The authors presented a very interesting contribution to the topic of stepped spillway hydrodynamics. Based on a water-tunnel study, they presented some detailed flow features, for example, in terms of the strain rate, which are valuable to designers. The authors stated that “stepped spillways have no documented damage.” It is partially correct. Indeed no cavitation damage and sign of cavitation pitting were reported on stepped spillways after more than 3,000 years of operation, but there were documented damages and failures of stepped spillway systems (Marsh 1957; Jansen 1983; Pravdivets 1993; Chanson 1995b, 2000, 2001a). In this discussion, a number of prototype stepped spillway tests are reviewed and the operational experiences are discussed with a focus on the stepped chute performances...