Over the past year, an open and comprehensive global consultation of environmental flow scientists, practitioners, and policy specialists was conducted to formulate a new international consensus definition of environmental flows and to articulate the essential role of environmental flows in restoring and protecting aquatic ecosystems and safeguarding key aspects of the world’s cultural and natural heritage. Environmental flows are highlighted as a central element of water resources management, and as a foundation for achieving the water-related Sustainable Development Goals. This consultation resulted in The 2018 Brisbane Declaration and Global Action Agenda on Environmental Flows (Arthington et al. 2018). The Declaration and associated Global Action Plan take into consideration emerging perspectives in eflows globally, including i) increasing research focus on and new methodological approaches to cope with uncertainty and non-stationarity in hydro-climatic systems, ecological dynamics, and human responses and interventions, ii) recognition of a wider spectrum of objectives in environmental flow assessment, ranging from flow regimes to restore the natural state and evolution of aquatic systems to flow regimes to meet ecological design criteria or sustain novel ecosystems, and iii) increasing attention to the social and cultural aspects of eflows not only as external factors impacting river ecosystems but also specific objectives for flow recommendations. The Declaration also includes an updated definition of environmental flows; “Environmental flows describe the quantity, timing, and quality of freshwater flows and levels necessary to sustain aquatic ecosystems which, in turn, support human cultures, economies, sustainable livelihoods, and well-being.” Scientists and engineers are called upon to engage with managers and policy makers in the co-design and development of research to i) quantify flow-ecology relationships and ecosystem services for all aquatic ecosystems that depend on fresh water, including groundwater dependent ecosystems, ii) investigate existing, and propose new, mechanisms for integrating e-flows implementation in water resource management, and iii) develop best-practice models to ensure full and equal participation of all cultures and stakeholders in eflow planning, assessment, implementation, monitoring, and adaptive management.