The Automated Geospatial Watershed Assessment (AGWA) tool is a GIS-based hydrologic modeling tool developed jointly by the U.S. EPA Office of Research and Development, USDA Agricultural Research Service, and University of Arizona. It was initially designed as a research tool for assessing the hydrologic impacts associated with landscape change at multiple scales, a context in which process-based models are a necessity. As potential management applications of the tool became more readily apparent and partners with specific management objectives were identified, AGWA was transformed into a highly versatile tool for environmental management and planning. A thoughtful software design facilitates linkages between different model and data types, thus promoting collaborative, interdisciplinary development. Both the development of AGWA and the tool itself are illustrative of the process of combining basic research with stakeholder-driven model and software development to build an integrated suite of management and planning tools. The United States Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the research described here under assistance agreement DW12939409 to USDA-ARS. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.