The Tsolum River Restoration Society works to enhance fish habitat features in the Tsolum River. As a result of past restoration efforts, the Tsolum River has recently had a return of naturally spawning salmonid species. The 2015 pink salmon return was estimated at 129,000 fish – as high as any historical record.
Located just downstream of the CVRD Fair Grounds, our 2015 project was selected because of the ongoing deterioration during seasonal high water events. Rapid bank erosion and channel migration occurring near the BC Hydro Line crossing had been tracked since 2004. This change was jeopardizing private property, a drinking water pipeline crossing and was reducing habitat quality for salmon rearing and spawning.
The river was expected to continue shifting its course while seeking a natural curvature and this action was resulting in the continued cutting into the left bank and behind the existing rock armour that had been placed by the Comox Valley Regional District in an earlier attempt to protect the waterline and private property.
In the first phase of the project in August, rock and large woody debris features were anchored in place along the bank to protect and further enhance the fish habitat. The placement of these features was engineered to shift the river channel energy away from the banks to minimize erosion.
During the December 2014 flood, the right bank upstream of the project site was weakened and eroded then during a spring wind storm several large trees came down, spanning the Tsolum River creating a partial blockage. These trees were assessed to pose a risk of catching debris that would result in and diversion of the river during winter water levels.
In the second phase of the project in October, the TRRS, BC Hydro, K’ómoks First Nation Guardians, River Meadow Nursery and the CVRD worked together to move the three large fallen trees by shortening and then swinging them along the right bank. By securing their root wads into the bank these trees now buffer the bank from further erosion by deflecting the river’s energy mid channel upstream, protecting the left bank phase one project work just downstream.
Finally, in phase three of the project, working between fall rains and the December 2015 high water levels that flooded the project site, TRRS volunteers, K’ómoks First Nation Guardians and the Cumberland Community School’s Outdoor Education students planted the project site riparian area with cedar, Sitka spruce and Douglas fir trees next to the existing mature trees and willow, red-osier dogwood and red alder trees along the open floodplain. The roots of these riparian plants will further stabilize the soft soils along this bank in times of future high water events.
The effectiveness of the project will be evaluated as part of the Tsolum River Recovery Plan Monitoring Plan. To learn more about this project and the Tsolum River Restoration Society or to provide feedback on the new Tsolum River Recovery Plan, the public is invited to attend the TRRS AGM Saturday, Feb. 20 at the Dove Creek Hall (3400 Burns Rd), 1 – 3:30 p.m. For more information on the TRRS or the ongoing project, visit tsolumriver.org