Work underway on Dunbar Creek dam removal project
Kelly Tunney | Herald-Standard
A backhoe with a jackhammer attachment incrementally demolishes one of the dams on the Dunbar Creek, installed a century ago to try to control flooding. The dams are being removed to allow the creek to resume its natural course and hopefully prevent erosion of Furnace Hill Road, which follows the course of the stream.
Dunbar Creek flows through one of the dams downstream from the demolition site; Schaetzle hopes funding will be approved to demolish the rest of the dams so that Dunbar Creek can find its natural course again.
Greg A. Schaetzle, a watershed scientist with the Western Pennsylvania Conservancy, explains the process of removing the dams from Dunbar Creek. A demolition crew worked through the week to remove the uppermost dam on the creek. Schaetzle said that recent cold temperatures, though uncomfortable for the crew, was better for the process than working in mud.
One section of Dunbar Creek will soon resemble what it looked like before it was dammed to provide water for the coal industry 100 years ago.
A crew from the Pennsylvania Game Commission started hammering away at one of the four old dams built in the creek in 1906 or 1907 by the Dunbar Furnace Co. to support its coke oven operations in what is now State Game Lands 51 in Dunbar Township.
The game commission is working with the Western Pennsylvania Conservancy and American Rivers to remove all four dams, which were breached, but still force the creek to flow in several different channels through the valley along Furnace Hill Road.
Work started last week on one dam and is expected to be finished this week. Grant money is being sought for the other three dams, which will be more difficult to demolish and remove. The goal is remove barriers to fish movement and improve water quality.
The creek is home to wild trout and is a popular destination for anglers pursuing stocked trout. The dams are located are in a delayed harvest, fly-fishing only section of the creek.
Removing the dams will allow fish to freely travel for spawning and feeding, and increase the oxygen in the water, said Lisa Hollingsworth-Segedy, of American Rivers.
“Dunbar Creek is one the best trout fisheries in Fayette County. It’s going to be an even more productive fishery when we’re done,” Hollingsworth-Segedy said.
The dam being removed was several feet thick, stood about 8 feet above ground and was originally about 300 feet long, but part it had been breached. Some large chunks of the concrete dam and the footer remained in the creek bed.
It is made of a mixture of concrete and round river rock, which appear to have been taken from the creek bed, said Greg Schaetzle, a water project manager for the Conservancy.
Using a hydraulic jackhammer, the workers had most of the above ground portion knocked down last week. They hadn’t started digging out the footer so no one knows how deep underground it is, Schaetzle said.
“A lot of that dam is underground. You can’t even see it. They can be up to 10 feet deep and they fair out underground. I don’t know how they did it 100 years ago without cement trucks,” said Steve Leiendecker, game commission land management officer.
“It seemed like a really big project, but the benefits totally justify the effort we’re putting in,” Hollingsworth-Segedy said.
This is the first dam removal undertaken by the commission’s local workers, but the work was proceeding nicely, Leiendecker said. The absence of rebar in the structure made demolition a little easier.
Digging out the footer of the dam could prevent flood water back up.
“We’re just going to keep after it to get it below grade. The next time it floods, hopefully water won’t build up behind that,” Leiendecker said. “It’s progressing as well as can be expected.”
Remaining portions of the old dams force water through openings in the structures as well as under and around them causing erosion. The dams also force flood waters to flow near the road.
“When this is removed, it will better align the stream,” Schaetzle said.
The section of the creek where the dam is located will look much different in the spring when plant growth will erase most of the evidence of the removal work.
“I’ll be curious to come back in a couple months,” Schaetzle said.
The Conservancy has applied to the state for a grant to remove the three other dams. American Rivers has agreed to provide the required matching funds. The game commission is designing the projects and applying to the Pennsylvania Department of Environmental Protection for permits to do the work.
Concrete and rock from the dam being removed is being placed on the hillsides bordering the creek valley to create habitat for snakes and other animals that utilize rocky habitat, Leiendecker said.