Determination of watershed characteristics is an important concept in all hydrologic designs. The watershed is defined in terms of a point named “outlet.” The designs in the watershed are being made with regard to the outlet. The watershed can be well defined as the area that can be considered a bounded hydrologic system, within which all live components are linked to each other regarding their water supply resources. Each watershed includes many smaller subwatersheds that transfer water to the outlet during a rainstorm. Watersheds come in all shapes and sizes. They cross county, state, and national boundaries; for example, the continental United States includes 2110 watersheds.