From Beachapedia
This page is available in multiple languages:Watershed (English)流域 (日本語)
Map of the Potomac River watershed, including DC and portions of Maryland, Virginia, West Virginia and Pennsylvania
A geographic area in which all sources of water, including rain fall, snow melt,
streams,
rivers, lakes, estuaries, and
wetlands, as well as ground water, drain to a common surface water body, usually the sea. Below is a short video explaining the basics of Watersheds 101.
