New Options for Westerly’s Potter Hill Dam Drum Up Old Concerns

General agreement dam is in bad shape - no consensus on solution

By Colleen Cronin / ecoRI News staff

The Potter Hill Dam in Westerly, R.I., was originally
built in the 1780s and is failing. (Cynthia Drummond)

Melissa Davy pulled a large binder out, peppered with multi-colored tabs and sticky notes. It contained survey information, project proposals, and diagrams.

“This is binder one of many,” she said.

The subject of all the paperwork and binders — Potter Hill Dam — has been one of her big projects since she started as assistant town manager about a year ago.

Both the dam and mill have fallen into disrepair since the mill stopped operating in the 1950s. In early 2022, the Town Council voted to demolish the mill to make way for a park, but didn’t take any action on the fate of the dam itself.

The possibility of removing the dam or lowering it has been hotly debated in town and in nearby Hopkinton, which borders the site.

Lowering or removing the dam would allow the passage of more fish upstream and take out the last obstruction to their migration on the wild and scenic Pawcatuck River.

But abutters, mostly on the Hopkinton side, fear how any action on the dam may impact the river and their properties upstream.

More recently, the town administrator and a mostly new Town Council — six of the members who voted not to remove the dam hit their term limits — decided, “We need to get the band back together,” Davy said.

This time around, Davy said the town is trying to offer a wider array of solutions and bring in more voices so, if anything is done to the dam, it’s a solution that fixes the most problems and addresses critics’ concerns.

Although ultimately it will be up to the Town Council to vote on any potential action, Hopkinton’s input is being considered.

“We want to make sure we’re looking at all the facets,” Davy said.

Problems with Potter’s Mill

Walking around Potter Hill Mill, it’s easy to see why the property is a hazard. A fire destroyed most of the building in the 1970s; it had closed two decades earlier. A large pile of debris sits outside the granite shell of the mill that would be dangerous to enter, Davy told ecoRI News on a fall walk through the property.

She pointed out large holes in the ground and hanging pieces of gnarled metal from the textile equipment, where fragments of cloth are still caught in parts of the rusted-out machines.

The locked chain-link fence around the property is warning enough.

The issues with the dam that once powered the mill are harder to notice because they are underwater, though some of the problems are easier heard than seen.

Walking through the property, even hundreds of feet from the river, there is the sound of water running below the building in the broken gates of the dam in places it shouldn’t be.

A 2022 inspection found the dam is in poor condition. Vegetation is overgrown throughout the structure, and the concrete is deteriorating and cracked in several places.

The cost of repairing the dam is estimated to be between about $2.75 million and $8.75 million.

The poor condition is a concern because it could lead to dam failure. The dam is classified as a “low hazard,” by the state Department of Environmental Management, which means that it likely would not result in a loss of life or major economic damage should it break, although the hazard assessment could be out of date.

Dams across the state are experiencing something known as “hazard creep,” which happens when the potential damage a dam could cause if it malfunctioned or failed increases because of increased development downstream. The state’s dam safety program is largely underfunded and understaffed, ecoRI News previously reported, and so hasn’t been able to undergo a recent audit of all the state’s dams to confirm or reclassify their current hazard level.

In addition to improving the safety of the dam, the town of Westerly set out to increase its climate resiliency through dam modification or removal, in an effort to restore wetlands around the river which can help the land act as a sponge in case of heavy precipitation and storm surge.

For the fish

On top of the potential problems for people, regardless of its condition, the dam impedes some fish from moving upstream.

There’s a coalition of several organizations, including DEM, the U.S. Fish & Wildlife Service, the National Oceanic and Atmospheric Administration, and The Nature Conservancy, which have been involved in considering possible solutions to improve fish passage.

James Turek, a restoration ecologist at the NOAA Restoration Center, has worked on Pawcatuck River restoration for about 20 years, and specifically on the issues at Potter Hill Dam since 2019.

He believes the dam’s removal or modification through the installation of a dam-wide, nature-like fishway would make a massive, positive impact on the surrounding environment.

