During the session of the SDG Local Solutions series, held on 30 April 2025 and co-organized by UNDP and the UNEP Copenhagen Climate Centre (UNEP CCC), two cities — Ahmedabad (India) and Port Louis (Mauritius) — shared their strategies for post-flood recovery and urban resilience. Their experiences provided valuable insights into how cities can respond to extreme weather events by combining localized diagnostics, nature-based solutions, inclusive governance, and innovative finance.
The video recording can be watched on our YouTube channel — in English and Spanish.
Cities around the world are facing an escalating crisis of urban flooding, amplified by rapid urbanization, aging infrastructure, and intensifying climate change. Nearly one-quarter of the global population resides in urban areas, which are increasingly vulnerable to rising water levels. Flooding not only damages infrastructure and livelihoods but also deeply impacts the emotional and social fabric of communities. Recovery requires not just rebuilding, but reimagining cities as resilient systems, integrating multiple solutions.
This article highlights two case studies — Ahmedabad, India, and Port Louis, Mauritius — showcasing how cities can transition from reactive recovery to proactive resilience.
Ahmedabad, India
Context and challenges
Ahmedabad, located in Gujarat, India, faces increasingly intense and concentrated rainfall due to climate change. Between 1970 and 2020, the city averaged 34 rainy days annually, totaling approximately 800 mm of rainfall. However, in extreme flood years, this same amount fell in just 14 days, with peak years reaching up to 1,500 mm. The city’s gray infrastructure has been overwhelmed, leading to repeated waterlogging, especially in low-lying and densely populated areas.
According to ICLEI South Asia’s analysis, 4.3% of the city’s area (20.8 km²) and 9.5% of the population (about 700,000 people) are directly affected by flooding. Vulnerable groups include 88,000 slum dwellers and 5,000 street vendors. Additionally, 28% of Bus Rapid Transit (BRTS) stations and 28.8% of traffic junctions are impacted, disrupting mobility and emergency response.
Solutions and interventions
Ahmedabad’s response is grounded in ICLEI’s Net-zero Climate Resilient Cities Methodology, which incorporates geospatial mapping, hydrological modeling, and actor-based vulnerability analysis down to the ward level.
Key interventions for 2025–2026 include:
- Seven sponge parks (INR 15 crores): dual-use green spaces that function as flood detention ponds during monsoons and recreational parks otherwise.
- Development and interlinking of lakes (INR 100 crores): reconnecting formerly linked lakes (e.g., Bopal-Ghuma, Gotila, Tragad) obstructed by unplanned urban growth.
- Eco blocks: over 1,000 infiltration blocks to improve groundwater recharge.
- Drainage infrastructure: rehabilitation of existing drainage and construction of new stormwater systems in flood-prone zones.
- Flood early warning system: improved alerts based on hydrometeorological monitoring.
- Actor analysis: to identify populations that are at the highest risk and tailor governance, service delivery, and infrastructural changes accordingly.
Lessons learned
Ahmedabad demonstrates that resilience depends on a blend of scientific analysis and community-centered governance. Its ability to localize solutions, prioritize hotspot interventions, and integrate green and gray infrastructure offers a replicable model for cities across the Global South.
Port Louis, Mauritius
Context and challenges
Port Louis, the capital of Mauritius, has a centuries-long history of devastating floods, often linked to cyclones and torrential rains. From the Dutch colonial era in 1673 to the deadly flash floods of 2013 (11 deaths in 90 minutes), the city has faced repeated inundations. In recent years, flash floods in January and April 2024 caused major infrastructure collapses and economic losses.
The city’s unique topography — trapped between a mountain range and the sea — amplifies the risks. More than 300 flood-prone zones have been identified across Mauritius, with 62 classified as high-risk. Within Port Louis, areas like Ruisseau Créole, La Poudrière Street, and the Waterfront remain especially vulnerable.
Flood impacts extend across economic and non-economic sectors:
- Infrastructure: damage to roads, bridges, port terminals, and utility networks.
- Economy: shutdown of businesses, banks, and transport services.
- Social systems: school closures, displacement, and psychological trauma.
- Health: risk of vector-borne diseases and hazardous material exposure.
Solutions and interventions
Despite numerous assessments and plans, Port Louis still struggles to implement resilient infrastructure. Challenges include limited urban space, old and undersized drainage systems, and insufficient maintenance of existing networks. However, the city is gradually moving toward an adaptive recovery model.
Proposed interventions include:
- Real-time early warning systems: recognized as a critical need.
- Emergency evacuation plans: under consideration for future contingency frameworks.
- Nature-based solutions (NbS): proposed NbS include infiltration drains, temporary flood ponds, water harvesting from buildings, and underground water retention systems.
- Policy reform: integrating climate adaptation into urban planning, revising building codes, and introducing private sector incentives.
The city is also exploring legal recognition of “the rights of nature” in future development projects — an ambitious move that would realign urban growth with ecological systems.
Lessons learned
Port Louis highlights the compound vulnerabilities of small island cities — coastal storms, dense urban fabric, and ancient infrastructure. While technical fixes are essential, the key lesson is governance: bold, coordinated, and inclusive action across all sectors is necessary. Without early warning systems, institutional clarity, and participatory planning, even the best solutions remain underutilized.
Conclusion
The experiences of Ahmedabad and Port Louis underscore that flood recovery is not just about restoring the status quo, but about building cities that can thrive amid future uncertainties. These cases illuminate the real-world application of loss and damage frameworks, climate finance, and nature-based adaptation.
Ahmedabad’s data-driven, community-localized planning contrasts with Port Louis’ urgent need for institutional reform and investment. Yet both cities demonstrate the importance of linking global negotiations to grounded local realities.
As climate change accelerates, urban resilience must move from theory to action. The future depends not just on what cities build, but on how — and with whom — they build it.
