The phenomenon and impact of abnormal weather caused by climate change is not limited domestically, and the frequency and magnitude of natural disasters are increasing. In Korea, heavy rainfall has occurred, and sea level rise is accelerating. This falls under domestic urban disasters, which cause severe damage due to multiple floods in the coastal cities. In this study, the risk of disaster in the coastal cities was examined using XP-SWMM. In order to tackle the risk of flooding due to sea level rise, we examined whether the performance targets for the prevention of disasters were appropriate. Performance targets for the prevention of disasters and various scenarios of sea level rise were applied to the urban drainage system in Changwon City, where flood damage had occurred due to sea level rise. In spite of the freefall conditions for the currently set performance targets for the prevention of disasters, it was confirmed that there is a greater risk of flooding due to sea level rise. The results of this study show the spatial variation of flood risk due to sea level change near the coastal cities. Furthermore, these results can be used as reference data for establishing countermeasures to tackle related disasters.