The Prison Pond Dam Has Been Removed from the Windsor Grasslands Wildlife Management Area
The Connecticut River Conservancy, Vermont Department of Fish & Wildlife, and other partners have completed removal of the Prison Pond dam in Windsor, VT.
Originally constructed in 1925, the one-acre pond was built to provide fire protection for the Southeast State Correctional Facility. In 2014, a modern water system was built to replace the antiquated and deteriorating pond fed fire suppression system, but the dam was not decommissioned at the time, and its condition has since continued to deteriorate. In 2017, the Vermont Fish & Wildlife Department acquired approximately 826 acres of the former correctional facility, including the pond and dam, to create the Windsor Grasslands Wildlife Management Area. After completing a series of dam inspections, engineering assessments, and cost-benefit analysis of options, it was determined that the best course of action was to remove the dam.
The decision to remove the dam was based on the following:
To improve aquatic habitat, stream equilibrium, and water quality in accordance with the goals and objectives of all Agency of Natural Resources departments.
Dam safety inspections rated the dam’s condition as Poor from 2006 to 2022, then downgraded to Unsatisfactory in 2023 following flooding that occurred that year, and ultimately further downgraded to Significant Hazard Potential by 2026 due to insufficient spillway hydraulic capacity, inadequate dam operating controls, and deteriorated structural integrity. Failure to remove the dam was anticipated to cause some degree of property/economic damage, environmental damage, and disruption.
This 18’ high by 160’ long dam was removed in September-October 2026. The work was made possible through the Vermont Department of Environmental Conservation’s (VT DEC) Clean Water Initiative Program (CWIP) - Dam Removal Block Grant administered by Watersheds United Vermont (WUV).
The Windsor Grasslands Wildlife Management Area is now free of obsolete hazardous structures and can be enjoyed by local communities and wildlife alike. It features a mix of forests, agricultural, and wildlife meadows including a variety of wildlife habitat types and public uses. The WMA is renowned for birdwatching with over 100 species observed in varied habitats! Community uses include hiking, cross-country skiing, and snowmobiling.
Dam removal in progress.
Removal of the dam will restore brook trout and other aquatic organism passage in the local stream (a tributary to Hubbard Brook), improve water quality (increase dissolved oxygen and reduce water temperature), and increase wildlife habitat. In addition to removing the concrete dam, this project removed 1,000 cubic yards of sediment trapped upstream of the dam, which will further help to improve water quality and restore natural stream flow. Site restoration also included adding wood into the new stream channel above the existing dam. In spring 2027, CRC will return to plant 320 native trees and shrubs including pollinator species in all disturbed areas.
Prison pond dam removal in progress. Old wagon wheel removed from Prison Pond dam.
Left: dam removal in progress. Right: this old wagon wheel was found in the concrete during dam removal! In 1925 they threw whatever metal and steel they had laying around in the concrete to make it stronger. Over the years we’ve found tractor parts, railroad tracks, and various other metal components in the oldest dams. More modern dams have rebar, but it wasn’t standard practice until the 1950’s.
For questions about the project, contact:
Ron Rhodes, Director of Programs
Connecticut River Conservancy
rrhodes@ctriver.org | 413-768-4994
