Increasing water stress in arid and semi-arid regions has highlighted the need for systematic tools to improve water management. This study evaluates the capabilities and limitations of the Australian Minerals Council Water Accounting Framework (MCA-WAF) through its implementation in an integrated iron ore-to-steel industrial complex supplied by multiple water sources. The study advances the framework by introducing complementary water-intensity indicators, assessing data quality, and demonstrating its role in supporting managerial decision-making. The methodology involved reconstructing the water flow network, preparing a physical water balance, and deriving performance indicators using predominantly measured data. Results show that the facility receives approximately 18.9 million m³ of water annually, of which 67% is supplied from transferred water sources. Operational water efficiency (reuse and recycling) was estimated at 14.9%, substantially below commonly reported international values, indicating considerable potential for improving water recirculation. In contrast, water consumption for iron ore concentrate production was only 0.61 m³ t⁻¹, lower than the global average, suggesting that inefficiencies arise primarily from system-level water management rather than production technology. The accounting process also revealed a significant gap between managerial perceptions and data-driven reality, with managers substantially overestimating the actual recycling rate. The findings indicate that integrating MCA-WAF with economic indicators can transform it from a reporting framework into an effective decision-support tool for sustainable water management.