158-582: Lady Bird Johnson Park , formerly known as Columbia Island until 1968, is an island located in the Potomac River in Washington, D.C. , in the United States. It formed naturally as an extension of Analostan Island in the latter part of the 1800s, and over time erosion and flooding severed it from Analostan, now known as Theodore Roosevelt Island. The U.S. federal government deposited material dredged from
316-539: A drainage area of 14,700 square miles (38,000 km ), and is the fourth-largest river along the East Coast of the United States . More than 6 million people live within its watershed . The river forms part of the borders between Maryland and Washington, D.C. , on the left descending bank, and West Virginia and Virginia on the right descending bank. Except for a small portion of its headwaters in West Virginia,
474-668: A European spelling of Patawomeck , the Algonquian name of a Native American village on its southern bank. Native Americans had different names for different parts of the river, calling the river above Great Falls Cohongarooton , meaning "honking geese" and "Patawomke" below the Falls, meaning "river of swans". In 1608, Captain John Smith explored the river now known as the Potomac and made drawings of his observations which were later compiled into
632-414: A breach may experience flooding similar to a natural event, while damage near a breach can be catastrophic, including carving out deep holes and channels in the nearby landscape. Under natural conditions, floodwaters return quickly to the river channel as water-levels drop. During a levee breach, water pours out into the floodplain and moves down-slope where it is blocked from return to the river. Flooding
790-400: A controlled inundation by the military or a measure to prevent inundation of a larger area surrounded by levees. Levees have also been built as field boundaries and as military defences . More on this type of levee can be found in the article on dry-stone walls . Levees can be permanent earthworks or emergency constructions (often of sandbags ) built hastily in a flood emergency. Some of
948-600: A distance of some 610 km (380 mi). The scope and scale of the Mississippi levees has often been compared to the Great Wall of China . The United States Army Corps of Engineers (USACE) recommends and supports cellular confinement technology (geocells) as a best management practice. Particular attention is given to the matter of surface erosion, overtopping prevention and protection of levee crest and downstream slope. Reinforcement with geocells provides tensile force to
1106-422: A dyke may be a drainage ditch or a narrow artificial channel off a river or broad for access or mooring, some longer dykes being named, e.g., Candle Dyke. In parts of Britain , particularly Scotland and Northern England , a dyke may be a field wall, generally made with dry stone . The main purpose of artificial levees is to prevent flooding of the adjoining countryside and to slow natural course changes in
1264-628: A gateway to Washington. The two bodies agreed to a proposal by urban planner C.A.S. Sinclair, who proposed a series of roads radiating outward from the Virginia end of the bridge. However, in December 1926, the CFA learned that Arlington National Cemetery was likely to expand eastward onto the property of the USDA Experimental Farm (which lay east of Arlington Ridge Road ). Because this significantly impacted
1422-472: A grove of hundreds of white pine and dogwood trees among the grass fields. The memorial was dedicated on April 6, 1976. The Boundary Channel of the Potomac River separates Lady Bird Johnson Park from the Virginia shoreline, while the main stream of the Potomac surrounds the island on the other three sides. As of 2007, the island consisted of 121 acres (490,000 m) of landscaped parkland. Located within
1580-444: A high suspended sediment fraction and thus are intimately associated with meandering channels, which also are more likely to occur where a river carries large fractions of suspended sediment. For similar reasons, they are also common in tidal creeks, where tides bring in large amounts of coastal silts and muds. High spring tides will cause flooding, and result in the building up of levees. Both natural and man-made levees can fail in
1738-602: 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 (923 m), the South Branch creates a series of bends and flows to the northeast by Springfield through Blue's Ford. After two additional horseshoe bends (meanders), the South Branch flows under the old Baltimore and Ohio Railroad mainline between Green Spring and South Branch Depot , and joins
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#17328554764081896-485: A map and published in London in 1612. This detail from that map shows his rendition of the river that the local tribes had told him was called the "Patawomeck". The spelling of the name has taken many forms over the years from " Patawomeck " (as on Captain John Smith 's map) to "Patomake", "Patowmack", and numerous other variations in the 18th century and now "Potomac". The river's name was officially decided upon as "Potomac" by
2054-661: A northeastern course along the western side of Jack Mountain (4,045 ft), followed by Sandy Ridge (2,297 ft) along U.S. Route 220 . North of the confluence of the South Branch with Smith Creek, the river flows along Town Mountain (2,848 ft) 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 ft) and Cave Mountain (2,821 ft),
2212-503: 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 Valley View Island to the west of town. Flowing north of Romney, the river still follows the eastern side of Mill Creek Mountain until it creates
2370-428: A number of ways. Factors that cause levee failure include overtopping, erosion, structural failures, and levee saturation. The most frequent (and dangerous) is a levee breach . Here, a part of the levee actually breaks or is eroded away, leaving a large opening for water to flood land otherwise protected by the levee. A breach can be a sudden or gradual failure, caused either by surface erosion or by subsurface weakness in
2528-754: A property-boundary marker or drainage channel. Where it carries a stream, it may be called a running dike as in Rippingale Running Dike , which leads water from the catchwater drain , Car Dyke, to the South Forty Foot Drain in Lincolnshire (TF1427). The Weir Dike is a soak dike in Bourne North Fen , near Twenty and alongside the River Glen , Lincolnshire . In the Norfolk and Suffolk Broads ,
