Watershed is an area of land that drains to a lake, river, wetland, or other waterway. Water from precipitation travels over forest, agricultural, or urban/suburban land areas before entering a waterway.

- A watershed is an area of land that drains to a lake, river, wetland, or other waterway.
- Water from precipitation travels over land (forest, agricultural, urban/suburban) or through underground aquifers before entering a waterway.
- Watersheds can vary in size; larger bodies of water have larger watersheds (e.g., the Chesapeake Bay Watershed covers 64,000 square miles and drains from six states).
- Virginia has nine major watersheds: Shenandoah-Potomac, Rappahannock, York, James, Eastern Shore of the Chesapeake Bay and coastal rivers, Chowan, Roanoke, New, and Tennessee-Big Sandy.
- These watersheds ultimately drain into three main bodies of water: the Chesapeake Bay, the Albemarle Sound in North Carolina, or the Mississippi River and Gulf of Mexico.