Discharge Coefficients of Standard Spillways at High Altitudes

This paper presents an experimental campaign conducted next to the Condoroma dam, in Perú, at 4075 m a.s.l. The tests carried out in this paper were conducted in a 21 m long channel located at the toe of Condoroma dam. The setup consisted of a series of standard profile spillways with a vertical upstream face of up to five different dimensionless heights (P/H_d) ranging from 0.5 to 2. The experimental results indicated that, the P/H_d ratio influences the discharge coefficients in Condoroma, and P/H_d ≥ 1 values are recommended for the design of the spillway profile. In addition, for all the P/H_d ratios studied, the discharge coefficients adjusted to the Condoroma altitude were lower than those reported by classical formulations used in conventional spillway designs. Finally, a generalized equation is proposed to estimate the discharge coefficient for standard spillways located in dams at similar elevations above sea level.