Flood — Dane, Wisconsin

2018-08-20 to 2018-08-22 · near Waunakee, Dane, Wisconsin

Event narrative

Black Earth Creek crested at 9.73 feet at Black Earth around 2:00 AM on 8/21/18, and at 16.6 feet at Mazomanie around 7:00 AM. The Sugar River and many other creeks and low lying areas continued to flood. The historic flooding resulted in hundreds of citizens rescued, evacuated, or stranded, especially along the highway 14 corridor which parallels Black Earth Creek and then continues into Middleton and Madison. Homes and businesses in Cross Plains, Black Earth, Mazomanie, Middleton, and the west side of Madison were most impacted. Overall, Dane County had 380 homes with affected damage, 857 homes with minor damage, 302 homes with major damage, and 5 homes destroyed. 27 businesses had minor damage and 17 suffered major damage.

A bridge was partially washed out on highway 14 near Black Earth, with highway 14 being closed from Middleton to the Iowa County line due to many washouts and high water. Many other roads in western Dane County were closed due to washouts and high water, including southbound 151 near Mount Horeb and large portions of highway 78. 5000 feet of railroad tracks on the Wisconsin & Southern Railroad were washed out between Mazomanie and Madison.

Wider weather episode

An organized and slow moving low pressure area within a very moist airmass resulted in 9 to 15 inches of rain and historic flash flooding from the west side of Madison to Mazomanie, and south to Belleville. State of Emergencies were declared with hundreds of homes flooded and hundreds of citizens evacuated or stranded in the flood waters. The flash flooding of streets and creeks on the west side of Madison resulted in the drowning death of one man. The already high levels of the Yahara Chain of Lakes reached record levels for the end of August into early September. This resulted in sustained flooding in sections of the isthmus in Madison and lakeshore areas of Lake Monona and Lake Waubesa. In addition to the historic flash flooding, one EF0 tornado occurred in Delavan in Walworth Co. A couple firefighters were indirectly struck by lightning and suffered minor injuries in Cross Plains. Lightning also was the cause of a house fire near Cross Plains.

View location on OpenStreetMap → (43.2052, -89.4772)

Source: NOAA Storm Events Database, event_id 780326. Narrative written by the NWS forecast office that issued the report.