2686-519: A ridge and increasing the river channel's capacity. Alternatively, levees can be artificially constructed from fill , designed to regulate water levels. In some circumstances, artificial levees can be environmentally damaging . Ancient civilizations in the Indus Valley , ancient Egypt, Mesopotamia and China all built levees. Today, levees can be found around the world, and failures of levees due to erosion or other causes can be major disasters, such as
2844-796: A role in Mike Lawson's The Second Perimeter , and in Phil Little and Brad Whittington's Hell in a Briefcase. Potomac River The Potomac River ( / p ə ˈ t oʊ m ə k / ) is a major river in the Mid-Atlantic region of the United States that flows from the Potomac Highlands in West Virginia to the Chesapeake Bay in Maryland . It is 405 miles (652 km) long, with
3002-412: A shorter route to the ocean and begin building a new delta. Wave action and ocean currents redistribute some of the sediment to build beaches along the coast. When levees are constructed all the way to the ocean, sediments from flooding events are cut off, the river never migrates, and elevated river velocity delivers sediment to deep water where wave action and ocean currents cannot redistribute. Instead of
3160-421: A shorter time interval means higher river stage (height). As more levees are built upstream, the recurrence interval for high-water events in the river increases, often requiring increases in levee height. During natural flooding, water spilling over banks rises slowly. When a levee fails, a wall of water held back by the levee suddenly pours out over the landscape, much like a dam break. Impacted areas far from
3318-649: A water intake 725 feet (220 m) 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
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#17328554764083476-447: A waterway to provide reliable shipping lanes for maritime commerce over time; they also confine the flow of the river, resulting in higher and faster water flow. Levees can be mainly found along the sea, where dunes are not strong enough, along rivers for protection against high floods, along lakes or along polders . Furthermore, levees have been built for the purpose of impoldering, or as a boundary for an inundation area. The latter can be
3634-606: A wavy green granite base, the statue stood atop a concrete plinth. In May 1934, the commission overseeing the memorial's construction asked the Works Progress Administration for a $ 100,000 grant to complete the granite steps. But no funds were forthcoming. Finally, funding for the memorial's completion began moving through Congress. With congressional support, the Works Progress Administration gave $ 39,000 to finish memorial in 1939. This included adding
3792-669: A year passed before the CFA approved pylon designs for Columbia Island in March 1929. But the great plaza and roads on the island needed further study. Work on the Boundary Channel Bridge began in the spring of 1929, but immediately ran into problems. An unstable rock shelf 13 feet (4.0 m) thick lay under the western abutment of the Arlington Memorial Bridge. This "rotten rock" had not been revealed by borings two years earlier, but now came to light as construction began on
3950-537: Is electrical resistivity tomography (ERT). This non-destructive geophysical method can detect in advance critical saturation areas in embankments. ERT can thus be used in monitoring of seepage phenomena in earth structures and act as an early warning system, e.g., in critical parts of levees or embankments. Large scale structures designed to modify natural processes inevitably have some drawbacks or negative impacts. Levees interrupt floodplain ecosystems that developed under conditions of seasonal flooding. In many cases,
4108-579: Is 302 mi (486 km). The river has two sources. The source of the North Branch is at the Fairfax Stone located at the junction of Grant , Tucker , and 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
4266-429: Is an elevated ridge , natural or artificial, alongside the banks of a river , often intended to protect against flooding of the area adjoining the river. It is usually earthen and often runs parallel to the course of a river in its floodplain or along low-lying coastlines. Naturally occuring levees form on river floodplains following flooding, where sediment and alluvium is deposited and settles, forming
4424-456: Is at least 3.5 million years old, likely extending back ten to twenty million years before the present when the Atlantic Ocean lowered and exposed coastal sediments along the fall line. This included the area at Great Falls, which eroded into its present form during recent glaciation periods. The stream gradient of the entire river is 0.14%, a drop of 930 m over 652 km. "Potomac" is
4582-546: Is below mean sea level. These typically man-made hydraulic structures are situated to protect against erosion. They are typically placed in alluvial rivers perpendicular, or at an angle, to the bank of the channel or the revetment , and are used widely along coastlines. There are two common types of spur dyke, permeable and impermeable, depending on the materials used to construct them. Natural levees commonly form around lowland rivers and creeks without human intervention. They are elongated ridges of mud and/or silt that form on
4740-965: Is currently re-bounding as a result of the ICPRB 's successful "American Shad Restoration Project" that was begun in 1995. In addition to stocking the river with more than 22 million shad fry, the Project supervised the construction of a fishway that was built to facilitate the passage of adults around the Little Falls Dam on the way to their traditional spawning grounds upstream. *denotes naturalized species; Sources: Striped mullet Mugil cephalus Spot Leiostomus xanthurus Spotted seatrout Cynoscion nebulosus Atlantic Croaker Micropogonias undulatus Levee A levee ( / ˈ l ɛ v i / or / ˈ l ɛ v eɪ / ), dike ( American English ), dyke ( British English ; see spelling differences ), embankment , floodbank , or stop bank
4898-537: 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 ft) and to its east by Sawmill Ridge (1,644 ft). This area is the habitat to 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
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5056-420: Is important in order to design stable levee and floodwalls . There have been numerous studies to investigate the erodibility of soils. Briaud et al. (2008) used Erosion Function Apparatus (EFA) test to measure the erodibility of the soils and afterwards by using Chen 3D software, numerical simulations were performed on the levee to find out the velocity vectors in the overtopping water and the generated scour when
