<p>Check dams are widely used worldwide to prevent sedimentation downstream. This study focuses on the impact of check dams on reducing sediment load in the Critical Sub-watersheds of sediment production within the Beheshtabad watersheds in Iran. The hydraulic model HEC-RAS (hydrologic engineering center-river analysis system) and the hydrologic model SWAT (soil and water assessment tool) were used to create a combined modeling system to achieve this goal. The main objective of this research is to identify the Critical Sub-watersheds of sediment production using the hydrologic model SWAT. Following this, The hydraulic model HEC-RAS is used to investigate the effects of check dams on sediment load in these sub-watersheds. The evaluation indicators of the SWAT model, namely the R², for the simulation of monthly flow and sediment load, indicate an acceptable accuracy of the model with values of 0.6, 0.59, 0.60, and 0.53, which indicate the satisfactory accuracy of the SWAT model. The result of the model shows that by implementing the maximum number of check dams in 5 critical Sub-watersheds using the HEC-RAS model, The sediment load can reduced by 76%–38%. The results demonstrate the effectiveness of such combined modeling systems in evaluating the impacts of check dams on flow and sediment.</p>