Big Meadow Creek Fish Baffles

In an effort to increase the wild steelhead populations, the Idaho Department of Fish and Game is working to restore steelhead habitat in the Potlatch River system.  Part of their approach is to remove barriers that impede access to spawning and rearing habit.  In the summer of 2018, Hatter Creek Earthworks LLC completed the Highway 8 Culvert Passage Improvements on Big Meadow Creek project for the Idaho Department of Fish and Game.   This project installed galvanized steel baffles in an existing culvert under State Highway 8 near Troy Idaho. 

Below is an Idaho Fish and Game video showing steelhead habitat restoration on Big Meadow Creek including footage of this project.

You can learn more about what the Idaho Fish and Game is doing to improve Steelhead habitat at

The existing Big Meadow Creek culvert under State Highway 8 is 16 feet wide and 200 feet long.  The floor of this culvert has a very smooth concrete surface which allowed the water to spread out and flow very fast and shallow through the culvert preventing steelhead passage.  This project installed nineteen steel baffles in the culvert to create a series of pools and also concentrated the stream in low flow conditions to a narrow channel.   The steel plate baffles were prefabricated off-site and then hot dip galvanized for corrosion prevention.   The baffles were anchored to the existing concrete and then new concrete curbs were poured in place under each baffle.  In addition to the steel baffles installed in the culvert, we installed a series of three rock weirs below the culvert using large boulders.

Water flowing through culvert prior to installing fish baffles
Galvanized steel baffles prior to installation
Lowering steel baffles into culvert. Each baffle weights approx. 300 lbs.
Baffles installed in culvert and anchored in place prior to pouring concrete.
Concrete forms were constructed for pouring the concrete footing under the steel baffles
Pouring concrete using z-boom concrete pumping truck and over 200 feet of line.
Concrete footings poured under each of the steel baffles.
Installing rock weirs below culvert using large boulders
Completed rock weirs
Stream flowing into culvert following construction
Following construction, the baffles created pools within the culvert
Large willow tree which was removed and replanted during construction has already started to produce new growth.