Recently, pre-monsoon rain has caused flooding in Bengaluru, known as the Silicon Valley of India.

• Over the past few years, Urban flooding has become one of India’s most urgent challenges in terms of climate and infrastructure, as it affects millions of people across urban centres.

About Urban Flooding

• The term urban floods refer to instances when a city receives massive levels of water due to heavy precipitation or other causes (such as cyclone or tsunami), which lead to the submergence of parts of or the entire city, and is coupled with the inability of the city infrastructure to drain the water quickly enough to prevent inundation.
• Concerning Data: As per the data from the government, over 17,000 people died due to floods and heavy rains in India between 2012 and 2021. 
• Constitutional Provision: As per 12th Schedule of the Constitution, urban planning including town planning, regulation of land use and construction of buildings is the function of Urban Local Bodies (ULBs)/ Urban Development Authorities. 
  • The mitigation measures for flood control and preparation of drainage plan comes under the purview of the State Government and Urban Local Bodies/Urban Development Authorities at city level. 
  • The Government of India supplements the efforts of the States through schematic interventions/ advisories. It provides financial and technical support to the States.

Reasons behind Urban Flooding in India

• Climate Change: Global Climate Change is resulting in changed weather patterns and increased  intensity rainfall events occurring in shorter periods.
  • Example: Chennai’s record 1,218 mm November 2023 rainfall – its highest in a century – exemplifies climate change intensifying cyclonic activity, with studies showing a 3x increase in such extreme rain events since 1950.
• Urban Heat Island Effect: According to the NDMA, the urban heat island effect has increased rainfall over urban areas.

• • The hot air pushes the clouds carrying rain higher as they cross the urban heat island.
• Encroachment in Low Lying Areas: The original built-up area of Indian cities has expanded and new developments are taking place in low-lying areas of Indian cities and towns due to rising land prices and less availability of land in the cities.
  • Most of the time, these developments take place on encroachments over lakes, wetlands, and riverbeds. 
• Sea Level Rise: Cities and towns that are near rivers, the ocean, interior cities, dams, and steep terrain are severely impacted due to sea level rise. 
• • For Example: Satellite observations have revealed that the rate of sea level rise is increasing and it rose by 0.11 inches from 2021 to 2022.
• Faulty Drainage System: The urban areas lack adequate drainage infrastructure capable of handling heavy rainfall events.
  • The issue is exacerbated by concretizing the drains and preventing the water from seeping to the ground. 
• Urbanisation: Rapid urbanisation, both planned and unplanned, is responsible for flooding. 
  • Grey infrastructure which includes the flyovers, widening of roads, urban settlements, contribute towards urban flooding in  waterlogged areas.
  • The recent floods in Bengaluru are examples of such planning failures. 
• Loss of Water Bodies and Green Spaces: A study by the National Institute of Urban Affairs revealed that major Indian cities have lost 70-80% of their water bodies over the last 40 years. 
  • This has led to reduced natural water storage capacity, increased surface runoff, and disruption of the natural water cycle.
• Lack of Effective Urban Governance: Despite the 74th Constitutional Amendment Act, key areas such as urban planning, land use and economic development have not fully transferred to city governments as required. 
  • This leads to poor urban governance and mismanagement.
• Illegal Mining: Illegal mining of river sand and quartzite causes soil erosion and reduces the water retention capacity of the waterbody increasing the speed and scale of water flow.
  • Example: Jaisamand Lake-Jodhpur, Cauvery river-Tamil Nadu, etc.

Action taken by Government To Combat with Urban Flooding

Institutional Framework and Arrangement

• National Disaster Response Force (NDRF): The Disaster Management Act 2005 has mandated the constitution of the NDRF for the purpose of specialized response to a threatening disaster situation or disaster.
• The National Crisis Management Committee (NCMC): It  comprises high-level officials of the GoI, headed by the Cabinet Secretary, will also deal with specified major crises.
• Central Water Commission (CWC): Flood forecasts are issued by the CWC in India. It provides a near real time five-day advisory flood forecast on its web portal.
• National Disaster Management Authority: NDMA is the apex body in India for disaster management.
  • Pre-Monsoon Phase:
    • Preparedness: Planning for Disaster Reduction: Focus on plans to respond to a threat or occurrence of urban flooding.
      • National Hydro-meteorological Network
      • National Meteorological Network
      • Local Networks for Real time Rainfall data
      • Doppler Weather radars
    • During Monsoon Phase:
      • Early Warning:  Measures to provide timely, qualitative and quantitative warnings to urban flooding based on the intensity of rainfall.
      • Effective Response and Management: Focuses primarily on emergency relief measures.
    • Post-Monsoon Phase:
      • Restoration and Rehabilitation: Necessary measures to stabilize the vulnerable situation and restore the utilities. 

