GIS Data Sources
EPA ArcGIS Server for water-related GIS data. This is not a web browser URL, but rather a an ArcGIS server address. Lots of information available from office locations to scaled watersheds for the United States.
Map and Geospatial Hub - ASU Library Map and Geospatial Hub advances the use of geographically-referenced information by expanding access to and support for cartographic resources and geospatial technologies across the ASU community and beyond.
watersgeo.epa.gov/ArcGIS/services/WC/WaterShedsWC : Can be used with ArcGIS Explorer. Under "Add Content," select "Add GIS Services." Go to the WC folder for watershed information.