Apr 11, 2023
The combination of a deep snowpack, a liquid equivalent exceeding 4 inches, and frozen soils due to persistently below-normal spring temperatures set the stage for flooding along the Big Sioux. However, a significant rise in temperatures, well above normal, triggered rapid snowmelt. The resulting runoff swiftly made its way into the Big Sioux River and its associated tributaries.||The Big Sioux river headwaters near Florence set a record flood stage. Points downstream along the Big Sioux River c
Source: NOAA National Weather Service Storm Events Database (event 1089080). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Grant County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.