Fish Passage at Stream Crossings
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, 1,159 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 2002 Forest and Range Practices Act.
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 MOE, 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.