Achieving water security is a complex challenge. Across the U.S. and around the world, communities are struggling to balance water usage between four competing needs: human well-being, economic activities, ecosystem health, and climate resilience. Yet many of our typical responses: rationing, price increases, infrastructure investment, or new management approaches are falling short. Achieving a long-term, sustainable balance between competing needs at a watershed level requires a combination of strong governance structures, adequate financing, and structured cooperation between cities, regions, and states, as well as basin-level water users, most easily developed through open and inclusive dialogue, and shared decision making. The collective impact model for structured collaboration offers a new approach to address complex problems such as water security. It recognizes that such complex social challenges are not caused and therefore cannot be solved by any single sector, agency, or organization. It builds on more traditional partnership models in the water sector such as integrated water resources management (IWRM), bringing the government, nonprofit, philanthropic, and corporate sectors together as equal partners with community-level water users to actively coordinate efforts, change behavior, and share lessons learned. This 30-minute webinar will provide a brief introduction to collective impact approach, describe the necessary mindset shifts for successful collaboration, and offer concrete examples of how this model can enhance existing partnerships in the water sector, as well as an opportunity for Q&A.