Council changes course on Potter Mill Dam work | Daily news alerts

WESTERLY — The tortuous path to revitalizing the historic Potter’s Hill Plant site has taken another twist, just a week before a new city council is elected.

The City Council abandoned the option of building a dam that would have eliminated it entirely, moving to a plan that tries to mitigate the impact on the floodplain downstream, particularly in downtown Westerly.

Engineering firm Fuss & O’Neill provided an update Monday on its work to date and said it has been trying to resolve the concerns of property owners along the river.

Those residents, many of whom live in nearby Hopkinton, worry the changes will flood their wells. There is also concern that a significant change in the elevation of the reservoir will have downstream effects, leading to flooding in Westerly. Last year, the Hopkinton City Council asked Westerly to abandon any options to build a dam that could lower water levels.

City officials and engineers said property owners whose wells were affected will replace those wells with deeper ones at no cost to the owner.

Since February, the board has considered three of several alternatives for building the dam, namely Alternatives A, B and E.

Alternative A, which involves removing the dam entirely and lowering the water level upstream of the dam by 6.8 feet, was the primary alternative for the Fuss & O’Neill study.

In addition to Alternative A, the board also included Alternative B, a 6-foot drop in the water level, and Alternative E, which would lower the water level by 3½ feet, for study and further recommendations.

To pursue any of the three options, FEMA would be required to agree to a “Map Revision Conditional Letter,” the firm said Monday. That’s because projects with a 100-year flood rise greater than 0.0 feet require a FEMA review before any construction. According to Fuss & O’Neill, there is a risk that one or more property owners or municipalities may not agree to cooperate or agree to submit such a letter to FEMA.

But the Alternative E modification, according to the firm, will avoid an increase in the height of the water surface downstream for 100 years. Another, called E2, avoids 50-, 100-, and 500-year downstream flood increases and limits 10-year increases to 0.01 feet or less.

According to Fuss & O’Neill, alternatives E can be both allowed and financed. Alternative E would best meet the project’s goals, officials say. Each also includes a series of riffles or step pools that allow watercraft to pass through the fishway.

The future of the dam has challenged several city councils, and it could continue with the next one.

“This board was given this project by the previous board,” said President William Aiello. “This council is doing everything it can to try to resolve this. I have no intention of bringing it up to the next council.”

The council voted 4-2, with Councilman Kevin Lowther II abstaining, to accept the second amended option E2. Councilors Joy Cordio, Dylan LaPietra, Phil Overton and Aiello voted yes. Councilors Mary Schialabba and Robert Lombardo voted against.

Fuss & O’Neill continues to gather data on the potential implications for property owners.

“We’re focusing on getting data from homeowners we haven’t heard from,” said Fuss & O’Neill engineer Nils Viberg. “Then we’re going to reach out individually and talk about the assessment that’s been done and whether there might be an impact on the well.”

In September, the board approved using $43,900 in grant money from the National Oceanic and Atmospheric Administration to hire Lighthouse Consulting Group as a public affairs consultant.

Several organizational supporters of Option A include the Wood Pocatuck Wild and Scenic Rivers Management Council, Save the Bay, the National Park Service’s Wild and Scenic Rivers Partnership Program, the New England Area Hunters and Anglers Chapter, and the Rhode Island Marine Anglers Association.

In 2019, the council approved a competitive application to finally demolish the former mill buildings. Since at least 1980, the city government has been trying to solve the problem of dilapidated buildings.

Westerly’s goal was to provide fish passage at Potter Hill Dam, the last barrier to fish passage on the main stem of the Pocatuck River. The project is part of a large-scale renovation of the former mill, which will be transformed into a public park.

In 2020, Westerly received a $100,000 grant, the first phase of multi-year funding from the NOAA Restoration Center, joined by the city, the Nature Conservancy and other potential sources to study fish passage improvements and flood mitigation, including full or partial levee removal .

In August, the city received an additional $683,000 in NOAA grants as part of another round of funding.

Money for fish passage projects comes from the federal Bipartisan Infrastructure and Inflation Reduction Act. According to NOAA, Westerly will receive up to $12.4 million over three years.

PARE Engineering conducted an assessment of the dam in August 2022, which included an analysis of the costs of leaving it intact and repairing it. Estimated repair costs range from $2.7 million to $8.8 million, according to the report.