Potomac River
The
Potomac River flows into the
Chesapeake Bay, located along the mid-
Atlantic coast of the
United States (USA). The
river is approximately 413
statute miles (665
km) long, with a drainage area of about 14,700 square miles (38,000 km²). In terms of area, this makes the Potomac River the fourth largest river along the Atlantic coast of the USA and the 21st largest in the USA. Over 5 million people live within the Potomac
watershed, where
precipitation provides the equivalent of over 8 m³ (more than 2,100 US
gallons) of water per person per year.
 |
Potomac River watershed |
The river forms part of the borders between
Maryland and
Washington, D.C. (the
District of Columbia) on the left bank and
West Virginia and
Virginia on the river's right bank. The entire lower Potomac River is considered part of Maryland, with the exception of a small tidal portion within the District of Columbia. Except for a small portion of its headwaters in West Virginia, the
North Branch Potomac River is considered part of Maryland to the low water mark on the opposite bank. The
South Branch Potomac River lies completely within the state of West Virginia except for its
headwaters, which lie in Virginia.
The Potomac River runs 383 miles (616 km) from the
Fairfax Stone in West Virginia to
Point Lookout, Maryland and drains 14,679 sqare miles (38,018 km²). The average flow is 4.86 million US gallons per minute (306.6 thousand liters per second). The largest flow ever recorded on the Potomac at Washington, D.C. was in March 1936 when it reached 275 billion US gallons per day (12 million L/s). The lowest flow ever recorded at the same location was 388 million gallons per day (17 thousand L/s) in September 1966.
The river has two sources. The source of the North Branch is at the
Fairfax Stone located at the junction of
Grant,
Tucker,
Preston counties in
West Virginia. The source of the South Branch is located near
Hightown in northern
Highland County, Virginia. The river's two branches converge just east of
Green Spring in
Hampshire County, West Virginia to form the Potomac.
Once the Potomac drops from the
Piedmont to the
Coastal Plain,
tides further influence the river as it passes through Washington, D.C. and beyond.
Salinity in the Potomac River
Estuary increases thereafter with distance downstream. The estuary also widens, reaching 11 statute miles (17 km) wide at its mouth, between Point Lookout, Maryland and
Smith Point, Virginia before flowing into the Chesapeake Bay.
The name
Potomac is a European spelling of an
Algonquian name which supposedly means "river of swans." Other accounts say the name means "place where people trade" or "the place to which tribute is brought" and that the name translated as "river of swans" was another word,
Cohongorooton. The spelling of the name has been simplified over the years from
Patawomeke to
Patowmack in the 18th century and now
Potomac. The river's name was officially decided upon as Potomac by the
Board on Geographic Names in 1931.
The Potomac River brings together a variety of cultures throughout the watershed from the coal miners of upstream West Virginia to the urban residents of the nation's capital and, along the lower Potomac, the watermen of Virginia's Northern Neck.
Being situated in an area rich in
American history and American heritage has led to the Potomac being nicknamed "the Nation's River."
George Washington, the first
President of the United States, was born in, surveyed, and spent most of his life within the Potomac basin. All of Washington, D.C., the nation's
capital city, also lies within the watershed. The 1859 siege of
Harper's Ferry at the river's
confluence with the
Shenandoah was a precursor to numerous epic battles of the
American Civil War in and around the Potomac and its tributaries. General
Robert E. Lee crossed the river, thereby invading the North and threatening Washington, D.C. twice in campaigns climaxing in the battles of
Antietam and
Gettysburg.
The
Patowmack Canal was intended by George Washington to connect the
Tidewater near
Georgetown with
Cumberland, Maryland. Started in 1785, it was not completed until 1802. Financial troubles closed the
canal in 1830. The
Chesapeake and Ohio Canal operated along the banks of the Potomac in Maryland from 1850 to 1924 and also connected Cumberland to Washington, D.C. This allowed freight to be transported around the
rapids known as the
Great Falls of the Potomac River, as well as many other, smaller rapids.
