Victoria’s strategies for the management of land, water and biodiversity are supported by evidence-based decision making. A mix of evidence is required to support continued improvements in decision making. Information on the condition of natural resources assists in prioritizing management investment and communicating the status of environmental assets to the community. The Victorian Waterway Management Strategy identified a need to align estuarine assessments with the state-wide condition assessment and reporting tools used for rivers, streams and wetlands. As such, an Index of Estuary Condition (IEC) has been developed for the purposes of: i) reporting on the condition of estuaries, ii) assisting the prioritization of management investment among estuaries, and iii) providing a baseline for assessing long-term changes in resource condition. The development of the IEC has drawn on research on the connection of estuaries to their catchments. Several indicators that have demonstrated relationships with pressures and stressors including catchment land use and nutrient loading, are incorporated into the IEC. These include the dominance of macroalage over macrophytes, planktonic chlorophyll a concentrations, and the representation of demersal species in fish assemblages. The first state-wide IEC assessment is being implemented in 2017-2019, for reporting in 2020. Citizen scientists contribute to the IEC by monitoring physical water quality parameters and chlorophyll a.