On pediment, alluvial slopes and plains in semi-arid environments small washes constitute potential flood hazards. Population expansion into these geologically less suitable areas represents a major engineering concern. In this study, four flood hazard zones were identified based on the hydrogeomorphic analysis of an area in central Arizona, USA. The flood hazard zones depicted as map units provide a basis for flood management plans which are highly beneficial to engineers and urban planners. As they are based on common geomorphic indicators it is considered they are applicable to other semi-arid environments.