Integrating Flood Risk Management Is Key to Building Resilient Social Infrastructure

Resilient social infrastructure is no longer optional—it is essential to safeguard lives and ensure the continuity of basic services. This is clearly demonstrated by two ongoing initiatives supported by the Inter-American Development Bank (IDB) in Brazil, in the cities of Porto Alegre and Manaus, which aim to strengthen infrastructure resilience to flooding through the Bank’s technical and financial support.

In May 2024, the Brazilian state of Rio Grande do Sul experienced its worst flooding in 80 years: more than 1.4 million people were affected and nearly 600,000 were displaced, according to the Center for Disaster Philanthropy. In Porto Alegre, the state capital, the Guaíba River reached 5.30 meters—its highest level since 1941—according to Reuters. Manaus emerged as the Brazilian city with the highest number of disaster risk alerts in 2024, recording 50 notifications, as reported by the G1 news portal.

The magnitude of these impacts underscores the urgency for governments to strengthen infrastructure resilience to hydrometeorological hazards. This requires investment in infrastructure that enables schools, health centers, and public spaces to remain operational under extreme conditions. Resilient social infrastructure is therefore critical to protecting lives and ensuring continuity of essential services.

To achieve this, hydrometeorological risk management must be integrated from the earliest stages of design and planning. At the IDB, we actively promote this approach in projects with local and state governments. We support the integration of resilience criteria into social infrastructure investments, comprehensive risk analysis, and institutional strengthening to address increasingly frequent and severe flooding events.

Incorporating hydrometeorological risk management into infrastructure design requires a clear distinction between exposure—the location of assets in areas susceptible to hazards—and vulnerability, understood as the conditions that increase susceptibility to damage. This conceptual clarity enables more effective technical and budgetary decision-making.

Designing for resilience means anticipating floods before they occur; incorporating lessons learned from previous events; elevating floor levels above expected flood depths; selecting materials that perform better in high-humidity environments where wood deteriorates and concrete cracks; and planning for alternative sources of water, energy, and communications when urban systems fail. It also entails building local capacity and empowering communities and governments to oversee, maintain, and adapt infrastructure over time—because resilience is a shared responsibility.

For social infrastructure to withstand increasingly frequent flooding, identifying risks is not enough. Risk information must be translated into concrete decisions across design, construction, and maintenance. The following strategies have proven effective:

1. Use Data to Inform the Location of Public Services
   Hydrological models, flood maps, and geotechnical studies help determine where facilities such as schools and health centers should be located to remain operational after extreme rainfall. Coordinated field visits are essential to validate collected data.
2. Protect Critical Services
   Ensuring accessibility, elevating floor levels, and locating essential equipment above risk thresholds may appear as minor design details on paper, but in practice, they make the difference between a health facility that is closed and one that remains operational during a crisis.
3. Adapt Materials to Climate Conditions
   In high-humidity environments, specifications such as ventilated roofs and vapor-barrier cladding improve durability and reduce maintenance costs over the asset’s life cycle.
4. Incorporate Nature-Based Solutions (NbS)
   Rain gardens, retention basins, and permeable surfaces can complement gray infrastructure while improving the local microclimate. These solutions are not merely technical devices; they also create shared public spaces and enhance urban drainage capacity.
5. Integrate Maintenance Across All Project Phases
   Training local teams in monitoring and preventive maintenance ensures that infrastructure operates safely and sustainably over time. Although often undervalued, maintenance is critical to ensuring that resilient infrastructure not only is delivered, but functions effectively in the long term—again reinforcing the principle of shared responsibility.

Following the 2024 flood, Porto Alegre has begun implementing the first investment of its IDB-supported operation: the construction of the CRAS Glória (Social Assistance Reference Center), a facility dedicated to community services. Climate and geotechnical risk analyses informed both the relocation and architectural design of the facility, which incorporates resilience measures such as elevated ground levels to reduce flood exposure. Based on field visits, flood maps, hydrological modeling, and soil studies, these decisions ensure that the facility is not located merely where space is available, but where it can remain operational even after extreme rainfall.

With IDB support, Manaus—the capital of the Brazilian state of Amazonas—is preparing investments in infrastructure designed to withstand both extreme flooding and severe low-water periods. From the design phase onward, solutions such as ventilated roofs, water-resistant coatings with waterproofing additives, and moisture-resistant door and window frames have been incorporated. The goal is to increase building durability by up to 40% and reduce life-cycle maintenance costs, an essential objective in a territory where extreme humidity poses a constant challenge to construction materials.

While Porto Alegre is already implementing technical redesigns of social facilities with resilience fully integrated into architectural layouts, Manaus remains in the project preparation phase, planning infrastructure that will be resilient by design. In both cases, across different regions of Brazil, the shared objective is to protect lives and ensure the continuity of essential services.

Investing in resilient infrastructure not only protects lives and physical assets but also represents a sound financial decision for policymakers.

Resilience strategies significantly reduce repair and reconstruction costs following disasters, leading to more efficient use of public and private resources. These savings can then be redirected toward new social development investments.

For this reason, the IDB supports local and state governments through risk analysis, resilient design, institutional strengthening, and access to innovative financing solutions. The Bank also promotes regional agendas that address disaster preparedness, response, and recovery; technical capacity-building; multisectoral coordination; and the sustainable development of infrastructure and public services. One example is the IDB Group’s regional program Ready and Resilient Americas, designed to strengthen disaster resilience across Latin America and the Caribbean (LAC).

In summary, investing in resilience is a strategic decision that protects lives, reduces losses, and improves quality of life.

To explore technical guidelines applicable to the design and adaptation of social infrastructure, we recommend the following publications:

• Green Schools, which provides guidance on sustainable, low-carbon, and resilient school infrastructure design;
• Green Buildings, offering methodologies to integrate and account for climate mitigation and adaptation measures;
• Hospital Design and Construction, presenting recommendations to improve infrastructure project management in the health sector.