Long-term sediment accumulation in the lake reduced the average depth of the lake from 8 feet in 1903 to 2.6 feet in 1985, which resulted in the deterioration of aquatic habitats and recreational areas in the lake. A detailed hydraulic analysis was needed to evaluate the feasibility creating islands in Peoria Lake. The major hydraulic considerations include determining the optimum locations for the islands in terms of minimizing the sedimentation rates around the islands. A hydraulic study was conducted to investigate the best locations for constructing islands in the lake. The study made use of the one-dimensional HEC-6 sediment transport model and the two-dimensional TABS-2 hydrodynamic model. Field data were also collected to establish existing lake-bottom profiles and velocity distributions at selected locations.