UPSC Syllabus Topic: GS Paper 3, Disaster and disaster management
Introduction
India’s cities face recurrent flooding every monsoon, exposing weak urban planning and outdated drainage systems. With rainfall becoming untimely and more intense due to climate change, Indian cities are still designed for a climate that no longer exists. Recent floods across Punjab, Delhi, Gurugram, Himachal Pradesh, and Kolkata reveal the urgency of shifting from calendar-based preparedness to rainfall-based planning.
The Growing Flood Challenge
- Shifting Monsoon Patterns: Unseasonal heavy rainfall — e.g., Mumbai recorded 4 mm in 24 hours in May 2025, while Delhi saw 81 mm in a few hours.
- Rising Intensity: A Council on Energy, Environment and Water (CEEW) study shows 64% of Indian tehsils have seen more heavy rainfall days, especially in Maharashtra, Tamil Nadu, Gujarat, and Karnataka.
- Economic Cost: Floods are India’s most damaging natural disaster; a single event now causes losses of about ₹8,700 crore.
- Changing Rainfall Distribution: One-day or one-hour cloudbursts overwhelm urban systems; rainfall that once spread across days is now compressed into hours.
Key Initiatives to Tackle Urban Floods
- Data-Driven Planning: Sub-daily rainfall analysis must guide drainage upgrades. The BMC (Brihanmumbai Municipal Corporation) widened drains to handle 120 mm/hour rainfall.
- Coordinated Sanitation and Drainage Management: Garbage blocks drains; separate municipal departments work on different schedules. Cities like Vijayawada use joint sanitation and engineering teams during rainfall alerts to reduce waterlogging.
- Updating Intensity-Duration-Frequency (IDF) Curves: IDF curves, mapping rainfall intensity over time, should be updated every 5–10 years. The BMC has proposed a new drainage master plan based on updated rainfall trends.
- Catchment-Based Hydrological Design: Drainage design should factor in micro-catchment topography and separate storm water from sewerage networks. This prevents overload and enhances resilience.
Lessons for Flood Preparedness
- Mission-Mode Resilience: Like vaccination drives, flood mitigation requires coordinated, targeted planning beyond seasonal assumptions.
- Real-Time Monitoring: Use IMD rainfall alerts, IoT-based drainage sensors, and citizen apps to enable immediate action.
- Integration of Departments: Drainage, sanitation, and disaster response must align calendars and share resources.
- Learning from Global Practices: Cities like Tokyo and Rotterdam adopt adaptive drainage systems that adjust to rainfall intensity in real time.
Challenges Remain
- Outdated Infrastructure: Many drainage systems are decades old and built for lower rainfall volumes.
- Urbanisation Pressure: Encroachment on wetlands, floodplains, and natural drains worsens waterlogging.
- Institutional Silos: Multiple agencies working independently delay response.
- Awareness and Preparedness: Citizens continue to dump waste into drains, aggravating blockages.
Conclusion
India is not losing to rainfall, but to the illusion that monsoon follows predictable patterns. The way forward lies in real-time rainfall-based planning, updated drainage infrastructure, and inter-agency coordination. Instead of asking “when will monsoon begin?”, cities must ask “are we ready for the rains already falling?”
Question for Practice
Examine how climate change has altered rainfall patterns in India and suggest reforms needed in urban planning and flood management.
Source: The Hindu
