ELLSWORTH, Maine — In response to a recent massive fish kill here at a hydroelectric dam, a Maine conservation group is demanding that the federal government not renew the operating license of Leonard Lake Dam unless it does more to protect migrating fish.

“The Great Wall of Ellsworth (Leonard Lake Dam) stands in the way of the recovery of [alewives and salmon] and all other native migratory fish, including the enormously valuable American eel,” Dwayne Shaw, executive director of Downeast Salmon Federation, said Monday.

Downeast Salmon Federation said the fish kill at Leonard Lake Dam proves that hydropower facilities are not environmentally friendly unless they include proper safeguards against harming fish species whose populations already have declined because of human activity.

The environmental group has complained for years about the impact that the Ellsworth dam has had on fish that migrate to and from the ocean. Brookfield Renewables is the parent company that owns the Ellsworth dam and the dam on the Androscoggin River between Brunswick and Topsham, which was the site of another recent fish kill.

Critics of the hydroelectric facilities have estimated that together they have killed “thousands” of fish in recent weeks.

Defending its environmental record, Brookfield said it has moved more than 650,000 river herring around the Ellsworth dam this year and, in response to concerns raised by the Downeast Salmon Federation, is making easing the passage of out-migrating eel a priority.

“We are constantly working to minimize the potential environmental impacts associated with our operations and activities,” the company said in a news release. “We have communicated our measures and observations to Maine Department of Marine Resources and [the state Department of Environmental Protection] and continue to modify our operations when needed to ensure that we are not contributing to fish mortalities.”

Black Bear Hydro LLC, the Brookfield subsidiary that owns and operates Lake Leonard Dam and about three dozen others in Maine, is in the midst of a five-year process for renewing its federal license for the dam for another 30 years. The Brunswick’s operating license from the Federal Energy Regulatory Commission is due to expire in 2029.

The Ellsworth dam, which most recently was relicensed in 1987, was built in 1907. It is upstream from the Route 1 bridge over the Union River in downtown Ellsworth. The Black Bear Hydro dam in Ellsworth that was built in 1923 at the south end of Graham Lake is part of the same license renewal application.

Shaw called Leonard Lake Dam “antiquated” because it has no built-in passageway for fish. Through a process called peak powering, Shaw added, the company dramatically and quickly changes the levels of Graham Lake, which has an adverse impact on ecological productivity, land values and public recreational use of the lake.

“We expect state-of-the-art fish passage to be installed as part of the on-going licensing procedure,” Shaw said. “We need the general public to support DSF in our campaign to stand up against this very powerful multinational corporation who has proven repeatedly its disregard for Mainers, our livelihoods and quality of life.”

Brookfield officials counter that FERC has determined that the company is already taking steps required by federal regulators to minimize fish mortality at the Ellsworth dam.

Patrick Keliher, commissioner of the Maine Department of Marine Resources, said his agency does not have regulatory authority over hydroelectric facilities but does have concerns about the harm the dams are doing to anadromous and catadromous fish. Anadromous fish are born in fresh water, live most of their lives at sea, then swim back upstream to spawn. Catadromous species, such as American eels, do the opposite.

Keliher added that DMR has not confirmed reports that possibly thousands of fish have died at the two dams in recent weeks.

Keliher blamed the drought for many of this year’s fish deaths. Low water levels cause shallow — often fatal — landings at the bottom of waterfalls or other dropoffs and can strand fish in pools where they can expire from lack of oxygen and food, he said.

“This is all being caused by drought conditions and very low flows,” the DMR commissioner said Friday before the rainy weekend. “What we need is … a good, big rain.”

Keliher added that the number of fish deaths in Ellsworth and Brunswick were relatively small, compared to the estimated size of their populations.

He said 2016 has been a “banner” year in Maine for alewives, for example, and that millions upon millions of juvenile alewives are expected to make the trip downstream this fall into the Gulf of Maine.

“There’s no immediate threat to the species,” Keliher said, “[but] we have concerns and we’re going to continue to talk to Brookfield.”

A news reporter in coastal Maine for more than 20 years, Bill Trotter writes about how the Atlantic Ocean and the state's iconic coastline help to shape the lives of coastal Maine residents and visitors....