Thinking inside the box (culvert): Developing a low-cost, easy-to-install retrofit prototype for fish passage

Project summary:

This project addresses a need to develop a low-cost, easy-to-install, and safe culvert retrofit for fish passage. Culverts can create barriers to fish movement due to fast-flowing water with no resting areas, shallow flow, and/or lack of cover. While new culvert design guidance addresses these concerns, there are many existing culverts that have known fish passage issues that are not slated for replacement. The research team previously investigated a potential solution: using mussel spat rope, a fibrous plastic rope that has been demonstrated to facilitate fish passage in New Zealand. This design showed promise in laboratory, fish, and field trials; however, despite interest, concerns over the release of plastic to the environment have inhibited its use. Therefore, researchers propose leveraging this experience to develop an entirely new solution that has similar benefits of the mussel spat rope installation (i.e. create low-flow resting areas, cover, and have minimal impact to culvert capacity) but is made with bio-based sustainable materials. The goals of this project are to: 1) identify appropriate materials and 2) design and test protypes in flume experiments. At the conclusion of this project, the research team will have a viable prototype design ready for field-scale testing and/or deployment as well as an analysis of manufacturing viability. Because of the commercial potential of this design, we will consult with the University of Minnesota Technology Commercialization to protect any intellectual property developed as part of this project.