The study strives to define the optimum position of a set of groins to minimize the erosion 450m away from the bank that faces the diversion channel at New Naga Hammadi Barrage on the River Nile south of Egypt. Diverse techniques were used to affect the flow pattern. Physical work was carried out to investigate and to evaluate the groins ability to protect the opposite bank of the diversion channel from erosion. A package of 2-d mathematical model based on finite element theory was used in attempt to simulate and predict the flow pattern surrounding a group of groins. The simulation is focused on the study of velocity in the longitudinal and transverse directions. Also, the working length of each group, the water level fluctuation and the geometry of scour holes were investigated. The study cases concluded the best performance working lengths for different variables and several recommendations were outlined.
