Study on Flood Control Facility Design Linking Retention Pond and Rainwater Pumping Station

The primary causes of flood damage in a basin include the inadequate water flow capacity of pipelines and rivers, along with the inability to drain inland water, owing to rising water levels. Flood response facilities, such as rainwater pumping stations (pump-integrated gate type) that actively drain inland water, and retention ponds designed to manage peak flood volumes, are essential. The focus of this study is the Gyeticheon Basin in Haman-gun, Gyeongsangnam-do. To manage flood risks, the proposal includes rainwater pumping stations for the downstream area and an off-line retention pond for the midstream area. This study develops a modeling method that simultaneously plans the side-weir of the retention pond and the rainwater pumping station. In addition, the analysis compared the flood control capacity in relation to the height and width of the side weir, and the operating water level (OWL.) of the pumping station. The results showed that when the (OWL.) of the rainwater pumping station surpasses the height of the side weir, the initial flood volume overflows the side weir, significantly reducing the flood control effectiveness of the basin. Consequently, if the side weir is designed to be low in the construction of a retention pond for flood control, or if a retention pond features a movable weir that tilts during the early stages of a flood, allowing water to overflow transversely into the pond, the flood control effectiveness can be significantly reduced. These findings are expected to aid in the design and operation of complex flood control facilities in future.