A Watershed is an area of land from which all water drains to a common body of water. The extent of a watershed is formed by the topography of an area, and hills and ridges form the boundary between watersheds. Small watersheds are part of larger watersheds, which in turn are part of even larger watersheds. Washington County’s watersheds are part of the Ohio River Watershed, which is part of the Mississippi River Watershed, which flows into the Gulf of Mexico. Yes, rain that falls in your back yard eventually makes it all the way to the Gulf of Mexico.  What happens in the headwaters (the small streams) effects water quality downstream.  Washington County has fifteen main watersheds, some of which are shared with neighboring counties and West Virginia.