Finesville Dam Study and Removal

The Finesville Dam served as the first full barrier on the Musconetcong River, a major tributary of the Delaware River, which is the largest undammed river on the east coast. With a committed coalition of stakeholders led by the Musconetcong Watershed Association, Princeton Hydro was contracted to complete a feasibility study and, in later phases, final engineering designs, permitting, and construction guidance. Funding support was provided by the NOAA–American Rivers partnership and US Department of Agriculture’s Natural Resources Conservation Service.

Finesville Dam was first built for an iron forge around 1751 and was later used to power a gristmill on the opposite side of the river. In the early 1900s, the dam was reconstructed with concrete. Given the area’s historic context, an archaeological survey was completed during the planning stages.

Princeton Hydro completed a full bathymetric survey of the impoundment, calculated the volume of sediment, and analyzed samples for geotechnical and chemical qualities. Hydrologic and hydraulic analyses were completed to determine if downstream properties would be impacted by increased flow. Princeton Hydro was then hired to develop a dam removal design to incorporate historic preservation objectives and adjacent landowner interests by retaining the abutments as a physical remnant of the dam on the site. In addition, a boulder weir was designed to maintain a falling water aesthetic spanning the channel and yet allows for free movement of fish.

With much fanfare and public attention, the historic dam was removed in November 2011, restoring fish passage from the Atlantic for the first time in almost 300 years. During construction, a professional archaeologist was onsite to document structural elements. Princeton Hydro coordinated with the contractor and local residents to set aside dam timbers and other features for long-term display.

Princeton Hydro and the contractor worked with adjacent residents to provide additional bank terracing and stabilization with soil lifts and live stake plantings to allow for continued public access. As a result of this successful removal, three miles of the Musconetcong River have been opened and attention has turned to upstream barriers.