SIOUX FALLS, S.D. – Joyce Rodman said it looked like Niagara Falls around her southwest Sioux Falls home late Thursday night and into Friday morning.
"It was horrible," she said about the 6.75 inches of rain that fell at her home on Silver Valley Drive near Dunham Park. Nearby, the National Weather Service said a record-setting 8 inches of rain fell in some other locations in the southwest part of the city of 165,000. The previous record-setting rain was 40 years ago in 1975 when 4.59 inches was reported, although meteorologists said they had to be careful about reporting records for the city because of varied amounts often reported.
Near the Joyce and Don Rodman home, the water rolled down from the hills to the west flooding the streets and washing out soil near culverts in the park. Down the street, neighbors had their driveways severely damaged by the rushing waters.
The rains, which started about 7:30 p.m. Thursday night and continued on until early Friday morning, came so fast and heavy that utility lines were exposed where the soil banks washed away just down the street from the Rodmans.
City emergency manager Regan Smith said that area was one of the hardest hit by the storms.
"We'll have to get a contractor out there and fill and repair that area," Smith said.
In other parts of the city, cars were stuck and damaged in the flooded streets.
One of the worst areas was in the heavily traveled The Empire mall area along 41st Street and Louise Avenue where an estimated 200 to 500 cars were stranded when the water rose to about 3 to 4 feet above the streets.
"It just came so fast that drivers couldn't get out," Smith said. "There were others that knew better and shouldn't have been out there."
The city and weather service had issued warnings about 60 to 80 minutes before the storm hit to stay off streets as flash flooding was on its way.
Smith said fire rescue squads escorted and carried stranded drivers and passengers from their vehicles in the mall area, but they didn't have to use search and rescue boats that were on hand. In all, he said the city's emergency Metro Communications 911 was flooded with about 1,600 calls.
"It was overwhelming," Smith said. However, he said he didn't believe anyone was injured.
On a tour of the city with Mayor Mike Huether Friday afternoon, Smith said the waters were receding and that the damage was fairly minimal to infrastructure.
"There's debris-landscaping rock and silt-from boulevards on the streets, that's our main concern," he said.
Manhole covers on streets also popped off and had to be put back in place.
However, he said the city's sewer systems appeared to be intact, which he credits to some of the recent improvements made by the city.
"It was a significant event, probably the worst we've had in at least 20 years. But we were satisfied with how we made it through," Smith said.
The rains didn't just come from one storm, said National Weather Service warning coordination meteorologist Todd Heitkamp of Sioux Falls.
He said the phenomenon of a series of thunderstorms known as "train echoes" involved storms redeveloping over and over again over the city delivering more rain with each storm.
"It's kind of like a train moving over and over the same tracks," Heitkamp said.
While the southwest part of town had 7.7 inches of rain in some areas, there wasn't that much in other parts of the city. The airport, on the northern edge of the city had only 2.65 inches, with other locations in the northwest and northeast getting 2 to 3 inches. In the southeast, there were heavier reports of 4 to 6 inches.
Heitkamp said it was the most since a summer of 2004 storm when the airport recorded 4.5 inches of rain. Before that, the last disastrous rainfall was that record-setter in a 24-hour period in 1975 when 4.59 inches fell at the airport.
Rainfall totals across the rest of southern South Dakota in the storms were much less. Total rainfall in Chamberlain was 2.29 inches. Tyndall received 1.65 inches, 1.60 fell in Burke, and a little more than an inch was reported in Bridgewater. Mitchell received less than a quarter of an inch.
The good news, said Heitkamp, was that no rain was predicted for the next week.