The “Cove” project scheduled for 2020-2021 is a bank stabilization, fish habitat enhancement, and restoration project.
The Flies-Only section of the Pere Marquette is an extremely valuable resource. It is the most heavily visited section of the river and the primary spawning grounds for naturally reproducing trout, salmon, and steelhead. Constant erosion has compromised many streambanks releasing tons of sand that covers spawning habitat.
The “Cove” lies just upstream from the 4th Claybank where the bank forms a ¼ mile peninsula. Over the last 15 years, the “Cove” has deteriorated and eroded approximately 25′- 40′. Sand has washed out, silted over, and reduced the productive spawning area directly downstream of the eroding bank by over 50%.
The goal is to stabilize the existing bank, limit silting over of spawning gravel, and to let the river naturally reestablish the spawning habitat. Bank stabilization will limit future erosion and slow the process of an “oxbow” effect, or the river cutting a new path through the peninsula and losing ¼ mile of prime river between the Cove and Alligator Alley. The bank stabilization is critical for both purposes.
PMTU was granted $8,000 of the estimated $35,000 cost by the TU National Embrace a Stream Program. During the 2020 Embrace A Stream fundraising campaign, an additional $15,000 was raised.
PMTU is working with the Conservation Resource Alliance to use 20’ oak timbers and drive them into the riverbed as vertical supports. Once the timbers are in place, additional 20’ oak/pine root wad laterals, steel or hemp fasteners, and a mixture of oak and pine slash will lock the material together. Landmark survey points will serve as a baseline to measure any potential post-project erosion.
There are two approaches to measure spawning gravel restoration. The first is performing an initial cross-section survey downstream of the “Cove” prior to starting the project. The same survey will be performed 6 months after project completion and data analyzed to quantify the restoration of the spawning habitat. Our goal is to increase lost spawning habitat by 25%-50% within one year after completion.
The next approach is to analyze brown trout redd spawning data following the project completion. PMTU has worked extensively with TU National on a 4-year Brown Trout Redd Survey Plan. PMTU’s Brown Trout Redd Survey in the Flies-Only section was implemented in the fall of 2018. Surveys were also done in 2019 and the 2020 survey is underway. Surveys will continue through 2021. These studies will provide four years of baseline data. The data from the “Cove” post project survey will be analyzed against 3 previous years of baseline data. Our goal is to increase brown trout redds by 25%.