Efficiency of Infrastructure Planning of Retaining Wall as Flood Control in Bangin River Pecatu Badung Bali

A problem often caused by floods is the destructive power of water. Retaining wall construction is one of the flood prevention efforts. The purpose of this study is to identify the problem of flooding in Bangin River in Pecatu Badung Bali in order to take appropriate measures against flooding. B. Ability to plan retaining walls. When planning a retaining wall structure, some analysis of hydrology, hydraulics, and building safety in consideration of economic aspects. The methods used in this study are quantitative methods, namely direct observation and field measurements. Then, recalculations are made based on the design flood discharges at different times for the planning of flood barriers. The design flood discharge results are 15.47 m3/s in Q1, 49.74 m3/s in Q2 and 65.89 m3/s in Q5. The results of the HEC-RAS modeling, the critical depth value at the discharge of the 2- year return period is 1.54 m, the 5-year return period is 1.80 m, the 10-year return period is 1.93 m, the 25-year return period is 2.06 m. and the 50-year return period is 2.04 m. The design height of the retaining wall is 2,91 m above the riverbed. Safety analysis of retaining wall structures calculated based on normal and seismic building stability, bearing capacity it was determined that the design met the requirements due to soil, reinforcement, and foundation correspondences.