Determination of hydraulic parameters of a headwater gate

To increase net volume of a reservoir metallic headwater gates installed along the spillway lip of the dam is suggested. When the water level in a reservoir rises to a permissible maximum the gate automatically rotates about its horizontal axis, and by lowering of the water level up to its minimum, the gate again automatically rotates its axis and closed. In open position of the gate water flows over its upper lip and below the lower lip. On the basis of the gate's model trial results thin-wall spillway (upper lip) rectangular opening flow coefficients have been obtained. Also was determined dependency of the water level relative lowering on the gate's relative opening. The results obtained by a number of long-term headwater gate automatic action model tests guarantee its reliable operation.