5214-451: Is permanently diverted through the gap. Sometimes levees are said to fail when water overtops the crest of the levee. This will cause flooding on the floodplains, but because it does not damage the levee, it has fewer consequences for future flooding. Among various failure mechanisms that cause levee breaches, soil erosion is found to be one of the most important factors. Predicting soil erosion and scour generation when overtopping happens
5372-573: Is prolonged over such areas, waiting for floodwater to slowly infiltrate and evaporate. Natural flooding adds a layer of sediment to the floodplain. The added weight of such layers over many centuries makes the crust sink deeper into the mantle , much like a floating block of wood is pushed deeper into the water if another board is added on top. The momentum of downward movement does not immediately stop when new sediment layers stop being added, resulting in subsidence (sinking of land surface). In coastal areas, this results in land dipping below sea level,
5530-402: 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 pollution from sewage and restore the beauty and ecology of this historic river. One of
5688-511: The Board on Geographic Names in 1931. The similarity of the name to the Ancient Greek word for river, potamos , has been noted for more than two centuries but it appears to be due to chance. 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,
5846-632: The Confederacy , and the Union's largest army, the Army of the Potomac , was named after the river. The Potomac River runs 405 mi (652 km) from Fairfax Stone Historical Monument State Park in West Virginia on the Allegheny Plateau to Point Lookout , Maryland, and drains 14,679 sq mi (38,020 km ). The length of the river from the junction of its North and South Branches to Point Lookout
6004-1404: The Fall Line . This 108-mile (174-km) stretch encompasses the Potomac from a short distance below the Washington, DC - Montgomery County line, just downstream of the Little Falls of the Potomac River , to the Chesapeake Bay . Along the way the following tributaries drain into the Potomac: Pimmit Run , Gulf Branch , Donaldson Run , Windy Run , Spout Run , Maddox Branch , Foundry Branch , Rock Creek , Rocky Run, Tiber Creek , Roaches Run, Washington Channel , Anacostia River , Four Mile Run , Oxon Creek , Hunting Creek , Broad Creek , Henson Creek, Swan Creek, Piscataway Creek , Little Hunting Creek , Dogue Creek , Accotink Creek , Pohick Creek , Pomonkey Creek , Occoquan River , Neabsco Creek , Powell's Creek , Mattawoman Creek , Chicamuxen Creek , Quantico Creek , Little Creek , Chopawamsic Creek , Tank Creek , Aquia Creek , Potomac Creek , Nanjemoy Creek , Chotank Creek , Port Tobacco River , Popes Creek , Gambo Creek , Clifton Creek , Piccowaxen Creek , Upper Machodoc Creek , Wicomico River , Cobb Island , Monroe Creek , Mattox Creek , Popes Creek , Breton Bay, Leonardtown , St. Marys River , Yeocomico River , Coan River , and Hull Creek . The river itself
6162-547: The George Washington Memorial Parkway and administered by the National Park Service . Columbia Island is in part natural, and in part man-made. Columbia Island did not exist in 1818 and at that time, Analostan Island (now known as Theodore Roosevelt Island ) was largely rock and quite close to the D.C. shoreline. Due to deforestation and increased agricultural use upstream, the river eroded much of
6320-545: The Interstate Commission on the Potomac River Basin . The compact was amended in 1970 to include coordination of water supply issues and land use issues related to water quality. Beginning in the 19th century, 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
6478-567: The Neoclassical mall and bridge to the informal landscaping of Arlington National Cemetery. Medary's argument proved persuasive to the CFA, and in late May the commission and Kendall announced a revised treatment in which a great plaza would be built on Columbia Island. From this plaza, roads would lead across the island to bridges which would connect with the proposed Mount Vernon Memorial Parkway and Lee Highway . The traffic circles were eliminated, and Columbia Island would be reshaped to allow for
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6636-512: The Nile Delta on the shores of the Mediterranean . The Mesopotamian civilizations and ancient China also built large levee systems. Because a levee is only as strong as its weakest point, the height and standards of construction have to be consistent along its length. Some authorities have argued that this requires a strong governing authority to guide the work and may have been a catalyst for
6794-572: 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. All navigable parts of the river were designated as a National Recreation Trail in 2006, and the National Oceanic and Atmospheric Administration designated an 18-square-mile (47 km ) portion of
6952-597: The US Geological Survey and the Fish and Wildlife Service , began to identify fish in the Potomac and tributaries that exhibited "intersex" characteristics, as a result of endocrine disruption caused by some form of pollution. On November 13, 2007, the Potomac Conservancy, an environmental group, issued the river a grade of "D-plus", citing high levels of pollution and the reports of " intersex " fish. Since then,
7110-547: The 1980s, through sewage plant upgrades and restrictions on phosphorus in detergents. By the end of the 20th century, notable success had been achieved, 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. In 2005 two federal agencies,
7268-557: The 200-acre (810,000 m) island had risen to 22 feet (7 m) feet above water. The following month, work began on the engineering and architectural drawings for the Boundary Channel Bridge . This bridge would cross Boundary Channel (which separated Columbia Island from Virginia) to connect Arlington Memorial Bridge with the planned Memorial Drive. Kendall's May 1927 design for Columbia Island generated lengthy debate for two years. Architect Milton Bennett Medary (who left
7426-638: The ABMC and Corps of Engineers, the United States Commission of Fine Arts (CFA) and the National Capital Parks Commission (NCPC) both had authority to approve aspects of the bridge. The CFA had extensive authority to review the look of the bridge. The CFA and NCPC first discussed the bridge approaches in January 1926, when they met jointly to discuss how the Virginia terminus would serve as
7584-610: The AMBC in April 1925 to jointly share the cost of dredging, which involved the removal of 2.5 million cubic feet (71,000 m) of river bottom, and the construction of 2,000 feet (610 m) of seawall and 15,000 feet (4,600 m) of levee. About 40 acres (160,000 m) of Columbia Island was to be removed in order to widen the main Potomac River channel, and the height of the island raised from 6 feet (1.8 m) above average water level to 22 feet (6.7 m) over two years. In addition to
