IAS/UPSC Coaching Institute  

04 Dec 2025 : Sting in the tail

 Editorial 1: Sting in the tail

Context

Ditwah ravaged Sri Lanka and revealed major infrastructure shortcomings in India.

 

Introduction

Cyclone Ditwah exposed the vulnerability of urban systems to extreme weather as prolonged rainfall turned into widespread flooding across Sri Lanka and Chennai. Despite upgraded drainage networks, the city struggled due to infrastructure gaps, geographical constraints, and limited predictive clarity. The event highlighted how incomplete planning and weak governance mechanisms continue to magnify disaster impacts in rapidly growing urban regions.

 

Impact of Cyclone Ditwah

  • Cyclone Ditwah lingered over Sri Lanka, unleashing continuous rainfall that triggered massive flooding, affecting 14 lakh people and causing 474 deaths.
  • After re-entering the Bay of Bengal, it regained strength briefly and brought heavy rains to north Tamil Nadu and south Andhra Pradesh.
  • By December 1, the storm weakened into a deep depression near Chennai, leading to 18 cm of rainfall in 24 hours, causing widespread waterlogging.
  • Though intense rain challenges any drainage system, public frustration rose as the storm was difficult to predict and the flooding seemed avoidable.

 

Urban Drainage and Infrastructure Gaps

  • Chennai’s stormwater network has been rebuilt since 2015 and further expanded after 2023, but cannot fully prevent flooding.
  • Integrated drainage projects are designed for short, intense bursts of rain, not prolonged heavy rainfall like Ditwah’s.
  • The GCC reported spending ₹5,200 crore to build 1,100 km of drains, but many smaller connector drains remain incomplete.
  • Encroachment and poor desilting, especially along the Kosasthalaiyar River, reduced the city’s capacity to manage excess water.

 

Geographical and Structural Challenges

  • Chennai’s flat terrain, rising paved surfaces, and reliance on three rivers flowing from neighbouring districts worsen urban flooding risks.
  • When upstream basins in Tiruvallur and Kancheepuram flood simultaneously with Chennai, water levels rise rapidly.
  • Broken drainage chains forced GCC to shut certain drains and pump stagnant water against reverse flow during the storm.
  • The lingering storm magnified these structural challenges, leading to repeated waterlogging in vulnerable pockets.

 

Governance, Planning, and Transparency Issues

  • The Thiruppugazh Committee (2021) produced a detailed flood-management report, but it remains unpublished, limiting public scrutiny.
  • Although the government refers to this report for design changes, drain upgrades, and requests for central funds, no unified implementation plan with a deadline exists.
  • Flood maps and elevation models for Chennai exist but are not consistently used for planning, enforcement, or disaster response.
  • To reduce recurring flood impacts, the State must release the report, ensure basin-level coordination, and align temporary measures such as pumping systems with long-term infrastructure upgrades.

 

Conclusion

The aftermath of Cyclone Ditwah underscores the urgent need for transparent governance, timely infrastructure upgrades, and reliable basin-level coordination. Unless Chennai integrates flood maps, enforces proper zoning, and completes long-pending drainage links, similar crises will persist. Publishing key reports and aligning long-term planning with temporary solutions are essential to strengthen the city’s resilience against increasingly frequent and intense storms.