Canal Engineers were worried about breaches at Anglers, especially since water has a tendency to surge into the canal above Great Falls, adding to the pressure on the weak walls by Anglers. To prevent catastrophic flooding from reaching the area, the Canal Company built the Stop Gate just upstream of Widewater. To many, it looks like a covered bridge, but the building above holds boards that once put in place create a wall across the canal to divert water from the canal back into the Potomac River just below the falls.
