The discussers would like to thank the authors for their remarkable demonstration aimed at the analytical determination of the discharge coefficient value of a shaft spillway operating under shallow heads. In hydraulic engineering, the determination of the discharge coefficient is one of the underlying issues. As a general rule, it is found out from laboratory tests carried out above a lower limit threshold of the relative heads. The discussers would like to share their point of view relating to this subject by adopting a different theoretical approach which leads to a result of the same magnitude. For the analytical determination of the discharge coefficient, the theoretical approach consists to compute the coefficient of the vertical contraction of the flow considering curvature effects as well as the coefficient of velocity taking accounts the velocity distribution
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