PITTSFIELD — Kirvin Park is set to swap invasive overgrowth for a thriving native habitat.
An ecological restoration at Kirvin Park will remove invasive plant species and reintroduce native vegetation to more than 17 acres near Sackett and Ashley Brooks to improve wildlife habitat, soil health and water quality.
City officials, the Housatonic River Natural Resources Trustees, and General Electric unveiled the project earlier this month to the public at Herberg Middle School. The restoration, part of GE’s cleanup obligations for the Housatonic River, targets floodplain areas to enhance the natural resources of the Housatonic River Watershed.
“These [invasive] species have taken over this floodplain community. They have a significant effect on the habitat functions [and] the biodiversity,” said Dennis Lowry, a wetland ecologist with consulting firm AECOM. “Our goal is to get rid of this community and turn it into a natural, native floodplain community.”
The project stems from a 2000 agreement between GE, the city, the U.S. Environmental Protection Agency, MassDEP and others, and builds on a 2019 assessment that identified part of the 225-acre park as a priority for restoration.
Lowry said the plan is to restore 10 acres of floodplains, create 1.23 acres and enhance 1.2 acres of wetlands near Sackett Brook, add trees across a 2-acre planting zone and establish a 2-acre pollinator habitat to support long-term biodiversity and plant growth.
Soil scientists and biologists defined the limits of the wetlands in 2022, and the group has been constantly monitoring the groundwater for the last three years through wells. They have also surveyed the soils and vegetation, groundwater levels, threatened and endangered species and cultural resources.
Common buckthorn gradually has overtaken much of the floodplain since the mid-1990s, forming dense thickets of woody shrubbery alongside other invasive species like honeysuckle, goutweed and bittersweet.
“There’s 88 total species out in this community, which is a good amount of diversity, but 90 percent of those plants are taken up by 15 of these invasive species,” Lowry said. “So the whole community changes as these species come in and kind of monopolize what’s out there.”
These species don’t just crowd out native plants — they disrupt the entire habitat by limiting biodiversity and the natural growth of other plants. They also alter soil chemistry, contribute to erosion and negatively affect water quality.
“They even affect the earthworms that are in there,” he said. “Mostly it’s an invasive European earthworm that’s associated with this type of community, as opposed to native earthworms.”
To restore the natural floodplain, crews will cut and chip woody invasive plants, including buckthorn, honeysuckle and bittersweet. The stumps will be treated with herbicide and the disturbed soil will be temporarily stabilized with annual rye grass.
After a year — assuming the invasive species are under control — teams will begin planting native vegetation.
About 12,000 native trees and shrubs, such as cottonwood, silver maple, pin oak and red maple trees, will be planted in the floodplain area, as well as vines and herbaceous ground cover. The wetlands also will see over 3,500 plantings with the addition of ferns.
Crews will flag and protect existing native species and conduct field screenings for wood turtles, a state-listed species. The team also plans to create new nesting sites for the turtles in higher parts of the floodplain.
“We’re not going to go in and clear cut this,” Lowry said. “We’re going to preserve the positive elements around the floodplain of the wetland.”
As part of the project, GE will also refurbish a footbridge across Sackett Brook to improve its stability.
The final version of the restoration plan, which is currently past the concept stage but can be tweaked based on public input, will be submitted in July, followed by a 30-day public comment period. A contractor is expected to be selected in the fall, and construction is scheduled from late 2025 into early 2026.
James McGrath, Pittsfield’s park, open space and natural resource program manager, said the park will stay open through construction and the city will “make every attempt to make certain that there are no conflicts between our projects and your use of the park.”