Wuikinuxv Nation and the Wuikinuxv Village are in Rivers Inlet along BC’s Central Coast. Access to Wuikinuxv Nation is by plane or boat, and the wharf facility in Wuikinuxv Village is a critical piece of infrastructure for the Wuikinuxv community. The facility provides access to fishing grounds, supply of essential goods and services, and economic opportunity.

Since its construction in 2006 and despite a redesign and refurbishment of its debris boom in 2011, the wharf sustained significant damage from large debris flows in the Waanukv River, which have worsened in recent years due to climate change. The Wuikinuxv Nation retained Westmar Advisors (Westmar) to develop, design, lead community consultation, and obtain environmental permitting for an improved wharf facility with an effective debris barrier. The remote location, high river flows, tidal influence at the wharf site, and sensitive salmon-bearing habitat created challenges. The team also had to work with limited technical information and a schedule with a narrow in-water work window. These factors and the importance of the project to the economic and social fabric of the community required close community engagement and innovative solutions in both design and execution.

Analysis of historical flows and debris impacts resulted in the design of a steel plate barrier wall supported by large steel pipe piles. A wharf facility with both in-water and upland improvements was designed downstream of the debris wall. Westmar managed the tendering process on behalf of the Wuikinuxv Nation and provided extensive field support during construction. Multiple consultants and contractors worked closely together as part of the project team to ensure the debris wall was finished in time to protect the wharf from spring freshet and the facility was completed in the winter of 2022.

Westmar engaged the Wuikinuxv Nation to understand their needs and the challenge posed by the debris flows that had overcome the existing debris boom. A steel barrier wall was envisaged that would be strong enough to withstand debris impacts, prevent overtopping, and avoid the formation of debris dams while also allowing fish to pass under the wall at all river water levels. A conceptual design was finalized and Westmar, with support from Hatfield Consultants (Hatfield), assisted the Wuikinuxv Nation to secure funding and regulatory approval.

Westmar completed detailed design and prepared specifications for tender, with geotechnical support from EXP, river and debris modelling from DHI, an Environmental Management Plan (EMP) from Hatfield, and civil engineering services from David Nairne & Associates. Westmar managed tendering and supported contractor selection through engagement with bidders. Construction was sequenced to ensure in-water work would be completed within the fisheries window. The debris wall was 97.5 m long and utilized steel sheet pipe piles 762 mm in diameter and up to 23.5 m long, driven up to 12 m into the riverbed, with steel plates welded between them. The protected area downstream of the debris wall was dredged to restore historical water depths under the floats and at the boat ramp. The upland area was improved to offer better safety, functionality, capacity, and amenities. Local skilled workers contributed 630 hours during construction.

Despite lack of detail on soil composition, pile driving proceeded on schedule and the debris wall was installed within the fisheries window. Construction and dredging were completed in accordance with the EMP, with no reportable environmental or safety incidents. The debris wall performed well during both the spring freshet and the fall high-water flows, effectively protecting the wharf facility. Work was fully completed in the winter of 2022.