The project in Charlestown is located along the Connecticut River, which comprises the New Hampshire-Vermont border. Charlestown is about 25 miles north of Keene.

A section of the Connecticut River’s left bank, near Charlestown’s wastewater treatment facility, was eroding at the rate of 8-10 feet a year, posing a threat to the plant’s stability. This section of the river is part of a pool used by the New England Power Company’s hydroelectric power plant in Bellows Falls, Vermont, located about seven miles downstream. The erosion of the river’s left bank was caused by the river’s high velocity during flood periods, and also its oscillating water levels, which fluctuated relative to the amount of electricity being generated at the plant.

To stem the erosion and protect the wastewater treatment facility, the Corps constructed 1,300 feet of stone slope protection along the east bank. The project was built between October 1974 and January 1975 at a cost of $113,000. The project was constructed under Section 14 of the Continuing Authorities Program.