Flooding in South Dakota, March 17 to 31, 2019

Moderate to major flooding occurred along the White River in Oglala Lakota County. Runoff from melting snow into the White River caused river ice to break up and jam. Additional flooding also occurred along White Clay Creek upstream and downstream from Oglala Dam due to the snowmelt.

Ice jams, combined with runoff from melted snow, caused minor to moderate flooding along the White River and other small creeks in Jackson County. Minor flooding occurred near Interior from March 22 through March 25. Further downstream, south of Kadoka, moderate flooding occurred with widespread flooding of agricultural land and outbuildings. On March 25, the high flows eroded away the river bank where the stream gage south of Kadoka was located. Based on high water marks, the USGS determined the river crested at 15.34 feet at the old location and 16.72 feet at the new upstream location. This would be the fourth highest river level at this location and the highest river level since 1982. Additional flooding occurred around the Long Valley and Wanblee areas, including along Fish Creek Road, where a county bridge was destroyed by flood waters.

Ice jams, combined with runoff from melting snow, caused moderate flooding along the White River. On March 22, the rising river forced the closure of US Highway 83. About a three-quarter mile stretch of Highway 83 was inundated when water backed up behind an ice jam downstream. On March 23, a record flow of 21,700 cfs was recorded at the site. This location has a period of record about 20 years.