The old dam made of wood built in 1849 was too damaged to effectively regulate the water level of the Richelieu. That's why a new dam was built between 1967 and 1969. Its operation uses a technology that is unique in America: it is the water pressure rather than the direct use of electric energy that activates the dam shutters.
The dam is open during the navigation season from mid-May to mid-October. It allows you to cross on foot over to the north bank of the Richelieu River to visit the Vianney-Legendre Fishway.