抄録
The ability of flood control in retarding basin depends on side weir, we must take care of river line and the flow of side weir. In other words, when there is curve near the side weir, flood control is depends on submerged overflow, we must decide the size of side weir using for hydraulic model test.In this paper, it is most suitable size of the side weir by hydraulic model test in Okura retarding basin which is planned on river Kurokawa in Kumamoto pref. We decide the best size of the side weir for flood control and decrease flood control capacity 64,000 m3 from the beginning design, in this way reduce the amount of digging and led to a reduction in construction costs.
