There are over 1,500 dams on rivers and streams in the Hudson River estuary, a 153-mile stretch of river between Troy and New York Harbor. Most of those small dams powered mills during the Industrial Revolution. But now the stone and metal barriers do very little except prevent fish from reaching their natural spawning grounds.
At least one of those dams, however, recently came out and may be the first of many dam removals in the estuary.
The city of Troy removed a six-foot metal barrier on a local stream known as Wynant’s Kill, according to the environmental group RiverKeeper. Over the following month, eels, suckers and yellow perch moved into the stream. But most importantly, river herring, also known as alewives, swam up river and began spawning for the first time in 85 years.
The alewives, along with other ocean-going species like shad, use freshwater rivers and streams in estuaries along the east coast for breeding. But since the 1960s stocks of those fish, a big part of the aquatic food chain, have plummeted as overfishing and reduced spawning habitat have taken a toll, RiverKeeper points out.
Though removing small dams can be costly, it’s a critical step in opening up breeding habitat and improving fish numbers. ‘Every dam should have an existential crisis,” John Waldman, a biology professor at Queens College tells Mary Esch for the Associated Press. “These are artifacts of the Industrial Revolution that are persisting and doing harm. We should decide which dams still serve a purpose and which should be removed.”
Frances Dunwell, coordinator of the New York’s Department of Environmental Conservation's Hudson River Estuary Program tells Esch that’s just what her agency hopes to do, with plans to remove as many dams in the estuary as possible by 2020. She says the agency has already targeted six unused dams for possible removal.
Other states are taking on similar projects. In 2014 Delaware removed a stone dam from White Clay Creek, allowing herring, shad and striped bass to swim up the river for the first time since 1777. In Maine, the removal of two dams on the Penobscot River in 2012 and 2013 led to the endangered short-nose sturgeon re-colonizing the river in 2015 after a 100-year absence.
The Wyants Kill dam came to the attention of the NY Department of Environmental Conservation and the city of Troy three years ago, Nicholas Buonanno reports for the Troy Record News. Captain John Lipscomb, who patrols the Hudson looking for problems and pollution for RiverKeeper, noticed a discharge coming out of an abandoned iron mill near the creek. When he investigated the problem on land with DEC staff, they discovered the dam and began discussing the possibility of its removal, culminating in the cooperative effort by the city, state and Riverkeeper last month.
“We’re very proud of the city of Troy for being the first in this initiative,” Lipscomb tells Buonanno. “By helping to restore life to this stream, Troy is demonstrating that communities can not only benefit from the river, they can also benefit the river in return. The river is better off today than before Troy took this action. How many communities can say the same?”