CHANGES IN STREAM HABITAT QUALITY FOLLOWING CULVERT RESTORATIONS IN NORTHERN GREAT LAKES STREAMS
Monitoring the effectiveness of culvert restorations is useful for predicting stream habitat and food web improvements and can aid restoration decisions. We monitored four culvert restorations in northern Wisconsin, three using bankfull/backwater design (BBD) and one using partial stream simulation design (SSD). We measured substrate composition, organic matter standing crop, silt depth, water depth, and current velocity upstream and downstream of the culverts, before and after restoration. We observed an increase in substrate size above and decrease below two of the BBD culverts following culvert replacement. Leaves, wood, and fine benthic organic matter standing crops decreased at two upstream BBD reaches and increased at another. Wood standing crop increased at the upstream SSD reach, likely exposed as fine sediment was flushed downstream. Silt depth decreased at two upstream BBD reaches, but increased downstream, while water depth decreased at the three BBD upstream reaches, and increased below for one reach. Current velocity varied across reaches and sites. Increased culvert size likely led to habitat quality improvements at the restored sites due to the transport of organic matter and silt from the above to below reaches or from the site entirely.
Coleson Wrege (Primary Presenter/Author), University of Minnesota, firstname.lastname@example.org;
Sue Eggert (Co-Presenter/Co-Author), USDA Forest Service, Northern Research Station, email@example.com;