Discharge Coefficients for Radial-Gated Ogee Spillways by Laboratory Data and by Design of Small Dams

Using the measured data on 15 laboratory models in USA, six and one prototype Turkey, discharge coefficients (C’s) of radial-gated ogee spillways for various gate openings lake water surface elevations are computed. Comparison these C’s 22 with ones given by Figure 9-31 Design Small Dams does not show close agreements. It is determined that C depends both angle Ɵ ratio d/H1, rather than only where d H1 opening upstream head, statistically significant regression equations computed individually each cases.