What is a watershed?
Every place on Earth is part of a watershed. A watershed is an area of land that drains into a body of water such as a lake, river, or stream. It is defined by the high points of the land that divide watersheds. Connecting the high points creates a ridgeline, much like a peak of a roof.
Rolling Road, an old colonial road used for rolling giant barrels of tobacco to ships in the Potomac River, runs along the ridgeline defining the southwest side of the Accotink Creek watershed. When you are out driving, walking or riding your bike, notice that you go uphill as you approach Rolling Road and downhill after you cross it.
How big is a watershed?
Watersheds come in all sizes depending on the size of the body of water. The Accotink Creek has several smaller streams, like Flag Run and Long Branch, which feed into it. Each of these smaller streams has a watershed, which is a sub-watershed of the Potomac River watershed, which is a sub-watershed of the Chesapeake Bay watershed. Watersheds are like Russian nesting dolls: a small one fits into a bigger one, which fits into a bigger one.
What is a watershed address?
Your watershed address is like your home address. If you live on Flag Run Drive in the town of Springfield, in the Commonwealth of Virginia, in the United States, then your watershed address is Flag Run, Accotink Creek, Potomac River, Chesapeake Bay.
Why are watersheds important?
Seventy percent of the surface of the Earth is covered with water, but only a tiny fraction of that water is fresh and available for our use. The fresh water that is stored in lakes, inland seas, and rivers accounts for only a thousandth of one percent of all the water on Earth. That water is constantly in motion. Water flows across the land and evaporates into the air where it becomes clouds. The water cycle continues when it rains again and that water flows across the land. While the water is flowing across the land in our watershed, it is available for our use. We use this water to make our lawns, gardens, and world beautiful, for swimming, fishing, boating, and reflecting sunsets, and for making the cars, newspapers, and things that make our lives easier and better.
Accotink Creek Watershed Facts
Location: Central Fairfax County, stretching from the City of Fairfax and the Town of Vienna to Annandale and north Springfield.
Size: 19,000 acres, which is about 20 square miles.
Land Use: Mostly residential and commercial, with parkland along the major streams.
Roads: Six major commuter arteries cross the watershed: Interstate 66, Route 29, Route 50, Little River Turnpike, Braddock Road, and the Capital Beltway.
Sediment Load: In 1986 it was estimated that 10,000 tons of sediment are carried into Lake Accotink each year by Accotink Creek. That’s about one metro bus a day.