Restoration Techniques: Floodplain Techniques

Explore Floodplain Techniques here by clicking on the menu bar below, or visit the Bioengineering and Construction pages.

  • Overview
    Important design considerations for floodplain restoration include topography, hydrology (floodplain/channel connection), target plant communities and varied substrate. Floodplain restoration techniques include reconnection of existing floodplains, development of new floodplain surfaces, creation of microtopography (i.e., small scale variations in height and roughness of the ground surface), creation of varied substrate conditions that will support native species in their appropriate niche, and recruitment and planting of appropriate native species.
  • Floodplain Surfaces
    Development of Floodplain Surfaces
    One approach to restoring floodplains is to create constructed point bars. Photo 20 shows a constructed point bar one year after construction. The point bar is primarily bar cobble substrate. Photo 21 shows the same site four years after construction. The willows are now up to ten feet tall; cottonwood seedlings and saplings blanket the cobble surface, and herbaceous vegetation is beginning to colonize the understory. Activities at this site included floodplain grading to support natural recruitment and plantings.

    Floodplain revegetation techniques include container planting with browse protection, competition suppression and natural recruitment on constructed floodplain surfaces. These are shown in photos 22 and 23.

    Photo 24 shows an example of a floodplain cross-section which identifies the types of substrates (e.g., historical alluvium, imported fill, sand/gravel cobble, sandy loam, silt loam), elevation and floodplain connection, and the target plant communities.
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  • Examples
    Figure 25 is a diagram of cover types and planting areas; Figure 26 shows a woody debris complex in cross section and plan view; Figure 27 is a construction detail for an off-channel wetland; Figure 28 is a diagram of conceptual cover types with their associated relative elevation; and figure 29 shows a plan for microtopography, large woody debris placement, and course wood placement.

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Kootenai Tribe of Idaho
P.O. Box 1269
Bonners Ferry, ID 83805
Phone: 208-267-3519

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