Roadside Revegetation

PLANNING PHASE ONE: ORIENT
areas in a mile of roadside due to changes in aspect, soil type, and road drainage. Roads in
mid-western states, however, often have only one revegetation unit that may encompass much
of a project area because of the uniformity of the landscape. The first step in developing a
revegetation unit is grouping major soil types together with similar characteristics important
for reestablishing native plant communities. For example, a project site with a group of soils
that are less than a foot deep would have a different set of revegetation treatments than
deeper soils and for that reason would be identified as a revegetation unit based on soil
depth. Grouping soils into revegetation units can also be done through the Ecological Sites
section of the Web Soil Survey. As described in Figure 4-5, a soils map and report are created
on the Web Soil Survey by delineating the project area on the interactive map of the U.S. At
the same time, a map can also be produced that groups soils by similar capabilities to create
distinct plant communities called “ecological sites” www.nrcs.usda.gov/wps/portal/nrcs/main/
national/technical/ecoscience/desc/. The ecological sites section of the Web Soil Survey also
lists the major native species for each ecological site for many parts of the U.S.
Revegetation units also designate areas that have the same revegetation objective. For example,
a road project may include a constructed wetland for maintaining or improving water quality.
In another area the objective may be to enhance pollinator habitat. These areas would be
designated as separate revegetation units because they would have different revegetation
treatments and species, which might include a pollinator species mix for the pollinator habitat
unit and an erosion species mix for the wetland unit. In addition, soil improvement treatments
for the wetland would be developed to enhance wetland species and maintain the proper
functioning of a constructed wetland. This may include creating manufactured soil that is
specific to wetland species and water filtration.
Road components also play a large role in delineating revegetation units (Figure 3-6 and Figure
3-9). In mountainous terrain, cut slopes and fill slopes are usually separate revegetation units
because of the differences in soil depth, slope gradient, and road drainage between the two
slopes. Table 4-4 shows revegetation units commonly associated with the components of a road.
The revegetation plan includes a revegetation unit map that locates revegetation units on
the road project map (Figure 4-8 and Figure 4-9). The revegetation plan further describes the
soils, climate, and vegetation of each revegetation unit and how the revegetation objectives
will be met.
Table 4-4 | Common revegetation units often associated with road components
Road Component
Cut Slopes
Ditches
Shoulders
Fill Slopes
Culvert Outlets
Engineered Slopes
Bridges
Disposal or Staging Areas
Abandoned Roads
Types of Revegetation Units
Cutslopes, snow drift fence, pollinator habitat
Amended ditches, wetlands, biorention swales, bioswales
Shoulders
Fill slopes, filter strips, amended fill slopes, wave-attennuating bioscreens, snow drift fence, pollinator habitat
Vegetated culvert outlets
Reinforced soil slopes, vegetated MSE walls, bioengineered slopes
Stream restoration terraces and slopes
Restored areas, pollinator habitat
Restored obliterated road, pollinator habitat
Roadside Revegetation: An Integrated Approach to Establishing Native Plants and Pollinator Habitat
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