500
Explain how to map a watershed and why it is important/useful to understand watershed ecology.
Draw a line from hilltop to hilltop around a stream or body of water. Everything inside that line delineates the watershed, that is, the area of land where all rain and other sources of water drain into the water bodies. Water flowing or falling inside the line could potentially enter the body of water. Any pollution flowing in runoff inside the line could enter the body of water as well.