Abstract Recent years have seen an increase in the intensity of extreme rainfalls and the frequency of floods caused by climate change. As a result, South Korea is facing an ever‐increasing risk of flooding due to typhoons in the summer season. In South Korea, since the implementation of the ‘Four Major Rivers Restoration Project’, a variety of eco‐friendly riverfront facilities, such as ecological parks as well as sports and recreation areas, have been constructed on floodplains. These riverfront facilities have a high risk of damage due to inundations during the rainy season. To perform hydraulic analysis and stability assessment of these facilities, accurate numerical modelling is necessary. First and foremost, it is crucial to address the dry/wet ( DW ) phenomena caused by rising and falling water levels. In this study, a two‐dimensional (2D) finite element model was developed and its applicability was checked against the results of various DW analyses. The developed 2D model was then applied to a natural river undergoing DW phenomena. In the validation test, the applied 2D model demonstrated a high correlation coefficient (R 2 = 0.954). Subsequently, using the results of the model, we calculated four types of flood risk indexes and analysed their correlations to evaluate the stability of the riverside facilities.