Appendix B: Bioengineering for Streambank Erosion Control -- Guidelines
Fork River, CO, experienced some failure. The lower half of the reach in which it was
installed washed out after a major flood in the spring of 1995. This was due to the problem
of insufficiently burying and keying in the bottom-most log of the revetment into the
streambed. Consequently, scour undermined the structure and it failed along the lower half
of the reach.
The root wad structure on Snowmass Creek, CO, had a partial failure. After the spring
runoff in 1994, the sponsor noticed minor damage around certain critical points that needed
maintenance, the addition of more root wad logs. The contractor instead placed rock at
inappropriate places. Consequently, the creek flooded during the spring runoff of 1995 and
the outside of the lower section of the upper meander washed out and eroded about six feet
of bank. In these two cases, it points to the need for properly keying in structures for toe and
end protection and to monitoring and possible maintenance early in the life of a
bioengineering project. This early monitoring and maintenance should be included in the
construction contract at the outset.