Urban Flooding

General Studies Paper-1

Context: Bengaluru rain has led to widespread waterlogging, severe damages and traffic disruptions.

• Environmentalists and water conservationists have flagged the poor status of the city’s current drainage system, which is outdated and ill-equipped to handle the city’s current population and rainfall intensity.

What are Floods?

• Floods are the most frequent type of natural disaster and occur when an overflow of water submerges land that is usually dry.

Types of Floods

• Flash floods are caused by rapid and excessive rainfall that raises water heights quickly, and rivers, streams, channels or roads may be overtaken.
• River floods are caused when consistent rain or snow melt forces a river to exceed capacity.
• Coastal floods are caused by storm surges associated with tropical cyclones and tsunamis.
• Urban flooding occurs as a result of land development. Permeable soil layers are being replaced by impermeable paved surfaces, through which water cannot infiltrate.
• This leads to greater runoff being generated, which can make rivers out of roadways and ponds out of car parks.

Causes of Urban Flooding

• Heavy or intense rainfall in a short period.
• Blocked or undersized drainage systems.
• Encroachment of natural drains, lakes, or wetlands.
• Loss of green cover, leading to reduced water absorption.
• Rapid urbanization without proper planning or zoning regulations.
• Outdated infrastructure that can’t handle current population or rainfall levels.

Solutions to Mitigate Urban Flooding

• Upgrading and maintaining stormwater drainage infrastructure.
• Protecting and restoring wetlands, lakes, and natural waterways.
• Promoting green infrastructure: rain gardens, green roofs, permeable pavements.
• Implementing urban planning policies to prevent construction on flood-prone areas.
• Rainwater harvesting and better solid waste management.

Government Initiatives

• Swachh Bharat Mission (Urban): While primarily focused on sanitation, this mission also emphasizes solid waste management and pollution control, which contribute to preventing waterlogging and flooding.
• National smart cities mission: It promotes the measures to manage urban flooding through rainwater harvesting, green spaces and proper drainage system.
• Atal Mission for Rejuvenation and Urban Transformation (AMRUT): The Mission focuses on developing basic urban infrastructure in cities and towns, particularly in the areas of water supply, sewerage and septage management, and stormwater drainage.
• Guidelines and Regulations: The government has issued guidelines for sustainable urban development, encouraging the incorporation of features like permeable pavements, green roofs, and retention ponds to enhance water absorption.

Conclusion

• Combining engineering solutions, smart urban planning, real-time technologies, and community participation is key to building flood-resilient cities and effectively mitigating the challenge of urban flooding in India.