Rivers and Watersheds

Virginia has been shaped by its rivers. Storms have carved away at the land since the continents and the atmosphere emerged, and the rivers have carried "Virginia" mountains to the oceans before the current mountains (or oceans) even existed.

Today we view the Blue Ridge and Allegheny Front as the primary topographic features directing water towards the east or west. However, Virginia's rivers have been carrying sediments downstream, reshaping the surface of the state, for eons. The New River was flowing even before the continents smashed into each other 200 million years ago, before "thundering lizards" left their dinosaur tracks in the sandstones of Triassic Basins.

Most Virginia rivers were redirected by the Appalachian Orogeny, 200 million years ago, and subsequent creation of the Atlantic Ocean. The New River is unique because it continued to flow through its old channel, and cut through the Appalachian Mountains as they rose. The current New River Gorge in West Virginia is just the most recent demonstration of how the energy in the New River's falling water can defeat the strength of rising rock...

A map of the hydrography of Virginia shows the rivers run in different directions - they don't all flow south, or "down the map." Rain falling in Southwest Virginia ends up flowing though Tennessee, Kentucky, and West Virginia to the Ohio River, then down the Mississippi River to New Orleans and the Gulf of Mexico. When the clouds move just a little further to the north or east, the rainfall will run downhill in the other direction. It can follow the Roanoke River watershed to Albemarle/Pamlico Sound, or the James River/Potomac River watersheds to the Chesapeake Bay.

When it quits raining, the rivers don't dry up immediately. Water in the ground seeps into the drainages, sometimes emerging in a defined location called a "spring" and sometimes adding more flow in less obvious ways to streams and rivers. A river will run even during a drought, as groundwater from previous rains seeps through the soil to the low spots. In a drought, those groundwater levels will gradually drop, just as a wet sponge left out in the sun will get dry at the top.

When the groundwater level drops below the level of the stream, then the "bed" of the stream - the sand. mud, or rocks in the bottom - will be exposed. In the summertime, many areas have edges of their streambeds showing rounded rocks and, occasionally, flopping fish in remaining pools of water. The rocks had rough edges when they first reached the earth's surface through erosion, but got rounded edges as the rocks were bounced around and washed downstream.

It's the natural cycle for rivers to etch the landscape, until ultimately (if left unaffected by other forces) the mountains are transformed into hills and then into a flat level plain. In the continental collisions before the Appalachian Orogeny 200 million years ago, 25,000-feet high mountains were located where Emporia and Richmond are located today. It was Virginia's rivers that eroded those mountains away. Today you can see the incredible sediments carried westward, in the layers of sandstone and shale stretching from western Virginia through West Virginia to the Great Lakes.

Thousands of feet of sediments eroded westward off the mountain ranges pushed up by the Taconic and Acadian orogenies, filling the lowlands in the center of the continent and forming today's Ohio, Indiana, and Illinois. Perhaps an equal amount eroded to the east, prior to the creation of the Atlantic Ocean. After the continents split again and the Atlantic was formed, the sediments on the Coastal plain and the Coastal Shelf were deposited primarily by rivers that, in their current locations, are known as the Potomac, Rappahannock, York, and James.

Much of the largest estuary in the Western Hemisphere is located in Virginia. The Chesapeake Bay is the drowned mouth of the Susquehanna and James rivers. Both rivers once ran separately to the Atlantic Ocean, before sea level rose after the last glacial period and formed the modern bay about 3,000 years ago. You can still see evidence of the separate river channels at the mouth of the bay. When the Chesapeake Bay Bridge-Tunnel was built, the U. S. Navy required a portion of the span be constructed as an underwater tunnel. This was intended to prevent an enemy from collapsing the bridge, blocking the shipping channels, and trapping the aircraft carriers at Norfolk. There are two tunnels now - the southern one in the deep channel that was carved by the ancestral James River, and the northern tunnel in the channel of the old Susquehanna River.

The southeast portion of modern Virginia is known today as both Hampton Roads and as Tidewater, but Tidewater is also applied to all portions of Virginia where the water level is affected by the tides - which is most of the land east of I-95 and north of US 460. Tidewater is not necessarily saltwater. Alexandria, Fredericksburg, and Richmond are tidewater ports. After a heavy rain upstream, the water in those ports may be completely fresh, with no brackish/salt water at the surface, but the tides will still cause the fresh water to rise and fall at the docks.

How Much of Virginia is Water?

Total Area	42,326
Land	39,598
Water	2,729
	1,000	Inland - All lakes, reservoirs, ponds, rivers, streams, creeks, or similar bodies of water.
	1,728	Coastal - Any embayments across which one can draw a closure line from 1 to 24 nautical miles in length (inland from the point at which the closure line is one mile or less, the water is treated as inland water). This line separates the coastal water from the territorial sea. For example, the coastal water of the Chesapeake Bay extends from this closure line towards the shoreline, and ends where the bay and its tributaries narrow to less than one nautical mile, at which point the water becomes classified as inland water.

In addition, Virgina has 451 square miles of "Territorial Waters." Territorial waters are located between the 3-mile limit and the shoreline or the line that represents the extent of either inland or coastal water.