Various Government Initiatives to Curtail Urban Flooding

• Jal Shakti Abhiyan: It is implemented with special emphasis being given for rainwater harvesting/groundwater recharge. 
• Amrit Sarovar Mission: The initiative was launched under Azadi ka Amrit Mahotsav to develop and rejuvenate 75 water bodies per district nationwide.
  • These revitalized water bodies will serve dual purposes – enhancing rainwater harvesting capacity while commemorating India’s 75 years of independence through sustainable water conservation efforts.
• Atal Bhujal Yojana: The initiative emphasizes demand-side groundwater management through water-saving interventions.
  • Key measures include promoting micro-irrigation (drip/sprinkler systems), transitioning to less water-intensive crops, and adopting mulching practices, all supported by government incentives.
• Atal Mission for Rejuvenation and Urban Transformation (AMRUT) 2.0: The policy mandates rainwater harvesting by channeling stormwater drains into uncontaminated water bodies (free from sewage/effluent).
  • It also prioritizes constructing and reinforcing stormwater drainage systems around these water bodies to enhance urban flood resilience.
• Model Building Bye Laws (MBBL): The Ministry of Housing & Urban Affairs (MoHUA) has formulated Model Building Bye Laws (MBBL), 2016 for the States/UTs. 
  • As per MBBL, all buildings having a plot size of 100 sq.m. or more shall mandatorily include the complete proposal of rainwater harvesting. 

Way Forward to Tackle Urban Flooding in India

• Early Warning and Technological Integration: Establish robust early alert systems using sensors and real-time data, as seen in Buenos Aires. 
  • Geospatial technologies and satellite data should also be used for flood vulnerability mapping, especially in informal settlements.
• Mandatory Climate Action Plans (CAPs): Amend municipal statutes to make CAPs a statutory obligation for cities, ensuring annual implementation with dedicated budgetary allocations and oversight by a climate cell.
• Sustainable and Climate-Resilient Urban Planning: Embrace planning that respects natural topography and hydrology. Integrate green spaces, construct flood-resilient infrastructure. 
  • Adopt the “Sponge Cities” model to absorb excess rainwater effectively.
• Improved Drainage and Water Management: Upgrade and regularly maintain stormwater drainage systems. 
  • Include rainwater harvesting and bioswales in infrastructure design to improve percolation and reduce runoff.
• Decentralized and Balanced Urban Development: Develop and incentivize growth in smaller cities to reduce migration pressure on metros. 
  • A national policy should discourage over-densification, aiming for sustainable economic and environmental outcomes.
• Nature-Based and Blue-Green Infrastructure: Restore wetlands, urban forests, and water bodies. 
  • Promote blue-green infrastructure that combines ecological restoration with urban design to manage stormwater and improve urban resilience.

• Collaborative Governance and Capacity Building: Create institutional mechanisms involving governments, civil society, academia, and industry. 
  • Build citizen awareness and launch large-scale education programs on disaster risk reduction and climate adaptation.
• Citizen Education and Behavioral Change: Launch a nationwide education program to instill disaster risk reduction behaviors in citizens, integrating risk mitigation into daily life, livelihoods, and occupational patterns.
• Emerging Technologies: Using AI and machine learning to predict flood scenarios and optimize flood management strategies.
  • Employing digital twins to simulate flood scenarios and assess the effectiveness of different interventions.

Conclusion

Bengaluru’s recurring floods highlight the urgent need for sustainable urban planning, robust drainage systems, and nature-based solutions. Adopting global best practices like sponge cities and smart monitoring, alongside collaborative governance, can enhance resilience and mitigate future flood risks.

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