Wilder Dam owner wants to change up water discharges to help environment

  • The Wilder Dam over the Connecticut River, seen from the air on Saturday, Dec. 9, 2017. (Valley News - Charles Hatcher) Copyright Valley News. May not be reprinted or used online without permission. Send requests to permission@vnews.com. Charles Hatcher

Valley News Staff Writer
Published: 12/9/2020 9:51:45 PM
Modified: 12/9/2020 9:51:36 PM

WILDER — The owner of the Wilder Dam is proposing to reduce the frequency and magnitude of how it discharges water to make electricity there and at two other hydroelectric facilities in southern Vermont, a move some stakeholders say could help endangered and threatened aquatic species and also reduce erosion.

Massachusetts-based Great River Hydro LLC, which acquired 13 dams along the Connecticut and Deerfield rivers from TransCanada in 2017 for $1.06 billion, proposed the flow changes for its dams in Wilder, Bellows Falls and Vernon as part of its amended final application to renew its license from the Federal Energy Regulatory Commission for another 30 to 50 years.

The proposal “focuses on creating” more stable river levels “by reducing the average frequency, average duration, and average range of impoundment fluctuation,” Great River Hydro license manager John Ragonese said in a letter Tuesday to the FERC.

What the company is proposing to do is akin to filling a bathtub and then letting it drain at the same rate water flows from the faucet, as opposed to draining it rapidly and refilling it, sometimes twice a day, which is what the current “peaking” license allows for power production.

Kathy Urffer, the river steward for the nonprofit Connecticut River Conservancy, said the current license allows fluctuations by as much as 5 feet, but that the proposal would limit the drop to about 1½ feet, though the company would have some flexibility to draw down more water to meet high demands for energy.

In a CRC video news conference on Wednesday, Urffer said the proposal “should have a lot of positive outcomes for the river health,” including improvements in aquatic habitat for rare and endangered species and that the “more stable impoundment should lead to lower erosional forces on the streambanks.”

However, she said, the benefits regarding erosion are more likely to be seen downstream from Wilder because Great River Hydro also operates the Comerford Dam in the Northeast Kingdom, which received a 40-year license in 2002 and still operates on the “peaking” routine.

“That may create fluctuations at the upper end of the pond,” she said. “For the Wilder impoundment, this is why we would like to see ongoing monitoring” to understand if erosion is still occurring north of Wilder.

Built in 1950 near the site of an existing hydropower plant, the Wilder Dam includes a 526-foot-long gravity concrete spillway that is 59 feet tall at its maximum height.

The dam’s impoundment area extends about 45 miles upstream, to a few miles south of Wells River, though the relatively flat terrain limits the “usable storage capacity” to about 13,350 acre-feet if river levels are drawn down by 5 feet at the dam, according to Great River Hydro documents.

Great River Hydro has denied that its dams are responsible for the erosion, which took out part of River Road in Lyme, saying it is caused by “naturally occurring high flows,” such as from major storms, that the dams can’t control or prevent.

“Our proposed operation will provide significantly more stable impoundment water levels and reduce flow fluctuation below the dams, which should, in turn, help address stakeholder erosion concerns on adjacent upstream properties and river shorelands,” Ragonese said via email.

Lyme resident John Mudge, who said surveys dating back to 1960 show he has lost 40 feet of land along the river from erosion, indicated he will continue to raise the issue in the long-running licensing process, and said he wanted to learn more about the proposal.

“Some may feel that this operation of the dam is an improvement for the aquatic life in the river, but I do not feel that it addresses the erosion, and it may only be conjecture that the aquatic life will be improved,” Mudge said via email.

Documents filed this week with FERC indicate the total value of the power generated in Wilder in 2019 was $10.3 million; just under $14 million in Bellows Falls; and $9.2 million in Vernon.

Ragonese said he couldn’t comment on how the dams under the proposed new operations levels “would be bid” into the regional energy market, but he said the dams would continue “to operate as a reliable, renewable hydropower resource in the New England region, providing energy, capacity, reserves and other services essential to the New England grid.”

While generally supportive, the Connecticut River Conservancy said it wants to see more “comprehensive enhancements for recreational and cultural considerations” from Great River Hydro, as well as more for “safe and effective fish passage.”

The group was less enthusiastic about an ongoing FERC licensing proposal from another company, FirstLight, which owns two Connecticut River facilities in western Massachusetts near the Vermont border, at Turners Falls and at Northfield Mountain.

Although FirstLight has proposed to build a “fish lift” at the Turners Falls dam to help fish migrate upstream, CRC said it is offering “nothing to minimize or fix erosion that has been a huge issue since Northfield Mountain Pump Storage began operating in 1972,” and is proposing “only meager additions” for river access for paddlers.

News staff writer John P. Gregg can be reached at jgregg@vnews.com or 603-727-3217.

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