The Big Muddy River watershed in Illinois, USA, has suffered from historical agricultural, mining, and levee practices, resulting in habitat loss and flooding issues in populated areas like Cape Girardeau. The impact of river channel geometry on flood behavior has been extensively studied, focusing on how floodplain reconnection can enhance meandering recovery, ecosystem services, and flood protection. However, there is a need to investigate what dimensions and locations of a flood-relieving impoundment could be built. Thus, this research aims to understand the relationship between river hydraulics and the impoundment area that allows flow passage to reduce flooding. The proposed study will develop an idealized domain that represents a riverine system with floodplain reconnection and could be tested under numerous simulations using a hydraulic model at a low computational cost. Morphological analyses of channel soil were conducted to set up the system based on real data, complemented by bathymetric and hydrologic data to simulate various flows based on exceedance probabilities. Established thousands of input combinations will be simulated using the 1D HEC-RAS. Obtaining graphical outputs allows us to analyze how the area of impoundments changes concerning the various input variables, helping to understand the relationships between flow changes, slope, and channel geometry to reduce flooding downstream on the Mississippi River. This will lead to understanding flood dynamics and the effectiveness of flood-relieving impoundments and contribute to habitat restoration efforts, flood management, and infrastructure planning by identifying areas where impoundments can be strategically located to enhance habitat and ecosystem services recovery.
