Homes and roads in McCook Lake area ravaged by flooding

A June 24, 2024, view of a home destroyed by flooding the previous night at McCook Lake in southeast South Dakota. (Courtesy of Dirk Lohry)

Makenzie Huber, Seth Tupper/South Dakota Searchlight

Homes were destroyed, roads were washed out, sinkholes opened up, a railroad bridge was swept away, and rescuers worked through Sunday night into Monday morning to save people from rising floodwaters in the McCook Lake area of southeastern South Dakota.

“It looks like the Grand Canyon here, and it’s just pouring in. What a disaster,” said McCook Lake Association President Dirk Lohry while kayaking the lake and surveying the damage Monday morning. He waded through trash and navigated currents that he said rivaled the Missouri River.

The lake is a 273-acre, horseshoe-shaped body of water ringed by homes around its northern shore. It’s just west of Interstate 29, while the Big Sioux River is just east of the interstate and the Missouri River is a short distance to the south.

As of Monday morning, the water on McCook Lake was rising about 6 inches an hour — already 10 feet above normal levels, Lohry estimated. While dozens of homes were flooded near the lake, several more were under threat as the water continued to rise.

 

The state, North Sioux City and private contractors built a levee Sunday evening across the interstate at Exit 4 in an effort to tie it in with other protective structures and reduce impacts to McCook Lake and North Sioux City from the Big Sioux, which is swollen from three days of rain last week.

Gov. Kristi Noem, speaking at a Monday morning press conference in North Sioux City, said the Big Sioux rose higher and faster than authorities anticipated Sunday as they were mobilizing the effort.

The river crested at a record 44.98 feet overnight, surpassing its old record from 2014 by 7.28 feet. Noem said the crest was 2 feet higher and came 17 hours sooner than an earlier forecast.

“We expected that we had overnight to build a levee,” Noem said, adding, “and then within an hour that had changed dramatically. We had to build that levee within a few hours.”

The Big Sioux River at Sioux City rose rapidly on June 23, 2024, and set a new record crest, as shown in this graph. (Courtesy of NOAA)
The Big Sioux River at Sioux City rose rapidly on June 23, 2024, and set a new record crest, as shown in this graph from the morning of June 24. (Courtesy of NOAA)

The state Department of Transportation closed a portion of Interstate 29 at 6 p.m. Sunday to build the levee. Noem said workers used sandbags as the water rose but soon switched to truckloads of clay offered by a local resident.

Noem said a levee was built in the same location during a 2014 flood, and water never reached it. This time it did, and Noem said the levee “did divert water.”

State and local authorities did not immediately have a count on the number of homes destroyed at McCook Lake. Union County Emergency Management Director Jason Westcott said rescuers conducted two sweeps of McCook Lake and would do a third, and he was “feeling pretty comfortable that almost everybody is out of that area.”

Westcott said work was underway Monday morning to open a donation site in North Sioux City, to open a shelter for displaced residents, and to draft a debris management plan for the cleanup. He encouraged people to check Union County Emergency Management’s Facebook page for updated information.

“We’re also asking everyone — this includes residents — to stay out of the flooded areas,” Westcott said. “A lot of these flooded areas are very dangerous at this time.”

The flooding resulted from 10 to 15 inches of rain that fell from Thursday to Saturday in the hardest-hit area of southeast South Dakota, northwest Iowa and southwest Minnesota, with totals exceeding 17 inches in some locations. Twenty-one of South Dakota’s 66 counties experienced flooding.

Estimated three-day rainfall totals in southeast South Dakota as of 7 a.m. Central time on June 22, 2024. (Courtesy of National Weather Service)
Estimated three-day rainfall totals in southeast South Dakota as of 7 a.m. Central time on June 22, 2024. (Courtesy of National Weather Service)

Noem said Sunday that at least one person had died as a result of the flooding, but she declined to provide further details on the death. The state Department of Public Safety separately reported that an 87-year-old man died Saturday near Harrisburg when he accidentally backed a utility terrain vehicle over a washed-out road section. The department declined to say whether that was the death Noem was referencing.

