Key Facts

Details of the Tamil Nadu Government sanction issued on 11 November 2026:

• Total Scale: 2,880 civil infrastructure projects cleared across the state.
• Geographic Coverage: Covers Greater Chennai Corporation (GCC), 24 municipal corporations, and dozens of municipalities and town panchayats.
• Core Focus: Desilting of historical tanks, desilting of disposal channels, and strengthening of surplus weirs.
• Retaining Walls: Concrete retaining walls sanctioned along surplus canals in Adyar, Cooum, and Kosasthalaiyar basins to prevent bank breaches.
• Road Relay Mandate: Local bodies directed to mill and relay roads strictly without raising surface elevations, preventing localized compound wall water stagnation.

GK Context

• Tamil Nadu relies heavily on the Northeast Monsoon (October to December) for over 48% of its annual rainfall.
• The traditional 'Eri' (tank cascade) system, engineered during the Chola and Pallava eras, historically acted as an integrated flood mitigation and irrigation network.
• In recent decades, rapid urbanization has fractured inlet and surplus channels, rendering urban sprawls like Chennai, Tambaram, and Avadi vulnerable to flash urban flooding.

Static GK

• The Tamil Nadu Protection of Tanks and Eviction of Encroachment Act, 2007 provides statutory powers to water resources authorities to identify, survey, and remove illegal structures from state waterbodies.
• The State Disaster Management Authority (TNSDMA), operating under the Disaster Management Act, 2005, oversees monsoon emergency response.

UPSC Mains Framework

GS Paper III (Disaster Management & Urban Planning): Discuss the imperatives of nature-based solutions and traditional hydrological cascade revival in building climate-resilient urban coastal settlements in India.