Virginia's Rivers
Watersheds
A watershed or drainage basin is the area of land that includes a major river and all of its tributaries. That means that all the surface water within a watershed will flow toward and into the main river of the watershed.
A drainage divide is the line of high ground that separates adjacent watersheds. Streams always flow downhill away from a drainage divide toward the main rivers on either side of the divide.
In Virginia, rivers flow either east toward the Atlantic Ocean or west toward the Ohio River which then flows to Mississippi River and then to the Gulf of Mexico. The Continental Divide is the drainage divide that separates east flowing rivers from west flowing rivers. The east flowing rivers include the Chesapeake Bay rivers, the Roanoke and the Chowan Rivers. West of the continental divide, there are the New, Tennessee, and Big Sandy basins. The Continental Divide itself separates the Roanoke River from the New River basins.
Chesapeake Bay Rivers
Virginia has 4 major river systems that flow into the Chesapeake Bay and then toward the Atlantic Ocean. They are, from north to south: the Potomac-Shenandoah River system, the Rappahannock River, the York River, and the James River.
The 4 rivers create three penninsulas or "necks" in the Coastal Plain: the Northern Neck, the Middle Neck, and the Virginia Penninsula (or Southern Neck) which includes Williamsburg and Hampton Roads. Cities where they cross the Fall Line are: Washington D.C. (Potomac), Fredericksburg (Rappahannock), and Richmond (James).
The Potomac-Shenandoah River Systems and the James River both have tributaries in the Valley and Ridge, then pass through the Blue Ridge, Piedmont and Coastal Plain before they reach the Chesapeake Bay. The Potomac system's tributaries reach into southern Pennsylvania, Maryland and West Virginia.
The James River basin dominates central Virginia and has the largest watershed area in Virginia. Lynchburg and Richmond are important cities along the James. An important tributary is the Appomattox River which drains much of the central Piedmont and has Petersburg as a Fall Line city.
The Rappahannock River begins as tributary streams flowing off the eastern slope of the Blue Ridge, then crosses the Piedmont and Coastal Plain.
The York River system begins in the Piedmont and passes through the Coastal Plain. Two major tributaries are the Mattaponi and the Pamunkey Rivers. These two rivers join to form the York River at West Point, Virginia.
Roanoke and Chowan Rivers
The Roanoke and Chowan Rivers both travel south into North Carolina before reaching Albemarle Sound at the Atlantic Ocean. The Roanoke River watershed is the larger of the two. It begins as tributaries in the Valley and Ridge, crosses the Blue Ridge near Roanoke, and passes through the Piedmont before it reaches the Coastal Plain. Smith Mountain Lake and Dam is is one of Virginia's larger recreational lakes and hydroelectric dams of the Roanoke River. Lake Gaston is also a hydroelectric and recreational lake along the North Carolina border.
The Chowan River system begins in the southside Virginia where the Nottaway and Meherin Rivers drain the southeast Piedmont. The Blackwater river, which begins near Petersburg is an important tributary that passes through the swampy areas of the Coastal Plain. The Chowan River itself forms at the confluence of the Nottaway and the Blackwater Rivers at the North Carolina-Virginia border and continues southeast where it empties into Albermarle Sound.
New River
The New River begins its extensive tributary system in the Blue Ridge of North Carolina, then travels north through the Valley and Ridge and eventually crosses into West Virginia in the Appalachian Plateaus before it reaches the Ohio River. It is not a "new" river at all, and has a long geologic history that is written here.
Tennessee River
The Tennessee River takes a long path that reaches the Ohio River by travelling southwest into eastern Tennessee and northern Alabama, and then turns northward where it briefly borders Mississippi and re-enters Tennessee and reaches western Kentucky. In Virginia, its upper tributaries drain the far southwest section of the Valley and Ridge. The Clinch River and and the North, Middle and South Forks of the Holsten Rivers are the larger tributaries of the Tennessee system in Virginia.
Big Sandy River
The upper tributaries of the Big Sandy River system drain the Applalachian Plateaus counties of primarily Dickenson and Buchanan. Further downstream, the Big Sandy and one of its tributaries, Tug Fork, forms the main state boundary between Kentucky and West Virginia. Its path is northward to the Ohio River.