The Automated Geospatial Watershed Assessment (AGWA) tool is a GIS-based multipurpose hydrologic analysis system for use by watershed, water resource, land use, and biological resource managers and scientists in performing watershed- and basin-scale studies. It uses readily available spatial data sets to parameterize and run two widely used watershed runoff and erosion models: the Soil Water Assessment Tool (SWAT) and KINematic Runoff and EROSion (KINEROS2) hydrologic models. AGWA is designed to support hydrologic modeling and watershed assessments at multiple spatial and temporal scales. AGWA’s current outputs are runoff (volumes and peaks) and sediment yield, plus nitrogen and phosphorus with the SWAT model. AGWA is available as an extension for ESRI’s ArcView 3.x and ArcGIS 10.x.