Maine’s three major Atlantic salmon rivers have been named among the most endangered rivers in the United States, the national conservation group American Rivers announced Monday.

The Kennebec, Penobscot and Union rivers – identified collectively as “Maine salmon rivers” – were ranked the fourth most endangered in the Washington, D.C.-based group’s annual report. The group cited the rivers’ significance to people and nature, the magnitude of threat they face and the existence of a major decision in the coming year that could affect their future.

The report said fifteen dams owned by Brookfield Renewable Energy – a subsidiary of a $600 billion Ontario-based global asset management firm – on the three rivers were hastening the extinction of endangered Atlantic salmon in the United States. Several of the dams are in the midst of their once-in-a-half-century federal relicensing reviews, when decision makers can impose new operating requirements on them or shut them down entirely.

“The future of Atlantic salmon now hangs in the balance. If we do not address the harmful impacts of these dams, we will lose these iconic fish forever,” Jessie Thomas-Blate, director of river restoration at American Rivers said in a statement. “Now is the time for everyone who cares about healthy rivers and salmon to speak up.”

The listing is the latest development in a bruising multifront war over the future of fish runs in some of Maine’s largest river systems and the survival of the last U.S. populations of Atlantic salmon. The struggle has pit Brookfield – which owns 38 hydropower dams in Maine and 5,300 worldwide – against state and national environmental and conservation groups and the Mills administration, which want four dams in the lower Kennebec removed to allow salmon to reach prime spawning habitat in western Maine’s Sandy River.

“This goes to show just how critical the situation is here in Maine for these rivers and the last remaining Atlantic salmon in the U.S.,” said John Burrows, executive director of U.S. programs for the New Brunswick-based Atlantic Salmon Federation, a conservation group. “We’re on the verge of losing a species that has been critical to livelihoods, recreation, the environment and the tribes.”


The Downeast Salmon Federation in Columbia Falls nominated the rivers for inclusion in the list, taking the unusual step of combining several rivers in one entry.

“It was really hard to tease out which river was the most endangered: Some suffer from acidity issues because of decades of industrial pollution, in others the genetic resource (of the local salmon run) is gone, and in others we have that resource but the dams are in the way,” said Brett Ciccotelli, DSF’s restoration and engagement coordinator. Ciccotelli works closely on the Union River, which runs through Ellsworth. “I think it’s really helpful to highlight some of the big common problems with the way Brookfield Renewable runs all of these rivers and the fact they are not doing their best to save fish.”

Brookfield did not respond to an interview request, but a Maine-based spokesperson sent a written statement defending how the company was addressing salmon conservation. David Heidrich, manager of investment relations for the Northeast, wrote that the main challenge to Atlantic salmon was mortality while in the ocean because of climate change effects “and not the existence of hydroelectric dams, most of which have been present for the past century.”

“Brookfield’s hydroelectric facilities provide 24/7 renewable energy that is critical in the fight against climate change and meeting the region’s climate goals,” Heidrich wrote, adding that the company’s dams on the three rivers have fish passages and most would get upgrades once FERC completes its licensing review process.

In recent years, the firm has been locked in a contentious battle with the state and conservation groups over the future of the Shawmut Dam in Waterville and three other lower Kennebec River dams.

In September 2021, the Atlantic Salmon Federation and three New England conservation groups sued Brookfield in federal court alleging the firm has been killing Atlantic salmon at its dams on the Kennebec in violation of the Endangered Species Act. That suit is expected to go to trial this summer, Burrows said.


Brookfield fired back later that month with a separate suit in state court alleging that the Maine Department of Environmental Protection violated a binding 1998 water management agreement with the company. It argued that the Department of Marine Resources couldn’t work with other state government agencies to develop their positions. The status of this case could not be determined Monday because court and state offices were closed for the Patriot’s Day holiday and Kennebec Superior Court’s records are not yet available online.

In November, the Federal Energy Regulatory Commission – the agency that oversees the relicensing of dams – announced they would conduct a comprehensive environmental review of the cumulative effects of four lower Kennebec River dams on salmon and other sea-run fish, a move that had long been sought by the conservation groups. FERC intends to issue a draft of its environmental impact study for the dams in August 2022 and a final version in February 2023.

The American Rivers report called for a series of actions to protect salmon in the three river systems. It called for the removal of the four contested dams on the lower Kennebec – the Lockwood, HydroKennebec, Shawmut and Weston dams – and to update management plans for Brookfield’s upper Penobscot River dams “to make any dams on the river safe and ‘invisible’ to migrating fish.”

On the smaller Union River, alewives and other fish have been killed in significant numbers passing downstream through Brookfield’s Ellsworth and Graham Lake dams. American Rivers said “passage for all native species must be assured” or the project should be decommissioned.

At the top of the American Rivers’ endangered rivers list was the drought-plagued Colorado River.

Maine has been a nationwide leader in the restoration of river systems and the sea-run fish that spawn in them. With the removal of Augusta’s Edwards Dam on the lower Kennebec in 1999 and the Great Works and Veazie dams in the lower Penobscot in 2012 and 2013, alewives, shad, blueback herring and salmon had access to thousands of miles of river habitat for the first time since the early 19th century.

The alewife run into the Sebasticook, a tributary of the lower Kennebec made accessible by earlier dam removals, is now the largest in the United States, with nearly 6 million fish, and a favorite bald eagle dining site.

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