ABSTRACT
ABSTRACT: A considerable number of embankment dams could experience overtopping during flood events. It can lead to significant damage due to the high energy of the overflow. Since the middle of the eighties, engineers have focused their interest on controlling safe overtopping. Research activities allowed to develop downstream slope surface protections and showed that stepped chutes are very effective. The paper includes a brief overview of these protections. In order to study and to improve the dissipation energy capacity of stepped chutes, alternative macro-roughness systems have been tested for nappe, transition and skimming flows, in a steep 30° slope flume. The results provide the characteristics of the aerated flow for conventional steps and steps fitted with endsills. This last one increases the efficiency regarding energy dissipation and ensures a good slope protection.
