Development of a Model of Flood Damage to Roads

The U.S. Army Corps of Engineers performs cost-benefit analyses to determine the economic efficiency of alternative flood hazard reduction plans. Calculation of damage to infrastructure is important in assessing the merits of a particular plan. Floods can damage roads directly, and there are indirect costs associated with travel delays and rerouting until damaged roads are restored to operating capacity. Through an expert elicitation, overtopping of road embankments in floods was identified as the major cause of physical damage to roads. An analytical computer model giving road damage based on flood hydrographs, originally developed for the Federal Highway Administration, is being updated for use by the Corps in an overall planning framework to estimate flood-associated damage. The model, after review, will be freely available for use. The model and planning framework are described.