Background Watersheds

Watersheds are the basic land unit for water resource management. A watershed is defined as an area of land in which all the incoming precipitation drains (i.e., "sheds") to the same place -- toward the same body of water or the same topographic low area (e.g., a sinkhole). The watershed's boundary, consequently, is defined by terrain and slope. Another way to consider this then, is that the water at the outlet of a watershed will be influenced by all activities upstream of that point, including reforestation.

The term watershed is typically used to describe a smaller area of land that drains to a smaller stream, lake or wetland. The term commonly used to define the larger area encompassing many watersheds is river basins. Watersheds can also be called as catchments.