Large Wood for the Platte in Benzie

A reach of the Platte River in Benzie County near the village of Honor was identified by CRA and MDNR Fish Division as being a good candidate for fish habitat improvement work as it’s very wide and shallow in comparison to reaches just upstream and downstream. This high width-to-depth ratio contributes to warming of water that should otherwise be cold on top of there being little channel bed diversity. MDNR fish shocking personnel surveyed the reach prior to construction and found high numbers of juvenile salmonids present, indicative of very good rearing habitat.

However, very few larger sized brown trout were at hand, indicating a lack of overhead cover and scour pools, both of which are crucial habitat types for larger trout. To improve these conditions, CRA proposed incorporation of wood material along the bank through the reach to induce scour holes, provide structure under which trout could hide during the day, and to help shunt the current closer to the center of the channel all the while maintaining navigability for paddlers and access for wading anglers.

Construction occurred at the end of September 2021 and consisted of hand-installing red and Scotch pine trees secured to the channel bed with oak pins. Early indications show some scour occurring around the trees but high flows will be required to accelerate this process and we’d expect to see more scour after this coming winter and spring (2022) are over.