The Illinois River is one of the major tributaries of the Upper Mississippi River and one of the major inland waterways in the United States. One reach along the Illinois River that provides great possibilities for the restoration of large river ecosystems is LaGrange Pool located between LaGrange Lock and Dam at river mile (RM) 80.2 and Peoria Lock and Dam at RM 157.7. River miles on the Illinois River are the distance measured from Grafton, Illinois, the confluence of the Illinois River with the Mississippi River. The segment of the Illinois River from LaGrange to Peoria is the least regulated and contains diverse physical environments that provide opportunities for experimentation with different restoration techniques. In addition, the availability of scientific data on geomorphology, water quality, and biota in LaGrange Pool was an important factor in selecting this pool for the study of restoration efforts. Detailed hydraulic modeling is required to provide information to assess the ecological and economic consequences of floodplain management options. The UNET model, containing partial differential equations for the conservation of mass and momentum, simulates one-dimensional unsteady flow through a full network of open channels, including single, dendritic, or fully looped systems. The UNET model can simulate water-level fluctuations due to changes in inflow from upstream or tributaries, channel and floodplain geometry, boundary conditions, or river roughness. In addition, the UNET model enables users to simulate levee failures and storage interactions, gated spillways and weir overflow structures, bridge and culvert hydraulics, and pumped diversions.