The symposium speakers will present cutting-edge, interdisciplinary research on the grand challenge of freshwater sustainability. Understanding the intersection of hydrological variability and human drivers of water resource availability and quality is critical to ensuring long-term sustainability of water resources systems for societal and ecosystem needs. The symposium will highlight current research and explore challenges in the emerging field of socio-hydrology. Moving beyond scenario-based approaches that aim to “predict future states,” the symposium speakers will focus on the co-evolution of socio-hydrologic systems. By this, we mean understanding multi-scalar observable patterns in, the bidirectional interactions between, and the social (economic and institutional) and biophysical (hydro-climatic and ecologic) processes that shape these systems. Speakers will address the following questions: What patterns are observed in the dynamics of water availability, appropriation, and distribution at different spatial and temporal scales? What underlying biophysical, ecological, socioeconomic, and institutional mechanisms shape these patterns? How does our understanding of the functional linkages of socio-hydrologic processes address and account for values of multiple actors -- reliability, equity, sustainability, security, and/or resilience? How can these desired states be defined and measured, so as to reflect the priorities of the most inclusive set of actors possible?