Effectiveness of Culvert Design for Improved Water Quality and Habitat

Research Issue

Culvert under road.Increasing storm magnitudes and frequencies and undersized culverts are resulting in major flooding, more failed road-stream crossings and economic losses due to closed transportation routes, impaired aquatic habitat, and barriers to aquatic organism passage. Land and resource managers have recently begun using new culvert replacement designs to replace failing road-stream crossings to improve flood resiliency. Given the large number of road-stream crossings across the nation that will require replacement, it is important to investigate the effectiveness of these new culvert designs for improving aquatic organism passage, stream habitat, and ecosystem function.

Our Research

Stream simulation design is a geomorphic and ecologically-based approach to designing road-stream crossings that mimic natural channel structure, sediment characteristics, water velocity, and depths in high gradient streams. In low gradient regions, the bankfull and backwater culvert design allows substrate to fill in naturally rather than constructing a channel within the structure.  The goal of our work is to examine the effectiveness of both designs on improving stream ecosystem processes, habitat quality, and aquatic food webs.  We are working with resource managers of the Chequamegon-Nicolet National Forest in northern Wisconsin to investigate ecological conditions upstream, downstream and within culverts before and after culvert replacements of various designs in multiple watersheds.

Expected Outcomes

Although aquatic organism passage and flood resiliency has been the primary design priorities of culvert restoration thus far, results from our research will help resource managers determine whether new culvert replacement designs also result in added ecological benefits such as improved aquatic habitat quality and increased ecosystem productivity.

Research Results

Olson, J.C.; Marcarelli, A.M.; Timm, A.L.; Eggert, S.L.; Kolka, R.K. 2017. Evaluating the Effects of Culvert Designs on Ecosystem Processes in Northern Wisconsin Streams. River Research and Applications. 33(5): 777-787. https://doi.org/10.1002/rra.3121.

Timm, A.; Higgins, D.; Stanovick, J.; Kolka, R.; Eggert, S. 2017. Quantifying fish habitat associated with stream simulation design culverts in northern Wisconsin. River Research and Applications. 33(4): 567-577. https://doi.org/10.1002/.3117.

Research Participants

  • Last modified: August 4, 2020