Sep 11, 2019
Spurred by a period of excessive precipitation from September 10-12 that resulted in 5 to 10 inches of rainfall in the middle to upper reaches of the Big Sioux River basin and 2 to 5 inches from Sioux Falls downstream, extreme rises occurred mid-month, with many basin locations reaching record stages.
Source: NOAA National Weather Service Storm Events Database (event 856547). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Lyon County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.