Mains Practice Questions

Introduction

Urban flooding occurs when intense and prolonged rainfall overwhelms the drainage systems of urban areas, leading to water accumulation on streets, roads, and buildings. It can also result from other factors such as poor drainage infrastructure and encroachment on natural water bodies.

• The confluence of rapid urbanization, climate change, and inadequate urban planning has exacerbated this crisis.

Body

Causes of Urban Flooding in India:

• Rapid Urbanization and Poor Planning: India's cities are expanding at an unprecedented rate, often without adequate infrastructure planning.
  • This leads to the concretization of natural drainage systems and encroachment on floodplains.
  • For instance, the 2022 Bengaluru floods were exacerbated by construction in low-lying areas and lake beds, disrupting natural water flow.
• Inadequate Drainage Systems: Many Indian cities have outdated and undersized drainage systems that cannot cope with intense rainfall.
  • Mumbai's century-old drainage system, for example, is frequently overwhelmed during monsoons, leading to widespread flooding as seen 2023.
• Climate change and Extreme Weather Events: Climate change is increasing the frequency and intensity of extreme rainfall events.
  • The 2023 Delhi floods, caused by the Yamuna River overflowing due to record-breaking rainfall, exemplify this trend.
• Solid waste Mismanagement: Improper disposal of solid waste often clogs drainage systems, exacerbating flooding.
  • This was a significant factor in the 2023 floods in Himachal Pradesh, where plastic waste blocked natural and artificial drainage channels.
• Loss of Water Bodies and Green Spaces: Urbanization has led to the destruction of natural water bodies and green spaces that act as natural flood buffers.
  • The shrinking of Chennai's Pallikaranai marshland from 50 sq km to just 3.17 sq km has contributed to the city's recurring flood problems.
• Deforestation in Catchment Areas: Deforestation in the upper catchment areas of rivers increases runoff and siltation, leading to more frequent and severe urban flooding downstream.
  • This has been observed in the case of Assam's recurring floods affecting cities like Guwahati.

Sustainable Urban Planning for Flood Resilience:

• Integrated Watershed Management: Implementing comprehensive watershed management plans that consider entire river basins can help mitigate flooding.
  • The "Room for the River" project in the Netherlands, which creates space for rivers to overflow safely, could be adapted for Indian cities.
• Green Infrastructure and Nature-based Solutions: Incorporating green infrastructure like rain gardens, bioswales, and permeable pavements can help absorb and filter stormwater.
• Sponge City Concept: Adopting the "sponge city" approach, which aims to absorb, clean, and use rainfall in an ecologically friendly way.
  • Mumbai’s efforts to implement sponge city principles in its new development plan are noteworthy.
• Sustainable Urban Drainage Systems: Implementing SUDS can help manage surface water by slowing down and reducing runoff.
  • Enforcing strict zoning laws to prevent construction in floodplains and low-lying areas.
• Restoration of Water Bodies and Wetlands: Reviving and protecting urban water bodies and wetlands can significantly enhance flood resilience.
  • The restoration of Bengaluru's Jakkur Lake has improved the area's flood resilience while providing other ecological benefits.
• Community Engagement and Early Warning Systems: Involving communities in flood management and implementing robust early warning systems.
  • Ahmedabad's heat action plan, which includes community outreach, could be adapted for flood resilience.

Conclusion

Addressing urban flooding in India requires a shift to sustainable, nature-based urban planning, aligned with SDGs 6, 11 and 13. By implementing adaptive infrastructure and fostering community resilience, Indian cities can become models of flood resilience and sustainable development.