Someone lives downstream from you and your actions determine the quality of their water. Even if you don't live on a river or even live close to a river you can impact the water quality of many people living far away. You are in the same boat though. You live downstream from someone who can impact your water quality. Everyone using water has to monitor what they might be introducing into a water body. Why? Because fences and property lines do not determine the biological boundaries of our land--watersheds do.

What is a Watershed?
The land that carries the water you use to a water body is called a watershed. A watershed is also known as a drainage basin because it is land that allows water to drain to marshes, streams, rivers, lakes, or to ground water. A watershed not only carries water. It can also carry pollutants. We have to pay attention to what is going on in the watershed, and identify potential sources for pollutants that might be contributing to that watershed. Knowing the potential sources of pollutants, the different land uses and practices playing out within a watershed, gives everyone a "heads up" on what pollutants to watch for. Got a lot of agricultural land in your watershed? Expect nutrients from fertilizers. Industrial development? Expect chemicals. Residential areas? Expect nutrients, sediment, and household chemicals.

Some water quality problems aren't only defined by the borders of a watershed. Economic and political boundaries also shape the problem.

Larger Watersheds

	Watersheds vary in size. As the size of the watershed increases, so do the number of potential pollutant sources, and the number of competing solutions. For example, the Mississippi river watershed drains 40% of the entire United States.
	That massive watershed can be broken down into several large watersheds, which can be broken down into smaller watersheds, scaling all the way down to areas that may be just a few square miles in size.
	By narrowing the scope of a problem, it’s easier to zero in on the threats to an individual water body, and to trace the sources of those threats.

Smaller Watersheds

Small watersheds, like the creek or stream running through your town, are just as important as bigger watersheds. In fact they are more important because acting locally helps solve the problems in your watershed and the larger watersheds it resides within.

On the local level you can monitor, cleanup, and restore rivers streams, wetlands, lakes, ground water, and estuaries and make a big difference. If everyone reduced the pollution that was infiltrating a stream on the local level you wouldn't have to worry about what pollution is coming downstream to you and the people downstream from you wouldn't have to worry about your pollution, there wouldn't be any!