Consulting Solutions that Work for People and the Environment

Removal of Merrimack Village Dam, Souhegan River, Merrimack, NH


The Merrimack Village Dam was the lowermost dam on the Souhegan River in Merrimack, NH. The Souhegan River empties into the Merrimack River, which is a coastal watershed. A dam of some fashion has been at this location for over 100 years. NH Dam Safety determined the dam did not meet current dam safety criteria, and there were continued operation, maintenance and repair costs, as well as liability issues. Since the dam provided no measurable benefits to the owner, in lieu of repairing the dam, the owner sought to remove it. Our work included: historical research of diadromous fish presence above the dam; management of wetlands delineation; bathymetric and dam surveys; HEC-RAS hydraulic modeling and analyses; sediment sampling; interpretation of sediment pollutant/toxicity testing; sediment transport analyses; sediment management plans, public outreach, Section 106 historic and cultural resource consultation, feasibility report, engineering drawings and permitting. The dam was successfully removed in 2008.