Appendix B: Bioengineering for Streambank Erosion Control -- Guidelines
This report synthesizes information related to bioengineering applications and provides
preliminary planning and design guidelines for use of bioengineering treatments on eroded
streambanks. It can be used by both planning and design elements, not as a cookbook, but
as a guide with tools to accomplish bioengineering projects. It presents a bioengineering
design model with examples in the text that describe specific case studies where certain
stream conditions, such as velocities, have been provided. It also describes appropriate plants
to use, their acquisition, and their handling requirements.
This report is divided into two volumes. The main report, Volume I, provides
bioengineering guidelines for streambank erosion control. Volume II presents several case
studies of bioengineering treatments applied to one or more streams in various geographic
locations around the continental United States.
The authors of this report do not attempt to assume that bioengineering for streambank
protection is a cure unto itself. First, bed stability, another whole subject area, must be
achieved before banks are addressed. If streambeds are not stable, it does little good to
attempt bank stabilization. This report does not attempt to address the details of fluvial
geomorphology, but the authors recognize that bioengineering must be done in consonance
with good river bed and planform stability design and there are several texts and engineer
manuals that address these subjects. Consequently, good bioengineering takes an
interdisciplinary team approach with expertise representing engineering, physical, and
biological fields, as well as others, a point re-emphasized throughout this report. The authors
also recognize that causes of streambank erosion are complex and can often be related to
land-use practices being conducted in the watershed and/or in the immediate vicinity of the
erosion problem on the streambank. Therefore, careful study should be made of the causes
of erosion before bioengineering is contemplated. Again, an interdisciplinary team is often
required to develop an optimum plan. Bioengineering must be done within the context of a
landscape approach, but erosion control must be addressed by reaches, from a practical
standpoint. The report provides a planning sequence, or bioengineering design model, that
is tailored to a zonal approach within reaches.
Vegetation, per se, is not a panacea for controlling erosion and must be considered in light
of site-specific characteristics. When vegetation is combined with low cost building materials
or engineered structures, numerous techniques can be created for streambank erosion control.
This report summarizes a number of techniques that utilize vegetation. For understanding
how vegetation can be used in bioengineering and as a basis for conceptualizing a
bioengineering design model, it is important to understand both the assets and limitations of
using planted vegetation.