June 2024 Extreme Rainfall and Flooding in South Dakota, Minnesota and Iowa

In June 2024, a multi-day rain event culminated in a record setting flood in southeastern South Dakota, southwestern Minnesota and northwestern Iowa. Area rivers flooded, eroded dams, washed away lake shorelines and flooded cities and agricultural fields. On June 20-23, 2024, an area south of Sioux Falls, SD reported rainfall totals of over twelve inches. This area of nine to twelve inches of rainfall amounted to a 48-hour rainfall total that exceeded the 1000-day return interval. For the month of June, the preliminary highest rainfall total was reported at Canton, SD, with 16.19 inches. Incredibly, this is the not the wettest June on record for this station that currently holds the South Dakota record for the wettest month ever, which occurred in June 2014, just ten years prior, with a monthly rainfall total of 19.75 inches. Rapidly rising water overtook cars, homes and recreational vehicles. Many evacuations took place in campgrounds and flooded cities and towns such as Rock Valley, Spencer, and Hawarden, IA. The Big Sioux River went over its banks to flood McCook Lake in South Dakota, causing significant erosion. A railroad bridge over the Big Sioux River collapsed into the water during high flow. The Rapidan dam in Blue Earth, MN was breached by the extremely high water and was accompanied by large debris that caused unsafe conditions for possible remediation during the flood. New record river elevations were set at multiple river gauges on six tributaries of the Missouri River, including portions of the Big Sioux, Vermilion, Rock, Floyd, Little Sioux and Des Moines rivers.