Providing tunneling and rock engineering specialized services

Wreck Cove Generating Station - Tunnel Remediation

Wreck Cove is the largest hydro station in Nova Scotia and produces approximately one third of the province’s hydroelectricity. Tunnel T-2, one of the station’s water conveyance tunnels, was constructed in the 1970s to convey water from the Wreck Cove Reservoir to Surge Lake, the head pond of the station. As a crucial part of providing clean, renewable energy, a hydro plant like the Wreck Cove station requires upgrading to continue operating. Following our tunnel condition assessment, Nova Scotia Power engaged us to support the design and tendering of remedial measures for the aging tunnel excavated in rock.

During our condition assessment, we identified a major collapse in the tunnel that required extensive remediation. Collecting geotechnical data to support the proposed design and construction of remedial measures, we conducted two drilling investigations. These comprised nine geotechnical boreholes, detailed core logging, televiewer surveys, and hydraulic conductivity testing. Our team performed stability analyses and developed and evaluated remedial options for the rehabilitation of the collapsed section within Tunnel T-2. We also provided conceptional designs for the remedial options, such as a bypass tunnel, and prepared cost estimates for these options.

In support of the tender phase of the project, we prepared technical specifications and drawings to help Nova Scotia Power take the next steps for the rehabilitation of the tunnel.