Stabilization of Highway Cut Slope with Extreme Slope Angle

MOYIE BLUFF PROJECT 1

Location: Cranbrook / Moyie, British Columbia

Client: Ministry of Transportation and Highways (MOTH)

Objective: To investigate the potential for soil bioengineering utilization in establishing vegetation on extremely steep slopes (1:1) in order to reduce surface erosion.

The Moyie Bluff trial site is located on highway 95 near the town of Cranbrook in southeast British Columbia.

The site was selected on very dense, rocky, and compacted glacial till slopes, which were excavated at 1:1. Previous hydro seeding treatment was not successful on these slopes. The site was treated in the spring of 2002, and monitored in the summer and fall of 2002 and in the summer of 2003.

The treatment consisted of alternating contour fascines and contour fascine / brush layer type structures. A special blend of growing medium was applied to the brush layer structures to provide nutrients and moisture retaining capacity. The species component used was 80% black cottonwood (Populus balsamifera ssp.trichocarpa) and 20% willow (Salix scouleriana), harvested locally.