The National Hydrography Dataset (NHD) produced by the USGS and EPA is a comprehensive database of the nation's water resources. Three seperate map layers from NHD are available:
- Flow lines (creeks, rivers and penstocks/flumes)
- Water bodies
- Watershed boundaries at the HUC-8 level
The map layers can be downloaded as apart of the AW Web Map Service (WMS) layer package.