With increasing
mining and
agriculture upstream and urban
sewage and
runoff downstream, the
water quality of the Potomac River deteriorated. This created conditions of severe
eutrophication. It is said that President
Abraham Lincoln used to escape to the highlands on summer nights to escape the river's stench. In the 1960s, with dense green
algal blooms covering the river's surface, President
Lyndon Johnson declared the river "a national disgrace" and set in motion a long-term effort to reduce sewage pollution and restore the beauty and ecology of this historic river. By the end of the 20th century, there was notable success, as massive algal blooms vanished and recreational fishing and boating rebounded. Still, the aquatic
habitat of the Potomac River and its tributaries remain vulnerable to eutrophication,
heavy metals,
pesticides and other toxic chemicals, over-fishing,
alien species, and
pathogens associated with
Fecal coliform bacteria and
shellfish diseases. It was designated as one of the
American Heritage Rivers in 1997.
Some commentators have suggested that, as the
Mason-Dixon line demarcated the North/South divide during the 19th Century, so the Potomac has come to separate the Red from the Blue States in 21st Century America [
1][
2][
3][
4][
5].Since 2000, the river has symbolized a political border between Democratic Maryland (the North's southernmost state) and Republican West Virginia and Virginia (the South's northernmost states)[
6]. As of 2006, no Red State lies above the Potomac River on the Eastern Seaboard, nor does any Blue one lie below it[
7].
Despite its status as a political buffer between the Red and the Blue, it has not gained the same kind of notoriety or fame as the Mason-Dixon Line as a cultural feature, likely because it has only acted as a functional boundary for six years, since the 2000 election. Barring some unusual political event (such as former Virginia governor
Mark Warner running for President in 2008), it seems likely that the trend will continue and that the Potomac will remain a sort of geopolitical trench between North and South for the forseeable future.
However, it must be noted that
Northern Virginia, the region located right next to the Potomac on the "red" side, has been voting blue with increasing consistency, notably
Fairfax County,
Arlington, and
Alexandria. Other areas, such as
Loudoun County and
Prince William County, are more conservative, but are rapidly becoming more Democratic. In the 2005 Gubernatorial election, the entire region continued to move away from the Republicans. Fairfax County, Arlington County, the cities of Alexandria,
Fairfax, and
Falls Church, and for the first time, Loudoun County and Prince William County, went to
Tim Kaine, the Democratic candidate for Governor. In 2006, Democrat Mark Herring swept every precinct in the 33rd state Senate District Tuesday, Jan. 31, en route to beating Republican Loudoun County Supervisor Mick Staton by a wide margin of 62 to 38 percent, evidencing Loudoun's transformation into a liberal county.
For 400 years Maryland and Virginia have disputed control of the Potomac and its North Branch, since both states' original colonial charters grant the entire river rather than half of it as is normally the case with boundary rivers. In its first state
constitution adopted in 1776, Virginia ceded its claim to the entire river but reserved free use of it, an act disputed by Maryland. Both states acceded to the Compact of 1785 and the 1877 Black-Jenkins Award which grants Maryland the river bank-to-bank from the low water mark on the Virginia side, while permitting Virginia full riparian rights short of obstructing navigation.
From 1957 to 1996, the Maryland Department of the Environment (MDE) routinely issued permits applied for by Virginia entities concerning use of the Potomac, however, in 1996 the MDE denied a permit applied for by the
Fairfax County Water Authority to build a water intake valve 725 feet offshore, citing potential harm to Maryland's interests by an increase in Virginia sprawl caused by the project. After years of failed appeals within the Maryland government's appeal processes, in 2000 Virginia took the case to the
Supreme Court of the United States, which exercises original jurisdiction in cases between two states. Maryland claimed Virginia lost its riparian rights by acquiescing to MDE's permit process for 63 years (MDE began its permit process in 1933). A Special Master appointed by the Supreme Court to investigate recommended the case be settled in favor of Virginia, citing the language in the 1785 Compact and the 1877 Award. On
December 9,
2003, the Court agreed in a 7-2 decision.
