The Peribonka dam is located in the heart of the province of Quebec, Canada. The project involves the construction of a main earth dam across a main and secondary valley, two main dykes and a hydroelectric generating Run-Of-River station with an estimated capacity of 385 megawatts. Under the main dam body, the construction of an exceptionally deep cut-off wall was required, to create a seepage barrier in highly permeable riverbed alluvia. Bauer was awarded the contract on the basis of an alternative design: the plastic concrete cut-off wall to be completely embedded in the bedrock, a design which avoided any potentially hazardous areas to be sealed by cement grouting. The cut-off wall was exceptional by its depth, reaching almost 116 m, and being surrounded by complex geotechnical ground conditions. Bauer commissioned a hydraulic cutter, the CBS CBC 135, the biggest ever manufactured, which included new features and was designed specifically for the construction of the Peribonka dam cut-off wall. Beside the extreme depth of the bed rock, the design was further complicated by the presence of hard rock including granite, with strengths at times in excess of 200 MPa, quasi vertical rock cliffs, rock overhangs, and gullies filled with coarse alluvia, including boulders.