Hydraulic design of classical stilling basins downstream of stepped chutes

New design information regarding the hydraulic behaviour of classical stilling basins downstream of stepped chutes is presented and discussed. An extensive experimental campaign revealed that classical stilling basins preceded by stepped chutes cannot be adequately designed using the principles developed for smooth chute approach flow, as is done in common engineering practice. As such, new practical design recommendations are proposed. The detailed design procedure is illustrated with examples of stilling basins downstream of smooth and stepped chutes.