Description: Several layers were examined as part of the highway improvement needs and risk analysis conducted for the 2022 State Transportation Plan. Identifying flood vulnerability risk for the primary highway systems was analyzed. The Iowa Department of Transportation (Iowa DOT Resiliency Working Group was tasked with developing a flood resiliency analysis that will be integrated into the Iowa DOT's decision-making processes and long-range planning activities. This resiliency analysis will provide Iowa DOT decision makers a high-level metric in order to prioritize locations of vulnerability to flood events. This analysis is composed of three different components with the goal of developing a composite metric to assess Iowa’s vulnerability to flooding. First, vulnerability to 100-year flood events is assessed for the entire Primary Highway System. This first component relates to the robustness of the network and will assess the network’s vulnerability and resistant qualities against flood events. The second measure relates to the redundancy of Iowa’s transportation system. For this analysis, redundancy will be a function of the availability of remaining network segments following a flooding event within each of Iowa’s watersheds. Finally, the transportation system will be prioritized by using a measure of criticality.
Copyright Text: Iowa Department of Transportation - Systems Planning Bureau