Syllabus
GS Paper 3 – Conservation, Environmental Pollution and Degradation, Environmental Impact Assessment, Disaster and Disaster Management, Developmental issues, Urbanization, their problems and their remedies.
Context
The recent flooding in Chennai has sparked conversations about urban floods in India.
Source
The Hindu | Editorial dated 06- December 2023
What is Urban Flooding?
- Definition of Urban Flooding:
- Urban flooding occurs when land or property in densely populated areas, such as cities, is submerged due to rainfall overwhelming drainage systems.
- Result of both higher precipitation and unplanned urbanization in catchment areas.
- Urbanization can amplify flood peaks by 1.8 to 8 times.
- Urban Flood Disasters in India:
- Hyderabad 2000, Ahmedabad 2001, Delhi 2002 and 2003, Chennai 2004, Mumbai 2005, Surat 2006, Kolkata 2007, Jamshedpur 2008, Delhi 2009, Guwahati and Delhi 2010.
Major Causes of Urban Flooding
- Impact of Changing Climates:
- Altered weather patterns and heightened intensity of rainfall events, attributed to climate change, contribute to more frequent and severe urban flooding.
- Urban areas grapple with the management of increased rainfall, overwhelming existing drainage infrastructure.
- Diminished Natural Absorption Capacity:
- Deforestation, the obliteration of wetlands, and the depletion of green spaces diminish the land’s inherent ability to absorb water.
- Swift runoff, bereft of natural vegetation, accumulates in urban areas, precipitating floods.
- Obstruction from Solid Waste and Debris:
- Inadequate disposal of non-biodegradable waste, encompassing plastics, obstructs drainage systems, giving rise to waterlogging and flooding.
- Deficiency in Public Awareness and Preparedness:
- Limited public awareness regarding responsible waste management, conscientious construction practices, and flood preparedness impedes the implementation of preventive measures and timely responses.
- Inadequate Drainage Infrastructure:
- Many Indian cities grapple with outdated or insufficient drainage systems incapable of withstanding heavy rainfall, resulting in waterlogging and subsequent flooding.
- Encroachment on Natural Waterways:
- Unplanned urbanization and encroachment onto natural drainage channels disrupt the unimpeded flow of water.
- Construction on floodplains and the obstruction of water pathways diminish drainage capacity, exacerbating the incidence of flooding.
- Suboptimal Urban Planning:
- Swift urbanization devoid of meticulous planning results in infrastructure development that disregards its impact on the natural drainage system.
- This impedes the natural flow of water, contributing to urban flooding.
- Intrusions on Drainage Channels:
- Escalating land prices and constrained availability lead to new constructions in low-lying areas without the concurrent widening of natural drains.
- Large-scale encroachments without drainage expansion diminish drainage capacity, culminating in flooding.
- Unregulated Water Release from Dams:
- Unplanned and abrupt water discharges from dams and lakes contribute to urban floods without affording sufficient public warning.
- Instances include the Chennai Floods in 2015 and the July 2023 flood in Delhi.
Impacts of Urban flooding
- Human and Material Losses:
- Urban floods pose a direct threat to human life and property, causing injuries, displacement, and loss of infrastructure.
- Water-borne diseases during flood periods contribute to health complications, adding to the overall impact.
- Disruption of Essential Services:
- Floods disrupt critical services such as electricity, water supply, and communication networks, compounding hardships for affected communities.
- Hindered rescue and relief operations further exacerbate the impact on essential services.
- Waterborne Disease Spread:
- Contaminated floodwaters elevate the risk of waterborne diseases, including cholera, typhoid, and diarrhea, posing additional health threats.
- Increased vulnerability to diseases contributes to the overall public health impact.
- Environmental Consequences:
- Floods contribute to environmental degradation through soil erosion, water pollution, and damage to ecosystems.
- High-speed floodwaters lead to the erosion of riverbanks and the loss of trees and plants during extreme flood events.
- Pollutants and debris carried by floodwaters harm water quality and aquatic life, further intensifying the ecological impact.
- Economic Repercussions:
- Businesses suffer losses due to infrastructure damage and operational disruptions, while the government incurs costs for rescue efforts, infrastructure repair, and rehabilitation.
- Economic consequences extend beyond the immediate aftermath of floods, impacting both local businesses and government resources.
