Task 4 - Modeling of Mitigation Projects

After the 2-Years MIKE SHE/MIKE 11 simulation was calibrated and validated, the preliminary concept project data was then implemented into the model for analysis. The goal was to confirm concept project performance during a 25-year, 3-day storm event, a 100-year, 3-day storm with two different antecedent conditions, and a 2017 year-long simulated period that included Invest 92L and Hurricane Irma storm events.

The model outputs confirmed the flood mitigation value of the projects as a combined system. Peak water levels were reduced in targeted areas that had demonstrated structure flooding as a result of the 2017 major storms. These peak water levels were reduced in these key downstream areas by one foot to several feet. In addition, the duration of peak stages was significantly reduced in many cases. The overall reduction of peak water levels and improvement in recovery time will provide significant benefits to the widespread prolonged road flooding previously encountered.