AUBURN — A little-known dam built in the early 1900s for hydroelectric power generation on the Little Androscoggin River is being dismantled.

The $3.5 million project, funded by the federal government, has been in the works since 2018, while the concrete structure has been obstructing the waterway for decades.

“It’s a dam a lot of people in Auburn don’t know about — out of sight and out of mind,” Sam Boss, chairman of the Auburn Conservation Working Group, said in a podcast last week.

The Littlefield Dam sits roughly 4 miles upstream from the confluence of the Androscoggin River, within city limits — tucked behind an industrial area between Hotel Road and Washington Street.

It is owned by Martindale Country Club, which supports the dam’s removal. It has been inoperable since flooding from a storm in 1936 rendered it useless, creating breaches in the dam on either side of the river.

Crews from Gorham-based Shaw Brothers Construction are using hydraulic hammers to break up and haul off what’s left of the original 3,500 cubic yards of concrete and three remaining turbines and gates.

For 90 years, the breached dam has blocked passage of migratory fish and been a navigable safety hazard on the river. An effort to repair the dam and return it to service in the mid-1980s went nowhere.

WHY REMOVE LITTLEFIELD DAM NOW?

There are 25 dams on the Androscoggin River and five on the Little Androscoggin, the latter stretching about 50 miles from Woodstock to Auburn. Most hydroelectric dams are licensed by the Federal Energy Regulatory Commission and must undergo a relicensing process every 30-50 years.

Part of that process involves assessments of balancing power generation with environmental protection, fish and wildlife, and public recreation. The relicensing process allows for public and municipal input.

During the process to relicense the Lower and Upper Barker dams, the city of Auburn became aware that the owner/operator — KEI Power Management owned by Kruger Energy of Canada — objected to the requirement to make alterations to the dams to allow for fish passage, because the Littlefield Dam, which sits upstream, was already blocking fish passage in the river.

The Maine Department of Marine Resources and National Oceanic and Atmospheric Administration have fisheries management plans for the Androscoggin River Watershed that prioritize fish passage and spawning on the Little Androscoggin.

Maranda Nemeth works for NOAA’s Office of Habitat Conservation, and took part in the Absolutely Auburn podcast discussing the Littlefield Dam project.

She said as long as the Littlefield Dam is obstructing the river, fish are not able to safely navigate it and water temperature and dissolved oxygen levels are negatively impacted by it.

“This is really important because native fish in the river need the clean water quality,” Nemeth said. “They also need open pathways so that they can survive and ultimately create the next generation and persist.”

According to the Maine Stream Habitat viewer, there are over 200 Atlantic salmon habitat units and more than 8,000 acres of potential river herring ponds upstream of the dam.

It has been more than 200 years since the last Atlantic salmon was documented trying to make its way up the Great Falls on the Androscoggin River in Lewiston.

However, NOAA, the state, and conservation groups say the dam’s removal has the potential to reconnect habitat for sea-run fish species like American shad, blueback herring, alewife, Atlantic salmon, American eel and sea lamprey.

Eric Cousens, executive director of public services for the city of Auburn, has been overseeing the removal project on the city’s behalf. He adds that there’s a tangible reason to be optimistic about the effort to encourage migratory fish.

“There’s been a stocking program at Taylor Pond and other ponds in the watershed for river herring or alewives,” he said. “They’ve successfully made their way down over the dams coming out of Taylor Pond, but they can’t get back up.”

The relicensing of Lower Barker Dam is completed, Cousens said, and requires the operator to build fish passage. While the Upper Barker Dam license renewal is still underway, it also will require fish passage, likely by 2031, he said.

AFTER THE REMOVAL

The Littlefield Dam is built on granite bedrock, which means there will be minimal downstream sedimentation problems, which can be a significant problem with dam removal projects.

Cousens points to what he calls, “a pretty neat phenomenon that I don’t think people realize happens right in our backyards.” The eel migration is already occurring in late May or early June.

“Dark, rainy nights and many eels still make it around these facilities and pass upstream. But many more could if they had an appropriate passage facility,” Cousens said.

It’s remarkable when you consider the decades of severe industrial and municipal pollution in the river, mirroring what happened to the Androscoggin River, considered the most polluted river in Maine.

Cousens points to the Sabattus River dam removal project last year that reconnected 75 miles of stream habitat by removing the Upper Town Dam and the Mill Remnant Dam in Lisbon.

“So, that’s really the first one where those fish have access all the way to their spawning grounds in Sabattus Lake,” Cousens added.

Removal of the Littlefield Dam will open up a little more than 70 square miles of habitat in the Little Androscoggin watershed. Maranda said it will also open up 9 river miles, which she called “substantial.”

Removal of the dam will also restore a natural flow of water, which will lower the water temperature and increase the level of dissolved oxygen in the river, something that’s expected to occur within weeks of the removal. That in turn will improve the health of the fish, mussels, birds and wildlife along the river.

“I would say, pretty simply, it feels pretty good,” Boss, of the Auburn Conservation Working Group, said of the dam removal. It’s a project he’s been involved with for some time — applying for grants to remove the dam since 2018.

As the water level above the dam drops with its removal, more riverbank is exposed. That means plants can regrow and that will happen almost instantaneously according to Maranda. She said bird watchers and hikers in the area will notice the difference.

Cousens said it will also mean a decent paddle trip could be in the offing from Hotel Road down to the upper Barker Dam. He said the city is working on a trail project that would extend the Riverwalk to the point where Taylor Brook dumps into the Upper Barker impoundment, with perhaps a boat launch.

Work on the dam is expected to be completed by the end of September, although monitoring and replanting along the river banks is expected to continue for several years.