Analysis of Flood Management of Linei River at Toboali City Using SWMM 5.1 (Case Study of the Rawabangun Region)

Rawabangun, is one of the areas in the city of Toboali, South Bangka Regency which is often hit by floods. There is the main river that passes through the Rawabangun area namely Linei River and wastewater from almost all of the drainage in Toboali city ends on this river. The Rawabangun area is ± 1 kilometer from the coast so that the sea tides have an effect on the output process of water in the river downstream channel. This study aims to analyze floods and how to handle it. The analysis is conducted by modeling the condition of the drainage and the river network using the Storm Water Management Model (SWMM) 5.1 software and the rainfall used is the rain with the return period of 5 years. From the analysis found 9 overflow points in the channel. Conducted the implementation of 3 alternatives for flood management, namely infiltration wells, retention ponds and modification of existing channels. From the analysis selected the most effective management in reducing flooding namely the handling with 1267 infiltration wells combined with 3 retention pools. The combination of these two treatments is able to overcome flooding in 9 channel overflow points.