Located in Severn Township is the small community of Port Severn, nestled around the south end of Little Lake, the community is rich with historical and archeological significance. Within the established community is the Port Severn Main Dam which carries Port Severn Road North overtop and is one of the main access roadways in Port Severn. Having been constructed in 1915-1916 the Dam and Lock 45 are part of the Trent Severn Waterways 386km connecting Georgian Bay with Lake Ontario.

This project is broken down into several sites: Main Dam, Blind Dam D, and Little Chute Dam G. The Port Severn Main Dam is a concrete gravity structure with nine (9) sluiceways with timber stop logs that are operated with a hydraulic log lifter. Blind Dam D, located approximately 195 m northeast of the Main Dam, is a concrete retaining wall founded on bedrock with an earth embankment, built to manage the water elevations and prevent flooding of adjacent lands.