Design of Logan City\u27s Storm Water Conveyance System

This report summarizes 10th West Engineers’ (10WE) storm water conveyance design for Logan City. The implementation of the design mitigates flood risk due to storm water discharge, helps improve local water quality, and uses infrastructure that would otherwise be abandoned. The system collects storm water discharged along 1000 West and transports the water to the holding pond located at approximately 2400 West 2200 North, Logan, Utah (see Figure 1). Logan City is located in northern Utah’s Cache County. As development and redevelopment occur, storm water runoff quantities will decrease due to new regulations. However, Logan City’s storm water system does not extend beyond 1000 West, which causes localized flooding. This project had three phases. First, 10WE collected data from both Logan City and through field investigations. Second, 10WE designed an efficient system to convey water from existing discharge locations to the holding pond. Third, 10WE completed this final report to submit to Logan City on the proposed storm water conveyance system. 10WE followed several design methods outlined in government manuals. 10WE’s post- construction recommendations for Logan City are: 1) mow banks of each channel annually; 2) conduct a system inspection yearly and after a storm that exceeds the 20-year event to ensure that all channels and diversion structures are operating as designed. 10WE collaborated with the client, Logan City, to ensure the design satisfied all the client’s goals. The client had three goals: design a gravity-fed system, minimize effect on wetlands, and produce an economical design. 10WE collaborated with Cutler Engineering, who designed a treatment process for the storm water, and Westside Drainage Solutions, who designed a drainage system for a farm