Upper Weiss Creek Family Forest Fish Passage Project

The project area included a section of Weiss Creek, a tributary to the Snoqualmie River in western Washington State, where an undersized, failing culvert blocked coho, cutthroat, and other native fishes from accessing miles of vital stream and wetland habitat. By interrupting habitat connectivity, even a single barrier can have a disproportionately large impact on the abundance and resiliency of wild fish populations.

Man-made barriers to fish migration have significant impacts on wild fish; limiting distribution, reducing access to spawning and rearing habitats, and disrupting the spatial habitat complexity historically available to fish populations. Whether for resident species that spend their entire lives in one watershed, or migratory species that travel thousands of miles, instream barriers compromise a populations’ ability to weather environmental uncertainties. Evolutionary fitness of the entire population is weakened when barriers restrict gene flow, creating small, isolated sub-groups that can suffer from inbreeding.

The Family Forest Fish Passage Program (FFFPP) assists private forestland owners in removing culverts and other stream crossing structures that prevent ESA listed salmonids from migrating upstream. Through the management of DNR’s Washington State Recreation and Conservation Office some 376 landowners have taken advantage of the program to remove 433 barriers since 2003.

Wild Fish Conservancy (WFC) staff replaced the failing culvert with a 34-foot long by 12-foot wide pre-fabricated modular wood bridge and added large woody debris (LWD) and rock weirs which increased flow capacity and provided wild fish access to critical spawning and rearing habitat upstream from the project site.