Potomac Watershed Map with Streams

Sub-watersheds of the Potomac River

Land Use Map-2006 Data

Land Use Map-1997 Data

Washington Metro Water Supply Service Areas (as of 2010)

USGS Potomac Watershed Stream Gages

Harmful Algal Bloom (HAB) Monitoring Locations

Additional maps can be found the Maps page of the Interstate Commission on the Potomac River Basin’s website.