Lower Wilson Pond Dam

Swanzey, New Hampshire | Town of Swanzey

The Town of Swanzey needed to improve the stability and safety of an earthen dam serving an 80-acre pond. The pond supports recreation and enhances the value of the homes located along its shoreline. The dam had seepage issues and did not meet current dam safety standards. Using articulated concrete blocks as overtopping protection, DuBois & King designed a rehabilitation that allowed the town to maintain the existing pond water level (visible from the road) and continue to offer this recreation resource. The choice to install overtopping protection resulted in a substantially lower project cost than more traditional methods, such as raising the dam or reconfiguring the spillway to accommodate for large storm events. Raising the dam would have also required raising the state highway carried by the dam, presenting a substantial additional cost. Our project team also designed a toe drain filter system to manage seepage. 

Markets:

Project Elements

• 18-ft-high, 340-ft-long earth embankment dam that supports recreation, aquatic habitat and wetland resources, and flood attenuation
• Maintaining existing dam height and the pond’s elevation were critical to satisfying town requirements and minimizing costs