We present a geomorphic reassessment of the Hume to Yarrawonga (H2Y) reach of the River Murray, a highly regulated corridor downstream of Hume Dam where flows are operated primarily for irrigation. Long-term regulation, combined with legacy desnagging, stock access and boating pressure, has altered the timing, duration and variability of flows, creating a mismatch between river behaviour and a strategic management focus that defined success as maintaining the historically mapped Murray main stem as the primary flow path.
We used multiple lines of evidence to diagnose change and reframe management intent, including long-term flow split monitoring, interpretation of LiDAR, top-of-bank mapping, DEM of Difference analysis, relative depth mapping, and targeted field observations. Findings highlight regulation-driven shifts in bank erosion mechanisms and the sustained engagement of anabranches, with implications for sediment transport, riparian recovery and system reconfiguration.
A key output is a simplified five-stage anabranch development classification (Stable, Emerging, Constrained, Developed, Captured) that converts complex behaviour into decision-relevant categories. We demonstrate how this framework supports geomorphically adaptive management by treating the “main channel” as a moving target, considering conveyance across the full corridor, and aligning interventions to developmental stage, while prioritising vegetation/roughness and “softer” approaches where appropriate, and planning for inevitable transitions in dominant pathways.
This is an example of geomorphically adaptive, process-driven management, which is becoming increasingly important across Australian fluvial systems, where regulation, land-use change and climate variability are accelerating channel adjustment and making corridor-scale, trajectory-led decisions essential for sustaining river values and managing risk.