To make optimum use of the River Nile water, a decision to construct a new barrage downstream the old Assuit Barrage was taken based on a detailed feasibility study. The impacts of constructing the new Barrage were assessed using the 2-D capabilities of a three-dimensional hydrodynamic model “Delft-3D”. The model was calibrated against measured data, precisely velocity distributions from field survey at the Barrage site. The impact of constructing the Barrage on the flow distribution and velocities was then investigated using this model. Model predicted hydrodynamic parameters, without and with the Barrage, were analyzed in detail. The model revealed that the best flow distribution between the left and right branches of Bani-Murr Island is 60% and 40% respectively. In the same context, the velocity comparison between baseline tests and the Barrage’s different operating schemes indicates that the proposed alternatives has almost no effect on the velocity magnitudes or flow distribution at the downstream reach, except for the case of passing 1000 m3/s through the powerhouse with equal flow distribution between Bani-Murr Island branches.