Flood in Yankton County, South Dakota

Flooding continued from August, but the James River near Yankton (YNNS2) soon fell below flood stage on September 4. However, excessive rainfall of 4 to 8 inches upstream September 10-12 (7.54 inches at Mitchell and 7.21 inches 7 miles south of Parkston) led to a rapid rise and a record crest 15.1 feet above flood stage on September 14. Five of the six bridges crossing the James River in Yankton county were closed. Innumerable roads were inundated and closed for several days, including major roadways of Highway 81 north of Yankton and Highway 46 west of Irene. Extensive amounts of agricultural land were inundated. Fifty-five homes were impacted by flood waters in Yankton county, with residents forced to take temporary shelter until floodwaters receded. Minor flooding continued at the end of the month.

Spurred by a period of excessive precipitation that saw from 4 to 9 inches of rainfall between September 10-12, the James River basin, which was in flood to start the month, saw extreme rises mid-month. Many lower basin locations reached record stages.