W Water is a crucial element for the survival of all creatures on Earth, especially humans. Thelimited availability of water requires the wise management of water resources, includingthe construction of dams. In Indonesia, several dams have been built, one of which is theSepaku Semoi Dam. This dam has a capacity of 10 million m3 with a flooding area of 280hectares and functions to reduce floods while supplying raw water at a rate of 2000liters/second to IKN and 500 liters/second to Balikpapan. Despite providing benefits, damsalso have the potential for danger if they experience failure, leading to disasters like flashfloods. This study focuses on analyzing the potential failure of the Sepaku Semoi Dam dueto the piping phenomenon. Using Zhong Xing HY21 software, simulations were conductedto understand the distribution of flood inundation, water depth, arrival time of floods,duration of inundation, and flow velocity. The analysis results indicate that the SepakuSemoi Dam does not experience failure due to overtopping. However, the simulationanalysis results emphasize that the condition of the dam\'s base during a design flood hasthe most significant impact compared to other factors. The analysis of flood inundationreveals that under extreme conditions (base piping), five villages are affected: Kel.Mentawir Village, Wono Sari Village, Suka Raja Village, Argo Mulyo Village, and TenginBaru Village. According to the Decision of the Director General of Water Resources No.257/KPTSD/D/2011 regarding the Classification of Dam Hazard, these villages fall intoZone 1, indicating a flood depth above 0.6 meters. Meanwhile, according to FEMA, Kel.Mentawir Village, Wono Sari Village, and Tengin Baru Village are classified as extreme.Argo Mulyo Village falls into the high category, and Suka Raja Village falls into themedium category.