Environmentalists celebrated the removal of a dam on a wildlife sanctuary in Pittsfield on Thursday.
Water is flowing naturally in Sackett Brook for the first time in more than 80 years. In October, a dam and a bridge were removed from the 8.5-mile stream. Tom Lautzenheiser, a scientist with Mass Audubon, oversaw the four-year project.
“The dam was serving no practical purpose any longer and generally speaking dams are liabilities in that as they get older unless you maintain them they are eventually going to fail,” Lautzenheiser said. “It’s easier to have a controlled failure by removing it than it is to let it fall apart on its own time because that can be a hazard.”
The Gravesleigh Dam spanned 60 feet across the brook, creating a recreational and fishing pond dating back to the 1930s. Lautzenheiser says the dam was located at a boundary of the Housatonic River floodplain, altering the natural flow of the stream.
“The river is going to behave differently above that point than below it naturally,” he explained. “So in a sense we’re restoring two systems by pulling out the dam. The more cobbled-bottom, rapidly flowing cold water system and the more slow-flowing floodplain.”
Part of the funding for the $400,000 project was provided by the city-owned Pittsfield Municipal Airport. An airport safety expansion project completed in the fall eliminated a portion of Wild Acres Brook, a cold water fishery. Mark Germanowski is the airport’s manager.
“We had no other stream system on the airport property to mitigate so we had to look off-site for other mitigation potential,” Germanowski said. “This was the site that was selected by DEP [Massachusetts Department of Environmental Protection] for us to use as mitigation to that impact.”
Lautzensheiser says the dam and the bridge were causing erosion, known as scours, along the banks and within the river channel itself. He says the brook and its surrounding area will be monitored over the next decade to see exactly what it does.
“It’s really fascinating to see the snow falls, the ice forms and then the river is just bouncing up and down all through those months,” Lautzenheiser said. “In one storm event, five inches of gravel is deposited on that bar and it grows out. The river kicks over one way and it kicks over the other. It’s really amazing to see. It’s almost like a living creature itself.”
The brook is located within 260 acres of the Canoe Meadows Wildlife Sanctuary. Sanctuary Director Rene Laubach says the dam and bridge removal are part of an ongoing effort to return the wetland area to its natural state after Mass Audubon acquired the site in 1975 with six buildings and plenty of fencing.
“One of the boundaries is the Housatonic River which this is tributary of and flows into the Housatonic a short distance downstream,” Laubach said. “So that creates a great wildlife corridor for birds moving up and down during migration.”
About 300 trees and other vegetation were planted along the banks of the brook and abutting fields to provide shade for cold-water aquatic animals and secure the soil. Lautzenheiser says Mass Audubon is considering placing a pedestrian bridge over the brook, but for now the only dams that would pop up would be built by beavers.
“This is really I think an ecological and restoration success story,” said Lautzenheiser.
