Hoving Home will reroute, widen waterway

The Philipstown Conservation Board determined on Tuesday (June 10) that there would be no significant environmental impacts if the Hoving Home removes a dam and reroutes a section of Philips Brook that runs through its property in Garrison.

The board's vote concluded the environmental review for the $1.8 million project, under which the treatment program for women plans to remove a 10-foot-high dam originally built decades ago to create a swimming pond. It will then move 800 feet of the brook north into a new 30-foot-wide channel that will be 3 to 5 feet deep, enabling it to hold more water.

Some sections of the stone wall constraining the brook as it flows west to Constitution Marsh will be removed, as will one of the footbridges and one of three lower dams, or weirs. Dirt excavated for the new channel will be used to fill 300 feet of the brook and the two other weirs.

Despite multiple repairs, the dam and the stone walls have sustained extensive damage from flooding and face greater water pressure as storms intensify and become more frequent, according to Inter-Fluve, the Cambridge, Massachusetts, firm overseeing the project.

If the dam failed, the rush of water could damage downstream properties, creating a liability risk for the Hoving Home, said Nick Nelson, a fluvial geomorphologist with Inter-Fluve who reviewed the project during a Conservation Board public hearing last month. The project is also expected to improve passage for fish and other aquatic species and reduce flooding along Snake Hill Road.

"There's water still flowing through, but what used to be a pond is filled with gravel and cobble," said Nelson. "If that dam were to fail catastrophically during a storm, all of that material would be washed downstream."

Hoving Homes submitted an application for a wetlands permit in June 2025. After neighbors raised concerns about potential flooding, the board asked its consultant, SLR Engineering, to review Inter-Fluve's projections. SLR found Inter-Fluve's modeling to be adequate. The Conservation Board, which still must issue a wetlands permit, concluded that the Hoving Home had taken steps to reduce temporary "moderate-to-large impacts" related to drainage, erosion and flooding during construction.

Beth Greco, the Hoving Homes president and CEO, said it plans to begin the project in the spring. Under a permit approved by the state Department of Environmental Conservation, Hoving will be prohibited from undertaking in-stream work from Oct. 1 to April 30, when trout spawn and incubate.

Once finished, the new channel will be wider and shallower than the existing one. Boulders will be placed along its bed to create "step pools" — areas of deeper water to slow the flow and reduce erosion of the banks. The pools also provide "resting stops" for fish and oxygen-rich water during periods of turbulence, according to Inter-Fluve.

Native plants will cover the new bank. In addition, according to Inter-Fluve, the reconstruction will avoid two areas of "archeological sensitivity" identified in consultation with the state Historic Preservation Office, which considers the site eligible for the National Register of Historic Places.

The configuration will send "additional flow" through a culvert that carries the brook under Avery Road, according to project documents. Walter Hoving received a $200,000 grant to replace the town-owned culvert, which is considered undersized. But Greco said last month that the property lines bordering the culvert prevent it from being widened. "It's in good enough shape to keep," she said.