Next spring, for the first time in more than a century, all types of migrating fish, from trout to shad to alewife and blueback herring, will be able to swim up the entire length of the Pawcatuck River to reach their historical spawning grounds.
WESTERLY, R.I. — Next spring, for the first time in more than a century, all types of migrating fish, from trout to shad to alewife and blueback herring, will be able to swim up the entire length of the Pawcatuck River to reach their historical spawning grounds.
The final piece in a series of projects that has been in the works for decades and has cost many millions of dollars will be completed in a couple of months when a rocky fishway is completed in place of Bradford Dam, a rock-and-timber structure that was built in the 1880s and demolished earlier this summer.
When the work is done, three of the six major dams on the Pawcatuck will be gone. The three others all have fishways, including Potter Hill Dam, where a fish ladder was recently cleared of sand and silt that had been obstructing it.
“It’s a huge impact, and it’s been a long road to get here,” said Scott Comings, associate state director of The Nature Conservancy, which is leading the Bradford Dam work.
Reaching this point has taken the efforts of a whole host of groups that, along with the Conservancy, include the Wood-Pawcatuck Watershed Association, the U.S. Fish and Wildlife Service and the R.I. Department of Environmental Management.
About half of the $1.8 million spent on planning and doing the Bradford Dam project came from post-superstorm Sandy recovery funds administered by Fish and Wildlife. The other half came from private foundations and donors that even included an unnamed property owner who gave the project the boulders that are being used to form the step pools to make it easier for fish to swim upstream.
The project achieves two major goals. First, taking down the dam removes a potential flood hazard on the river, which is why the federal money came from the Sandy fund. The dam wasn’t in good shape and if it collapsed in a storm, a torrent of water and debris would have washed downstream.
And two, the dam removal fits in with larger conservation goals. There was a fish ladder at the dam, but, said Comings, it was impossible for some fish to navigate.
Shad and herring are part of an invaluable link in the food chain, serving as prey for bigger fish like striped bass and bluefish as well as wading birds, raptors and seabirds, such as roseate terns. If the project boosts the numbers of migratory fish in the Pawcatuck, as it’s expected to, the effects will be widespread.
“They are the foundation of the whole marine ecosystem,” Suzanne Paton, senior biologist with Fish and Wildlife, said. “As the population of migratory fish increases, the total number of juvenile fish will increase as well. That supports our whole fishing industry as well as a healthier ecosystem.”
The Pawcatuck River is part of the largest watershed in Rhode Island, winding 34 miles southwest from its source at Worden Pond, in South Kingstown, to its terminus in Little Narragansett Bay, which empties into the Atlantic Ocean.
The river has a long history of industrial use. At one point, as many as 10 dams were on the river, built to power Industrial Revolution-era factories. Some have washed out and others have been removed, including, most recently in a 2015 Conservancy-led project, White Rock Dam, which was in Westerly on the southern reaches of the river.
There were also a trio of projects spearheaded by the Wood-Pawcatuck Watershed Association that included removing the dam at Lower Shannock Falls, creating a natural fishway at Kenyon Mill dam, and installing a fish ladder at Horseshoe Falls.
Bradford Dam was built to power the mill complex on the west side of the river that the Bradford Dyeing Association ran for nearly a century until it was succeeded by Bradford Printing & Finishing. The company fully supported removal of the 6-foot-high structure that spanned the 200-foot width of the river, Comings said.
Where the dam stood won’t revert back to a completely free-flowing river. Instead, rows of rocks, or weirs, are being created that will act as steps for fish to swim up. The weirs will slow the flow of the river and they are low enough to allow shad, which are weak jumpers, to get above them into shallow pools where they can rest before taking the next step.
There will be eight weirs in all, two more than a similar fishway at Kenyon Mill dam.
Work at Bradford Dam started in June when Salem, Massachusetts-based SumCo Eco-Contracting carved a bypass channel out of the east riverbank to allow the Pawcatuck to continue flowing during construction. Coffer dams were erected on either side of the dam and the channel in between was drained of water to create a dry work area.
The dam came down last month. A broken concrete abutment near the mill complex is all that’s left now, but it too will soon be demolished.
On a recent afternoon, two excavators worked side by side placing the rocks that will form the first weir. As each stone went in, a worker checked the elevation against plans drawn up by engineering firm Fuss & O’Neill.
“They’re following the engineering design to the inch,” Paton observed
© Copyright 2006-2017 Gatehouse Media, LLC