Study of the relation between hydraulic jump and the flood water level in the river on the downstream of a spillway

Abstract

Kuningan Dam which is located in Kuningan District, West Java has 21,8 km2 watershed area. This dam also acts as a flood control facility which functions supported by the reservoir’s topography and its spillway building. The spillway building releases excess water from the dam into the downstream area. In the downstream part of the spillway, usually, hydraulic jump phenomenon occurs which depends on the flood water level of the river. The hydraulic jump used in the designing process of stilling basin length. The stilling basin in the spillway building generally designed using Q100. The spillway in Kuningan Dam is designed as a closed conduit channel. In this study, the Kuningan Dam spillway is re-designed as an open channel using ogee type spillway. Based on the modeling result, the length of hydraulic jump that occurs when modeled with the return period discharge of Q25 is 21.54 m, Q50 is 16.65 m, and Q100 is 0.98 m. It is seen that in Q25 the jump was the furthest, so an elaborate study regarding hydraulic jump phenomenon and design standards of the spillway is required.