Water in the ground seeps into the drainages. When it quits raining, streams do not dry up immediately. It can follow the Roanoke River watershed to Albemarle/Pamlico Sound, or the James River/Potomac River watersheds to the Chesapeake Bay. When the clouds move just a little further to the north or east, the rainfall will run downhill in the other direction. They do not 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. 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.Ī map of the hydrography of Virginia shows the rivers run in different directions. The New River is unique because it continued to flow through its old channel, and cut through the Appalachian Mountains as they rose. Most Virginia rivers were redirected by the Appalachian Orogeny, 300 million years ago, and subsequent creation of the Atlantic Ocean. The New River was flowing even before the continents smashed into each other 300 million years ago, before "thundering lizards" left their dinosaur tracks in the sandstones of Triassic Basins. Virginia's rivers have been carrying sediments downstream, reshaping the surface of the state, for eons. Today the Blue Ridge and Allegheny Front are the primary topographic features directing water towards the east or west. Source: US Geological Survey (USGS), Richmond 1:24,000 scale topographic map (2010) John's Church on March 23, 1775, is on the high ground (watershed divide) between Shockoe Creek and Stony Run/Gillie Creek In another billion years, old mountains will be flattened by erosion, new mountains will be uplifted by tectonic forces, and rivers will move their channels as the perpetual process of erosion continues to reshape the landscape.Ĭhurch Hill in Richmond, site of Patrick Henry's Give Me Liberty or Give Me Death speech at St. What we see today is a brief snapshop, in geologic time. 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. Source: US Geological Survey (USGS), Reference and Outline Maps of the United States - Rivers and Lakes Rivers and Watersheds of Virginia Rivers and Watersheds of Virginia
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