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Water Quality Video Series: What is a Watershed?

Water Quality Video Series: What is a Watershed?


A watershed is an area of land where water naturally drains to one point. Rainfall, snowmelt, and other precipitation falls on the land and flows downstream into a single lake, river, or stream.

Watersheds can be large or small. The largest watersheds in the United States cover several states and drain into oceans. However, you can look at very small areas as individual watersheds, such as your back yard.

Watershed boundaries are natural and manmade features that change the direction of where water flows. Hills and ridges are natural watershed boundaries because rain falling on one side of a hill will flow in one direction, while rain falling on the other side of the hill will flow into another.

It is normal for watersheds to cross the borders of counties and states. Watersheds even flow from one country to the next. It is common for watersheds to follow streams and rivers from rural to urban areas and vice-versa.

Why are watersheds important?

It is important to keep watersheds as clean as possible for many reasons.

  • Watersheds are the source of the water we drink.
  • We use watersheds for recreational uses, such as boating, swimming, and fishing.
  • Wildlife depends on watersheds for food, water, and shelter.

What can harm my watershed?

Nonpoint source pollution is the largest source of water pollution and the biggest threat to the health of our watersheds. Nonpoint source pollution is a variety of chemicals that precipitation washes from the land into streams and rivers. Common nonpoint source pollution includes oil residue, fertilizers, pesticides, pet waste, and soil.

As water moves through the watershed, it picks up more and more nonpoint source pollution. This harms the quality of your watershed and others downstream.

What can I do to protect my watershed?

State and local governments, volunteer groups, and water quality professionals are working together across Indiana in Watershed Planning Groups. These groups study water quality, find the source of problems, and develop plans to improve our waters.

There are many ways that you can participate in watershed planning groups. Common activities include helping develop a watershed improvement plan, educating neighborhoods about good water quality practices, and waterway cleanup projects.


Pollution isn't cute. It may be easier to leave pet waste on the ground, but what if every Hoosier did the same thing?

Multiply your choice by the six million people living in Indiana. Remember, it is the little things that we do every day that can help, or harm, water quality the most. Take a minute to do what is best for our water.

Find out more about nonpoint source pollution, and how to improve water quality by going to this website.

It's your watershed, your home, your future!

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