It s the area surrounding and delivering water to the local stream, river, lake, or wetland. Other terms you might see that refer to watersheds are catchment area and drainage basin . Homes, farms, ranches, forests, small towns, big cities and more can make up a watershed. Some cross county, state, and even international borders. They come in all shapes and sizes and can vary from millions of square miles, like the land that drains into the Gulf of Mexico, to an acre or two that drain into a pond.
Watersheds are nature's way of dividing up the landscape.
Rivers, lakes, estuaries, wetlands, streams, even the oceans can serve as catch basins for the land adjacent to them. Ground water aquifers serve the same purpose for the land above them. The actions of all the people who live within a watershed affect the quality of the waters that drain into and from it. Every watershed is unique and has a different size, shape, and drainage pattern, or system of rivers and streams. Two factors that determine the varying natural characteristics of watersheds are geology and climate.