# A Practical Approach on Reducing the Flood Impact: A Case Study from Romania
## 1 Introduction  
Floods are unpredictable hydrological phenomena that can have a devastating impact on communities. They are influenced by various factors such as climate, terrain geomorphology, slope, soil type, vegetation, etc. [1]. Besides these, anthropogenic influences can exacerbate or mitigate the effects of the flood, altering natural water flow. These changes include urbanization, deforestation, and infrastructure (like roads and bridges) [2]. River dams can regulate river discharge, but their failure can have catastrophic downstream effects [3]. For example, The Teton Dam in Idaho, USA, built in 1976, broke in June of the same year at the first filling, causing damages of USD 300 million. The cause of this disaster was internal erosion in the dam [4]. In 2013, 134 bridges were destroyed, and 1035 roads were damaged in Guerrero state in Mexico due to two tropical storms. The economic loss was estimated at over USD one billion. Roads and bridges were crowded, and their structure was damaged. The drainage systems of the highways or railways were also overloaded. Events such as the Teton Dam failure in Idaho and the destruction of numerous bridges and roads in Guerrero state, Mexico, underscore the urgent need for measures to reduce infrastructure's vulnerability to hydrological phenomena [5]. Embankments situated at a higher level than the floodplains should provide a protective barrier for roads or railways [6]. However, they can act as a river dam when inappropriately positioned, leading to water accumulation. In this respect, most articlesdiscussed the impact of floods on the bridge piers [7; 8; 9; 10; 11; 12], others proposed improved hydrodynamic models for the bridge pier flow [13; 14], and fewer have investigated the impact of the bridge pier on the flood apparition [15; 16]. For example, [PERSON] et al. [17] documented the damages along the Ahr Valley railroad line in Germany, particularly focusing on bridges, which are often the weakest points during flood events. The article demonstrates that under significant pressure, an embankment can fail. Other authors [18] indicated the effects of flooding on railway infrastructure. They show that floods can cause significant economic damage and decrease structures' resistance. A bridge with an insufficiently large opening can further exacerbate the situation, as it hinders the rapid drainage of water during high flows [4]. Despite the topic's importance, only a few articles addressed the following question: How the infrastructure (railway embankments and bridges) favors flooding? This gap in research will be the focus of the present article. Some examples are presented. [PERSON] et al. [19] analyzed the influence of a highway embankment in the case of a flood from northern Italy when 40 km\({}^{2}\) of land was covered by water. For hydraulic modeling, they used data from the rainfall-runoff model and hydrographic data collected during the flood. Comparisons of the simulation results in the scenarios with and without the highway indicate the structure's hydraulic impact. [PERSON] et al. [18] draw attention to the fact that the infrastructure itself is among the factors that can favor the flooding apparition. [PERSON] [20] highlighted the impact of building an embankment on land use in a floodplain within a Polish city, contrasting it with a similar city that lacks such a structure. She emphasizes the advantages of the embankment for land use management and its environmental benefits. Assessing the resilience of a rail embankment located in a flat area against a flood with a 200-year return period, [PERSON] [21] indicated that maintaining railway operations during a flood can influence the safety of the embankment. Other authors have considered physical-based modeling approaches for producing flood hazard maps. [PERSON] et al. [22] highlight the importance of including relevant terrain elements in models that simulate large-scale flooding to determine the dynamics of the events.