7742-619: The Arlington Memorial Bridge Commission and an officer in the Corps of Engineers, formally opened Memorial Avenue and the Boundary Channel Bridge. (Memorial Avenue was only 30 feet [9 m] wide and unpaved, but the Corps was working to have it widened to 60 feet [18 m] and have it paved by July 1.) The worsening federal budgetary situation nearly led to a complete halt in Columbia Island's development. On April 7, 1932,
7900-619: The Boundary Channel Bridge had come to a standstill. Tracks of the Rosslyn Branch of the Pennsylvania Railroad ran along the Virginia shoreline. In order to avoid an at-grade crossing with Memorial Drive, the CFA proposed in June 1927 that these tracks be lower by 20 feet (6.1 m). Since that meant extending the Boundary Channel Bridge, new engineering studies of the bridge were needed. The Corps and CFA were still studying how to depress
8058-399: The Boundary Channel Bridge were also finished. By the end of June 1930, some additional filling in of Columbia Island was all that was needed to finish the Arlington Memorial Bridge. But no construction had occurred on the Columbia Island great plaza, its monumental columns, or the two pylons as the CFA had still not approved a final design for these. Additionally, work on the western half of
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#17328554764088216-399: The Boundary Channel Bridge. Additionally, a thin layer of sand and gravel was discovered lying atop the bedrock of the eastern abutment of the Boundary Channel Bridge. Both obstacles had to be removed before construction could proceed further. By June 30, 1929, the Arlington Memorial Bridge's western abutment was finished (except for exterior masonry facing), and many of the concrete columns for
8374-543: The Boundary Channel was approved in January 1942. In 1948, the northwesterly bridge connecting Columbia Island to Lee Boulevard (now Arlington Boulevard) was rebuilt. Another bridge linking Columbia Island and Virginia was proposed in 1958. At that time, one possible route for the Theodore Roosevelt Bridge was south of Little Island (the southern tip of Theodore Roosevelt Island which had become detached from
8532-620: The CFA in 1927) wrote to the Commission of Fine Arts in January 1928 after having seen Kendall's proposal. Medary argued that the National Mall ended with the Lincoln Memorial and the two great roads leading from it – the Rock Creek and Potomac Parkway (RCPP) and the Arlington Memorial Bridge. Columbia Island, he said, should reflect a simple, formal dignity that helps ease the transition from
8690-399: The CFA, and Arlington Memorial Bridge consulting engineer W. J. Douglas to restudy the columns. The Washington Post reported that several AMBC and CFA members, as well as member of Congress, were increasingly worried as well about the huge cost of the columns. The columns themselves were estimated to cost at least $ 500,000, with another $ 100,000 needed for their foundations. The CFA took up
8848-515: The Columbia Island great plaza in January 1935, but again could come to no decision. Without funds, little action other than bridge construction or marginal improvements could be made. Improved landscaping designs for the Boundary Channel Bridge were also submitted in January 1935, and approved in March 1936. Seven months later, the CFA began studying the design for the lighting scheme for the Arlington Memorial Bridge, Columbia Island, and Memorial Drive. Minor elements of Columbia Island were completed in
9006-561: The House of Representatives deleted the project's entire $ 840,000 budget for fiscal year 1933 (which began July 1, 1932). Design and other work on the great plaza came to an immediate halt. So did the Corps' final push to fill in the island, as well as all landscaping and road grading. The CFA met in November 1932 to discuss how the incomplete work might be fixed to appear complete or become functional. Franklin D. Roosevelt took office as President of
9164-547: The Humpback Bridge began in January 2008. The bridge, which had not been renovated since its construction, now carried 75,000 vehicles a day – far more than it was designed for. Improvements included widening the bridge, adding balustrades to separate the sidewalks from the vehicular traffic lanes, and building an underpass through the Lady Bird Johnson Park side landing to allow pedestrians and cyclists to pass through
9322-538: The Lincoln Memorial and Arlington House in Arlington National Cemetery. William Kendall, however, was so adamant about retaining the memorial columns that he personally wrote President Hoover (who technically chaired the AMBC) in early October 1931 outlining his reasons for keeping the columns and telling Hoover to move the airport if they interfered with flight. On October 12, Hoover ordered AMBC staff, Kendall,
9480-615: The Mississippi, stretching from Cape Girardeau , Missouri , to the Mississippi delta . They were begun by French settlers in Louisiana in the 18th century to protect the city of New Orleans . The first Louisiana levees were about 90 cm (3 ft) high and covered a distance of about 80 km (50 mi) along the riverside. The U.S. Army Corps of Engineers, in conjunction with the Mississippi River Commission, extended
9638-496: The Mt. Vernon Trail. A children's garden was constructed on Lady Bird Johnson Park in spring 2008. After President Johnson's death in 1973, Brooke Astor and Laurence Vanderbilt began planning a memorial grove in his memory. Johnson loved this park while he was president, and the national memorial was authorized by Congress on December 28, 1973. A grove with a monolith of Texas granite was installed in 1975, along with walking trails and
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#17328554764089796-434: The National Park Service constructed a 300-foot (91 m) footbridge over the Boundary Channel in 1977 to connect a new, 30-car parking lot in the north Pentagon parking area to both. The cost of the footbridge and parking lot was $ 500,000. In spring 1987, the National Park Service repaved the South Washington Boulevard bridge to Lady Bird Johnson Park, and began planning to reconstruct the bridge by 1991. Reconstruction of
9954-601: The North Branch to form the Potomac. This stretch encompasses the section of the Potomac River from the confluence of its North and South Branches through Opequon Creek near Shepherdstown, West Virginia . Along the way the following tributaries drain into the Potomac: North Branch Potomac River , South Branch Potomac River , Town Creek , Little Cacapon River , Sideling Hill Creek , Cacapon River , Sir Johns Run , Warm Spring Run , Tonoloway Creek , Fifteenmile Creek , Sleepy Creek , Cherry Run , Back Creek , Conococheague Creek , and Opequon Creek . This section covers
