In this paper, the effect of the sediment bed elevation on dam-break flow over mobile beds is scrutinized using the volume of fluid (VOF) method. While the equations of motion are tackled employing the finite-volume and standard k-ε turbulence closure model. The morphological characteristics are studied using the van Rijn bed load transport model. The results show that an increase in the downstream bed elevation leads to reducing: a) the flow advancing distance and water rising over the end wall, b) the sediment transport rate downstream and c) the reservoir releasing rate. It causes the formation and evolution of two hydraulic jumps and corresponding scour holes in the near field and the downstream channel.

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