Water Resources Research Act Program

Details for Project ID 2018GA386B

A Hybrid Approach of Analyzing Urban Flood Risk: A Case Study in the City of Atlanta, GA

Institute: Georgia
Year Established: 2018 Start Date: 2018-03-01 End Date: 2019-02-28
Total Federal Funds: $13,008 Total Non-Federal Funds: $36,860

Principal Investigators: Nirajan Dhakal

Abstract: The Atlanta metropolitan area has been one of the most rapidly urbanizing population centers in the United States since the mid-20th century [Wright et al., 2012] and is projected to continue expanding in the next several decades. The City of Atlanta is susceptible to flooding from the Chattahoochee River as well as several creeks that flow through the city. In recent years, Atlanta has experienced severe flooding that has caused substantial damage along Peachtree Creek, Proctor Creek and Utoy Creek. The floods of September 2004 and September 2009 are two such notable events. The magnitude of damages and loss of life caused by these events have motivated serious re-assessment of current flood infrastructure and flood policies for emergency preparedness and response. Therefore, it is important to provide easy to read graphical information related to flood hazard to the public, city planners and emergency managers. Flood inundation maps are very essential for municipal planning, emergency action plans, flood insurance rates, and ecological studies [Goodell and Warren, 2006]. The aim of this proposed 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). We will use a hybrid approach in identifying flood risk zones and assessing the extent of impact of the hazard by integrating HEC-RAS, GIS and HAZUS technologies. The specific objectives of this study are: (1) simulation of flood flows of different return periods using a hydraulic model (HEC-RAS), (2) production of estimated flood-inundation maps at various stream stages using the U.S. Army Corps of Engineers HEC–GeoRAS computer program and a geographic information system (GIS); (3) modeling the social, physical and economic effects of estimated floods on critical infrastructure and surrounding communities using HAZUS computer program; and (4) combining the results of HEC-RAS, HEC–GeoRAS and HAZUS in a single map. The results of this project can assist the decision-making authorities to stay informed about the possible higher magnitude flood risk areas in the three watersheds and integrate this information while developing flood policies for emergency preparedness and recovery planning as well as mitigation plans.