- Psychological Toll:
- Loss of shelter and separation from relatives during floods create emotional distress, leading to enduring psychological trauma.
- Recovery processes are time-consuming, adding to the psychological burden on affected individuals.
- Urban Disruptions and Economic Standstill:
- High population density in urban areas leads to millions being displaced annually, disrupting economic activities and causing a standstill.
- Infrastructure damage, including transportation links, hampers communication and contributes to economic and social disruptions.
Major Interventions
- NDMA’s Response to Mumbai Floods (2005):
- Following the Mumbai floods in 2005, NDMA took specific steps to address urban flooding as a distinct disaster, separating it from general floods.
- Atal Mission for Rejuvenation of Urban Transformation (AMRUT):
- Implementation of AMRUT, an initiative focused on providing essential civic amenities in urban areas to enhance the overall quality of life.
- Smart Cities Mission:
- Introduction of the Smart Cities Mission to drive economic growth and elevate living standards by fostering local development and utilizing technology for smarter outcomes.
- HRIDAY Mission (National Heritage City Development and Augmentation Yojana):
- Implementation of HRIDAY Mission, aimed at conserving heritage, urban planning, and promoting economic growth in heritage cities.
NDMA Guidelines
- Enhanced Hydro-Meteorological Network:
- CWC should expand the real-time hydro-meteorological network to cover all urban centers, aligning with emerging priorities in managing urban flooding.
- Strengthened Local Data Networks:
- Design and reinforce local hydro-meteorological data networks to comprehensively address the requirements of urban flooding.
- Installation of Water Level Recorders:
- Deploy state-of-the-art automatic water level recorders throughout the drainage network, extending beyond administrative boundaries if necessary.
- Restoration of Water Bodies:
- Undertake efforts to restore water bodies through de-silting and other measures, including the revival of water bodies repurposed for different uses.
- Emergency Medical Response Systems:
- Establish local-scale emergency medical response systems for medical preparedness, emergency treatment, mortuary facilities, and disposal of bodies and carcasses.
- Hedging Mechanisms for Vulnerability Reduction:
- Evolve suitable hedging mechanisms, such as life and property insurance, to mitigate vulnerability to urban floods.
- Public Awareness and Preparedness:
- Create public awareness about the importance of maintaining safety kits, including medicines, torches, identity cards, ration cards, important documents, and non-perishable edibles before the monsoon season.
- Media Engagement for Awareness:
- Motivate media companies to initiate or expand awareness generation programs as part of their Corporate Social Responsibility (CSR).
- Community First Responder Support:
- Encourage local residents to form Community Level First Responder Support, comprising ex-servicemen, retired police personnel, paramilitary forces, and Resident Welfare Associations (RWA).
What must be the Way forward?
- Institutional Arrangements:
- Establish a unified flood control implementing agency at the city level, comprising administrative officials, doctors, police, firefighters, NGOs, and emergency service providers.
- Greening Cities:
- Utilize natural defenses, such as East Kolkata’s wetlands, as effective flood defense mechanisms.
- Enhance urban greenery for multiple benefits, including flood control.
- Blue Green Infrastructure Development:
- Utilize Blue Green Infrastructure as a sustainable natural solution to urban and climatic challenges.
- Emphasize water management and robust infrastructure development for improved living environments.
- Rainwater Harvesting Mandate:
- Ensure every building in the city incorporates Rainwater Harvesting as an integral component.
- Blue indicates water bodies, while green indicates trees, parks, and gardens.
- Flood Vulnerability Mapping:
- Identify vulnerable areas through topography and historical inundation data analysis.
- Maintain records of water bodies and wetlands at city and village levels for flood avoidance, tolerance, and resilience.
- Effective Water-Shed Management:
- Construct flood walls, raised platforms along flood-prone river basins, and clean and deepen drainage channels in entire river basins.
- Implement bioswales along roadsides for rainwater percolation and maintain catchment areas free from encroachment and pollution.
- Disaster-Resilient Public Utilities:
- Make public facilities like hospitals and schools disaster-resilient.
- Ensure these facilities can function without hindrance during inundations.
- Sensitization and Rehabilitation:
- Create awareness about flood preparedness and mitigation measures.
- Conduct response drills and educate residents on the risks of illegal constructions near drains and water bodies.