1. areas of land that drain into a particular river, lake, or other body of water
Usage: geography; environmental science
2. ridges of high land that separate different drainage areas
Usage: geography
3. crucial turning points or moments of significant change
Usage: figurative

Examples

• The Amazon and Mississippi watersheds are among the world’s largest.
• Pollution in urban watersheds affects downstream water quality.
• Mountain watersheds provide fresh water to millions of people.
• The Rocky Mountains form watersheds that divide eastward and westward flowing rivers.
• The invention of the internet marked one of the great watersheds in human communication.
• Many historians consider 1989 a watershed year for democracy in Eastern Europe.
• Conservation efforts focus on protecting critical watersheds from development.