Flow depth computation at the toe of an overflow dam in steeply-sloping case

Abstract

Using a definition sketch, a theoretical development is proposed to define the functional relationship between the various parameters of the flow at the toe of an overspill dam. After conversion to dimensionless form, the USBR diagram for determining the velocity at the toe of a steeply-sloping spillway is replaced by a single curve. With the data collected in situ by USBR, the proposed theoretical equation is adjusted to allow for friction along the downstream face of the spillway. Finally, a convenient relationship for calculating the depth of flow at the downstream toe of an overspill dam with a steeply-sloping downstream face is proposed. It concerns steep slopes ranging from 1 on 0.6 to 1 on 0.8.