Road-stream crossings often create barriers to the passage of fish and other organisms, eliminate access to large areas of habitat, and have a major detrimental effect on aquatic organism populations - particularly salmonids.
Undersized culverts are prime examples of such barriers. Water tends to flow through insufficiently sized culverts at a high velocity - often too high for safe fish passage. High velocity flow can also erode the streambed at the bottom end of a culvert, causing a drop in elevation that fish may not be able to clear when traveling upstream.
Through generous funding from the Oregon Watershed Enhancement Board, in 2011, SDCWC completed a Fish Barrier Assessment and produced a prioritized list of fish passage barriers to guide future restoration in the Salmon River watershed. A detailed report is available in electronic and hard-copy.