Canal Flood Protection

The wee wolves rolling on the bike today.

This looks like a covered bridge crossing over the canal not too far from Billy Goat’s Trail, but in fact it’s a stop gate.

What’s a stop gate? Basically, it’s a way to protect the canal when the Potomac is at flood. The building you see here houses a winch and thick planks of wood. When the Potomac River is on the verge of flooding, a temporary dam, or stop gate, is created by using the winch to lower the heavy planks one by one through the floor and into groves that have been cut into both sides of the stone foundation. Some river water is let through, but the majority is stopped from rushing downstream into the canal and causing damage. After the flood is over, the planks are winched back up into the building, until the next flood.