Watersheds
What are Watersheds?
The watershed is the total area of land that contributes runoff to any body of water. Land uses in a watershed determine the quality of surface water in smaller streams and waterways. They can then influence the water quality of larger streams. For example, point source discharges, urban runoff, runoff from landfills and runoff from agricultural areas may contain sediments, organic material, nutrients, toxic substances, bacteria or other contaminants. When these substances are present in significant concentrations, they may interfere with some stream uses.
Hoosier Riverwatch organizes data from volunteer stream monitors by watershed location using the map: Indiana Watersheds: 8-Digit Hydrologic Unit Code Areas." Delineated by the U.S. Geological Survey, hydrologic units represent the geographic boundaries of water as it flows across the landscape. In Indiana, the Department of Environmental Management also uses this watershed scale to organize official data on the quality of the state's surface water.
Watershed Address
As you can see from the map, each watershed name also has an associated 8 digit number or code. This number is representative of the size of the basin. Larger basins are represented by smaller numbers. Each of the watersheds shown also has smaller sub-watersheds which are represented by 11-digit and 14-digit numbers.
Knowing your "watershed address" is important to understanding the influences on the water quality in your stream or river. You will also understand where water in your stream comes from and where your waterway flows.
What is your watershed address? Click to view map of Indiana Watersheds.
To get help determining your watershed and to learn more about it, visit the U.S. EPA's Surf Your Watershed Site.
