The weather might have been cool and wet this fall, but that didn’t stop the Elk River Alliance and their amazing volunteers from joining forces to work on a couple of stream bank restoration projects. Thanks to the world of ecological restoration, it is possible to stabilize and rehabilitate an eroded bank by using plants instead of conventional methods, such as riprap. A major benefit of using plants as opposed to conventional bank stabilization methods is that they add to the longterm health of the aquatic ecosystem by providing shelter, habitat and adding nutrients to the stream.
Stream banks can be bioengineered by placing live plant material in the side of the bank and allowing the material to grow. Many plant species, such as willows and cottonwoods, can be grown from cuttings into full, healthy plants.
This means that shoots can be harvested and planted in the fall while they are dormant and then in the spring, when it warms up and the snow melts, they will start to bud and grow roots and shoots. These roots will continue to grow into the eroded soil over the next several years and will stabilize the ground.
This is exactly what volunteers did to help a stream bank on Lizard Creek! The site had failed in 2013 and the ERA had previously banded together with concerned citizens and park users to restore the site. The slope was well on its way to becoming stabilized, but to reduce the erosion that was still occurring they came around for a second pass. More cottonwood and willow cuttings were harvested and planted into the bank between the existing rows. By this time next year, these new cuttings will already be stabilizing the soil.
Another way that stream banks can be stabilized is by planting young plants that will continue to grow in them. This technique is more costly, but can be equally effective if care is taken to give the plants their best shot with lots of water and soil amendments.
At the other stabilization site on Alexander Creek, volunteers removed invasive plants that commonly grow in disturbed areas and then planted native riparian vegetation along the eroding stream bank. Native plant species like cottonwood, trembling aspen, willow, and red osier dogwood were used due to their fast growth rate and aggressive root development. These were planted in an area where a well-established tree already exists, so attempts to stabilize the bank without disturbing the mature tree were taken.
The project will continue further upstream in November where more cuttings will be placed into the soil to stabilize the bank. Volunteers are needed on November 7th to help take these cuttings. Further, root wads and footer logs will be placed in the stream to deflect the water’s energy as it comes around the bend. In addition, they will also provide fish habitat in the stream.
ERA would like to thank their amazing sponsors and funders who made these projects possible. They are: Lotic Environmental, Teck, Fish and Wildlife Compensation Program, Sparwood and District Fish and Wildlife Association, Columbia Basin Trust, Recreational Fisheries Conservation Partnerships Program and Canfor.
Anyone interested in learning more about these projects and volunteering on November 7th should message beth@elkriveralliance.ca with their inquiries.
