Champlain Canal Lock 12

Lock 12

View from the south before lowering to Lake Champlain level.
Phone Number: (518) 499-1700
Lift: 15.3 feet
How to Lock Through

Lock C12 is located right in the heart of old Whitehall, seven miles from Lock C11. This unique lock is in the center of the historic part of town and makes for a nice place to walk to. There is a bridge crossing the canal/river over the lock which gives a unique prospective of boats locking through.

The lock lowers boats 15.3 feet from the Champlain Canal into Lake Champlain. The lock master can be reached on VHF channel 13 or by phone at (518) 499-1700.

Siphon spillway

Wood creek enters Lake Champlain here in Whitehall. Historically this is the location of the final lock on the Champlain Canal. As such, local mills and other buildings were built in the area utilizing creek's water supply. When the canal was enlarged to today's size, the existing mills, buildings and residences in Whitehall ideally would remain intact, while also allowing the proper depth of pool of water to be created. The required the location of a lock at this location, but it would be significantly wider than the old lock. This wider lock impedes the natural flow of water. To combat this, an innovative spillway was used.

Champlain Canal Lock C12.  The dam and siphon spillway are to the left.
Champlain Canal Lock C12. The dam and siphon spillway are to the left.

Developed specifically for use on the canal system, which was the first known use of such a spillway, it uses internal siphons to allow large amounts of water without a large horizontal distance. Utilizing about one-third to one-fifth the space, this spillway carries water through internal passageways and over it in the conventional sense. Six internal and independent passageways use the siphon principle. With clever design, these siphons start and stop automatically depending on the height of the water. A conventional overflow is also used here. This provides a location for floating debris to bypass the lock. This passage is not sufficient in size alone to bypass waters in times of high water.

This spillway is located perpendicular to the flow of the creek, opposite the lock. It can be best viewed from the bridge above. The siphon outlets are by design below the water line. The main inlet is also submerged under water during the year. But if the water flow low, like found during late summer the upper air inlet holes which are designed to break the siphon may be visible. In such a case you can be assured that the siphon is not working at its full potential. Boaters need not worry about its currents as it is located away from navigable waters.


Lock 12 and the associated dam and siphon spillway was built as part of Contract Number 15, which was awarded to the Atlantic, Gulf and Pacific Company on August 9, 1906. This contract also included other work in the area, such as excavating the canal and protecting its sides, constructing Lock 11, Dam Number 4, a highway, two masonry culverts, five bridges with their piers and abutments and other incidental details between Lake Champlain at Whitehall to just over a half mile north of Comstock, a length of 6.8 miles.

The contractor started operations by building dikes on October 10, 1906. The dredge and large plant were built on the ground, and work started in November, 1906. Work was started on actual lock in March, 1007. Dredging was started on May 30, 1907 on the canal prism.

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