Flood in Lake County, South Dakota

Heavy rain from September 10-12 (as much as 8.81 inches 2 miles north of Chester, 7.36 inches 4 miles west northwest of Rutland, and 7.01 inches 2 miles south of Winfred) led to widespread areal flooding. Flooding was most significant around Madison, where ponding waters led to the evacuation of 30 people by boat and payloader. As many as 200 residences were inundated by water in Madison. Highway 34 was closed both east and west of Madison, Highway 19 was closed south of Madison, and travel was not advised across most of the county with water over most township and county roads. Lake Herman State Park was closed due to high water and remained so for most of the month. No wake zones were established on Lake Madison, Lake Herman, and Brant Lake. Other flooding resulted in the loss of crops and damage to public infrastructure including numerous county and township roads, culverts, and some bridges. Property damage costs are rough estimates. Crop loss estimates provided by the United States Department of Agriculture.

A frontal zone remained locked in place under southwest flow aloft as a series of mid-level waves moved across the region over a three day period. Widespread heavy rainfall resulted and amounts reached two-day records for several locations including Platte (6.29 inches), White Lake (6.28 inches), Bridgewater (8.05 inches), Montrose (5.63 inches), Alexandria (8.30 inches), Madison (7.63 inches), Howard (7.05 inches), 2 miles south of Winfred (7.01 inches), and 2 miles north of Chester (8.52 inches). Flooding, both river and areal, tallied nearly $17 million dollars in damages across southeast South Dakota.