Despite nearly two more months of winter on the calendar, officials are already issuing outlooks suggesting more flooding in the area is likely. This is due to rivers, lakes, and streams being full along with the ground being saturated from last year prior to the start of winter.
The National Weather Service released a graphical outlook of likely flooding scenarios. Currently the prediction for the most likely scenario, which would be a “normal end of winter”, would have minor and major flooding along the Big Sioux River. The river levels around Dell Rapids are shown to have a greater than 50% chance of major flooding. If a “drier end of winter” scenario happens, the river levels around Dell Rapids are predicted for a greater than 90% of minor flooding.
Another probability graph by the National Weather Service shows a 25-50% chance of moderate flooding (14.0′) of the Big Sioux River in Dell Rapids from the mid-March to mid-April time frame. That same graph shows a 10-25% chance of major flooding (15.0′). (https://water.weather.gov/ahps2/probability_information.php?wfo=fsd&gage=ders2)
No matter the outcome of the rest of this winter, the message from leaders is the same. People need to be prepared for another round of flooding this spring.