Q.18. Flooding in urban areas is an emerging climate-induced disaster. Discuss the causes of this disaster. Mention the features of two such major floods in the last two decades in India. Describe the policies and frameworks in India that aim at tackling such floods. [UPSC 2024 GS P-3]

Causes of Urban Flooding

Urban flooding is increasingly recognized as a climate-induced disaster, driven by a combination of natural and human-induced factors. The main causes include:

1. Climate Change: Rising temperatures lead to more intense and erratic rainfall patterns, which contribute to flooding. This has increased the frequency of extreme weather events like cloudbursts and heavy downpours.
2. Inadequate Drainage Systems: Rapid urbanization often leads to outdated or insufficient drainage infrastructure, which is unable to cope with heavy rainfall, resulting in waterlogging and urban flooding.
3. Unplanned Urbanization: Expanding cities encroach on natural water bodies and floodplains. This reduces natural absorption areas for rainwater, exacerbating surface runoff during heavy rainfall.
4. Impermeable Surfaces: Increasing concrete surfaces, such as roads and buildings, reduce the land’s natural capacity to absorb rainwater. This leads to higher runoff and greater chances of flooding.
5. Encroachment on Water Bodies: Construction on wetlands, lakes, and rivers obstructs natural water channels, making it difficult for excess rainwater to drain, contributing to flooding.
6. Deforestation and Loss of Vegetation: Vegetation helps in water absorption and reduces runoff. Urban deforestation increases surface runoff, causing flash floods.
7. Poor Waste Management: Blockages in drains caused by plastic waste and garbage exacerbate urban flooding, preventing rainwater from flowing into storm drains.

Major Urban Floods in India in the Last Two Decades

1. Mumbai Floods (2005):
   • Cause: On July 26, 2005, Mumbai received 944 mm of rainfall in 24 hours, the heaviest rainfall recorded in the city’s history. Inadequate drainage systems and blocked stormwater channels worsened the situation.
   • Impact: Over 1,000 deaths, severe disruption of transportation, power outages, and property damage. The economic losses were estimated at $1.2 billion. The flooding also exposed the city’s poor drainage infrastructure and lack of preparedness for extreme weather events.
2. Chennai Floods (2015):
   • Cause: Excessive rainfall during the northeast monsoon, exacerbated by the release of water from overflowing reservoirs, led to severe flooding. Encroachment on wetlands and poor urban planning worsened the disaster.
   • Impact: Over 500 people died, thousands were displaced, and economic losses were estimated at ₹14,000 crore (approximately $2 billion). The floods paralyzed the city, severely affecting infrastructure, power supply, and essential services.

Policies and Frameworks in India to Tackle Urban Floods

India has implemented several policies and frameworks to manage and reduce the risks associated with urban flooding:

1. National Disaster Management Plan (NDMP):
   • India’s NDMP, first introduced in 2016, provides a comprehensive framework for disaster risk reduction, preparedness, and response. It emphasizes urban flood risk mitigation through early warning systems, improved drainage infrastructure, and building resilient cities.
   • The NDMP promotes coordination between the National Disaster Management Authority (NDMA) and local governments to implement flood prevention measures and increase public awareness.
2. Urban Flooding Guidelines (2010):
   • Issued by the NDMA, these guidelines focus specifically on managing urban flooding. They emphasize the development of flood forecasting and early warning systems, regular maintenance of drainage systems, the preservation of natural water bodies, and the need for flood zoning in urban planning.
   • The guidelines encourage the use of rainwater harvesting, stormwater management, and sponge city concepts to enhance the city’s capacity to absorb excess rainwater.
3. National Action Plan on Climate Change (NAPCC):
   • The NAPCC, launched in 2008, includes missions such as the National Water Mission and the National Mission on Sustainable Habitat. These aim to promote sustainable urban development, improve water management, and reduce the impact of climate change on cities.
   • The plan promotes sustainable urban planning, including climate-resilient infrastructure, preservation of urban water bodies, and green infrastructure to mitigate the impact of floods.
4. Atal Mission for Rejuvenation and Urban Transformation (AMRUT):
   • Launched in 2015, AMRUT focuses on improving urban infrastructure, including stormwater drainage systems, water supply, and wastewater management in 500 Indian cities. One of its objectives is to prevent flooding by upgrading drainage systems and promoting rainwater harvesting.
5. Smart Cities Mission:
   • This mission, launched in 2015, aims to develop 100 smart cities across India. Part of its agenda is to incorporate resilient urban infrastructure, such as advanced drainage systems, disaster management technologies, and sustainable water management practices, into city planning to prevent urban flooding.
6. Flood Forecasting and Early Warning Systems:
   • The Central Water Commission (CWC), in collaboration with agencies such as the India Meteorological Department (IMD), has developed flood forecasting systems that provide early warnings in flood-prone areas. Advanced warning systems and flood monitoring technologies are crucial in minimizing loss of life and property.
7. Sponge City Initiative:
   • Indian cities are exploring the concept of “sponge cities,” which focus on enhancing the city’s ability to absorb and retain water. This includes the use of porous materials in urban construction, protecting wetlands, and building water-retention structures to mitigate flooding.

Conclusion

Urban flooding, driven by climate change and poor urban planning, poses a growing threat to cities in India. The government has recognized this and introduced several policies and frameworks, such as the NDMP, Urban Flooding Guidelines, and the Smart Cities Mission, to mitigate flood risks. However, successful flood management requires comprehensive urban planning, improved drainage infrastructure, and stronger community engagement to build long-term resilience against flooding disasters.