Environmental flows in the upper Murrumbidgee River: evaluating flow delivery and governance to inform future environmental flow agreements

Context In 2002, an inter-governmental agreement was established to deliver environmental flows for the Snowy, Murrumbidgee and other montane rivers, the first legally binding agreement of its kind in Australia. River health had been declining owing to flow diversion for hydropower and agriculture. Aims To assess the extent to which environmental flows have been delivered in the upper Murrumbidgee River, the effectiveness of governance arrangements and the lessons that can be learned from this example to inform future environmental flow agreements globally. Methods This research evaluated 18 years of environmental release data, historic flow data and studies of river health. Governance arrangements were evaluated against the OECD Principles on Water Governance for effectiveness, efficiency and trust and engagement. Key results Environmental releases to the upper Murrumbidgee River were below the 27-GL annual target in 10 of the 15 years from 2008 to 2022. The average annual environmental release volume over this period was 18.9 GL. Conclusions The target was consistently not met because of insufficient volumes of water being allocated for environmental releases. Implications Future agreements can benefit from the findings, including setting enforceable targets, ensuring independent scientific oversight and implementing a flow response monitoring program with public reporting.