In the present paper, a 3D numerical model has been applied to predict the flow hydrodynamics around power intakes within the Dez dam reservoir. The Dez dam is a 203 m high, double arch concrete dam which is constructed by Italians in 1962. Since then, sedimentation in reservoirhas continued and since the dam does not have bottom outlet, the reservoir bed level is raising by a rate of about 2.5...