When phase two of the Hofmann Dam removal project kicks off this spring, as early late February, the first order of business will be to attend to the re-grading of Swan Pond Park.
The work includes a number of other improvements, including repairing the WPA-era retaining wall along the river and laying a new walking path from the sledding hill to the far end of the park near Barrypoint bridge.
The village of Riverside’s preferred material for the new walking path has been approved, said Village Manager Peter Scalera. The hope is that the chip and oil walking path will blend in better with the natural setting in Swan Pond Park.
According to Jeff Zuercher, project manager for the Army Corps of Engineers, the path will be made of rock chips poured over a bituminous liquid, in three layers. Initially, the plan called for a concrete walking path.
The chip and oil path ought to be more durable than the simple gravel path in place now. The gravel tends to wash away during flooding events.
The WPA wall will be repaired using stones that have been displaced or by fabricating new ones that resemble ones that are now missing.
“We’ll try to recreate it as closely as possible,” Zuercher said.
In addition, invasive species that have sprouted between the retaining wall and a second, inner wall will be removed and treated with an herbicide to kill their root systems.
“It should be cleaned up quite a bit,” said Zuercher.
One matter that remains unclear at this point is the fate of three electric utility poles in Swan Pond Park. The poles are located in an area that will become a swale that will aid in draining the park after flooding.
Scalera said two solutions are being considered. The first would be to remove the utility poles entirely and run the electric lines underground. That would also necessitate running the lines under the river instead of over it.
The second solution would be to move the electric poles farther north, closer to Burling Road. While the village prefers the former, there has been no word on the cost for doing that or who would be on the hook for payment.
“We’re hoping to get numbers from ComEd,” Scalera said, adding that the agency responsible for paying is “to be determined.”
As far as the notching of Hofmann Dam itself, work could begin in late spring or early summer. The center 150 feet will be jackhammered or sawed apart, said Zuercher, who added that explosives will not be used.
“It’s going to be a similar method [as Fairbank Dam] but with bigger equipment,” said Zuercher. “You’ll see a much larger excavator out there.
Zuercher said that initial plans for removing sediment behind Hofmann Dam have been scrapped. He said that there is a clear channel in the middle of the river and that the plan now is to stabilize the sediment along both banks instead.
“What we’re really counting on is the contractor stabilizing sediment upstream,” said Zuercher. But he has to prove it before they can take that dam out.
“We did a sediment survey and there’s a complete channel behind the dam,” he added. “We’ve determined it can be stabilized in place.”