Concrete Dam Removal

Spoonville Dam

Spoonville Dam RemovalPrinceton Hydro initiated engineering assessment and completed final design for the Farmington River Watershed Association and its project partners for this exciting, fast-paced fish passage improvement project, which included both the removal of the Spoonville Dam and the design of a nature-like fishway at the Winchell-Smith Dam.

The Farmington River is a renowned Wild & Scenic River in Connecticut and this project looked to improve fish passage for historic runs of diadromous fish at both sites. The Spoonville Dam, a 35 foot high concrete dam that was partially breached during the historic 1955 floods, is the first partial barrier to fish passage on the Farmington River. The dam is located in the Tariffville Gorge, just downstream from an outstanding whitewater rapids heavily utilized by whitewater enthusiasts. A transparent design process and open lines of communication with whitewater boaters were critical parts of the development of the final design, in order to ensure project buy in from the key project stakeholders.

The scenic gorge provided many unique surveying challenges for Princeton Hydro. The swift flow in this reach has been responsible for multiple deaths, so safety during our field investigation was critical. Our staff developed an innovative cabling system that allowed us to safely collect detailed bathymetric data on this swift river.

Due to the large scale of the dam and its challenging access issues within the gorge, our engineers estimate of probable cost came to approximately $1.4 million for the dam’s removal. Our design and cost estimate incorporated the option of low level explosives to break up the dam and the large dam fragments into manageable-sized debris prior to removal from the site. The project effort was completed, from initial site investigation through engineering assessment and final design, in just six months.