As part of a multi-agency partnership, the U.S. Army Corps of Engineers (USACE) Nolin River Lake was the first reservoir in the Louisville District to install large concrete reef balls as both fish habitat and as a wave break for bank stabilization measures.
The collaboration is part of a larger effort with the Kentucky Department of Fish and Wildlife Resources (KDFWR), Friends of Nolin, Friends of Reservoirs, and the Reservoir Fish Habitat Partnership to complete a $300,000 bank stabilization project. This included installing rip rap using the longitudinal peak stone toe protection (LPSTP) method to promote bank stabilization, planting native seed and shrubs to target pollinators, and creating more bank fishing opportunities by enhancing fish habitat with various fish attractors.
The concept of using reef balls as fish habitat came about due to a strong partnership with KDFWR. Jeremy Shiflet, a fisheries biologist for the KDFWR offered to collaborate on this project and suggested a partnership with the Reservoir Fish Habitat Partnership, a non-profit group that works to improve fish habitat, working alongside government agencies.
The grant awarded through Reservoir Fish Habitat Partnership included $30,000 for patented fiberglass reef ball molds, supply kits, and training from Reef Innovations to make the reef balls. While the reef balls are primarily for fish habitat, USACE also plans to experiment using the larger balls as wave breaks to further protect the shoreline.
To date, accomplishments include over 1,000 feet of bank stabilization structure installed, 2,600 square feet of fish habitat structures deployed, 48 reef balls placed, and 4,500 square feet of native seed planted. Weather permitting, the final step of the project will be planting over 1,000 live stakes with assistance from Friends of Nolin in the spring.
Louisville District plans to continue installation of bank stabilization projects in coordination with Chris Haring from the USACE Engineer Research and Development Center. Haring visited in 2019 through a water operations technical support request and has provided consultation for prioritizing projects and incorporating Engineering with Nature through the application of natural and nature-based features sedimentation and sustainability techniques.
This effort will help keep sediment in place and provide multiple benefits that include improved water quality, increased habitat for aquatic life, reduced siltation, and protecting and prolonging the function of the flood control structure.