Virginia v. Maryland, 129 S.Ct. 598.The original charters are silent as to which branch from the upper Potomac serves as the boundary, but this was settled by the 1785 Compact. When West Virginia seceded from Virginia in 1863, the question of West Virginia's succession in title to the lands between the branches of the river was raised, as well as title to the river itself. Claims by Maryland to West Virginia land north of the South Branch (all of
Mineral and
Grant Counties and parts of
Hampshire,
Hardy,
Tucker and
Pendleton Counties) and by West Virginia to the Potomac's high water mark were rejected by the Supreme Court in two separate decisions in 1910.
State of Md. v. State of W.Va., 217 U.S. 1 State of Md. v. State of W.Va., 217 U.S. 577The source of the
North Branch Potomac River is at the
Fairfax Stone located at the junction of
Grant,
Tucker and
Preston Counties in West Virginia.
North Branch tributaries
Tributaries are listed in order from the source of the North Branch Potomac River to its mouth.
*
Stony River (West Virginia)
*
Abram Creek (West Virginia)
*
Savage River (Maryland)
*
Georges Creek (Maryland)
*
New Creek (West Virginia)
*
Limestone Run (West Virginia)
*
Wills Creek (Pennsylvania/Maryland)
*
Evitts Creek (Maryland)
*
Patterson Creek (West Virginia)
**
Mill Creek (West Virginia)
*
Dans Run (West Virginia)
*
Green Spring Run (West Virginia)
The
South Branch Potomac River has its
headwaters in northwestern
Highland County, Virginia near
Hightown along the eastern edge of the
Allegheny Front. The mouth of the South Branch lies east of
Green Spring in
Hampshire County, West Virginia where it meets the
North Branch Potomac River to form the Potomac. A
topographic map of the confluence of the North and South Branches can be viewed
here.
South Branch nomenclature
Early pioneer sources claim that the indigenous
Native Americans of the region referred to the South Branch Potomac River as the
Wappatomaka. Other variants of this name throughout the river's history were
South Branch of Potowmac River,
South Branch of the Potowmac River,
South Fork Potomac River,
Wapacomo River,
Wapocomo River,
Wappacoma River,
Wappatomaka River, and
Wappatomica River.
Places settled in the South Branch valley bearing variants of "Wappatomaka" include
Wappacoma plantation built in 1773 and the
unincorporated hamlet of
Wappocomo (sometimes spelled Wapocomo) at
Hanging Rocks, both north of
Romney on
West Virginia State Route 28.
South Branch headwaters and course
The exact location of the South Branch's source is northwest of Hightown along Parkersburg Pike (
U.S. Route 250) on the eastern side of Lantz Mountain (3,934 feet) in Highland County. From Hightown, the South Branch is a small meandering
stream that flows northeast along Crab Bottom Road through the communities of
New Hampden and Crab Bottom. At Forks of Waters, the South Branch joins with Strait Creek and flows north across the Virginia/West Virginia border into
Pendleton County. The river then travels on a northeastern course along the western side of Jack Mountain (4,045 feet), followed by Sandy Ridge (2,297 feet) along
U.S. Route 220. North of the confluence of the South Branch with Smith Creek, the river flows along Town Mountain (2,848 feet) around
Franklin at the junction of U.S. Route 220 and
U.S. Route 33. After Franklin, the South Branch continues north through the
Monongahela National Forest to
Upper Tract where it joins with three sizeable streams: Reeds Creek, Mill Run, and Deer Run. Between Big Mountain (2,582 feet) and Cave Mountain (2,821 feet), the South Branch bends around the Eagle Rock (1,483 feet) outcrop and continues its flow northward into
Grant County. Into Grant, the South Branch follows the western side of Cave Mountain until its confluence with the
North Fork at
Cabins, where it flows east to
Petersburg. At Petersburg, the South Branch is joined with the
South Branch Valley Railroad, which it parallels until its mouth at
Green Spring.
