Science in Practice Portal

In past years timber access road construction often failed to adequately provide for or consider the needs of anadromous fish (BLM Manual 5110) . Many metal culverts placed in streams used by anadromous fish have blocked fish passage when installed with the lower end too high above the stream (BLM Manual 6760) . The size of culvert, bottom type and stream banks all influence the type of facility that can be installed to provide fish passage when an impassable culvert is located. One solution to a specific problem is discussed here. This solution cannot be applied randomly but it does provide an idea upon which engineers can build designs and make appropriate modifications.