Flash Flood in Ozaukee County, Wisconsin

The flash flooding of streets, creeks, rivers, and low lying neighborhoods in Mequon, Thiensville, Cedarburg and southern Grafton. More specifically, the flash flooding of Pigeon Creek washed out a portion of Highland Rd. The flash flooding of Olau Creek flooded Pioneer Rd. just west of Port Washington Rd., and also flooded Port Washington Rd. just north of Pioneer Rd. The same creek flooded a portion of Bonniwell Rd. The flash flooding of the Little Menomonee River flooded a portion of County Line Rd. between Tamerland Dr. and Granville Rd. The Mequon Nature Preserve experienced flooding including its Education Center. Other roads were closed near the flooded Milwaukee River. At least 400 basements experienced flooding due to excessive runoff or sewer backups. Several vehicles stranded in floodwaters with some floating in relatively deep water.

A historic flash flood and record rainfall occurred over portions of the Milwaukee Metropolitan Area and Southeast WI resulting in damages in the $100s Millions. Warm, moist, and unstable air rose along a stalled front to produce numerous thunderstorms and more than 10 inches of rain in many locations. Widespread flash flooding of streets, creeks, rivers, and low lying neighborhoods occurred. A homeless camp in Milwaukee underneath 1st Street Bridge adjacent to the surge of record flooding on the Kinnickinnic River was swept away. One or two deaths may be a result of this flash flooding with a couple others missing. Thousands of residential homes or businesses sustained major flood damage with dozens classified as destroyed due to 1st floor flooding, basement flooding or foundation collapse. Residential sewage backups, and raw sewage released into rivers and Lake MI by many municipalities was common. A small number of complete road washouts and swift water rescues occurred, in addition to dozens of people stranded in their vehicles in deep, still water in low lying areas. First responders had difficulty getting to their 911 calls including stranded motorists and flooded neighborhoods, due to the numerous flooded roads. Dozens of people were evacuated or relocated from their flooded homes and neighborhoods. Longer duration areal flooding and river flooding, which ranged from moderate flooding to record flooding, then continued for a couple more days. In addition to the flash flooding, a couple hikers were struck by lightning, via a ground current from a nearby strike on a tree, on the Ice Age Trail near Palmyra. They were initially rendered unconscious but did survive.