This paper describes our experiences in applying spatially explicit, quantitative methods to Melbourne Water’s Healthy Waterway Strategy, and how they informed stakeholder deliberations on the identification of actions and targets for ecological values in the strategy’s participatory framework. We developed habitat suitability models for 51 macroinvertebrate families, 13 native fish species and platypus, and applied quantitative methods (Zonation) to prioritise cost-effective management actions throughout the >8,000km stream network to optimise the conservation and restoration of instream animal diversity.   

Using examples, we elaborate on benefits (that were not possible with previous approaches) including:

• better use of available biological data, with discrete, point-location data used to generate spatially continuous estimates of instream biodiversity at unsurveyed sites
• improved granularity in mapping of biodiversity patterns, alerting stakeholders to values, constraints and opportunities they might have been unaware of
• ability to integrate and model strategic considerations such as different aspects of climate change impacts (warming, drying), land use change and their interactive effects
• ability to quantify the expected difference made by management actions, and to account for costs so that action planning can be based on cost-effectiveness
• ability to spatially prioritise management actions, and to interrogate and critically debate alternative actions at specific locations for planning and target-setting
• improved ability to map, summarise and communicate decision-relevant data to different audiences
• repeatable analyses that can be scrutinised, error-checked, critiqued and built upon

Finally, we discuss some of the nuances of communicating the workings of quantitative tools and their outputs for use in participatory settings.