Mains Practice Questions

Approach:

• Introduce by briefing about current flood management practices in cities and data of NDMA on Urban Flooding
• Delve deeper into Current Flood Management Strategies in Indian Cities
• Highlight Effectiveness of These Strategies
• Suggest Improvements for Effective Flood Risk Management
• Conclude with Guidelines by the Central Water Commission on Urban Flood Management.

Introduction:

Despite projects like storage reservoirs in cities like Mumbai, India remains highly vulnerable to urban flooding. Out of the total geographical area of 329 million hectares, more than 40 million hectares are flood-prone (NDMA). This underscores the need for targeted, effective flood risk management and sustainable urban planning.

Body:

Current Flood Management Strategies in Indian Cities:

• Expansion of Stormwater Drains: Many cities have been focusing on the improvement and expansion of stormwater drainage systems to prevent waterlogging during heavy rains.
  • In cities like Mumbai and Bengaluru, drainage capacity is being enhanced to cope with higher rainfall volumes.
  • In cities like Delhi and Kolkata, regular desilting of existing drainage systems is being carried out to increase their capacity.
• Flood Forecasting and Early Warning Systems: Cities are adopting advanced flood forecasting tools and sensors to collect real-time rainfall data, river water levels, and stormwater conditions.
  • For example, Chennai has set up sensor networks in water bodies that provide live data for better flood prediction.
• River and Lake Rejuvenation Projects: In cities like Bangalore and Hyderabad, river rejuvenation projects are being undertaken to prevent overflow and flooding.
  • These initiatives aim to manage the water flow and reduce urban flooding by rechanneling rivers and lakes.
• Floodplain Zoning and Land Use Planning: In cities like Mumbai, Ahmedabad, and Pune, floodplain zoning is being implemented extensively to ensure that no new constructions are made in flood-prone areas.
• Coastal Flood Barriers: Coastal cities like Chennai and Mumbai are constructing seawalls and tidal gates to protect from storm surges and high tides, which can worsen flooding during the monsoon season.

Effectiveness of These Strategies:

Despite several flooding mitigation strategies efforts to modernize infrastructure, existing systems often fall short in managing the rising intensity of rainfall, leading to widespread waterlogging and urban paralysis during heavy rains due to:

• Inadequate Infrastructure and Overwhelmed Systems: Existing infrastructure fails to handle the intensity of current rainfall patterns. This results in widespread urban flooding, economic losses, and disruption of daily life.
  • Example: Delhi’s drainage system, designed in the 1970s, has not been updated to accommodate the city's growing population and changing rainfall patterns. This led to heavy flooding in 2023.
• Loss of Natural Water Bodies: The unchecked encroachment on wetlands, lakes, and floodplains in urban areas reduces the ability of cities to absorb rainfall and mitigate floods.
  • Example: Bengaluru has lost 79% of its lakes, significantly diminishing its flood resilience, as these lakes once acted as natural flood buffers.
• Poor Waste Management: The failure to manage municipal solid waste adequately leads to clogged drains and reduced water flow capacity.
  • Example: During the 2020 Mumbai floods, waste accumulation in the drainage system contributed to severe waterlogging.
• Lack of Holistic and Preventive Measures: The current strategies often focus on post-flood relief rather than preemptive measures.
  • There is a tendency to address flooding only when it happens, with little long-term planning or structural resilience built into urban design.
  • Example: After the catastrophic floods in Chennai (2015), recovery efforts were focused mainly on short-term relief rather than rebuilding flood-resilient infrastructure.

Improvements for Effective Flood Risk Management:

• Implementing the "Sponge City" Concept: The Sponge City approach focuses on creating permeable surfaces, restoring urban wetlands, and building green spaces that can absorb and store rainwater. This concept can significantly reduce the risks of surface runoff and waterlogging.
  • Cities like Beijing and Shanghai have adopted this model with considerable success. Indian cities, particularly Mumbai, could benefit from integrating these practices into their urban planning.
• Adopting Smart Stormwater Management Systems: Leveraging IoT-based sensors and real-time data analysis can help cities better predict and manage flood risks.
  • Singapore’s Smart Water Assessment Network (SWAN) provides real-time data to improve flood management.
    • Indian cities like Delhi could integrate similar technologies to improve their response times and flood resilience.
• Restoring Urban Wetlands and Lakes: Urban wetlands and lakes should be protected and restored to enhance flood resilience.
  • Example: Kolkata’s East Kolkata Wetlands play a crucial role in flood mitigation and wastewater treatment. Other cities can follow this model to restore urban wetlands and lakes to their former capacity.
• Green Infrastructure and Vertical Gardens: Cities should integrate green infrastructure into urban development. Vertical gardens, green roofs, and permeable pavements can help absorb rainwater and reduce the burden on drainage systems.
  • Milan’s Bosco Verticale (Vertical Forest) is an innovative model that uses buildings to reduce runoff and improve air quality. Adopting similar designs in flood-prone Indian cities could reduce surface runoff significantly.
• Strengthening Zoning Laws and Ecological Conservation: Stringent enforcement of zoning laws to prevent construction in flood-prone and ecologically sensitive areas is crucial.
  • Additionally, compensatory afforestation and ecological conservation should be promoted to mitigate urban flooding.
• Community-Led Flood Management: Engaging local communities in flood risk management can create a more resilient urban environment.
  • Nagdarwadi, Maharashtra, transformed from a water-scarce area to a water-sufficient one through community-led rainwater harvesting initiatives. Such grassroots-level actions can be scaled across other Indian cities.
• Revamping Public Awareness and Disaster Preparedness: Public awareness campaigns on flood preparedness, waste management, and water conservation can reduce the strain on urban infrastructure during floods.
  • Rotterdam's “water squares,” which serve as multifunctional spaces that store excess rainwater during heavy rains, also act as educational hubs for flood management. Similar initiatives can help raise awareness and build local resilience.

Conclusion:

Urban flooding in India requires urgent and sustained action, as current measures, though necessary, are insufficient to handle the scale of the problem. The Guidelines by the Central Water Commission on Urban Flood Management provide a framework for cities to integrate flood risk management into urban planning, emphasizing sustainable drainage systems, flood zoning, and climate resilience.