What is a watershed?

Watershed diagram showing flow of water downhill to water body

A watershed is the area of land where all of the water that drains off of it goes into the same place—a river, stream or lake. The smallest watersheds are the drainage areas for small streams and lakes. Think about your local creek or river. Where does it start? What type of landscape does it flow through? Where does it end up? All of the area covered is a watershed.

Each small watershed is part of the more extensive watershed for a larger stream or lake in the vicinity. These larger watersheds are, in turn, part of even larger drainage networks, and so on. The largest-scale watershed is called a basin. Minnesota has ten basins, some of which include portions of neighboring states or Canada.

Major watersheds

The largest watersheds within a basin are called major watersheds. These are the drainage networks of the basin's largest rivers or lakes. There are 80 major watersheds in Minnesota. For each of these, MPCA works with other state agencies and local partners to identify water restoration and protection needs throughout the watershed and to determine how best to address them. Learn about MPCA’s major watershed approach to water quality restoration and protection.

Find information about your watershed.