Concurrent Sessions A: Passage Effectiveness Monitoring in Small Streams III - Fish Passage Analysis Through Circular Culverts in Northeast Ohio: Identifying the Design Parameters Linked With Passage Success

Abstract

Following a previous study (Baral et al., 2012), a detailed investigation incorporating field observations and more fish species has been carried out in Northeast Ohio to determine the percentage of culverts that act as barriers for fish passage and to identify the design parameters that can be associated with passage success. After a desk study and field visits, 55 culverts were chosen from an inventory of 5,837 culverts provided by the Ohio Department of Transportation for further analysis of passage success in FishXing and HEC-RAS. The results from FishXing analysis suggest that out of the 54 culverts analyzed, 11% are partial barriers and 89% are complete barriers. The analysis in HEC-RAS shows that out of the 40 culverts analyzed, 55% are partial barriers and 45% are complete barriers. The additional morphological data used by HEC-RAS models resulted in discrepancies in the computed velocities and depths between the programs which in turn resulted in the different predictions of complete barriers and partial barriers. Student’s t-tests (p \u3c 0.05) showed that the difference in the average perched height between partial barriers and complete barriers was significant for the output of both FishXing and HEC-RAS. An additional analysis was carried out in FishXing for two species by changing culvert design parameters independently so as to examine the effect of changing those parameters on passage success. The alteration of culvert parameters included increasing diameter, decreasing length, decreasing slope, increasing Manning’s roughness, and embedding the culverts with gravel substrate (n = 0.04). For greenside darter, embedding the culverts resulted in an additional 36% of culverts being partial barriers and had a greater impact on increasing passage success compared to varying other design parameters. Similar analysis for largemouth bass exhibited a less noticeable difference. Further analysis and discussion will be presented