Erosion Control Toolbox: Rolled Erosion Control Product Flap With Brush Layering


 Brush layer fill slope

This treatment uses locally obtained green cuttings, a Rolled Erosion Control Product such as coir netting, structural backfill material and local topsoil to construct embankment (fill) slopes. More specifically, this treatment consists of placing layers of:

  • Geosynthetic reinforcement - typically placed 2' on center vertically
  • Backfill - typically structural material
  • Rolled Erosion Control Product - coir/coconut blankets placed every other geosynthetic layer or 4' on center vertically, which "flap over" and protect the slope face
  • Local topsoil or compost to provide a rooting media for cuttings
  • Green locally harvested cuttings of cottonwood or willow

When to Use This Treatment

Consider Using With

How is This Treatment Constructed

  • Structural backfill is placed in 8-inch lifts, and "keyed-in" to the adjacent existing slope at least 6.5 feet horizontally. Lifts of backfill are compacted to 90% by track-mounted crawlers.
  • A geosynthetic reinforcement layer is placed horizontally between structural backfill lifts, typically every 2' on-center vertically.
  • Following placement of the first geosynthetic reinforcement layer (and at every other primary geosynthetic reinforcement layer thereafter) coir netting is placed and fastened longitudinally with fabric anchors.
  • A layer of local topsoil and compost is placed on top of the coir netting.
  • A layer of green locally harvested cuttings is placed on top of the local topsoil and compost growth media.
  • Placement of structural backfill and geosynthetic reinforcement continues in layers, like a cake. At every other geosynthetic reinforcement layer, typically every 4' on-center, coir netting is draped or flapped over the slope face, and a layer of harvested cuttings, topsoil, and compost is placed.

 Brush layer with R E C P flap drawing detail

Note: This typical section is schematic only and is not to be used in a contract document. The scale, key dimensions, and critical details have been intentionally omitted.


  • Provides immediate slope reinforcement with unrooted brush cuttings and horizontal geotextiles. As roots develop, slope stability and shear resistance are improved by creating a rooting matrix with geogrids throughout structural lifts.
  • Cuttings create slope breaks that shorten slope length and reduce stormwater runoff velocities.
  • Promotes vegetation establishment, cover, and natural recruitment.
  • This treatment does not require wrapping the backfill, and is less labor intensive to construct than RECP Wrap.
  • Provides the resistive force necessary to hold the soil firmly in place in lieu of compaction by trackwalking.
  • The slope face is stabilized and protected from storm events as the embankment is constructed, therefore construction may resume immediately after rainfall.
  • Yields a stable and aesthetically pleasing slope compatible with its natural surroundings.
  • Promotes vegetation establishment and natural succession.


  • Unsuitable for embankment (fill) slopes steeper than 1.5:1 (H:V), or slopes with limited access.
  • Requires accessible, local stand of cottonwoods or willows from which to harvest cuttings.
  • May require supplemental irrigation during establishment period, particularly during the first dry season and on south-facing slopes.

Technical Design Tips

  • Always protect the face of embankment (fill) slopes steeper than 2:1 (H:V) to prevent slumping of soil from between horizontal geotextile layers.
  • Consider covering (flapping) the face of 2:1 (H:V) embankment (fill) slope faces, based upon evaluation of constraints to compaction, angle of repose, backfill material, and rainfall intensities.
  • Backfill lifts typically range from 2 - 4 feet thick. Consider specifying Local Topsoil in the outer face of structural backfill lifts.
  • Fill slopes steeper than 2:1 (H:V) typically require reinforcement by a geosynthetic fabric such as a geogrid. Geosynthetic reinforcement strength needs to be sufficient to meet slope engineering requirements and should be specified by a geotechnical engineer.
  • Consider the benefits and liabilities of natural geosynthetic products versus longer lasting inorganic (plastic) products.

Updated: February 1, 2019