.... Specialising in reducing accelerated erosion

Stabilization of Highway Cut Slope Trials using Compost and Straw Wattle Applications

MOYIE BLUFF PROJECT 2

Location: Cranbrook / Moyie, British Columbia

Client: Dawson Construction Limited

Objective: To help stabilize an extremely steep highway cut slope by holding the weathered, compacted glacial till on the slope using soil bioengineering techniques.

The Moyie Bluff trial sites are located on highway 95 near the town of Cranbrook, in southeast British Columbia. These sites were part of a major highway widening project.

Trials were conducted on two sites (1 and 2). Both sites received a combination of the following treatments: straw wattles, brush layers, live staking, planting of native seedlings and hydro seeding. In addition site 1 received a compost application.

These techniques are expected to address surface erosion (rill and gully formation) by establishing a woody tree & shrub component, along with grasses and legumes.

The species used in the brush layer structures consisted of 80% black cottonwood (Populus balsamifera ssp. trichocarpa) and 20% willow (Salix scouleriana), harvested locally. The native seedlings consisted of a mix of cottonwood and alder (Alnus ssp.).

Monitoring of the sites was done in fall of 2005. Survival was found to be very poor on Site 2; nearly all the planted vegetation was dead. On Site 1, however, where the compost was applied, survival was much better. Some of the cottonwood planted in brush layers was still growing and many of the cottonwood and alder planted as seedlings were doing relatively well.

 

 
 
 
 
Site 1, March 2003

site 1, March 2003

Preparation work, March 2003

preparation work, March 2003

Installation Site 1, March 2003

Installation Site 1, March 2003

   
Structures installed, April 2003

Structures installled, April 2003

Compost application Site 1, April 2003

Compost application Site 1, April 2003

   

 

Site 2, March 2003

Site 2, March 2003

 

Preparation work Site 2, April 2003

   
Installation of straw wattles and brush layers

Installation of straw wattles and brush layers

Structure installed, April 2003

Structure installed, April 2003

   
Installation Site 2, April 2003

Installation Site 2, April 2003

Work completed Site 2, April 2003

Work completed Site 2, April 2003

   
Hydro seeding, April 2003

Hydro seeding, April 2003

Early growth, July 2003

Early growth, July 2003

   
Site 2, July 2003

Site 2, July 2003

Site 2, August 2003

Site 2, August 2003

   
 
Site 1 compost applied here, September 2005

Site 1 compost applied here, September 2005

   
 
Site 1 alder growing, September 2005

Site 1 alder growing, September 2005

Site 1 cottonwood cuttings growing
September 2005

Site 1 cottonwood cuttings growing, September 2005

   
Site 1 cottonwood cuttings growing
September 2005

Site 1 cottonwood cuttings growing, September 2005

Site 1 cottonwood seedlings growing
September 2005

Site 1 cottonwood cuttings growing

   
 
Site 2, September 2005

Site 2, September 2005

Site 2, note area with and without straw wattles application, September 2005

Note area with and without straw wattles application, September 2005

   

home

Copyright © 2010

Stabilization of Highway Cut Slope ~ Landslide Restoration