Minnesota
A large swath of heavy rain fell across most of southern Minnesota during Saturday, August 18, and Sunday, August 19, with the highest totals in the far southeast counties of the state. Twenty-four hour rainfall totals of 15.10 inches (384 mm) were recorded in Hokah, which easily broke the old state record of 10.84 inches (275 mm). An unofficial twenty-four hour total of over 17 inches (432 mm) was recorded near Caledonia. During the entire weekend rainfall event, parts or all of 28 counties in Minnesota received at least 4 inches (102 mm) of rain. The highest total for the entire event was 18.17 inches (462 mm) near La Crescent.
Southeast Minnesota and southwestern Wisconsin are in the Driftless Area, which was not covered by the last glaciation, and therefore is not covered by deep layers of glacial till. The soils therefore are thin and less able to retain water; they lie atop porous rock into and through which surface waters can rapidly drain into the water table. The highly dissected topography, characterized by steep hills and bluffs and deep coulees, gives steep gradients to the drainage and makes streams highly erosive. As the rains far exceeded the absorption rate of 1.5 inches (3.8 cm) in six hours, flash floods rapidly overflowed the water courses and spread across the valley floors. The towns of Stockton, Houston, Elba, Minnesota City, and portions of Winona, on the Mississippi River, were evacuated. Citizens were moved to Saint Mary's University in Winona, Lewiston, and Caledonia, Minnesota. Massive bluffs gave way in Brownsville and several homes were completely washed away. Governor Tim Pawlenty ordered 240 National Guard soldiers to help and declared a state of emergency in six counties. The Minnesota Army National Guard soldiers guarded communities that were cleared out after the flooding early August 19. The Army Corps of Engineers opened up the floodgates on the rising Root River to release some of the water creating pressure on the dike in Houston.
High flood waters on the Middle Branch of the Whitewater River, which runs through Whitewater State Park, destroyed three bridges and damaged campgrounds, bathhouses, a group dining hall, and water and sewer systems in the park. About 500 campers were staying in Whitewater State Park at the time. The park was closed to the public on August 20, 2007, for an indefinite period of time. E. coli bacteria were found in the Rushford's water supply, and residents were urged not to use it until the city's water system could be flushed.
Amtrak train service between Minneapolis and La Crosse, Wisconsin was shut down for a week because of damage to the tracks. Passengers were bussed between the two until repairs could be made. The passenger rail line resumed service on August 27.
State Senator Sharon Erickson Ropes stated after initial flooding, "This is the worst disaster that's hit southeast Minnesota in a lifetime." Four thousand two hundred homes were damaged or destroyed in the state, and seven deaths were reported. It is estimated that there has been $67 million in damage. Dodge, Fillmore, Houston, Olmsted, Steele, Wabasha, and Winona counties were declared federal disaster areas.
Read more about this topic: 2007 Midwest Flooding