway (CAF). India offers stopover sites to over 90% of the species that use this route [2]. Tamil Nadu's proposed Mamallan reservoir in the Kovalam–Nemmeli backwaters near Chennai shows how a city's search for water can destroy such habitat [1].

How water infrastructure damages wetlands

• Habitat change: Dredging and bunding turn shallow tidal mudflats into deep, still water. This removes the food that mudflat feeders like the garganey depend on [1].
• Flyway-scale value at stake: A September 2026 survey counted about 3,500 waterbirds of 51 species. These included over 1,500 garganey, over 700 greater flamingos and 25 species protected under the Convention on Migratory Species (CMS) [1].
• Bad timing: Work during the August–September arrival window does the most harm [1].
• Damage to India's standing: India hosts and funds the CAF Coordinating Unit under CMS [3]. Harming its own stopover sites weakens that leadership.

Why it happens

• Mapping gap: The site's active mudflats are not shown in the coastal zone management plan [1]. Yet India's CAF action plan relies on CRZ rules to protect coastal wetlands [2].
• "Wasteland" mindset: Planners see open mud as empty land to fill, not as habitat.
• Late, informal checks: The Palluyir Trust objected only after work had begun. No required pre-project bird survey flagged the site [1].
• Real demand: Chennai's growing population needs drinking water. The real question is where and when to build, not whether to build.

Way forward

• Schedule dredging outside the migration months, and order a bird-use survey before further work [1].
• Add active mudflats to coastal zone management plans so that CRZ protection actually applies [2].
• Update the 2018–23 national CAF plan to require flyway-site screening of state water projects [2][3].
• Widen supply sources through wastewater reuse, rainwater harvesting and revival of existing tanks.

Water security and healthy wetlands are not rivals, because both depend on intact water systems. With accurate mapping, seasonal timing and early screening, Chennai can secure its water without breaking the flyway. That would honour India's CMS commitments, its CAF leadership and SDGs 6 and 15.