Stabilization of Stream Channel using Live Gravel Bar Staking Techniques

BIGHORN CREEK PROJECT

Location: Fernie, British Columbia

Client: Tembec Industries Inc.

Objective: To accelerate vegetative growth in riparian and floodplain areas in order to stabilize gravel accumulation along reach 4 of Bighorn Creek. To enhance and create fish habitat.

Bighorn Creek is located in south eastern British Columbia near the town of Fernie. It is a major tributary of the Wigwam River and is valuable from a fisheries perspective.

The instream work was carried out with approvals and prescriptive direction from the Ministry of Water Land and Air Protection. The Live gravel bar staking work was done on a total of nine gravel bars over a distance of 2 kilometres. This work was carried out for Tembec Industries Inc. under the supervision of Ethan Askey, P.Ag. of Confluence Environmental Consulting. Terra Erosion Control Ltd. implemented the field work in October of 2001.

The treatment consisted of machine- assisted hand planting or "live staking" of gravel bars and a live palisade using live cuttings. The live palisade was established to provide a stout riparian cover of cottonwood trees adjacent to the eroding bank. The following species were used: 56% black cottonwood (Populus balsamifera L. ssp. trichocarpa), 35% willow (Salix scouleriana) and 9% red osier dogwood (Cornus sericea). The length of the live stakes ranged from 1.2 to 1.5 m and were treated as follows: 1/3 were soaked for 24 hours; 1/3 were soaked and the protruding end (20 cm) painted, and 1/3 were only painted on the protruding end (20 cm).

Monitoring in the fall of 2002 indicated that the treatment of flood plain areas using "live staking" was successful. The sites were further monitored in the summer of 2003, and the results showed a survival rate average of 55% ranging from 30 to 90 % on the different gravel bars. The live stakes planted near logs or large woody debris appeared to have had better survival and growth. Also observed was volunteer Salix exigua establishing itself on the various gravel bars. This site will be further monitored to assess root establishment in the coming years.