Erosion Control Toolbox: Mulch

Introduction

Mulch involves placing a blanket of organic material on fill slopes, cut slopes, and other disturbed roadside areas to reduce erosion and weed competition. Mulch is typically applied at a depth of 2" - 3".

The mulch specification allows the designer to select from the following materials:

• Composted green material
• Tree bark
• Wood chips
• Coarse woody grindings
• Pine needles
• Shredded bark

When to Use This Treatment

• Typically applied on slopes 2:1 (H:V) and flatter
• Use to reduce raindrop splash erosion and competition from weeds
• Typically applied 2"-3” deep (270-400 cubic yards/acre)

Benefits

• Improved protection from raindrop splash erosion
• Reduced competition from weed species
• Reduced stormwater runoff volume and velocity
• Improved infiltration rate
• Conserves soil moisture
• Improved potential for vigorous long term vegetation coverage
• Easy application by pneumatic blower trucks or bulldozers (in flat areas)

Limitations

• Requires temporary storage space within the project limits to stockpile materials
• Applying high levels of organic materials may not be appropriate in arid regions of the state
• Functional longevity of less than three years

Standard Specifications

• Refer to Standard Specifications - Section 20 Landscape

Consider Using With

To effectively treat sites with poor soils (compacted, nutrient depleted, or poorly draining), consider combining this treatment with:

• Preserve Existing Topsoil
• Incorporate Materials
• Fiber Rolls when slopes are greater than 3:1 (H:V)

Plans and Details

• Sample Erosion Control Legend

Specify Mulch in the Erosion Control Legend:

Estimate Information

• Use BEES code 205035 Wood Mulch

External Links

• David Steinfield, Scott Riley, Kim Wilkinson, Thomas D. Landis, Lee Riley, et al. 2017. "Roadside Revegetation, An Integrated Approach to Establishing Native Plants and Pollinator Habitat"

 

 

Updated: November 8, 2019