Thornbury Dam and Fish Ladder

It’s that time of year when the Chinook salmon frolic and jump along the fishway ladders at the Thornbury Dam while curious spectators awe in their beauty.  Visitors snap photos and wait patiently for the fish to jump from ladder to ladder as the fish head up the Beaver River to spawn.

The Thornbury Dam and Fish Ladder is a local landmark used primarily to control the flow of water to the river mouth area.  In 2003, a fish ladder was installed which begins just below the dam on the Hwy. 26 bridge. Without this ladder the fish would not be able to pass upstream to spawn. 

While visiting this annual phenomenon of nature, park your vehicle in the lot next to the Town Hall and make your way to the viewing platforms and witness the fish in action!  And if you happen to miss it, check out the dam in the spring (usually April) while the rainbow trout travel along jumping from one level to the next.

 A little history:


The original dam was built in the 1850’s to serve the first mills that were planning to locate in Thornbury.  Later on, in 1912, the dam washed out and was eventually replaced by the current dam. The Ministry of Natural Resources (MNR) acquired the dam from the township in the 1970’s and is now managed solely by them. 


Exciting news this year:  The Ministry installed an underwater camera and sensor to track the type and number of fish, along with data to record peak times when the fish are passing by.


According the Biotactic Fish and Wildlife Research team, “fish passage to suitable spawning grounds is critical to the survival of rainbow trout and Chinook salmon. The location of physical barriers, such as dams, may prevent the upstream movement of adult fish to spawning areas.” 


With the installation of the passive fishway, migrating salmon and Rainbow trout have access to several kilometres of cold water streams in the Beaver River watershed.  Upstream, the migrating trout and salmon also pass through three other fishways located at the Haines, Clendenan and Slabtown Dams.  Easier access to the spawning areas results in greater numbers of rainbow trout and Chinook salmon in southern Georgian Bay. This in turn allows increased opportunities for sports fishing and viewing.”


With the end of October just around the corner, you’ll want to take a trip to Thornbury to check this out for yourself!  Grab the kids, pack a lunch and cross your fingers in hopes that you’ll be the lucky one to ‘catch a big one’ in action! 

For more information on the Fishway, please contact the Ministry of Natural Resources at

News provided by Century 21 Millennium.

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