California Department of Transportation
Caltrans > Landscape Architecture Program > Erosion Control Toolbox
 

Erosion Control Toolbox

Welcome to the Caltrans Erosion Control Toolbox, a one-stop reference for erosion control standards and guidance. The purpose of this site is to provide Caltrans Landscape Architects with a single location that provides access to the information necessary to design successful, effective and cost efficient erosion control treatments.

 

Erosion Control Technical Guide

The Caltrans Technical Guide to Erosion Control Treatment, first presented in the "Key Concepts" Erosion Control training is now available online. Click here to download a copy of the Erosion Control Technical Guide. Please note that the "BMP Data Sheets" formerly included in the Technical Guide are available by clicking on the underlined links below.

Erosion Control Treatment Overview

The table below provides a general overview of various erosion control Best Management Practices (BMPs) together with a very rough idea of cost. Select the erosion control treatment(s) most suited to meet your project deficiencies.

Click on the hyperlink at left to obtain more specific information regarding a BMP.

IMPROVE SOIL HEALTH
  M A X. S L O P E ( H : V )   B E N E F I T S C O S T
  4:14:1
 3:13:1
 2:12:1
 1.5:11.5:1
 1:11:1
 Cut or Fill? Soil Cover (1) Soil Health (2) Infil-
tration
(3)		 Cost/
Acre
(4)
Roughen Soil OK OK OK OK Not Recommended C/F Low Medium Medium -
Decompact Soil Dot Dot Not Recommended Not Recommended Not Recommended C/F Low Medium High -
Stepped Slopes N/A OK OK Medium Not Recommended C Low Medium Medium -
Local Topsoil OK OK OK Medium Not Recommended C/F Low High Medium -
Imported Topsoil OK OK OK Medium Not Recommended C/F Low Medium Medium -
Compost
(Incorporate)		 Dot Dot Dot Not Recommended Not Recommended C/F Low High High -
 
PROVIDE SOIL COVER & IMPROVE SOIL HEALTH
  M A X. S L O P E ( H : V )   B E N E F I T S C O S T
  4:14:1
 3:13:1
 2:12:1
 1.5:11.5:1
 1:11:1
 Cut or Fill? Soil Cover (1) Soil Health (2) Infil-
tration
(3)		 Cost/
Acre
(4)
Duff Dot Dot Dot Medium Not Recommended C/F Medium High Medium $40,000
Mulch Dot Dot Dot Medium Not Recommended C/F Medium Medium Medium $20,000
Compost Blanket Dot Dot Dot Medium Not Recommended C/F Medium High High $15,000
 
PROVIDE SHORT TERM SOIL COVER
  M A X. S L O P E ( H : V )   B E N E F I T S C O S T
  4:14:1
 3:13:1
 2:12:1
 1.5:11.5:1
 1:11:1
 Cut or Fill? Soil Cover (1) Soil Health (2) Infil-
tration
(3)		 Cost/
Acre
(4)
EC (Punched Straw) Dot Dot Dot Not Recommended Not Recommended F Medium Low Low $12,000
EC (Hydroseed) Dot Dot Dot Not Recommended Not Recommended C/F Medium Low Low $10,000
EC (Type BFM) Dot Dot Dot Dot Medium C/F Medium Low Low $15,000
RECP Jute Mesh Dot Dot Dot Not Recommended Not Recommended C/F Medium Low Low $12,000
 
PROVIDE LONG TERM SOIL COVER
  M A X. S L O P E ( H : V )   B E N E F I T S C O S T
  4:14:1
 3:13:1
 2:12:1
 1.5:11.5:1
 1:11:1
 Cut or Fill? Soil Cover (1) Soil Health (2) Infil-
tration
(3)		 Cost/
Acre
(4)
RECP Netting (Type A) Dot Dot Not Recommended Not Recommended Not Recommended C/F High Low Low $35,000
RECP Netting (Type B) Dot Dot Dot Dot Medium C/F High Low Low $35,000
RECP Netting (Type C) Dot Dot Dot Dot Medium C/F High Low Low $35,000
RECP Blanket
(Type A) 		N/A N/A Dot Dot Medium C/F High Low Low $25,000
RECP Blanket
(Type B) 		N/A N/A Dot Dot Medium C/F High Low Low $25,000
RECP Blanket
(Type C) 		N/A N/A Dot Dot Medium C/F High Low Low $25,000
RECP TRM (Type A) N/A N/A Dot Dot Not Recommended C/F High Low Low $30,000
RECP TRM (Type B) N/A N/A Dot Dot Dot C/F High Low Low $37,000
RECP TRM (Type C) N/A N/A Dot Dot Dot C/F High Low Low $45,000
 