10112-448: The Pennsylvania Railroad tracks three years later. Informal negotiations had, by the end of June 1930, come to an agreement that the line would be moved closer to the river, and that an underpass through the bridge (accommodating two side-by-side tracks) and the depressed tracks should be constructed first before the railroad took title to the new line. This would permit uninterrupted rail service. The Pennsylvania Railroad also agreed to cede
10270-436: The Potomac River and enlarge Columbia Island, so on April 1, Secretary of War John W. Weeks ordered the expenditure of $ 114,500 to dredge the river between the Highway Bridge and the Lincoln memorial. The dredged material was to be dumped on Columbia Island. To ensure the island could support the bridge, the Corps also planned to construct a 20-foot (6.1 m) levee around the island. The Corps reached an agreement with
10428-449: The Potomac River on the island between 1911 and 1922, and again from 1925 to 1927. The island was also reshaped by the government at this time "to serve as the western terminus of Arlington Memorial Bridge and a symbolic entrance into the nation’s capital." Located within the park are the Lyndon Baines Johnson Memorial Grove , Navy – Merchant Marine Memorial , and the Columbia Island Marina. The island, park, memorials, and marina are part of
10586-405: The Potomac River was repeatedly dredged to deepen the channel and to widen the distance between Analostan/Theodore Roosevelt Island and Columbia Island (so that the "Virginia Channel" west of Analostan/Roosevelt Island would not flood easily). Dredged material was piled high on Columbia Island, helping to build it higher, lengthen and broaden it, and give it its current shape. Filling in of the island
10744-437: 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 1785 Mount Vernon Compact and the 1877 Black-Jenkins Award which granted Maryland
10902-442: The Potomac as its principal source of drinking water with the opening of the Washington Aqueduct in 1864, using a water intake constructed at Great Falls. An average of approximately 486 million US gallons (1,840,000 m ) of water is withdrawn daily from the Potomac in the Washington area for water supply , providing about 78 percent of the region's total water usage, this amount includes approximately 80 percent of
11060-799: The Potomac from just above Harpers Ferry in West Virginia down to Little Falls, Maryland on the border between Maryland and Washington, DC. Along the way the following tributaries drain into the Potomac: Antietam Creek , Shenandoah River , Catoctin Creek (Virginia) , Catoctin Creek (Maryland) , Tuscarora Creek , Monocacy River , Little Monocacy River , Broad Run , Goose Creek , Broad Run , Horsepen Branch, Little Seneca Creek , Tenmile Creek , Great Seneca Creek , Old Sugarland Run, Muddy Branch , Nichols Run, Watts Branch , Limekiln Branch, Carroll Branch, Pond Run, Clarks Branch, Mine Run Branch, Difficult Run , Bullneck Run, Rock Run , Scott Run, Dead Run, Turkey Run, Cabin John Creek , Minnehaha Branch, and Little Falls Branch . The Tidal Potomac River lies below
11218-411: The Potomac, including bass , muskellunge , pike , walleye . The northern snakehead , an invasive species resembling the native bowfin , lamprey , and American eel , was first seen in 2004. Many species of sunfish are also present in the Potomac and its headwaters. Although rare, bull sharks can be found. After having been depressed for many decades, the river's population of American shad
11376-889: The Potomac. As it flows from its headwaters down to the Chesapeake Bay, the Potomac traverses five geological provinces: the Appalachian Plateau , the Ridge and Valley , the Blue Ridge , the Piedmont Plateau , and the Atlantic coastal plain . Once the Potomac drops from the Piedmont to the Coastal Plain at the Atlantic Seaboard fall line at Little Falls , tides further influence
11534-594: The South Branch bends around the Eagle Rock (1,483 ft) outcrop and continues its flow northward into Grant County . Into Grant, the South Branch follows the western side of Cave Mountain through the 20-mile (32 km) long Smoke Hole Canyon , until its confluence with the North Fork at Cabins , where it flows east to Petersburg . At Petersburg, the South Branch Valley Railroad begins, which parallels
11692-584: The Spectrum , S.R. Larson's America Occupied , Allan Leverone's Final Vector , and Mary Eason's Killer Moves . Sean Flannery has mentioned the Columbia Island Marina and the Boundary Channel in his novel Moving Targets , as did Kim Stanley Robinson in his Forty Signs of Rain . Sheri Holman has mentioned the marina and the Pentagon Lagoon in her novel The Mammoth Cheese , and the marina has played
11850-503: 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. 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,
12008-494: The United States in March 1933. Convinced that massive federal spending on public works was essential not only to "prime the pump" of the economy but also to cut unemployment, Roosevelt proposed passage of the National Industrial Recovery Act . The act contained $ 6 billion in public works spending. The act passed on June 13, 1933, and Roosevelt signed it into law on June 16. The Public Works Administration (PWA)
12166-503: The United States into World War II would put significant strain on the local road networks. A new arterial, Army-Navy Boulevard (now called Army-Navy Drive) was under construction to connect Pentagon City and points south to the Pentagon. The road then continued northwest past the Pentagon to Columbia Island, where it was to run up the center of the island and connect with the Arlington Memorial Bridge. A bridge carrying Army-Navy Boulevard over
12324-512: The Virginia side of the river, it was not completed until 1802. Financial troubles led to the closure of the canal in 1830. The Chesapeake and Ohio Canal operated along the banks of the Potomac in Maryland from 1831 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. Washington, D.C. began using
12482-428: The agencies announced that PWA money would be used to construct bridges on the north and south ends of the island in anticipation of links with Lee Highway and a new highway the state of Virginia and Arlington County were discussing constructing in the south. (The southern bridge carrying the parkway became known as the Humpback Bridge because it had a slight rise in its center.) To connect to these bridges, completion of
