Open Collaboration Hydrology (OCH) is an online community and platform devoted to promoting the use and development of open and collaborative water science and management tools. As part of the Voices for Science AGU program, this presentation shares OCH's story, approach, and communication channels. Moreover, this presentation will share the profound impact of open and collaborative approaches on expanding the boundaries of water systems knowledge and its management. Open Collaboration Hydrology embraces participatory/collaborative modelling principles, open science, and the Free Open Source Software standards (FOSS) to facilitate the convergence of diverse perspectives, understandings, and beliefs about water systems. This presentation also aims to inspire attendees by showcasing the transformative potential of Open Collaboration in hydrology and inviting them to engage in making water science resources equitable, accessible, and inclusive for everyone.