Watersheds

The Basics
Keeping North Dakota’s lakes and streams clean demands more than dockside diligence. Even if you don’t live along the shores or banks, you may be contributing to the pollution of lakes and streams. Lakes and streams are larger than their shorelines. They’re part of a system called a watershed.

What is a watershed?
Water from rainfall or snowmelt that doesn’t evaporate or soak into the soil runs into ditches, streams, wetlands, or lakes. The land area from which the water drains is called a watershed.

Watersheds may vary in size. If water from a few acres drains into a little stream, those few acres are its watershed. This stream and others like it run into larger streams or lakes. Small watersheds make up larger ones. It’s easy to see how the watersheds of North Dakota’s lakes can have land areas many times larger than their lake surfaces.

Simplified...
A watershed is simply defined as, "an area of land that drains to a common point, usually a stream, river, lake or wetland".

For more on the basics click these:
Water and People
Water Cycle
WATERSHED IQ TEST