Posted on June 30, 2025
NORTH SIOUX CITY — An ongoing dredging operation at McCook Lake has pulled out numerous fallen trees, a lawnmower, part of a shed, lumber, sewer and water pipes and other materials that washed into the lake during the catastrophic flooding last summer.
The contractor, Three Oaks, Inc., began dredging the lake May 15, said Kelly Connors, a North Sioux Cityan who co-owns the firm with partners Ben Murphy and Paul Koskovich. The work has to be completed by Aug. 1, under the terms of a contract awarded in April by the South Dakota Department of Game, Fish & Parks.
The contract for slightly over $1 million specifies the removal and disposal of 20,000 cubic yards of material from the 273-acre oxbow lake.
Connors declined to comment on whether that limit is sufficient, given the vast amount of material that washed in. An email and phone calls to the department for comment were not returned.
“I’m a resident there too, and we lost a home in this as well,” Connors said, adding that he was “trying not to have an opinion” on the department’s handling of the McCook Lake situation.
The lake cleanup has been a source of considerable consternation in the southern Union County community. Earlier this year, a bill to provide $2 million in state funding for the cleanup was rejected in the South Dakota House. By then, residents were growing upset that Game, Fish & Parks had yet to furnish a plan to clean the lake.
On Tuesday, a delegation of state legislators, led by Reps. Chris Kassin and Bill Shorma and Sen. Sydney Davis, toured the lake. North Sioux City Mayor Chris Bogenrief said lawmakers will try again in their next session to secure state funds for a more comprehensive rehabilitation of the lake.
Bogenrief said the current dredging project only covers about 10 percent of the lake’s surface — the part that was most severely impacted by the flood, not far off Exit 4 on Interstate 29. He said a complete dredging of the lake, to a depth of 10 feet, would cost somewhere in the neighborhood of $12 million.
“There’s still debris and trees and things out in other parts of the lake,” Bogenrief said.
The McCook Lake Association is trying to raise funds to keep Three Oaks dredging the lake past Aug. 1.
The lake, in its current state, is not especially safe for high-speed boating due to the debris, Bogenrief said.
“I think they’ve marked with buoys most of the debris that’s still out in the lake,” he said. “So, people are just kind of at their own risk right now.”
The material pulled from the lake is “not by any means” salvageable, Connors said, and has been properly disposed of at a landfill. A vehicle that was swept into the lake was removed earlier by Stockton Towing, Connors said.
A crew of four has been working on shore and aboard a 40’x40′ barge in the lake, which carries an excavator to remove the material. The waterlogged debris is dumped onto another, smaller barge and transported to the shore, and then disposed of.
The flooding took place over June 23-24 last year, part of historic flooding that inundated the region. State and local authorities acted under a flood mitigation plan from 1976, which called for using the Exit 4 overpass as a sort of giant makeshift levee, directing the floodwaters into McCook Lake, and away from the rest of North Sioux City.
But last year’s flood shattered previous records. Rushing water from the swollen Big Sioux River destroyed or damaged dozens of homes along McCook Lake’s North Shore Drive and Penrose Drive. The flood plan was criticized after the flooding as out-of-date and excessively hazardous to McCook Lake.
