Culverts are considered one of the most appropriate intersectional hydraulic structures utilized in transferring and directing flow water underneath embankments at roads, highways and railroad in large numbers in drainage basins. The outflow from the culvert outlet is typically in the form of a horizontal jet with streamlines parallel to the bed due to high velocity. The streamlines change pattern with the impact between the outflowing jet from the culvert and the tailwater surface and the resulting velocity changes. This flow pattern change results in increased flow turbulence and generation of secondary flows in the form of vortices in this region, eventually separating and transporting bed particles to the downstream region and developing a scour hole at the culvert outlet. The transported sediments accumulate downstream, forming an elevation on the bed. In time, the energy from the vortices is dissipated through the volume of water in the hole and the scour hole reaches equilibrium. With the passage of time and repetition of the flooding through the culvert, if the necessary measures are not taken regarding the issue in this region, the scour moves upstream and erodes the structure's foundation, interfering with its stability. Protecting the culvert's downstream area against the scouring phenomenon is an essential issue to be addressed when designing culverts, which are passages for transferring water. This study explored the effect of present artificial roughness with different geometric arrangement and dimensions for different slopes on the scouring downstream of a culvert. One of the most important findings of this study was that the maximum culvert slope investigated (5.5% slope) played a greater role in reducing the maximum scour depth downstream of the culvert than the rest of the slopes did. Moreover, the volume and area of sedimentation in tests on the 5.5% culvert slope were smaller than those for other slopes. The tests with a minimum height of artific