In its eastern course from Petersburg into
Hardy County, the South Branch becomes more navigable allowing for
canoes and smaller river vessels. The river splits and forms a series of large islands while it heads northeast to
Moorefield. At Moorefield, the South Branch is joined by the
South Fork South Branch Potomac River and runs north to
Old Fields where it is fed by Anderson Run and Stony Run. At
McNeill, the South Branch flows into
the Trough where it is bound to its west by
Mill Creek Mountain (2,119 feet) and to its east by Sawmill Ridge (1,644 feet). This area is the habitat to endangered
bald eagles. The Trough passes into
Hampshire County and ends at its confluence with Sawmill Run south of
Glebe and
Sector. The South Branch continues north parallel to
South Branch River Road (
County Route 8) toward
Romney with a number of historic plantation farms adjoining it. En route to Romney, the river is fed by Buffalo Run,
Mill Run, McDowell Run, and
Mill Creek at
Vanderlip. The South Branch is traversed by the
Northwestern Turnpike (
U.S. Route 50) and joined by Sulphur Spring Run where it forms another island to the west of town. Flowing north of Romney, the river still follows the eastern side of Mill Creek Mountain until it creates a horseshoe bend at
Wappocomo's
Hanging Rocks around the George W. Washington plantation,
Ridgedale. To the west of
Three Churches on the western side of
South Branch Mountain (3,028 feet), the South Branch creates a series of bends and flows to the northeast by
Springfield through Blue's Ford. After another horseshoe bend, the South Branch flows under the old
Baltimore and Ohio Railroad mainline between
Green Spring and
South Branch Depot, and joins the North Branch to form the Potomac.
South Branch tributaries
*
Big Run (West Virginia)
*
Lunice Creek (West Virginia)
*
Mill Creek (West Virginia)
*
Mill Run (West Virginia)
*
North Fork South Branch Potomac River (West Virginia/Virginia)
*
South Fork South Branch Potomac River (West Virginia/Virginia)
North Fork South Branch Potomac River
|
The North Fork of the South Branch below Seneca Rocks in Pendleton County, West Virginia |
The
North Fork South Branch Potomac River forms just north of the Virginia/West Virginia border in
Pendleton County at the confluence of the Laurel Fork and Straight Fork along Big Mountain (3,881 feet). From
Circleville, the North Fork flows northeast through Pendleton County between the Fore Knobs (2,949 feet) to its west and the River Knobs (2,490 feet) to its east. At
Seneca Rocks, the North Fork is met by Seneca Creek. From Mouth of Seneca, the North Fork continues to flow northeast along the western edge of North Fork Mountain (3,389 feet) into
Grant County. Flowing east through North Fork Gap, the North Fork joins the South Branch Potomac at the town of
Cabins, west of
Petersburg.
South Fork South Branch Potomac River
The
South Fork South Branch Potomac River forms just north of
U.S. Route 250 in
Highland County,
Virginia near
Head Waters and empties into the South Branch Potomac River at
Moorefield in
Hardy County,
West Virginia.
This stretch encompasses the stretch of the Potomac River from the
confluence of the North and South Branches to the
Great Falls of the Potomac River at
Great Falls, Virginia.
