One of the most important parts of a watershed is the land right next to the stream, called the riparian area. First, these trees, shrubs, and tall grasses can shade a stream to keep it cool. These plants can also provide habitat for land animals that like to spend time near water, such as raccoons, hawks and herons. Leaves and other plant parts fall into the stream and become food for a lot of the insects that live there. Finally, these plants and their roots act as a screen for the stream.
When water flows across the land to join the stream, it sometimes carries with it chemicals and sediment from human activities. The plants and their roots can hold back the sediment and clean the chemicals out of the water, helping the stream stay cleaner.
It is important for people who own land near a stream help the stream keep a healthy riparian area. Farmers should not plant their crops all the way to the edge of a stream, and landowners should not mow down the plants close to the water. (photo courtesy of USDA NRCS)