Water Stewardship Information Sources
| Citation | BC Forest Practices Board. 2009. Fish Passage at Stream Crossings, Special Investigation. BC Forest Practices Board. FPB/SIR/25. |
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| Organization | BC Forest Practices Board |
| URL | https://www.bcfpb.ca/sites/default/files/reports/SIR25%20-%20Fish%20Passage%20at%20Stream%20Crossings.pdf |
| Abstract/Description or Keywords | This Forest Practices Board report presents the results of an investigation of fish passage at stream crossings in 19 watersheds in the central and northern interior and on Vancouver Island, British Columbia. In total, 1,110 crossings of fish‐bearing streams were examined. Each watershed had a mix of crossings built before the implementation of the 1995 Forest Practices Code of British Columbia Act (the Code), after the implementation of the Code, and also after the replacement of the Code with the Forest and Range Practices Act (FRPA) in 2004. The number of stream crossings within British Columbia is constantly increasing due to new road development. Government estimates that there are approximately 370,000 stream crossings in the province, of which about 76,000 are culverts on fish streams (BC Ministry of Environment 2008). For this reason, fish stream crossings may be the single most important habitat impact affecting fish. There have been numerous studies of stream crossings in the province. Nearly all of these studies have focused on fish passage through closed bottom structures (CBS). However, watersheds also contain a variety of other crossing types, including open bottom structures (OBS) such as bridges, log culverts, arch culverts, and open box structures. This study is the first to examine fish passage in context: on a watershed scale, in a large number of watersheds, reporting on the overall fish passage through road crossings. This investigation shows that, for the 19 watersheds examined, 42 percent of all stream crossings in fish‐bearing habitat have a high likelihood of passing fish, with individual watersheds ranging from 20 to 94 percent. The remainder have a moderate to high risk of causing fish passage problems. For important and critical habitat, 72 percent of crossings have a high likelihood of passing fish; for marginal habitat, the number is only 12 percent. Open bottom structures were used on 39 percent of all crossings, including 66 and 77 percent of crossings of important and critical habitat, respectively. Open bottom structures account for most of the observation of success in providing for fish passage. Fish passage is often highly impeded by closed bottom structures, which were used in 61 percent of the stream crossings. They were used in 91 percent of crossings of marginal habitat, where they presented a moderate to high risk to fish passage in 96 percent of cases. Closed bottom structures were also used in 34 percent of the stream crossings of important habitat and 23 percent of the crossings of critical habitat, where the Board found that they present a moderate to high risk to fish passage in 90 percent of the cases.This study leads the Board to conclude that road crossings constitute a widespread risk to fish passage in these watersheds, especially when closed bottom structures are used. |
| Information Type | report |
| Regional Watershed | Province |
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| Comments | |
| Project status | complete |
| Contact Name | BC Forest Practices Board |
| Contact Email | [email protected] |