Freese and Nichols is in the final phase of a comprehensive evaluation, hydraulic modeling, alternatives assessment and improvement plan for the aging Central Arlington Heights Neighborhood urban drainage system. Freese and Nichols began the project with hydraulic modeling of the 464-acre watershed using EPA-SWMM software and identifying “hot spot” flooding locations. Our team converted the models to InfoWorks SD/2D to evaluate storm drain trunk lines during design storm conditions and to complete an accurate, cost-effective improvement program. We evaluated several improvement alternatives including tunneling, deep detention and conventional open cut methods. Our current efforts consist of a final study to evaluate incremental improvements and final design for two subsurface detention projects.