12640-616: The airports. But no decision was made. By April 1932, work was well under way on relocating the Pennsylvania Railroad tracks. The new, slightly shifted route had been graded, tracks laid, and the western end of Boundary Channel Bridge designed. While there were some delays in completing the railroad underpass, work was well advanced. The formal dedication of the Hemicycle, Memorial Avenue, and Boundary Channel Bridge occurred on April 9. Colonel Ulysses S. Grant III , executive director of
12798-462: The approaches to the bridge, the CFA asked Kendall to restudy Sinclair's proposal for the Columbia Island terminus. Kendall presented the revised design for the street and highway approaches for the Virginia landing in May 1927. His plan was for a series of traffic circles on Columbia Island. By June 30, 1927, dredging of the Potomac River was nearly complete. The reshaping of Columbia Island was finished, and
12956-636: The battles of Antietam (September 17, 1862) and Gettysburg (July 1–3, 1863). Confederate General Jubal Early crossed the river in July 1864 on his attempted raid on the nation's capital. The river not only divided the Union from the Confederacy, but also gave name to the Union's largest army, the Army of the Potomac . The Patowmack Canal was intended by George Washington to connect the Tidewater region near Georgetown with Cumberland , Maryland. Started in 1785 on
13114-497: The bridge and its connection to Arlington National Cemetery essentially finished, Congress hesitated to provide funds for Columbia Island. To cut costs, the CFA deleted the Green Revival temples and the many statues scheduled for Columbia Island. Rather than building extensive roads north and south on the island when no connections were ready to be made, the CFA also agreed that only short segments of these avenues be built adjacent to
13272-411: The bridge on the island's east side, and several larger-than-life Greek Revival and Romanesque Revival statues scattered about the island. Bids for the construction of the Boundary Channel Bridge were opened on July 18, 1928. The project was divided among several contractors. North Carolina Granite Co. provided the below-water granite, Hallowell Granite Works provided the granite for the voussoirs and
13430-477: The bridge rather than crossing the parkway. The reconstruction also removed the notorious "hump" in the middle of the bridge. However, the masonry facing of the bridge was retained to protect the historic character of the bridge. The bridge reconstruction was complete in 2011, and the bike/pedestrian underpass opened in November. The underpass connected the Columbia Island Marina and the LBJ Memorial Grove with
13588-583: The bridge; for the improvement of B Street NW as a new ceremonial avenue to link to the bridge; and for the construction of a roadway (eventually called Memorial Drive ) between the bridge and the main gate of Arlington National Cemetery as well as a new ceremonial entrance at this gate (subsequently known as the Hemicycle ). Preliminary designs for the bridge showed it terminating on Columbia Island, which necessitated expansion of Columbia Island. The United States Army Corps of Engineers already planned to dredge
13746-634: The catastrophic 2005 levee failures in Greater New Orleans that occurred as a result of Hurricane Katrina . Speakers of American English use the word levee , from the French word levée (from the feminine past participle of the French verb lever , 'to raise'). It originated in New Orleans a few years after the city's founding in 1718 and was later adopted by English speakers. The name derives from
13904-416: The catching near Fletcher's Boat House of a Striped Bass estimated to weigh 35 lb (16 kg) was seen as a further indicator of the continuing improvement in the health of the river. The average daily flow during the water years 1931–2018 was 11,498 cubic feet (325.6 m ) /s. The highest average daily flow ever recorded on the Potomac at Little Falls, Maryland (near Washington, D.C.),
14062-619: The city of Vancouver , British Columbia , there are levees (known locally as dikes, and also referred to as "the sea wall") to protect low-lying land in the Fraser River delta, particularly the city of Richmond on Lulu Island . There are also dikes to protect other locations which have flooded in the past, such as the Pitt Polder, land adjacent to the Pitt River , and other tributary rivers. Coastal flood prevention levees are also common along
14220-426: The columns on September 29. Grant agreed that, should an investigation show a hazard, the columns would have to be eliminated. The CFA agreed that street lights should be placed alongside the roads on Columbia Island both as an aid to vehicular traffic and as a means of warning air traffic. But the CFA was adamantly opposed to floodlighting the memorial columns, for they would compete with the softer lighting illuminating
14378-412: The design commission to the firm of McKim, Mead and White , which appointed architect William Mitchell Kendall to be the lead designer. Congress subsequently authorized construction of Kendall's bridge on February 24, 1925. The legislation authorizing construction of the bridge also provided for the construction of approaches (on-ramps, off-ramps, and pedestrian areas) on both the D.C. and Virginia ends of
14536-480: The development of systems of governance in early civilizations. However, others point to evidence of large-scale water-control earthen works such as canals and/or levees dating from before King Scorpion in Predynastic Egypt , during which governance was far less centralized. Another example of a historical levee that protected the growing city-state of Mēxihco-Tenōchtitlan and the neighboring city of Tlatelōlco,
14694-497: The drinking water consumed by the region's estimated 6.1 million residents. As a result of damaging floods in 1936 and 1937, the Army Corps of Engineers proposed the Potomac River basin reservoir projects , a series of dams that were intended to regulate the river and to provide a more reliable water supply. One dam was to be built at Little Falls, just north of Washington, backing its pool up to Great Falls. Just above Great Falls,
14852-572: The earliest levees were constructed by the Indus Valley civilization (in Pakistan and North India from c. 2600 BCE ) on which the agrarian life of the Harappan peoples depended. Levees were also constructed over 3,000 years ago in ancient Egypt , where a system of levees was built along the left bank of the River Nile for more than 1,000 kilometers (600 miles), stretching from modern Aswan to
15010-479: The earth together. On the land side of high levees, a low terrace of earth known as a banquette is usually added as another anti-erosion measure. On the river side, erosion from strong waves or currents presents an even greater threat to the integrity of the levee. The effects of erosion are countered by planting suitable vegetation or installing stones, boulders, weighted matting, or concrete revetments . Separate ditches or drainage tiles are constructed to ensure that
