What is a Lock?

The Great Bridge Lock on the canal is a unique guard lock that protects water quality by controlling the meeting of fresh water from Currituck Sound in North Carolina and salty water from the Elizabeth River, which connects to the Chesapeake Bay. When those waters mix, plants and animals are endangered. In 1915, the lock was left open, and by 1930 the mixing had adversely affected wildlife in Currituck Sound and harmed the natural ecology. A new lock was completed in 1932 and remains in operation today. It is also a reversible head lock with two sets of gates at each end. Locks raise and lower water levels, and depending on water levels on each side, operators open or close four sets of gates and valves in different combinations to direct the water in the lock. As many as 20 boats can fit in this lock.

Chesapeake, Virginia · United States