Urban expansion and flooding

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Context:

• The national capital is undergoing one of the world’s fastest urban expansions, with little regard for the land’s natural topography and drainage capacity. This has left Delhi vulnerable to flooding during spells of intense rainfall.

Article details:

Unchecked Urban Expansion in Delhi :

• Urban expansion in Delhi and surrounding NCR cities has been rapid and largely unplanned.
• Between 1991 and 2011, Delhi's geographical size nearly doubled, absorbing erstwhile rural areas into urban sprawl.
• Cities like Bahadurgarh, Ghaziabad, Faridabad, Noida, and Gurugram have also experienced significant urbanization.

Unchecked Urban Expansion in Delhi

Impact of Urbanization on Drainage:

• The expansion has ignored Delhi's natural topography and drainage patterns.
• Historic cities in Delhi were built on higher ground, allowing rainwater to naturally drain. However, new developments lack this foresight.
• High-intensity rainfall leads to significant runoff due to inadequate drainage systems that cannot handle the volume of water.

Concrete and Drainage Issues:

• Urbanization has led to extensive concretization, reducing natural soil percolation and increasing surface runoff.
• Nallahs (drains) have been concretized and turned into sewage dumps, exacerbating drainage problems during heavy rains.
• Construction in low-lying areas, including floodplains along the Yamuna, worsens flooding as these areas are unable to absorb water.

Planning and Governance Challenges:

• There is a lack of comprehensive planning and a "water masterplan" to manage clean and waste water flows.
• Existing infrastructure like the Pragati Maidan Tunnel fails during monsoons due to inadequate planning for drainage.
• Destruction of water bodies—over 600 have been filled up for real estate—has eliminated natural flood management systems.

Immediate Impacts and Losses:

• Recent heavy rainfall resulted in widespread flooding, causing traffic disruptions, power cuts, property damage, and loss of lives (11 fatalities reported).
• Inadequate desilting of drains by civic authorities exacerbates flooding issues during monsoons.
• There is a need to preserve water bodies and incorporate green spaces that can absorb rainwater.
• Suggestions include setting up filtration pits to redirect water to aquifers without contaminating them, promoting gravitational flow over pumping.

Way ahead:

Comprehensive Urban Planning:

• Implement robust urban planning frameworks that integrate land use, transportation, housing, and infrastructure development.
• Ensure zoning regulations are enforced to control sprawl and prevent encroachment on agricultural land and natural habitats.

Sustainable Infrastructure Development:

• Prioritize investments in sustainable infrastructure such as efficient public transport systems, water supply networks, sewage treatment facilities, and waste management systems.
• Promote green building practices and incorporate renewable energy sources into urban development projects.

Preservation of Green Spaces and Water Bodies:

• Protect and enhance green spaces, parks, and urban forests to mitigate the urban heat island effect and improve air quality.
• Preserve and restore natural drainage systems, including rivers, lakes, and wetlands, to manage stormwater and prevent flooding.

Promotion of Compact and Mixed-Use Development:

• Encourage mixed-use developments that integrate residential, commercial, and recreational spaces within walkable distances.
• Promote vertical growth through high-density development to conserve land and reduce sprawl.

Community Engagement and Participation:

• Involve local communities in the planning and decision-making process to ensure their needs and concerns are addressed.
• Foster partnerships between government, private sector, and civil society to promote sustainable urban development practices.

Adoption of Smart City Concepts:

• Embrace smart city technologies to enhance urban management, improve efficiency of services, and optimize resource allocation.
• Utilize data-driven approaches for better urban governance and citizen engagement.

Capacity Building and Governance Reforms:

• Strengthen institutional capacities at local government levels to effectively plan, manage, and monitor urban growth.
• Enhance transparency, accountability, and responsiveness in urban governance to promote equitable and sustainable development.

Conclusion:

• Population growth projections indicate Delhi will surpass Tokyo as the world’s most populous city by 2030, underscoring the urgency of effective urban planning.
• The focus needs to shift towards sustainable urban development that includes robust drainage systems, preservation of natural drainage patterns, and adequate green spaces.

Source:

https://indianexpress.com/article/explained/how-urban-expansion-makes-delhi-susceptible-to-flooding-9427017/