Estimating Flooding at River Spree Floodplain Using HEC-RAS Simulation

River renaturation can be an effective management method for restoring a floodplain’s natural capacity and minimizing the effects during high flow periods. A 1D-2D Hydrologic Engineering Center–River Analysis System (HEC-RAS) model, in which flood plain was considered as 2D main channel 1D, used to simulate flooding restored reach of Spree River, Germany. When computing this finite volume difference approximations using Preissmann approach are 1D models, respectively. To comprehend sensitivity parameters several scenarios were simulated different time steps grid sizes. Additionally, dikes, dredging, changes vegetation pattern mitigation measures. The model predicted that would occur mostly downstream portion majority without measures, whereas with floodplain greatly reduced. By preserving balance on channel’s floodplain, area needs kept good condition. Therefore, mitigating measures area’s economic environmental aspects must light potential floods.