Floods are among the most significant natural hazards, posing serious threats to infrastructure, the environment, and human communities. These hazards can cause extensive damage; therefore, effective management and mitigation—particularly in high-risk areas—are essential. In this regard, flood hazard mapping and zoning serve as powerful tools in natural disaster management, helping identify vulnerable areas and supporting proper planning for risk reduction. Flood hazard and inundation maps are of particular importance for evaluating the potential depth and severity of flood damages. By providing accurate information on flood distribution and enabling simulations under various scenarios, these maps facilitate preventive decision-making and risk reduction. In this study, to calculate the flood peak discharge, meteorological and hydrometric data from the Poldokhtar hydrometric station were utilized. The flood hydrograph for return periods of 30, 100, 300, and 1000 years was obtained from the Poldokhtar station, with peak discharges of 2340, 3385, 4540, and 6121 cubic meters per second, respectively. Subsequently, using the HEC-RAS hydraulic model and incorporating DEM data (with resolutions of 40 cm, 1.5 m, and 10 m), as well as Manning’s roughness coefficients based on land use and the generated hydrographs, flood inundation maps were produced. Finally, by preparing a Weak Points map derived from the flood modeling and delineating the river boundaries, 22 scenarios corresponding to the 30-, 100-, 300-, and 1000-year return periods were analyzed. Based on these, flood depth and hazard maps (considering depth and the product of depth and velocity) were developed to support optimal decision-making in flood risk management.