But wildlife suffered. The dams and their millponds raised water temperatures in parts of the stream and decreased dissolved oxygen levels, and primitive fish ladders didn’t allow many herring through. Eventually, much of the mill industry moved to the South and the dams fell into disrepair – yet the fish were still cut off from their spawning grounds.
“At one point there were seven dams over the course of a mile and a half,” says David Gould, the environmental manager. “That’s a lot of obstructions for a fish to migrate through in such a short distance. That’s simply devastating to a population.”
The initial dam removal, in 2002, was the first of its kind in coastal Massachusetts. The community has also worked on modernizing fish ladders, diverting polluted storm water flows, and preserving land around the Billington Sea.
Most New England dams are quite small compared with their western counterparts—perhaps 10 to 20 feet tall. But to fish, “even a two-foot dam is a barrier,” says Brian Graber, director of the Northeast river restoration program of American Rivers, a nonprofit group involved with the Town Brook project. Throughout New England, removing aging dams is usually much cheaper than updating them, and many of the region’s dams are becoming safety hazards. In one town or another, “We’re having public safety emergencies pretty much every time there’s a big storm,” Graber says.
At the moment, New England dams are being demolished at the rate of a dozen per year. Scores are currently being considered for destruction in Massachusetts alone. Yet removing the dams—which can mean draining historic millponds, not to mention bulldozing and replanting river channels—changes the aesthetics of rivers and eliminates structures that may trace their roots back centuries.
Some worry that removing Town Brook’s dams will erase an important chapter of history. In its present form, the brook “is a microcosm of the evolution of American life” across four centuries, telling the story of how religious refugees became farmers and fishermen, then millworkers, and finally, suburban commuters, says Jim Baker, a Plymouth historian and author of Thanksgiving: The Biography of an American Holiday. “There’s plenty of brooks around and plenty of fish. But once you take out history, it’s never coming back.“
These sentiments are common in lesser-known communities throughout New England. Many times “a dam was built and the town grew around the business,” explains Eric Hutchins, a National Oceanic and Atmospheric Administration fisheries biologist involved with the Town Brook project. “It’s often a place where grandparents worked and children played. A lot of these towns get their names from dams.”
On Town Brook, a compromise of sorts has been struck. Though the restoration team hopes to remove or lower five of the six dams, they currently have no plans for the most historic structure—the dam at the site of a 1636 mill, where a re-created gristmill still operates today. Workers instead installed a state-of-the-art aluminum fish ladder, carefully lining it with stone to blend in with the mill, a popular tourist site.
But these days, Gould notes, the strengthening herring run is a tourist attraction all on its own.