To remove the wetlands from Aberdeen Regional Airport, the preferred plan is to pump the water east to the James River.
That was the conclusion presented at a public meeting Thursday at the Aberdeen Public Safety Building.
Engineers have studied four options for removing the airport wetlands, said Todd Yerdon, who works for HDR Engineering in Sioux Falls.
Pumping the water to a major drainage channel is thought to be the best option, Yerdon said. The water could go to either Moccasin Creek, which is five miles away, or seven miles to the James. Engineers picked the James, partly because Moccasin Creek flows into the James anyway.
The other three options Yerdon presented involve on-site detention, either above or below ground, and having an off-site detention area.
Aberdeen Regional Airport contains 16 wetlands, which together total 56 acres.
In studying the property, engineers divided the airport into eight basins, Yerdon said. To pump the water to the James, the eight basins would need to be combined into one pumping source, before being sent via forcemain to the James. Above-ground detention would be required on airport property, he said.
Yerdon detailed three pumping options. In the first one, a lift station would be located on the southeast corner of the airport property. The second pumping option would use a more centralized lift station located between the two runways. In the third option, the lift station would be at the airport's low point, west of runway 17/35, which runs north and south. The forcemain needed for the plans ranges from 5.8 to 7.5 miles.
Helms and Associates hired HDR to do the designs for storm water removal. At the beginning of the meeting, Terry Helms of Helms and Associates said there's no doubt that removing airport wetlands will impact stormwater runoff.
But Yerdon said the goal is to direct stormwater around “rather than through” neighbors. “Our goal is no harm to the neighboring properties,” Yerdon said.
An area that's concerned about the wetland removal is Jobee Acres, which consists of 31 homes southeast of the airport.
Aberdeen attorney Drew Johnson, who represents the Jobee Acres Association, said the group's response to the options was “very favorable.”
Jobee Acres residents prefer the second pumping option. That plan puts the water for the holding pond in the middle of the overall airport property. If the water is pumped from there, “it's probably not going to affect Jobee Acres at all,” Johnson said.
Johnson thinks everyone who lives near the airport should be pleased, because the engineers are trying to avoid harming the surrounding property. “And I think these three options will do that. We're pleased with what we saw tonight.”
About 50 people attended the meeting, which lasted about 55 minutes.
One of the attendees, Stan Beckler, suggested that the whole airport be used as a retention pond. He also had concerns about a plan for two ponds. Ducks, he said, would fly between the ponds. Yerdon said the ponds will be pumped dry. “You won't just have sitting water out there,” he said.
Another man suggested installing drain tile. Aberdeen transportation manager Mike Wilson said the cost of that idea would be prohibitive.
The two runways at the airport are being decoupled to improve safety. When the project is done, the runways will no longer intersect. About 1,200 feet will be added to runway 17/35 and about 800 feet will be added to 13/31, the diagonal runway.
As part of the environmental assessment done for the project, the wetlands were found to be a wildlife hazard. Since the wetlands have become a safety issue, they have to be removed as part of the decoupling project, Wilson said after the meeting.
Although it's not yet certain, Helms said the 56 acres of wetlands could be replaced by up to 80 acres. One tentative site for wetlands is at Willow Dam, he said.
The point of the meeting was to share preliminary design concepts and gather input, Yerdon said. Final details have not been settled and nothing is set in stone, he said. Written comments and questions are still being accepted. Hopefully, they will be received by April 4, Helms said.