In this study, a hydrologic assessment approach implemented in a safety-inspection methodology for river bridges in Turkey was developed in which various hydrologic indicators such as morphometric parameters, land cover and use, precipitation magnitude and type, flood history, and presence of retention structures were selected to assess hydrologic behavior and flash-flood potential of the bridge watershed. According to the proposed approach, hydrologic grading of the watersheds was performed by summing up the grades of the indicators and classifying the bridge watershed with regard to the flash-flood susceptibility of the bridge. This hydrologic assessment approach was applied to 10 river bridges in the Western Black Sea Basin in Turkey, where bridges are often affected by severe flash floods. It was found that the selected indicators encouragingly exhibited the flood potential and hydrologic behavior of the watersheds by comparing the grades of the bridges considered. So, hydrologic assessment could enable engineers to take necessary precautions against effects of flooding on river bridges both in design and operation stages. (C) 2019 American Society of Civil Engineers.