Dam Break Flood Modeling and Analysis of Its Effect on Downstream Localities, Mihăileni, Romania

Abstract A dam is a hydrotechnical structure facilitating water storage, supply, or electricity generation. At the same time, it plays a crucial role in protecting downstream communities from flooding. Despite the many benefits of a dam, it can pose a risk to downstream settlements in the event of an accident. Both globally and nationally, numerous dams are approaching or have already exceeded their designed lifespan, thus presenting an increased risk concerning structural stability. Considering their continuous degradation and the increased rainfall caused by climate change, it becomes essential to analyze various dam failure scenarios and develop emergency response plans to minimize the loss of human life and material damage. This study focuses on analyzing the Mihăileni Dam in Romania. The effect of this dam’s failure is simulated using the HEC-Ras software version 6.5, based on a 2D hydraulic model, utilizing high-resolution digital terrain model, as well as up to date hydrological data. The study examines the changes in the flood wave along the river, its propagation time, and the number of affected communities and houses following the accident. The results of the simulation are presented, including flood extent boundaries, depth and velocity raster, which can be used to generate detailed maps showing the flood wave’s impact. These maps serve as the basis for developing an emergency action plan in the event of a dam failure and are a crucial tool for intervention teams in emergency situations. The studied dam failure scenario was adopted in accordance with the existing methodology and legislation in Romania, ensuring the accuracy and relevance of the simulation within the local context.