Turek said the dam impedes the passage of American shad, which is “less in number” than its cousin the herring, but “greater in value and importance.”

In the Connecticut and Rhode Island area, anglers once caught shad in abundance, leading local communities to host shad festivals and bakes. The construction of dams on the Pawcatuck and Connecticut rivers obstructed the fish and severely reduced the population, Turek said.

Brook trout and American eel are also important creatures that can’t make their way up the river because of the dams.

There was a fishway installed on the dam in the 1970s, but Turek said it functions better as a net for DEM to inspect what’s in the river than to allow fish to migrate and spawn upriver.

“People didn’t understand what the fish needed, so they built a crappy fishway,” he said. “The fishway is terrible.”

“The concrete fish ladder alongside the river was constructed in the early 1970s and with limited efficiency passes river herring, American shad, trout and other resident freshwater fish,” according to DEM spokesperson Evan LaCross.

The inspection report from 2022 for the dam also noted “joint sealant deterioration, scour, and hairline cracks throughout the fish ladder.”

“Generally, dam removals can potentially benefit some species and improve water quality, but may also impact other species or upstream wetlands,” LaCross wrote in an email to ecoRI News. “Fish monitoring has continued on the Pawcatuck River and DEM’s Division of Fish and Wildlife has partnered with USFWS to install video monitoring of returning migratory fish on the lower sections of river.”

‘Varying degrees of change’

Fuss & O’Neill, the engineering firm working with the town of Westerly on the dam, has offered eight different options with “varying degrees of change,” Davy said. The Town Council will pick three of those options, likely sometime later this month, to study further.

The options involve lowering the water level of the head pond, formed above the dam, by anywhere from 6.8 feet to 6 inches.

All the options have been presented at meetings both in Westerly and Hopkinton. Although Westerly owns the dam and ultimately has the legal authority to make changes, Hopkinton officials and residents have spoken up about their opinions.

The Hopkinton Town Council passed a resolution in December asking the Westerly Town Council to “decline to pursue any options for the dam that could result in lower water levels.”

Hopkinton Town Council member Sharon Davis said she has listened to the residents in her town who are concerned about how dropping the water level will impact their wells and their own recreation areas on the pond.

Scott Bill Hirst, who grew up in Ashaway near the dam, and currently sits on the council as vice president, agreed.

Both said they were glad the project would replace any impacted wells but still felt a lower head pond was a big issue for their constituents, who currently use boats in the area upstream. His worry focuses in on how that may affect people’s property values.

Hirst understands the concerns about the fish, as a former Conservation Commission member, but said he fears changing the dam and head pond could impact other wildlife upstream that have become part of the local environment since the dam was installed.

“If they do take the dam down, I want the water level to stay essentially the same,” he said.

Carl Rosen, a resident who lives on the pond, said his well and property will be impacted by a water level drop.

But beyond the personal impact of the changes, Rosen said he feels frustrated about what could happen to the current ecosystem if the dam is modified.

“If I go out to the wetlands and I cut down a tree or I try and clear something, the DEM is going to be banging on my head and my door and fining me, yet they’re proposing dropping the water level three and a half feet,” he said.

“We would be reasonably happy with a six-inch drop,” he said, although there are some in the community he has spoken to who would like to see no drop. “I’m not going to worry about six inches.”

NOAA’s Turke recognized that removing or lowering the dam could impact property owners that live above it, both by lowering the head pond and possibly draining shallow private wells.

The impact on the water level diminishes the father away the river gets from the dam itself, he explained, adding that dropping the pond a few feet would be “imperceptible” to observers not using tools to measure the difference.

Other criticisms, however, like that the wetlands will be destroyed if the project goes forward or that the dam wouldn’t be a safety issue if it failed, Turek does not agree with.

“There’s some people that just don’t want to have change in their lives,” he said.

He said he wants “to do a project that will benefit a lot of people.”

“There’s no viable ‘Don’t do anything’ option,” he said. “You can’t just let the thing sit forever.”