Champlain Canal Lock 9

Lock 9

Lower size of Lock C9 has a unique wooden dock.
Phone Number: (518) 747-6021
Lift: 16 feet
How to Lock Through

Lock C9 on the Champlain Canal is located in the town of Smith's Basin, six miles from Lock C8. It is very similar to the other locks on this stretch of the canal; it is in the quiet country side which makes it a nice place to stop and enjoy some solitude. There is docking on both the upper and lower side of the lock, with picnic tables located on the upper side. The lower side has a very nice wooden dock with old fashion street lights.

This is the first lowering lock for northbound boats, lowering boats 16 feet, from an elevation of 140 feet to an elevation of 126 feet. The lock master can be reached on VHF channel 13 or by phone at (518) 747-6021. Note that there is no Lock C10. Lock C11 is north-east by nine miles.

Siphon spillway

Of note here is a unique spillway that was developed specifically for use on the canal system. During times of heavy rain the canal waters rise quickly. To combat large fluctuations in water levels, the canal uses spillways, similar to dams, to allow this excess waters to divert this water. At lock 9, there was not enough space to fit a conventional spillway, so a new spillway was developed.

Utilizing about one-third to one-fifth the space, this spillway carries water through internal passageways and over it in the conventional sense. Four 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 can be seen on the southeast side of the lock. Boaters should say clear from the lock, it may appear that there is little flow nearby, but a majority of the flow remains unnoticed as it is through the underwater passageways.


Champlain Canal Lock 9 and siphon spillway were let under Contract Number 25. This contract was awarded to the Atlantic, Gulf and Pacific Company on November 19, 1906, the same company that was awarded contract 15 a few months earlier. The earlier contract included, among other structures, Champlain Canal Locks 11 and 12.

Contract Number 25 was included excavating the canal and protecting its sides, constructing Locks 9 and 10 (Note that the latter lock was never actually built), necessary spillways, power plants and appertaining structures, bridge substructures and approaches, retaining walls, highways and other incidental details about 0.6 mile north of Comstock (border with contract 15) and Dunham's Basin road; this gave a total contract length of about 13 miles.

The dredge and plant were built on the ground and started in December, 1906. Operations were started by building dikes, April 22, 1907. The dredging started August 1, 1907.

Champlain Canal Lock C9.  The siphon spillway is on the right.
Champlain Canal Lock C9. The siphon spillway is on the right.  
Lock Sign.
Lock Sign.  
The lower side of the siphon spillway during construction.
The lower side of the siphon spillway during construction.  
The upper side of t siphon spillway during construction.
The upper side of t siphon spillway during construction.  
Building plans for the siphon spillway.
Building plans for the siphon spillway.  
<< Lock 8
Lock 11 >>
Champlain Canal
Main Pages Champlain Canal Home Albany to Troy Waterford to Schuylerville Fort Edward to Whitehall HistoryPhotos Locks
Towns AlbanyTroyWaterfordMechanicvilleSchuylervilleFort EdwardFort AnnWhitehall © 2006-2013. All Rights Reserved. With assistance from Uptick Analytics.