Flash Flooding in South Dakota, September 2 to 3, 1999

Very heavy rains from thunderstorms repeatedly going over the same area resulted in extensive flash flooding in a 30 to 40 mile wide band from Fort Pierre in southeast Stanley County to Hecla in northeast Brown County. Rainfall amounts in this corridor ranged from 3 to 7 inches. As a result, the communities of Blunt in Hughes County and Onida in Sully county were severely flooded. Most of the homes and businesses were flooded throughout Blunt and Onida causing severe damage. Only a few homes in these communities were spared from receiving water in there basements. Most homes also experienced sewer backup. The sewer systems in both Onida and Blunt were flooded and shutdown. Many people had to go to temporary shelters as a result of the flooding. Aberdeen and Fort Pierre had a lot of street flooding resulting in road closures and detours. Also, several basements in Aberdeen and Fort Pierre had sewer backup. The heavy rain flooded many township and county roads along with several state and U.S. highways. Sections of Highways 14, 20, 83, and 1806 along with many other roads in central and northeast South Dakota had to be closed. Many of the township and county roads had massive amounts of gravel washed away. Some bridges received minor damage with some culverts also lost. A few pets and livestock were also lost as a result of the flooding. Many acres of crops were flooded throughout the area. The DM & E railroad had some of its trackline flooded for a time. Some rainfall amounts included, 3 inches at Fort Pierre, 4 inches at Hecla and in the Aberdeen Area, 5 inches at the Sand Lake Wildlife Refuge and at Blunt, 6 inches at Seneca, 7 inches 10 miles southeast of Gettysburg and at Onida.