Declining water security and rising water demand present a daunting environmental challenge for the Anthropocene that will necessitate unprecedented control and management of global hydrology. The same water upon which society depends is the foundation for myriad ecological processes and interactions essential for threatened biodiversity. This may increasingly lead to conflicts over human and environmental needs for freshwater. This talk introduces the concept of Human-Environment Water Conflict (HEWC) as a novel analytical lens and rhetorical tool for sustainable water management and freshwater biodiversity conservation. I argue that recognizing HEWC (1) connects seemingly disparate conservation cases by shared characteristics, facilitating a unified approach to managing environmental water needs, and (2) provides a conceptual bridge for applying successful water management frameworks in conservation contexts. The current disciplinary landscape of ecological science and environmental management has the tools necessary to address HEWC, but new cross-disciplinary efforts are needed to link research to policy and management applications. I review contemporary frameworks that could be brought to bear on HEWC, examples of HEWC across ecological realms and aspects of the hydrological cycle, and highlight potential research priorities for addressing this looming conservation issue. This synthesis is intended to broaden the dialogue for transdisciplinary work at the nexus of freshwater resources and biodiversity conservation.