<![CDATA[The Copong Weir in Garut Regency is a hydraulic structure that functions as a provider of irrigation water; however, sedimentation problems often arise, reducing storage capacity and disrupting the weir’s function. Therefore, a quantitative study of sediment transport is needed to support more effective management. This study aims to analyze sedimentation at the Copong Weir using the HEC-RAS 6.6 software. The research stages include hydrological analysis using probability distributions to obtain design discharges, hydraulic analysis, and sediment transport simulations. The hydrological analysis results show peak discharges for return periods of 2 years at 453.37 m³/s, 5 years at 560.08 m³/s, 10 years at 625.66 m³/s, 25 years at 704.21 m³/s, 50 years at 759.43 m³/s, and 100 years at 814.87 m³/s. The HEC-RAS simulation produced Mass In Cum values that increased in line with higher discharges, ranging from 11,351.94 tons (Q2) to 18,743.90 tons (Q100). Meanwhile, Mass Bed Change Cum indicated both deposition and erosion variations. At Q2, deposition of 51.64 tons occurred, whereas from Q5 to Q100 erosion predominated, with the highest value at Q100 reaching -3,291.73 tons. These results confirm that higher discharges accelerate riverbed erosion and increase the volume of transported sediment. Thus, HEC-RAS 6.6 can be effectively used to analyze sedimentation at the Copong Weir. The findings provide a quantitative picture of the relationship between discharge and sedimentation and can serve as a reference for planning sediment management to maintain the weir’s function optimally.]]>
