The discusser would like to thank the authors for presenting discharge coefficient data for nonvented trapezoidal labyrinth weirs with quarter-round and half-round crest shapes for sidewall angles of 6, 8, 10, 12, 15, 20, and 35°. Different sets of weir models having weir height P 1⁄4 15.24 cm and P 1⁄4 30.48 cm are studied by the authors. The work by the authors in accomplishing the regression equations applicable to discharge coefficients is really appreciated. These accurate equations are applicable to the trapezoidal labyrinth weirs that have sidewall angles of 6, 8, 10, 12, 15, 20, and 35° with head to weir height ratio of 0.05 ≤ Ht=P ≤ ∼0.8 − 0.9. The regression equations presented by the authors are selected over polynomial relationships because of their improved data representation (R ≥ 0.99) and extrapolation performance (they remain well behaved up to Ht=P ≤ 2.0). It worth noting that for other wall angles between 6 and 35°, the interpolation procedure should be employed to obtain the discharge coefficients. The application of the linear interpolation technique for determining the values of the discharge coefficients for intermediate values of the sidewall angle seems to be inappropriate because of the nonlinearity of the discharge coefficient curves. However, in practice it is very suitable to have a single equation applicable to any sidewall angle between 6 and 35°. Thus, the discusser would like to introduce unified regressionbased equations for discharge coefficients (based on experimental data presented in original paper), which are valid for any sidewall angles between 6 and 35°. For this, the head to weir height ratio (Ht=P) and sidewall angle (α) are considered as independent variables in the proposed equations for discharge coefficients. It should be noted that the thickness and the crest curvature of the weirs may influence the flow pattern and cause different values of the discharge coefficient (Azimi 2013). This investigation attempts to find a generalized and unified equation for the discharge coefficient of the labyrinth weir. The proposed equation renders the authors’ study more valuable and will be accurate and easy to use in practical situations.