Water is a critical nexus for many of the 21st century's biggest global problems, including food supply, energy production, disaster risk, infrastructure, hygiene and sanitation, and sustainable development, with strong, multifarious ties to nearly all of the UN’s Sustainable Development Goals (SDGs). As a response to the global urgency of water resources issues, the hydrological science, water resources management, and engineering communities have declared 2023-2032 the decade of "science for solutions", calling for the strategic alignment of hydrological research with global priorities for sustainability and human well-being. Hydrologists and engineers are advocating for Translational Water Research (TWR), the coordination across water-related disciplines to solve urgent water-related problems. Here, we highlight freshwater biodiversity conservation as a key opportunity for impactful TWR, review the disciplinary subfields and theory that contribute to bridging the gap between hydrologists, engineers, and freshwater ecologists, and highlight the potential role of freshwater biology in contributing to global water resources efforts. We argue that through closer interdisciplinary collaboration with hydrologists and other water resources professionals, freshwater ecologists can not only gain a more holistic understanding of the role of fresh water in sustaining biodiversity across the hydrological cycle, but also address the ongoing freshwater biodiversity crisis and contribute substantially to solving societal water problems through the SDGs. Among other key topics, we include implementation gaps in Ecohydrology, the potential for water-related Nature-based Solutions to protect biodiversity while providing for societal needs, and under-recognized impacts of hydrology on biodiversity. We encourage freshwater ecologists to recognize the importance of their research in addressing global water resources challenges and to seek interdisciplinary collaborations with professionals and academics in other water-related sciences.