are rectangular galvanized wire baskets filled with stones used as pervious, semiflexible
building blocks for slope and channel stabilization. Live rooting branches may be
placed between the rock-filled baskets.
protect slopes and streambanks from the erosive forces of moving water. Rockfilled
s or mattresses can be used as retaining walls for slopes, to armor
the bed and/or banks of channels, or to divert flow away from eroding channel sections.
Rock-filled or vegetated rock gabions
are used on streambank sections subject to excessive
erosion due to increased flows or disturbance during construction. Gabions
can be specified
where flow velocities exceed 6 ft/sec and where vegetative streambank protection alone is
not sufficient. Gabions
can be used to construct deflectors or groins intended to divert flow
away from eroding streambank sections. Gabions
are also used to construct retaining walls
and grade control structures. Gabion walls are appropriate where:
The vertical integrity of a soil bank needs a higher tensile strength to reduce
sloughing of the streambank.
There is moderate to excessive sub-surface water movements that may be creating
erosion and damaging other types of non permeable structures.
An excessively steep stream bank must be stabilized and vegetative or extreme
mechanical means of stabilization (i.e., pulling back bank) are not feasible due to site
Where slope must be modified while heavy machinery is unavailable to the site.
Fill must be disposed of along an eroding streambank (fill can be placed behind
gabion to modify slope).
A retaining or toe wall is needed to stabilize the slope.
Rock riprap is an appropriate practice but the available or desired rock size (smaller)
is not sufficient alone to resist the expected shear stress exerted on the revetment.
Gabions allow the use of a smaller size rock than would be possible without the wire
baskets because the rock is bound by the wire mesh, creating a more monolithic