The City of Atlanta is susceptible to flooding from Chattahoochee River. The magnitude of damages caused by past floods has motivated re-assessment of current flood infrastructure and policies for emergency preparedness and response. Therefore, it is important to provide flood hazard information to the public, city planners and emergency managers. The aim of this study is to support emergency response in Peachtree, Utoy and Proctor Creek watersheds in Atlanta by producing comprehensive inundation maps for flood events of different return periods (10-, 25-, 50-, 100-, and 500-year floods). A hybrid approach will be used to identify flood risk zones and assess hazard impact by integrating HEC-RAS, GIS and HAZUS technologies. The objectives of this study are: (1) simulation of floods of different return periods using a hydraulic model (HEC-RAS), (2) production of estimated flood-inundation maps at various stream stages using the HEC–GeoRAS computer program and geographic information systems (GIS); (3) modeling social, physical, and economic effects of floods on critical infrastructure and surrounding communities using HAZUS software; and (4) combining the results into a single map. Our results can assist the decision-making authorities to stay informed of possible higher magnitude flood risks while developing flood policies for emergency preparedness.
