Westerly council, residents, consultant weigh in on dam-removal options

WESTERLY — Although they have yet to formally commit, members of the Town Council say they are leaning toward an option that would lower the dam that crosses the Pawcatuck River at the Potter Hill Mill, thereby maintaining the river's water level at near-current depths.

Members of the council expressed their thoughts during a meeting Monday when a representative of an environmental engineering firm that has been studying ways to address the dam to improve fish passage, reduce flood risks, and restore the river's habitat discussed results of the ongoing study as well as his firm's recommendations. The study is being conducted by Fuss & O'Neill of Providence under a three-year grant secured by the town from the National Oceanic and Atmospheric Administration.

Fuss & O'Neill, in a preliminary technological memorandum, recommended Alternative 2, which would entail complete removal of the dam and creation of a riffle-pool channel. Residents who live along the river in Westerly and Hopkinton said the approach outlined in Alternative 2 would severely narrow the river and lower its water level. The approach would also harm their drinking water wells.

Nils Wiberg, Fuss & O'Neill's chief water resources engineer, said removal of the dam would allow for compete realization of the benefits of other dam-removal projects conducted in previous years along the river.  Sudden failure of the dam or its spillway gates would hurt the drinking water wells and present a flood risk, he said.

Wells that are identified as likely to be affected by complete removal of the dam would be replaced as part of the project prior to removal of the dam, Wiberg said.

Partial or full removal of the dam is intended to restore a natural channel providing unimpeded migratory fish passage.  According to Fuss & O'Neill's memorandum, removal of the dam and restoration of this section of the river will also re-establish natural flows and eliminate risk of dam failure, reduce flood elevations and risks to upstream and downstream infrastructure and properties, remove a safety risk to recreational paddlers, restore wetlands affected by over a century of impoundment, restore ecological river processes, improve resilience to climate change, and avoid long-term operational and maintenance requirements associated with the dam.

"Alternative 2 best achieves the project's goals, but we would like to incorporate other input," Wiberg said.

The dam is designated as being in poor condition due to the deterioration of its sluice gates, which have not been maintained in years, according to the memorandum. However, Councilor Sharon Ahern noted that the state Department of Environmental Management has designated the dam as being a "low hazard" structure.

"That  means if it failed tonight it does not pose significant risk to human life or economic damage downstream, so that's an important factor," Ahern said.

Ahern and some of the neighbors said emergency officials have raised concerns about the effect removing the dam would have on the ability of fire departments to rely on the river as a source of water when fighting fires near the river. River rescues might also become more complicated due to changed accessibility if the dam is removed, residents said.

A lawyer who has focused on environmental law, Ahern said she was concerned about the effects of total removal on the wetlands and said an assessment of the dam's effect on the environment should also consider potential effects on those who live along the river.

Moriah Drive resident Wayland Curry, a kayaking enthusiast, said he was concerned that removing the dam would negatively affect paddlers' ability to get through the river. Removal of a dam in Bradford has made passage more difficult, he said.

Carl Rosen, who lives on River Road in Ashaway, questioned the accuracy of predictions about the effects of completely removing the dam, saying climate change could render the predictions inaccurate.

Business owners who own property and work downstream of the dam should be invited into the study process, said Jennifer Brinton, whose Grey Sail Brewing of Rhode Island on Canal Street is adjacent to the river.

The council will discuss the dam project again during an upcoming workshop meeting and then vote on supporting a specific alternative at a different meeting in the future, Ahern said.