STEEP SLOPE TECHNIQUES
  M A X. S L O P E ( H : V )   B E N E F I T S C O S T
  4:14:1
 3:13:1
 2:12:1
 1.5:11.5:1
 1:11:1
 Cut or Fill? Soil Cover (1) Soil Health (2) Infil-
tration
(3)		 Cost/
Acre
(4)
Stepped Slopes N/A OK OK Medium Not Recommended C High Medium Medium -
Brush Layering N/A OK OK Dot Not Recommended F High Medium Medium -
RECP Flap N/A N/A Dot Dot Not Recommended F High Medium Medium $50,000
RECP Wrap N/A N/A Dot Dot Not Recommended F High Medium Medium $60,000
Soil Filled RSP N/A N/A Medium Dot Not Recommended C High Medium Medium -
Cellular Confinement N/A N/A Dot Dot Not Recommended C High Medium Medium $45,000
Wire Blanket N/A N/A N/A Dot Dot C High Medium Medium $100,000
Wire Mesh Confinement N/A N/A N/A Dot Dot F High Medium Medium -
 

Legend (Maximum Slope)
Dot Recommended
Medium May or may not be recommended based on site conditions.
Not Recommended Generally Not Recommended
N/A Not Applicable - this treatment is typically not used in these conditions.

Legend (Benefits)
High Great Benefit
Medium Moderate Benefit
Low Minimal Benefit
(1) Treatments rated highly beneficial for soil cover include those that provide protection from raindrop impact and splash erosion. Treatments that provide good cover include loose mulches such as bark and compost, fiber included as part of hydroseeding, and rolled erosion control nets and blankets.
(2) Treatments rated highly beneficial for soil health include those that improve soil texture, soil structure, fertility, and soil microbiology. Treatments that notably improve soil health include compost incorporate, duff, and reusing local topsoil.
(3) Treatments rated highly beneficial for infiltration include those that slow runoff, improve soil structure and open up the soil texture to encourage infiltration of stormwater rather than encouraging runoff. Treatments that notably improve infiltration include compost incorporate, roughen soil and reusing local topsoil.
 

Legend (Cost Information)
- Construction cost information not available.
(4) Very rough estimate of construction cost per acre. Construction cost varies greatly due to size of area treated, accessability, slope steepness, geographic location and economic health. For greater detail, click on the estimate number in the right-hand column.

What is the Goal?

When selecting and combining various erosion control treatments, it is important, foremost, to clearly identify "success". While the specific definition of "success" will vary depending upon specific site conditions, in general, a successful erosion control treatment will address three specific areas - soils, water, and vegetation.

The goal of effective erosion control is twofold:

  1. Maintain water quality - keep soils in place.
  2. Increase Infiltration - reduce runoff.

The Natural Environment As "Success"

In the natural environment, these goals are fulfilled by vegetation, mulch/duff, and porous soils. Vegetation and the mulch/duff layer protect the soil from raindrop impact and surface erosion. Healthy, porous soils infiltrate water reducing runoff, and provide the water necessary to sustain healthy vegetation. The mulch/duff layer protects the soil surface from erosion, provides nutrients to sustain vegetation, and feeds soil microorganisms that contribute to a well draining soil structure.

The Post-Project Environment

In the post-project environment, maintaining water quality and site hydrology is challenging because the natural vegetative cover and corresponding mulch/duff layer have been removed. Compaction by equipment together with the removal of organic material leads to very low infiltration rates. Unless addressed, these conditions lead to runoff, erosion, transport of sediment, and high runoff velocities and volumes.

 

The Way to the Goal

The key to getting the post-project site to function (from a stormwater runoff standpoint) similar to the natural, undisturbed site is to restore the functionality that has been removed. In general, the "successful" erosion control solution addresses:

  1. Soil Cover
  2. Healthy Soil
  3. Sustainable Vegetation

Soil Cover

Bare soil requires the protective cover provided by a mulch product (bark mulch, compost blanket, pine needles, straw, duff) or hydroseeding. These products protect the soil surface from erosion due to raindrop impact and sheet flow.

Healthy Soil

Healthy soils maintain stormwater quality and control erosion by their open structure that facilitates infiltration of runoff, and by providing the nutrients and soil biota necessary to support long-term sustainable vegetative cover. To maintain stormwater quality, disturbed roadsides that feature highly compacted sterile soils typically require decompaction and/or incorporation of organics such as compost to restore soil health.

Sustainable Vegetation

Sustainable vegetation is dependent upon selecting the proper mixture of plant types (grass, annual, perennial, forb, cutting, sod, liner, woody shrub) and species for specific site environmental conditions (geographic location, elevation, exposure, soil type). The short-term goal is to quickly establish vegetative cover to provide protection from raindrop impact and sheet-flow erosive forces. The long-term goal is to establish healthy mature vegetation that requires minimal replanting, supplemental water, or maintenance.

An erosion control solution that ensures a well drained soil including organic material and healthy soil biota, a surface mulch layer of duff/mulch, together with regionally appropriate plant material mimics the functionality of the natural environment, and with time should perform in a similar manner - protecting water quality and managing the runoff rate and volume.