NOTE: The Land and Water Area for the U.S., Virginia, and Surrounding States: 1990 table (from Section 8, " Geography and Climate," in 2000 Virginia Statistical Abstract) includes Territorial waters in the state total for water area. The 1993 Statistcal Atlas included territorial waters as a separate item. However, territorial waters were not decribed separately in Table No. 380, Section 6, "Geography and Environment", in the annual Statistical Abstract of the United States

Atlantic Ocean

Chesapeake Bay

Drinking Water

Floods and Floodplains

Ground Water

How the Potomac River Shaped the Settlement of Northern Virginia

How Watersheds Define the Boundaries of Virginia

Hydrologic Units

Lakes, Dams and Reservoirs

Rivers of Virginia

So Why Do We Care About Watersheds and Divides?

Topography and Coal Railroads

Virginia's Most Pristine Water Body

Water Rights

Watershed and Divides

Watersheds of George Mason University

Wetlands

Which Way Do the Rivers Run?

Wind Gaps and Stream Piracy

Links

• American Rivers
  • Clean Water Act basics
  • Paine Run (one of the "Most Endangered Rivers of 2001")
• American Whitewater
  • Virginia Navigability Report
  • Virginia Rivers
• Center for Watershed Protection
• Chickahominy Watershed Alliance
• Clean Virginia Waterways
• Environmental Protection Agency
• American Heritage Rivers
• Basins
• Drinking Water State Revolving Fund
• State allotments
• EPA Surf Your Watershed in Virginia
• Envirofacts
• EnviroMapper for Watersheds
• Hydrologic Units in USA
• National Watershed Forum
• River Corridors and Wetlands Restoration
• WATERS (Watershed Assessment, Tracking & Environmental Results)
• Watershed Academy
• Watershed Profiles
• Wetlands
• Float Fishermen of Virginia
• Friends of the Shenandoah River
• Friends of the Rappahannock
• Guest River Restoration Project (one of several awards from the Renewable Natural Resources Foundation
• Mattaponi and Pamunkey Rivers Association
• National Academy of Sciences - Commission on Geosciences, Environment and Resources
• New Strategies for America's Watersheds (1999)
• National Association of Conservation Districts
• National Forest watershed planning
• Jefferson National Forest Draft Wild And Scenic Rivers Eligibility Determinations (July, 1997)
• National Watershed Network
• National Weather Service - River Forecast Centers
• Navigable Rivers, 1930
• Pennsylvania Watersheds
• Powell River Project
• River Basins in North Carolina
• RiverLink - Links
• Saving Our Watersheds (National Wildlife Federation)
• Shenandoah Valley Pure Water 2000 Forum
• Shenandoah Watershed Study (SWAS)/Virginia Trout Stream Sensitivity Study
• St. Mary's Wilderness Liming Project
• The Nature Conservancy:
• "Rivers of Life: Critical Watersheds for Protecting Freshwater Biodiversity "
• Getting Our Feet Wet: aquatic Conservation in the Field - Cattle, Cutting, and the Clinch from Troubled Waters: Protecting Our Aquatic Heritage
• Upper Tennesee River Roundtable
• US Army Corps of Engineers
• Institute for Water Resources
• Natural Resource Management Gateway
• Water Resources Gateway
• US Department of Agriculture
  • Stream Corridor Restoration
• US Geological Survey (USGS)
• Daily Streamflow Conditions for Virginia
• Hydrologic Unit Maps
• Real-Time Water Data for Virginia
  • NWISWeb - Water-Quality Data for the Nation
  • NWISWeb Data for Virginia
  • Real-Time Data for Virginia: Streamflow
• The Quality of Our Nation's Waters, U.S. Geological Survey Circular 1225
• Water Quality in the Albemarle-Pamlico Drainage Basin, North Carolina and Virginia, 1992-95, U.S. Geological Survey Circular 1157
• Water Quality in the Potomac River Basin, Maryland, Pennsylvania, Virginia, West Virginia, and the District of Columbia, 1992-96, U.S. Geological Survey Circular 1166
• Water Resources of Virginia
• Water Science for Schools
• Water Use in the United States
• Water Watch
• What percentage of Virginia is water? How does that compare to other states...
• Virginia Association of Soil & Water Conservation Districts
• Soil & Water Conservation Districts Listed by County/City (why would Arlington County and 24 independent cities not be in a soil and water conservation district?)
• Virginia Coast Reserve: Long-Term Ecological Research
• Virginiaconservation.org
• Virginia Department of Conservation and Recreation - Soil and Water Conservation Programs
• Virginia's Dam Safety Program
• Virginia's Floodplain Management Program
• Virginia's Erosion and Sediment (E&S) Control Program
• Virginia Department of Environmental Quality - Water Programs
• Virginia Department of Health
  • Fishing Restrictions And Health Advisories In Effect For Virginia Rivers
• Virginia Institute of Marine Science
  • Effects of Hurricane Floyd on the York and Pamunkey Rivers
• Virginia River and Watershed Groups
• Virginia Save Our Streams
• Virginia Tides and Benchmarks
• Virginia Transportation Research Council
  • Constructed Wetlands for Stormwater Management (VTRC Report No. 98-R35)
  • Controlling Highway Runoff Pollution in Watersheds Supplying Drinking Water Reservoirs (VTRC Report No. 00-R7)
  • Testing of Ultra-Urban Best Management Practices (VTRC Report No. 01-R7)
• Virginia Water Resources Research Center
• Watershed Radio
• Watersheds - Where the Atmosphere Meets the Earth

References

groins on James River, to reduce erosion
at Fort Boykin (Isle of Wight County)