Mitigating Channel Incision Via Sediment Input and Self‐Initiated Riverbank Erosion at the Mur River, Austria

At the border section of the Mur River between Austria and Slovenia, systematic river training and hydroelectric power plants have led to a channel incision with considerable ecological and technical consequences. A sediment transport model predicted further incision if no countermeasures are implemented. The thin gravel layer (≈ 0.5 m) poses the threat of a river-bed break-through, calling for urgent action. In a Basic Water Management Concept, several types of ecologically oriented countermeasures have been proposed. Recently, one measure that combines self-initiated riverbank erosion with sediment input from a newly constructed side-arm has been implemented. To determine the success of the measure, we conducted a detailed survey along with particle tracking by telemetry. The results show the anticipated response. At least for the present, short-term development, the measure effectively mitigated the incision.