Urban Flooding

Urban flooding is an increasingly critical issue faced by cities worldwide, characterized by the inundation of land in urban areas due to an overflow of water from river channels, poor drainage, or heavy precipitation. The phenomenon poses a significant challenge, especially in densely populated cities with inadequate urban planning and infrastructure. In this article, you will learn about Urban Flooding, causes, impacts, government initiatives etc.

This article will provide key insights for GS Paper- III Environment, ecology and disaster management of UPSC IAS Exam.

Table of Content

• Urban Flooding 
• Causes of Urban Flooding in India             
• Impacts of Urban Flooding           
• Government Initiatives to control Urban Flooding
• Way Forward     
• Conclusion         
• Frequently Asked Questions         

Urban Flooding

• Urban Flooding refer to instances when a city receives massive levels of water due to heavy precipitation or other causes (such as rapid snowmelt or a storm surge caused by a cyclone or tsunami), lead to the submergence of parts of or the entire city.
• It occurs when heavy rainfall overwhelms drainage systems, leading to water inundation in densely populated areas like cities.
• Unlike rural flooding, which primarily results from high precipitation over flat or low-lying areas, urban flooding is often exacerbated by unplannedurban development.
  • This unplanned growth can significantly increase flood peaks and volumes.

Causes of Urban Flooding in India

• Encroachments on Drainage Channels: In many urban areas, rising land prices and limited space have led to new developments in low-lying areas, which often encroaches on lakes, wetlands, and riverbeds, and accompanied without increasing area under natural drains.
• Climate Change: Climate change has intensified extreme weather events, including short bursts of heavy rainfall that result in higher water runoff. The urban heat island effect also contributes to increased rainfall in urban areas, leading to flooding.
• Unplanned Tourism Activities: Non-biodegradable waste from religious and cultural activities pollutes the urban water bodies, which during floods often overflows into urban areas. Example: Ashtamudi Lake in Kollam, Kerala, suffers from oil spills from boats.
• Unplanned release of water from dams: Sudden and unplanned releases of water from dams and lakes can cause urban flooding, often without giving residents enough time to react.
• Illegal Mining Activities: Illegal mining of river sand and quartzite for construction depletes the natural beds of rivers and lakes, causing soil erosion, reducing the water retention capacity of these bodies and increasing the speed and scale of water flow.

Impacts of Urban Flooding

• Loss of Life and Property: Urban floods frequently result in fatalities and injuries, either directly from the floods or indirectly from water-borne diseases that spread during the flooding. They also cause localized destruction, damaging buildings, property, and crops.
• Ecological Impacts: Floodwaters can uproot trees and plants, while the high speed of floodwaters can cause severe riverbank erosion.
• Impact on Animal & Human Health: Stagnant stormwater and contaminated drinking water lead to numerous health issues, including outbreaks of diseases.
• Psychological Impacts: The loss of homes and humans due to flooding creates significant emotional distress. The recovery process is often slow, leading to long-term psychological trauma for those affected.

Government Initiatives to control Urban Flooding

• Standard Operating Procedures (SoPs) on Urban Flooding: Issued by Ministry of Housing & Urban Affairs (MoHUA), it provides for a predefined set of directives, that needs to be adopted by different agencies during urban flooding.
• Manual on Storm Water Drainage Systems, 2019: It guides for hydrologic & hydraulic design of storm water drainage systems and includes, planning, designing, detailed engineering, operation and maintenance of various components of urban storm water drainage systems.
• Amrit Sarovar Mission: It aims at developing/ rejuvenating 75 Amrit Sarovar (Pond) in each district of the Country, totaling about 50,000 Amrit Sarovars across the country.
• Atal Mission for Rejuvenation and Urban Transformation (AMRUT) 2.0 Scheme: It provides for harvesting the rainwater as storm water drains into the water body & strengthening of storm water drains around water body.
• Model Building Bye Laws (MBBL), 2016: It has a provision which states that buildings having a plot size of 100 sq.m. or, more shall mandatorily include the complete proposal of rainwater harvesting.

Way Forward

• Developing Blue-Green Infrastructure: Emphasizing sustainable natural solutions, such as sponge cities, can help tackle urban and climatic challenges. Blue-Green Infrastructure involves creating spaces that integrate water bodies like rivers and tanks (blue) with green spaces such as trees, parks, and gardens.
• Flood Vulnerability Mapping: To reduce flood risks, it is crucial to identify vulnerable areas through the analysis of topography and historical flooding data.
• Effective Watershed Management: Implementing measures such as building flood walls, creating raised platforms in flood-prone river basins, and regularly cleaning and deepening drainage channels shall extend across entire river basins, and not just urban areas.
• Disaster-Resilient Public Utilities: Ensuring that public facilities like hospitals and schools, and essential services such as food, water, health, and sanitation, are disaster-resilient is crucial. These facilities shall be located to areas where they can function without disruption during floods.
• Sensitization and Rehabilitation: Raising awareness about flood preparedness and mitigation measures, including conducting response drills, is important.
• Institutional Arrangements: Establishing a unified flood control agency at the city level is essential. This agency should include city administrative officials, doctors, police, firefighters, etc., to ensure a coordinated and effective response to floods.

Conclusion

Urban flooding remains a formidable challenge that underlines the urgency for integrated urban planning and resilience strategies. As cities expand, it becomes crucial to incorporate sustainable water management practices, robust infrastructure development, and community-based preparedness programs.

Strengthening policy frameworks and enhancing cooperation among governmental bodies, local communities, and private stakeholders are key to mitigating the impacts of urban floods. Ultimately, the ability of urban areas to adapt and respond to these challenges will determine their sustainability and livability in the face of increasing climatic uncertainties

Ref: Source-1

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