Melbourne Water invests significantly in the management, protection, and restoration of waterways to enhance their resilience and ecological health. A key focus is the removal of barriers to fish movement. To maximise the effectiveness and efficiency of these efforts, decisions must be guided by the best available science.
Spatial analysis conducted with the University of Melbourne has identified thousands of barriers across the greater Melbourne region, many of which may need removal to meet outcomes under Melbourne Water’s ‘Healthy Waterway Strategy. The cost of mitigating all barriers in Melbourne Water’s operating region is unmanageable, and so Melbourne Water needs to prioritise instream barriers for removal in a way that considers ecological and cultural benefits and available program funding cycles. Therefore, a prioritisation framework is needed to identify the highest benefit-cost barriers for removal.
We developed a pragmatic, transparent, and repeatable prioritisation framework grounded in global best practices. This quantitative approach integrates LIDAR-derived barrier data, habitat models, a fishway cost-estimate model, and an optimisation algorithm to prioritise barriers for removal in a way that optimises ecological return on investment. A multi-criteria assessment is used to identify barrier mitigation options and identify factors influencing project feasibility. Input from key stakeholders is also embedded in the process, ensuring the outcomes are sensible and fit for ‘real world’ application. The outcome is a prioritised list of barriers for removal, from which Melbourne Water can develop it’s 1-10 year investment program for fish barrier removal across its operating region.