The heavy rainfall filled rivers and creeks that run south and east to the Missouri River in the southeast corner of the state, putting McCook Lake, North Sioux City and Dakota Dunes in the crosshairs of the collected floodwater. Authorities issued a voluntary evacuation order for the Dakota Dunes area Sunday.

The road in front of Morgan Speichinger’s McCook Lake home was washed away overnight. Her family’s house is flooded. Some of her neighbors’ homes are almost entirely submerged, and another is split in half.

Speichinger evacuated with her husband, two toddlers and dogs before the water reached her home, alerting neighbors to evacuate as well.

“There was nobody telling people that water was in our backyards,” Speichinger said. “Within 30 minutes of us seeing the water and leaving, there was water in our basement.”

Beyond the damage at McCook Lake, Westcott, the local emergency manager, said some damage in other areas was prevented.

“What occurred yesterday was a result of a mitigation effort,” Westcott said Monday morning. “Mitigation is designed to lessen the effects of flooding in our area, and also lessen the effects on critical infrastructure. If we did not take the mitigation effects that we took yesterday, much of North Sioux City would be under water.”

But that diverted water seemed to go straight into McCook Lake and into Speichinger’s backyard, she said. Her house was delisted from the flood zone a few years ago after officials reviewed and updated a flood map, so she doesn’t have flood insurance. She’s worried that the actions of Gov. Kristi Noem and other authorities — or lack thereof — have cost her family their home and that they won’t find an acceptable replacement.

Gov. Kristi Noem leads a press conference June 23, 2024, in North Sioux City on flooding in the area. (Courtesy of Governor's Office)
Gov. Kristi Noem leads a press conference June 23, 2024, in North Sioux City on flooding in the area. (Courtesy of Governor’s Office)

“I’m pretty mad at Kristi, because she makes it sound like they did a great thing, but in reality it hurt a huge part of our community,” Speichinger said. “They said they had this plan set in place since at least the previous flood. I’m angry that they saved the Dunes and the business district but not us.”

Lohry said that his association attempted to have city officials review the diversion plan in 2014, but lamented that they didn’t “push hard enough” and that their concerns “fell on deaf ears.” Officials should review the plan now, he said.

Scott Vetos’ lakeside house hadn’t flooded yet Monday morning, but his pontoon and lift were on the other side of the lake. While the state did build a levee, it wasn’t fast enough to help McCook Lake residents, he said.

“This was intentional. This is basically a triage thing,” Vetos said. “To us, living on the lake, we’re not happy about the ‘Let’s flood McCook Lake and save Sioux City’ move.”

Lohry estimates that once the water stops flowing into McCook Lake, the water level will drop about an inch per day. He said it’ll take months for the lake’s residents to return to normal.

Beyond the damage around McCook Lake, Noem said Monday that a BNSF Railway bridge on the Big Sioux River had been destroyed by the flooding.

Noem encouraged everyone affected by floods to document their damages and share the information with their insurance provider and local emergency manager. She said that information will help the state prepare its application for aid to the Federal Emergency Management Agency.

U.S. Rep. Dusty Johnson attended the Monday press briefing and said he and the state’s two U.S. senators will press hard for federal support.

“Having seen some of the damage, having a sense of how high these waters are, I would be surprised if there will not be a robust federal assistance when we talk about recovery,” Johnson said.

Some Missouri River tributaries — including the James and Vermillion rivers — were still rising Monday, with crests not expected until later this week. State Geologist Tim Cowman said the varying pace of crests on those rivers should help prevent further damage in the McCook Lake, North Sioux City and Dakota Dunes area.

“It will take a while for that water to get down here,” Cowman said. “Our feeling is that the Big Sioux will obviously be past its crest and will have dropped enough that we’ll be seeing drops in the Missouri by the time those pulses from the James and the Vermillion get here. So I don’t anticipate that the Missouri River later in this week would get any higher than it is today, and actually would be lower than it is today.”

Noem welcomed those projections but cautioned against complacency.

“As you can tell, clearly, things change quickly.”

The state Department of Transportation, meanwhile, said the I-29 closure was extended Monday morning between exits 2 and 26. A lengthy detour has been established with maps available on sd511.org.