Flash Flooding and Flood in Wisconsin, July 10, 2000

A long line of severe thunderstorms moved east at 50 mph across south-central and southeast Wisconsin during the pre-dawn and early morning hours. Besides powerful winds, flash-flood producing rains accompanied the storms. Numerous large trees and power lines were toppled where the severe storms produced straightline downburst winds. In Gratiot (Lafayette Co.), one of the toppled trees landed squarely on a home. Janesville (Rock Co.) experienced a variety of weather hazards. Numerous trees were blown down across the city, with one damaging a home. Lightening struck a power transformer on the west side of the city, cutting off electricity to about 600 customers. In addition, 1.67 inches of rain fell in the pre-dawn hours, resulting in urban flooding. A few manhole covers reportedly popped into the air due to the pressure from the fast-moving runoff. Water depth was reported to be 6 to 12 inches. Elsewhere across south-central and southeast Wisconsin, debris removal and new power poles and lines were the order of the day.Yet another round of serious flash flooding occurred across the central part of Sauk County from the Lime Ridge area east to the Devil's Lake and Baraboo area. After the intial line of storms moved through the county, several additional thunderstorms developed over the western part of the county and repeatedly trained across the same locations. An unofficial 6 to 8 inches of rain fell during the pre-dawn hours, but 3.5 inches were registered at the Baraboo Wastewater Treatment Plant. Nearly every creek and stream in this swath exceeded flood stage experienced rapid increases in water levels which . Highway 113 leading southeast out of Baraboo had several sections washed out. Highway 159 up to Devil's Lake was closed due to the flooding. Highway 12 from West Baraboo down to near the old Badger Ammo Plant was flooded and closed. Several of the hiking and biking trails, and camping spots around Devil's lake had washouts. Several roads on the south side of Baraboo experienced washouts or undercuts as creeks and streams draining north out of the Baraboo Bluffs became raging currents. Mud covered many of the roads in the southern part of Baraboo, and water/mud marks were left at the 8 foot mark in some businesses! Crop damage and soil erosion was substantial in surrounding farm lands.Flash flooding hit the southeast part of Walworth County after 2 inches of rain fell in 1 hour on saturated ground. Nippersink Creek quickly exceeded its banks in the Pell Lake and Genoa City area. Ten homes experienced structural or contents damage, and one home was destroyed. Eight people were left homeless and 6 families were evacuated. Several roads had washout sections and many others had gravel shoulder washouts. Surrounding agricultural lands sustained crop washouts or soil erosion.