Executive Summary

The direct impacts of flooding can be estimated reasonably accurately but considerable uncertainty still surrounds the indirect impact, the “cascading” effects. To support decision-making on enhancing flood resilience, assessments and associated tools need to go beyond focusing only on direct flood impacts, as indirect impacts on the economic functioning of a region may be much larger, therefore influencing recovery time and resilience.

Consideration of critical infrastructure (CI) for this purpose is significant as failure of one CI can cause cascading effects to other geographic areas and socio-economic sectors than those directly affected. For example, a failing power substation may affect a larger area than the area that is flooded with impacts extending far beyond the period of flooding. Despite these risks, assessments of critical infrastructure are not yet rooted in adaptation planning.

Typical critical infrastructure in Broward county, functioning (above) and disrupted and damaged after hurricane Irma in 2017.
Photo courtesy of Andreas Burzel (Deltares) and Paul Krashefski (Broward County).