Runoff from fields, lawns, and pavement could carry potentially harmful materials from our watersheds to our rivers. Even if you live, work, or play far from a river, your actions could have an impact on the quality of the water in the area. These effects could be felt far from the point of origin. This video from KET’s Raindrops to Rivers shows how smaller watersheds flow into larger ones.
https://nm.pbslearningmedia.org/resource/ket09.sci.ess.water.wshed/what-is-a-watershed/