This study endeavors to develop a comprehensive flood routing model and ascertain dam breach parameters at the Sepaku Semoi Dam. Driven by the escalating threat of floods due to climate change and urban expansion, effective water management strategies are imperative. The increasing demand for water, juxtaposed with limited supply, underscores the pivotal role of dams in maintaining water resources, despite the inherent risks they pose in the event of failure, including loss of life, property damage, and environmental degradation. Focused on the potential causes of dam collapse, particularly overtopping and piping, this research investigates whether the Sepaku Semoi Dam has experienced overtopping through flood routing analysis, complemented by the calculation of breach parameters using the Zhong Xing HY21 model. The primary aim is to enhance understanding of flood dynamics around the dam and bolster the reliability of flood hazard predictions. Through Gap analysis, the study underscores the urgent need for improved flood risk management and understanding of dam failure potential. Employing a methodology that integrates hydrological and hydrodynamic modeling, the study aims to provide deeper insights into flood patterns around the dam and facilitate more precise calculations of dam breach parameters. The implications of this research extend to enhanced flood risk mitigation, emergency planning, and increased dam infrastructure reliability. The study's unique approach lies in its holistic integration of flood modeling and dam breach parameter calculation, which aligns with practical disaster risk management needs. Flood routing analysis indicates that the Sepaku Semoi Dam has not experienced overtopping, as evidenced by the remaining guard heights exceeding the standard guard height, while breach parameters reveal critical insights into potential dam failure scenarios.