ELLSWORTH, Maine — In order to reduce fish die-offs and large swings in water levels at Graham Lake, federal officials are recommending fish passage improvements and other operational changes to two dams on the Union River.
The recommendations are among several listed in a draft environmental assessment of the two dams that was released last week by the Federal Energy Regulatory Commission. The agency is considering whether to require the changes as a condition of renewing its operating license for the two dams, which are owned by Black Bear Hydro, a subsidiary of Brookfield Renewable.
The issues of fish deaths caused by the lower of the two dams, which sits just upstream of where Route 1 crosses the Union River in downtown Ellsworth, and of low water levels in Graham Lake, which is located partially in Ellsworth four miles upstream from the lower dam, have been the primary complaints about the dams made by local residents and environmental advocates. The lower dam is used to generate power with four turbines, while the upper dam is used solely to control water flow downstream to the lower dam.
A spokeswoman for Brookfield declined this week to comment on the FERC recommendations, saying the company was still going over the agency’s draft document.
“Brookfield Renewable is reviewing the Draft Environmental Assessment, and we will provide written comments directly to FERC within the 60-day comment period,” Samantha Edwards said.
Comments on the draft document can be submitted online from now until Jan. 20.
The license for the dams, each of which is roughly 60 feet tall, was last renewed in 1987. Brookfield is seeking a renewal of the license that would last until 2057.
In the 439-page draft assessment, officials at the federal agency indicate they support some improvements proposed by Black Bear Hydro, such as constructing at each of the two dams upstream ramps for baby eels, also known as elvers, which support an annual fishery in Maine worth $21 million.
Agency officials say they support the company’s proposal to install a guidance system just above the lower dam to direct fish away from where water flows into the dam to the turbines, and to make adjustments to existing downstream passage design elements. They also say Black Bear Hydro can continue transporting seasonally migrating salmon and shad upstream by the existing trap-and-truck method, in which fish are trapped at the bottom of the dam in downtown Ellsworth and then moved by truck to Graham Lake, while conducting mandatory tests of the system to gauge how effective it is.
But staff at FERC make additional recommendations not proposed by Black Bear Hydro.
They say water levels at Graham Lake should be maintained between 98.5 and 103 feet above sea level. The current FERC license requires the company to maintain water levels in the lake between 93.4 and 104.2 feet above sea level — a range of nearly 11 feet — which lakefront property owners say has turned parts of the lake into large expanses of mudflats.
The agency also says that operation of the four turbines should be adjusted during certain times of day and of the year, including temporarily stopping some or all of the turbines, to help protect migrating fish. And the eel ramp at the lower dam should be constructed along the rock ledges on the eastern end of the dam, where baby eels are known to climb up the exposed rock during their nighttime spring migrations.
An environmental group that has been vocal about the operation of the dams said that the proposal to limit drawdowns at Graham Lake to 4½ feet instead of nearly 11 feet could be “a real win” for the lake’s water quality and lakefront property owners.
But Brett Ciccotelli, a fisheries biologist with Downeast Salmon Federation, said more still could be done. He said the group would like to see “state-of-the-art” upstream fish passage installed at the dams within three years, rather than allowing the trap-and-truck method to continue, and that with modifications there should be “zero fish kills in the turbines.”
The group also wants the state to require Black Bear Hydro to support a Union River stocking program for salmon and shad, and to upgrade the the “antiquated” turbines to improve their efficiency and reduce their environmental impact, he said.
“We’re disappointed that FERC’s staff suggestions fail to require big changes or real investments in the Union River’s fisheries,” Ciccotelli said. “There are some good operational changes FERC suggests that could reduce the severity of fish kills, but nothing that will stop them completely, and [there are] no improvements for multi-species upstream passage.”