The Occoquan Watershed is a region in northern Virginia that drains into the Occoquan River. This watershed covers approximately 1,000 square miles and includes parts of several counties, such as Prince William and Fairfax. It plays a crucial role in managing water resources and supports diverse ecosystems. The watershed is vital for local communities, providing drinking water and recreational opportunities. It is home to various wildlife species and habitats, making it an important area for conservation efforts. The Occoquan Reservoir, located within the watershed, serves as a primary water supply for the surrounding regions.