Rainfall–runoff modeling was compared using two methods: hydrologic (NRCS) and hydraulic (HEC-RAS). The study aimed to simulate runoff hydrographs and compare them to measured values. Results showed that the hydraulic method produced more accurate peak flow and runoff depth estimations compared to the hydrologic method. Larger watershed areas, flow return periods, and rainfall events improved peak flow predictions for both models. Total runoff depth estimations improved only for larger rainfall events. This suggests that using a hydraulics-based approach for rainfall–runoff modeling can lead to better predictions for peak flow and direct runoff, which could impact how engineering analyses are performed for hydraulic structure design and stormwater management.