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Nonpoint Source Water Pollution

Nonpoint Source > What is a Watershed? What is a Watershed?

A watershed is an area of land that collects and drains water from high points (hills) to low points (valleys). When rain falls in a watershed, the water travels over natural and manmade terrain features toward the lowest point. Any area that drains water to one location is a watershed. This means that watersheds can be as small as a backyard or as large as the land that drains into the Great Lakes.

Unlike the straight lines of city, county and state boundaries, watershed borders are wavy or jagged because they follow terrain features. Watershed boundaries often overlap political boundaries, which can make watershed management difficult.

No matter the size, watersheds are important because they supply us with water for drinking, recreation, industry and agriculture. Lakes, rivers and wetlands provide habitat for countless species of animals, insects and plants. Changes to the Indiana’s terrain can affect watersheds and the resources they provide.

Land development can dramatically affect how rainwater is moved through watersheds. Hard surfaces don’t absorb water, which puts more stress on nearby grassy areas to absorb rainwater. This problem is usually fixed by installing storm water drainage, such as gutters, surface drains, storm sewers and ditches. However, these are not natural solutions and can lead to flooding, damage water bodies and harm wildlife.

More Information:

Additional Resources:

  • U.S. EPA Watersheds page: The Environmental Protection Agency’s watersheds page.
  • U.S. EPA Surf Your Watershed: Find your local watershed, plus data and local volunteer groups.
  • Center for Watershed Protection: A nationally recognized watershed organization, with plenty of information and useful links.
  • HUC Finder and Watershed Group Finder: Developed through the Indiana Watershed Leadership Program. HUC Finder provides a quick way to identify the 8, 10, and 12-digit Hydrologic Unit Code (HUC) for any point in Indiana. The 8, 11 and 14-digit HUCs in the older system are also provided, for reference between the two systems. Watershed Group Finder helps find active watershed groups anywhere in Indiana.