15168-538: The eastern side of Lantz Mountain (3,934 ft) in Highland County. From Hightown, the South Branch is a small meandering stream that flows northeast along Blue Grass Valley Road through the communities of New Hampden and Blue Grass . 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
15326-516: The facing on the piers 10 feet (3.0 m) above mean low water level. The Woodbury Granite Company provided the coping granite and balustrades . Hallowell delivered its granite in May 1929, North Carolina Granite delivered its by June, and Woodbury Granite delivered roughly half its granite by June 30, 1929. The construction contract itself was awarded to the N.P. Severin Company in October 1928. Nearly
15484-886: The foundation does not become waterlogged. Prominent levee systems have been built along the Mississippi River and Sacramento River in the United States , and the Po , Rhine , Meuse River , Rhône , Loire , Vistula , the delta formed by the Rhine, Maas/Meuse and Scheldt in the Netherlands and the Danube in Europe . During the Chinese Warring States period , the Dujiangyan irrigation system
15642-524: The great plaza as late as January 1938, no improvements were made. Memorial Avenue was completed in September 1938. The final elements on Columbia Island were constructed in 1939 and 1940. In April 1939, Congress approved $ 100,000 to build the last connections between the bridges and central traffic circle on the island, as well as build sidewalks, trails, and parking lots and to improve landscaping there. The CFA, after four years of deliberation, finally approved
15800-416: The great plaza. Eliminating the statuary on the island and on the Boundary Channel Bridge saved $ 478,000. Due to settling, additional dredged material was deposited on Columbia Island in October and November 1930. The new goal was to raise the island to 30 feet (9.1 m) above the average water level. There were still problems in designing the final segment of Boundary Channel Bridge in November 1930, but
15958-551: The huge memorial columns planned for Columbia Island would be a risk to aviation. Both bodies ignored him. On September 28, 1931, the United States Department of Commerce told the CFA that the tall columns were a risk to aviation. The Commerce Department said that the columns would seriously interfere with air traffic using Hoover Field, and demanded that the CFA either eliminate the columns or floodlight them brightly. The Washington Board of Trade added its opposition to
16116-450: The impact is two-fold, as reduced recurrence of flooding also facilitates land-use change from forested floodplain to farms. In a natural watershed, floodwaters spread over a landscape and slowly return to the river. Downstream, the delivery of water from the area of flooding is spread out in time. If levees keep the floodwaters inside a narrow channel, the water is delivered downstream over a shorter time period. The same volume of water over
16274-456: The inland coastline behind the Wadden Sea , an area devastated by many historic floods. Thus the peoples and governments have erected increasingly large and complex flood protection levee systems to stop the sea even during storm floods. The biggest of these are the huge levees in the Netherlands , which have gone beyond just defending against floods, as they have aggressively taken back land that
16432-465: The island underwent a natural process of settling . By 1941, settling had damaged the abutments of the Boundary Channel Bridge, and the Bureau of Public Roads placed steel struts under each abutment in April to shore them up. Bridge work on Columbia Island continued in the 1940s. In January 1942, the United States Department of Defense realized that rapid expansion of the Pentagon workforce due to entry of
16590-483: The island. CFA members began to question whether the columns were effective in memorializing the reunited North and South, although there was still agreement that they were integral to the great plaza's design. Nonetheless, Kendall was asked to restudy the issue yet again. Additionally, by now the Great Depression was having a severe and negative impact on funding for the entire Arlington Memorial Bridge project. With
16748-482: The issue at its regular meeting in early November. But when CFA members expressed skepticism about the issue, Senator Hiram Bingham (an aviation enthusiast) began organizing aviation interests to oppose them. Bingham also threatened to introduce legislation in Congress to bar any aviation hazards from being erected in the D.C. area. On November 27, 40 postal and air transport pilots wrote to President Hoover demanding that
16906-620: The junction of Grant , Tucker and Preston counties in West Virginia. From the Fairfax Stone, the North Branch Potomac River flows 27 mi (43 km) to the man-made Jennings Randolph Lake , an impoundment designed for flood control and emergency water supply. Below the dam, the North Branch cuts a serpentine path through the eastern Allegheny Mountains. First, it flows northeast by the communities of Bloomington , Luke , and Westernport in Maryland and then on by Keyser , West Virginia to Cumberland , Maryland. At Cumberland,
17064-549: The laboratory tests, empirical correlations related to average overtopping discharge were derived to analyze the resistance of levee against erosion. These equations could only fit to the situation, similar to the experimental tests, while they can give a reasonable estimation if applied to other conditions. Osouli et al. (2014) and Karimpour et al. (2015) conducted lab scale physical modeling of levees to evaluate score characterization of different levees due to floodwall overtopping. Another approach applied to prevent levee failures
17222-460: The lamppost design for the island in January 1940. The last major improvement to the island came in September 1940, when a "racetrack" feature – a larger outer traffic circle – was constructed to handle the rapidly increasing north–south traffic on the island. This permitted north–south motorists to avoid the bottleneck at the traffic circle (which now largely handled just east–west traffic). With filling operations on Columbia Island suspended in 1932,
17380-410: The last years of the 1930s. A second northern bridge, designed to link with Lee Boulevard (now known as Arlington Boulevard ) was approved in 1937. The Joseph A. LaVezza & Sons construction company immediately began work on the $ 24,875 bridge. This new bridge, and (at last) the bridge over the Pennsylvania Railroad tracks were completed in July. Although the CFA continued to confer on plans concerning
