By 2050, extreme summer rainfall events are projected to bring approximately 25% more rainfall than they do today. In response to these challenges, the European Union recently adopted the Critical Entities Resilience (CER) directive. While this directive primarily targets national critical infrastructure, much of it is situated within cities, where additional local critical infrastructure responsibilities exist.

A new Urban Insight report from Sweco “Expect the Unexpected: Floods and Critical Infrastructure” delves into cities’ preparedness to withstand rainfall-induced floods’ impact on critical infrastructure. It explores how cities can prepare for unforeseen events and proactively plan to enhance both urban and critical infrastructure resilience.

Assess risks for both technical and social infrastructure

The study shows that city assessments predominantly prioritize technical infrastructure over social infrastructure like hospitals, nurseries, and elderly care facilities. 77% of the studied policies mention the electricity sector in relation to rain induced floods, while only 27% of the policies mention not self-reliant groups living in elderly and nursery homes. Also crisis centres, prisons and banks rarely or never occurred as critical facilities in the climate adaptation and resilience strategies in the studied cities.

The report stresses the need to tackle asset vulnerability together with hazard exposure. Cascade effects are a major concern when critical infrastructure fails due to extreme rainfall, as seen in many of the cases described in the report. Almost none of the 26 cities have studied cascade effects in detail, the report shows.

Building resilience in critical infrastructure – key insights

Sweco’s combination of policy analysis and stakeholder input allowed for the formulation of 8 main insights that project managers and policymakers should consider in their work. One of these recommendations is about choosing the right location. For example, when rebuilding a hospital, consider locating it in a location that will not be flooded instead of in a floodplain. But water managers cannot perform this analysis alone, as not only knowledge about the location and depth of possible floods is required, but also knowledge about the vulnerability of the assets themselves.

“To enhance critical infrastructure resilience, we need to delve into asset-level vulnerability, considering factors such as location, construction, and design”, says co-author Martijn Steenstra, climate adaptation expert, Sweco Netherlands. “We must also acknowledge the interdependence of infrastructure systems and prevent cascade effects through cooperation among authorities and divisions.”

Building resilience in critical infrastructure therefore requires a holistic, interdisciplinary approach. Policymakers, project managers, and cities must collaborate to assess and mitigate climate risks comprehensively. Initiatives should encompass hazard exposure, asset vulnerability, cascade effects, and psychological impacts, recognizing that climate change and knowledge evolve over time.

Ending the report is a guide describing seven steps for a more resilient infrastructure in cities, going from determining vulnerable infrastructure to monitoring the implementation.