A watershed is a topographically-defined area of land that contributes water, nutrients, pollutants, and sediments to a common downstream point such as a stream, river, or lake. When it rains, water moves downhill across the land’s surface or underground. Moving farther downhill by force of gravity, the water converges into a progressively larger system. The U.S. Geological Survey (USGS) defines a watershed as “the land area that drains water to a particular stream, river, or lake and can be identified by tracing a line along the highest elevations between two areas on a map” (USGS, 2014). Watersheds are comprised of many smaller subwatersheds or subbasins.
A watershed based approach is a flexible framework for managing water resource quality and quantity within specified watersheds. This approach includes stakeholder involvement and management actions supported by sound science and appropriate technology. The watershed planning process works within this framework by using a series of cooperative, iterative steps to characterize existing conditions, identify and prioritize problems, define management objectives, develop protection or remediation strategies, and implement and adopt selected actions as necessary. Using a watershed approach, addresses problems in a holistic manner and the stakeholders in the watershed are actively involved in selecting the management strategies that will be implemented to solve those problems (EPA, 2008).