BROOKSVILLE – The alewives are running into Walker Pond again.

A local crew from the state Department of Transportation on Wednesday removed a beaver dam from under a bridge on Route 175, opening the passageway for the distinctive strain of alewives to swim from Mill Pond into their spawning grounds in Walker Pond.

It took the power of a backhoe to shift the beaver dam from under the road.

“There’s no way we could have budged it with just these rakes,” said crew member Ike Allen.

Allen and Greg Varnum paddled across Mill Pond to the bridge and stood by while backhoe operator Russ Grindle used the jaw bucket and a wooden beam to push the beaver dam from under the road into Mill Pond. Allen and Varnum then pounded signposts into the pond bottom to keep the dam in place while Grindle loaded debris into a dump truck.

The debris from the beaver dam filled the 5-cubic-yard dump truck.

This is the second time this year the DOT crew has been down to the small bridge to remove a beaver dam, according to crew chief Chris Woodward. They were at the same site about a month ago to take out a dam on the Mill Pond side of the bridge.

“The beaver are a continual problem,” Calvin Hale, a game warden with the Department of Inland Fisheries and Wildlife, said Wednesday. “Every year we go through this with them. We come in and clear them out so the fish can get in.”

The Walker Pond alewives are distinctive because they are much smaller than the normal alewives seen in Maine’s coastal rivers and streams. They grow to only about 9 inches in length. Theirs is the only alewife run like that in Maine and maybe in the world, according to state officials.

Like other alewives, the smaller fish are anadromous, spending the majority of their lives at sea, but returning to freshwater rivers, streams or lakes to spawn. The juvenile alewives will leave the fresh water in the fall and head downriver.

Trappers working for the department had live-trapped one or two beavers in the spring when the DOT crews removed the dam. The remaining beavers rebuilt the dam in about a month, an indication, Hale said, that there are not a lot of beavers left around the bridge.

“If you had four or five of them living in a lodge, you’d see a lot more activity,” he said.

There may be some beaver activity farther down the brook, Hale said. He plans to check the area for other beaver dams that might be hampering the fish run. The fish seem to be moving up the brook and through the fishway pretty well, according to Marine Patrol Officer Dale Sprowl.

Although there was a low run coming up the fishway on Wednesday, the removal of the beaver dam ought to allow the fish to get onto their spawning grounds, he said.

Hale stressed that the beavers are wildlife too, and also have to be taken into consideration during this process. The department does not want to remove them permanently from Walker Pond or the small brook that runs from the pond to the Bagaduce River, he said.

“We’d never get rid of the beaver in that stretch,” he said. “There’s always been beaver there and there always will be. We just need to keep the area clear for that one month so the fish can get up there. After that, they can go back to building their dams.”

DIF&W works cooperatively with the state Department of Marine Resources to ensure that the alewives have a clear way from the Bagaduce River up a small, man-made fishway around a dam and into Walker Pond. They’ve had help over the years, particularly from local resident Richard Closson. DIF&W granted Closson a permit to tend the fishway, and for years he has worked to make sure the fish could get from the river up into Mill Pond.

That effort has paid off, and both Sprowl and Hale believe that the Walker Pond run is beginning to come back after several years of low numbers.

“That’s a success story down there,” Hale said. “We’re bringing something back.”