Constructed in 1914, the Great Dam in Exeter, New Hampshire, was outdated, unsafe, impacted water quality, and affected ecological integrity within the Exeter River. The New Hampshire Department of Environmental Services (NHDES) identified several safety problems with the Great Dam, most notably its inability to pass the 50-year storm event with adequate freeboard. VHB served as the lead consultant for this project, starting with a Feasibility and Impact Analysis, continuing through the subsequent design and permitting phase, and ultimately through the construction phase. The goals of this project were to reduce threats to public safety, improve fish passage, and increase oxygen levels in the water—all while respecting history, stakeholder concerns, and the river’s ecosystem.
VHB provided multi-disciplinary consulting services, including survey and engineering design, environmental analysis and permitting, cultural resource evaluation and mitigation, and construction observation services. Among one of the largest dam removals in New Hampshire, the $1.8-million project involved removing the entire existing dam spillway, including the fish ladder and lower dam. VHB also helped the Town of Exeter win more than $800,000 in state and federal grant funds to offset the cost to the community.