Flood in Minnehaha County, South Dakota

Numerous flooding reports across the city of Sioux Falls and Minnehaha County, with several closed roads. Reports through social media as well as law enforcement. Other flooding resulted in extensive damage to public infrastructure including numerous county and township roads, culverts, and some bridges.

Snow melt and heavy rainfall (measured 2.74 inches at Hartford, 2.25 inches at Colton, and 2.49 inches at Sioux Falls) resulted in extensive flooding of the Sioux Falls park system near the natural channel of the Big Sioux River around the southern side of Sioux Falls. Water, and the broken ice cover from the river system, caused extensive damage to city property with numerous bridges and buildings completely destroyed, equipment damaged, and miles of bike trail washed out. Around 80 homes were inundated by floodwater with evacuation of 17 residents and their pets, as water reached the highest levels since construction of the homes. Water filled the tunnel on 57th Street under Interstate 229, flowed onto several portions of Interstate 229, and over 26th Street east of Interstate 229 and Cliff Avenue south of I-229. The Big Sioux River at Western Avenue (gage site WAVS2) reached the highest stage on record cresting 9.15 feet above flood stage on March 14. The river remained at minor flood stage at the end of the month. Property damage costs are rough estimates.

After excessive two-day rainfall during September 10-12 (8.74 inches at Flandreau, 7.81 inches at Dell Rapids), the Big Sioux River above Dell Rapids (gage site DBRS2) reached the highest stage on record of 9.00 feet above flood stage on September 13. Extensive flooding of homes occurred in Dell Rapids, some as far as three city blocks from the river. A dozen homes were deemed to have substantial damage, and removed after being flooded. Jasper Road east of Dell Rapids was closed due to water over the roadway.