Shaft spillway with deflector downstream of vertical bend

This study considers the hydraulic design of a shaft spillway with a constriction at the upstream end of the vertical bend. The effect of key factors relating to the capacity of the crest, shaft and tunnel is assessed using hydraulic model investigations of several spillways and available experience from other relevant research. As a result, new expressions for the discharge and velocity coefficients have been established. An algorithm for the design procedure, based on previous experience, is also presented.