The Arc-en-Maurienne has its source near the village Bonneval-sur-Arc in the Haute-Maurienne in the department Savoie, France. The mean river slope varies from 6 per cent to 0.2 per cent (Marnézy, 1999). The river flow is strongly influenced by numerous hydropower facilities, including three river dams located in the middle reaches, and water is deviated from the Arc to the river Isère and vice versa.