Flood propagation modeling: Case study the Grand Ethiopian Renaissance dam failure

Despite significant improvements in design methodologies, dams and water-retaining structures failures continue to occur. Dams' failure analysis plays a crucial role in the development of dam safety planning and emergency action. Since the Grand Ethiopian Renaissance Dam (GERD) has been built, there have been many concerns about its safety and its effects on downstream countries in case of its failure. In this paper, the GERD break was modeled by using the USACE Hydrologic Engineering Center's River Analysis System (HEC-RAS). Two dimensions model under different failure scenarios was suggested. Moreover, outflow hydrographs and flood inundation maps were presented due to dam breach. Finally, it was concluded that, in case of catastrophic failure, flow depths may vary from 3 to 10 m in some residential areas, such as Khartoum. Furthermore, the water surface elevation may reach 184 m above msl (mean sea level) in Lake Nasser in case of dam failure with a fully stored GERD reservoir. Moreover, the maximum flow would reach 325,928 m3/sec which is more than 21.5 times the total capacity of the dam spillway. Finally, the paper's outcomes may assist decision-makers in developing alternate plans to deal with the dangers of GERD break.(c) 2023 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

Automated summary

Despite improvements in design methodologies, dam failures still occur. Dam failure analysis is crucial for safety planning. This study modeled the break of the Grand Ethiopian Renaissance Dam (GERD) using the USACE Hydrologic Engineering Center's River Analysis System (HEC-RAS). Different failure scenarios were suggested, and outflow hydrographs and flood inundation maps were presented. It was concluded that in case of catastrophic failure, flow depths may vary from 3 to 10 m in residential areas, and the maximum flow would exceed the dam's total capacity. These findings can assist decision-makers in developing alternate plans to deal with the dangers of GERD break.