This thesis aims to investigate the end sills in stepped spillways and to assess their effect on energy dissipation. For this
purpose, physical models of four steps were built on stepped spillways. End sills were installed at the end of each step of the spillway. The energy dissipation could be increased by different behaviors, depending on the characteristics of the end sills (height, shape, and V notch angle). The dimensional analysis was used to link the various parameters influencing the studied phenomena. All end sills used enhanced energy dissipation, reduced the relative scour depth, reduced the relative scour length and reduced the relative scour volume. Increasing the relative height of solid and rectangular partially hollow end sills, enhanced energy dissipation. Minimizing the V notch angle of V notch end sills enhanced energy dissipation.