Barr developed a new probable maximum flood (PMF) study for the Upper Peninsula Power Company. The project included hydrologic and hydraulic modeling and analyses on the upper three reservoirs on the Dead River, a tributary to Lake Superior near Marquette, Michigan. The study covered a 141-square-mile area. HEC-HMS was used to develop a hydrologic model of the watershed. Because there were no stream gages along the study reach, model calibration was performed by adjusting the model parameters to match observed reservoir water levels for storm and snowmelt events. NEXRAD data from the National Centers for Environmental Information (NCEI) data archive to develop precipitation input for the storm events. Snowmelt events were based on the change in regional snow water equivalent (SWE) gridded data obtained from the National Snow and Ice Data Center.
The calibrated model was used to simulate the PMF. The probable maximum storms (PMSs) resulting from the 24-hour mesoscale convective storms and 72-hour synoptic storms were estimated using the WMPMS computer program, based on updated estimates of probable maximum precipitation (PMP) for Wisconsin and Michigan. The PMS was estimated for cool and warm seasons. For the cool season, the 100-year SWE was also inputted into the model. The analysis was documented in a report and reviewed by the Federal Energy Regulatory Commission’s (FERC’s) Chicago and Washington dam-safety staff.