Erosion Control Toolbox: Brush Layering
Introduction
![Brush layering](/-/media/dot-media/programs/design/images/brshlyrng.jpg)
Brush layering work includes harvesting green cuttings from existing cottonwood or willow stands and embedding these cuttings in horizontal layers perpendicular to the slope face.
Click here to watch a short video about Brush Layering.
When to Use This Treatment
- Most commonly used to construct 2:1 (H:V) embankment (fill) slopes.Can be used with excavation (cut) slopes if combined with stepped slope techniques.
- Coordinate the use of this technique with Caltrans Division of Engineering Services (DES) Office of Geotechnical Services, which may prepare a Geotechnical Design Report for slopes greater than 2:1 (H:V).
- This treatment is used to provide erosion protection, increase vegetative cover, and enhance habitat.
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.
Consider Using With
Benefits
- Provides immediate surface slope reinforcement with unrooted brush cuttings
- Slope stability and shear resistance increase as root development occurs
- Creates slope breaks that shorten slope length and reduce stormwater runoff velocities
- Creates vegetative filters that trap sediment
- Promotes vegetation establishment, cover, and natural recruitment
Limitations
- Requires accessible, local stand of cottonwoods or willows from which to harvest cuttings
- Harvesting of cuttings may require a permit and a project construction window
- Not recommended for rocky slopes, slopes with extremely low soil moisture through the dry season, or slopes with limited equipment access
- May require supplemental irrigation during establishment period, particularly during the first dry season and on south-facing slopes
Details
- Brush Layer With Soil Wrap Detail (Microstation Format)
- Brush Layer With Soil Wrap Over RSP Detail (Microstation Format)
- Brush Layer vs RSP Comparison (Microstation Format)
Estimate Information
References
- David Steinfield, Scott Riley, Kim Wilkinson, Thomas D. Landis, Lee Riley, etc. al. 2017."Roadside Revegetation, An Integrated Approach to Establishing Native Plants and Pollinator Habitat, 2017"
- 3.6.1 Vegetation Field Assessment
- 5.3 Obtaining Plant Materials
- 5.4 Installing Plant Materials
- 5.4.3 Installing Cuttings
Updated: February 12, 2019