Major and record-setting floods occurred in southeastern South Dakota in late June after back-to-back days of training thunderstorms. From the morning of the 20^th through the morning of the 22^nd, over 13 inches of rain fell across the area. The initial salvo on the 20^th dropped over 7 inches near Chamberlin and nearly 5 inches in the Mitchell area. Sioux Falls received a rather large quantity as well, with just over 3.5 inches reported. Soils were already saturated in the area, with some locations recording over 4 inches during the previous 7 days. The combination of heavy rainfall on saturated soils led to widespread flash flooding on the 20^th, but there was little time to recover, as the heavy rainfall returned the very next day. Many areas received another 4 inches on the 21^st, with the Canton area recording a whopping 7.75 inches. A storm of this magnitude for the area is exceptionally rare, with a recurrence interval of around every 1,000 years.  

When the final drop had finally fallen, much of the area was underwater but that would end up being the least of the problems. On Friday, June 21^st, the South Dakota Office of Emergency Management (OEM) reached out to counties after the heavy rain on the 20^th to gauge flood damage and answer resource requests. The US Army Corps of Engineers (USACE) was contacted by Governor Kristi Noem, and they responded by lowering releases at Fort Randall and Gavins Point dams.  

On the 22^nd, the river forecast division projected the Big Sioux River to reach 38.4 feet, breaking the previous record of 37.7 feet. The USACE was contacted again by Gov. Noem, and an emergency declaration executive order was released. Sioux Falls diverted water into holding containers that quickly filled. Residents in the area were asked not to do laundry, use the dishwasher, take showers, or anything else that would contribute unnecessary wastewater to the already stressed system. One fatality was reported due to a car accident after the shoulder of a road had been washed away.  

An Emergency Operations Center (EOC) opened the morning of the 23^rd to prepare for rescues. The gauge at Big Sioux reaches 35.14 feet and was projected in the afternoon to peak the next day at 42.3 feet. However, the actual peak was 44.98 feet- 7.28 feet above the record. I-29 closed at 6pm allowing construction of the levee to divert water away from North Sioux City and Dakota Dunes towards McCook Lake. Dakota Dunes was issued a voluntary evacuation order due to a history of flooding. A text alert went out to McCook Lake residents at 8:21 pm.  

While the levee mitigation did work to save North Sioux City from damage, there was devastating damage at McCook Lake. More than 50 homes sustained damage, some minor damage while others were swept away into the lake. Residents of McCook expressed their frustration for the lack of communication- both before the flood and the days following. Many residents did not report receiving a text warning to evacuate but instead heard about it through neighbors, others in the community, or took notice of the rising waters, and they were given less than two hours to evacuate. For those who were unable to evacuate at that time, rescuers came on boats and reported that everyone was out by Monday. However, the area was not safe and lacked power, gas, and sewer service. Police were brought in to keep people out and work with residents to view their destroyed home or access what remained of their damaged home.  

Downstream of the Missouri River, Omaha, Bellevue, Blair, Nebraska City, and Plattsmouth in Nebraska report minor to moderate flooding along the river. Kansas City, Kansas issued a warning about the potential contamination of the water due to the risk of untreated sewage and higher concentrations of contaminants being washed downstream from the upstream floods.