Rainbow Trout Migration and Passage at Denny's Dam, Saugeen River

Previous radiotelemetry studies in the Saugeen River were designed to investigate how the removal of the Truax Dam in Walkerton, Ontario, affected fish passage and movement throughout the Saugeen River, focusing upstream of Denny's Dam (here). Starting in Spring 2023, studies have been conducted whose aim has instead shifted to investigate the passage success of fish at the Denny's Dam modified pool-weir-orifice fishway. These studies help to address an important knowledge gap regarding how many fish from the migration run entering the Saugeen River from Lake Huron can actually pass this partial downstream barrier, and potentially reach upstream tributaries to spawn. Fishway performance evaluations were conducted in Spring 2023, 2024, 2025 and Fall 2024 and are currently ongoing. Each season ~30 adult rainbow trout were captured at the Denny's Dam fishway, implanted with coded radio transmitters, released 150m downstream of the dam and tracked throughout the remainder or the migration period using primarily a combination of mobile telemetry and fixed tracking stations located throughout the watershed. To-date total fishway efficiency has varied between 14% and 33% in the spring for spring-run fish and for fall-run fish was 10% in the fall and 34% the following spring.

Find additional details regarding the fisheries offset and compensation project here, the biomass electrofishing survey component of this project here, the redd count survey component here, and the videographic survey component here.

The most recent annual summary of all project component findings to-date (Fall 2025) can be found here.
A detailed summary of all radiotelemetry findings to 2022 can be found here. The March 2024 publication of all radiotelemetry results can be accessed through the link at the top of the page.