Upper Potomac tributaries
*Above the fall-line
**
North Branch Potomac River (Maryland/West Virginia)
**
South Branch Potomac River (West Virginia/Virginia)
**
Little Cacapon River (West Virginia)
***
North Fork Little Cacapon River (West Virginia)
***
South Fork Little Cacapon River (West Virginia)
**
Cacapon River (West Virginia)
***
Capon Springs Run (West Virginia)
***
Dillons Run (West Virginia)
***
Edwards Run (West Virginia)
***
Lost River (West Virginia)
***
Mill Branch (West Virginia)
***
North River (West Virginia)
****
Grassy Lick Run (West Virginia)
****
Tearcoat Creek (West Virginia)
**
Sir Johns Run (West Virginia)
**
Sleepy Creek (West Virginia/Virginia)
***
Meadow Branch (West Virginia)
**
Cherry Run (West Virginia)
**
Back Creek (West Virginia/Virginia)
***
Tilhance Creek (West Virginia)
**
Opequon Creek (West Virginia/Virginia)
***
Middle Creek (West Virginia)
***
Mill Creek (West Virginia/Virginia)
***
Tuscarora Creek (West Virginia)
**
Antietam Creek (Pennsylvania/Maryland)
**
Shenandoah River (West Virginia/Virginia)
***
North Fork Shenandoah River (Virginia)
****
Cedar Creek (Virginia)
***
South Fork Shenandoah River (Virginia)
**
Catoctin Creek (Virginia)
**
Catoctin Creek (Maryland)
**
Monocacy River (Maryland)
**
Seneca Creek (Maryland)
**
Difficult Run (Virginia)
**Dead Run (Virginia)
**Little Falls Creek (Maryland)
**
Pimmit Run (Virginia)
|
The Pentagon, looking northeast with the Potomac in the distance. |
The Tidal or Lower Potomac River lies below the
Fall Line. This stretch encompasses the Potomac from about one mile below the Washington, DC - Maryland line, just below the
Little Falls of the Potomac River where the tidal river begins, to the
Chesapeake BayTidal Potomac tributaries
*Donaldson Run (Virginia)
*Windy Run (Virginia)
*
Spout Run (Virginia)
*
Rock Creek (DC/Maryland)
*
Tiber Creek (DC) (paved over)
*Rocky Run (Virginia) (paved over)
*
Washington Channel (DC)
*
Anacostia River (DC/Maryland)
**
Northwest Branch Anacostia River (Maryland)
***
Sligo Creek (Maryland)
**
Northeast Branch Anacostia River (Maryland)
*
Four Mile Run (Virginia)
*
Piscataway Creek (Maryland)
*
Occoquan River (Virginia)
**
Bull Run (Virginia)
**Broad Run (Virginia)
**Cedar Run (Virginia)
*
Neabsco Creek (Virginia)
*
Mattawoman Creek (Maryland)
*
Quantico Creek (Virginia)
*
Aquia Creek (Virginia)
*
Nanjemoy Creek (Maryland)
*
Port Tobacco River (Maryland)
*
Wicomico River (Maryland)
*
Popes Creek (Virginia)
*St. Clements Bay (Maryland)
*Breton Bay (Maryland)
*
St. Marys River (Maryland)
*
Yeocomico River (Virginia)
*
Hull Creek (Virginia)
*
List of cities and towns along the Potomac River*
List of crossings of the Potomac River*
List of islands on the Potomac River*
List of tributaries of the Potomac River*
List of variant names of the Potomac River*
List of Maryland rivers*
List of Virginia rivers*
List of West Virginia rivers*
Arakawa River, the Potomac's
sister river*
Advanced Hydrologic Prediction Service -
Baltimore/Washington (Sterling, VA) - including Potomac River levels
**Potomac River level at
Williamsport**Potomac River level at
Harpers Ferry**Potomac River level at
Point of Rocks**Potomac River level at
Little Falls**Potomac River level at
Wisconsin Avenue*
Interstate Commission on the Potomac River Basin (ICPRB) *
Potomac Conservancy*
Potomac Heritage National Scenic Trail*
Potomac Riverkeeper*
Potomac Watershed Partnership*
Potomac Watershed Roundtable*
Prince William Conservation Alliance*
Stewards of the Potomac Highlands*
West Virginia Division of Natural Resources