17538-523: The levee system beginning in 1882 to cover the riverbanks from Cairo, Illinois to the mouth of the Mississippi delta in Louisiana. By the mid-1980s, they had reached their present extent and averaged 7.3 m (24 ft) in height; some Mississippi levees are as high as 15 m (50 ft). The Mississippi levees also include some of the longest continuous individual levees in the world. One such levee extends southwards from Pine Bluff , Arkansas , for
17696-420: The levee. A breach can leave a fan-shaped deposit of sediment radiating away from the breach, described as a crevasse splay . In natural levees, once a breach has occurred, the gap in the levee will remain until it is again filled in by levee building processes. This increases the chances of future breaches occurring in the same location. Breaches can be the location of meander cutoffs if the river flow direction
17854-468: The levees in the area, created for the purpose of farming the fertile tidal marshlands. These levees are referred to as dykes. They are constructed with hinged sluice gates that open on the falling tide to drain freshwater from the agricultural marshlands and close on the rising tide to prevent seawater from entering behind the dyke. These sluice gates are called " aboiteaux ". In the Lower Mainland around
18012-533: The main channel, this will make levee overtopping more likely again, and the levees can continue to build up. In some cases, this can result in the channel bed eventually rising above the surrounding floodplains, penned in only by the levees around it; an example is the Yellow River in China near the sea, where oceangoing ships appear to sail high above the plain on the elevated river. Levees are common in any river with
18170-518: The main island due to erosion). District of Columbia officials asked permission in January 1958 to build a small approach bridge to the Roosevelt span over Boundary Channel, but the CFA refused a month later. By June 1958, the bridge's location had shifted north to the southern end of Theodore Roosevelt Island, making a bridge over Boundary Channel moot. In 1958, the northwestern bridge linking Columbia Island to Arlington Boulevard (the former Lee Boulevard)
18328-445: The majority of The Lake being drained in the 17th century. Levees are usually built by piling earth on a cleared, level surface. Broad at the base, they taper to a level top, where temporary embankments or sandbags can be placed. Because flood discharge intensity increases in levees on both river banks , and because silt deposits raise the level of riverbeds , planning and auxiliary measures are vital. Sections are often set back from
18486-454: The much larger Seneca Dam was proposed whose reservoir would extend to Harpers Ferry. Several other dams were proposed for the Potomac and its tributaries. Operational Non-Operational Planned, but never built When detailed studies were issued by the Corps in the 1950s, they met sustained opposition, led by U.S. Supreme Court Justice William O. Douglas , resulting in the plans' abandonment. The only dam project that did get built
18644-633: The nation's capital was to be located on the river. 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, such as the 1861 Battle of Ball's Bluff and the 1862 Battle of Shepherdstown . General Robert E. Lee crossed the river, thereby invading the North and threatening Washington, D.C., twice in campaigns climaxing in
18802-589: The new parkway alignment with the old. Veterans of the United States Navy and the United States Merchant Marine had long argued that there was no memorial commemorating their service anywhere in Washington, D.C. Congress rectified this in the 1920s, and a memorial designed by 1922. However, fund-raising for the memorial took far longer than expected. Ground on Columbia Island for the memorial
18960-482: The northern bank and widened the gap between Analostan Island and the shore and simultaneously large deposits of silt built up around Analostan Island. By 1838, Analostan had almost doubled in length toward the south and by 1884, the new southern part of Analostan Island was defined and built up, and supported a well-established wetland . However, the river gradually eroded the center of Analostan Island, severing Columbia Island from its parent body. Between 1911 and 1922,
19118-702: The north–south roadway to pass along the axis of the island. The great plaza was intended to contain two 166-foot (51 m) high columns representing the Union and the South . The two columns were to be surmounted by gold statues of Nike . Additionally, the CFA concluded that there should be two 40-foot (12 m) high pylons at both the eastern and western ends of the bridge. These pylons were to be inscribed with bas-relief images representing national accomplishments, and topped by statues of golden eagles. Kendall's design also included two large, round Greek Revival temples close to
19276-399: The ocean migrating inland, and salt-water intruding into freshwater aquifers. Where a large river spills out into the ocean, the velocity of the water suddenly slows and its ability to transport sand and silt decreases. Sediments begin to settle out, eventually forming a delta and extending to the coastline seaward. During subsequent flood events, water spilling out of the channel will find
19434-422: The old right-of-way to the government once the new tracks and tunnel were operational. Otherwise, construction on the Boundary Channel Bridge was complete. The CFA again considered designs for the Columbia Island plaza in July 1930. Repairs to the levees on Columbia Island were made that same month. In September, the CFA reviewed but did not approve designs for the memorial columns, and for additional landscaping on
19592-484: The overtopping water impinges the levee. By analyzing the results from EFA test, an erosion chart to categorize erodibility of the soils was developed. Hughes and Nadal in 2009 studied the effect of combination of wave overtopping and storm surge overflow on the erosion and scour generation in levees. The study included hydraulic parameters and flow characteristics such as flow thickness, wave intervals, surge level above levee crown in analyzing scour development. According to
19750-678: The park are the Lyndon B. Johnson Memorial Grove, the Navy–Merchant Marine Memorial, and the Columbia Island Marina. Lady Bird Johnson Park is accessible from downtown Washington via the Arlington Memorial Bridge , from Arlington National Cemetery via Memorial Drive, and from Northern Virginia via the George Washington Memorial Parkway. The Mount Vernon Trail runs along the side of the island facing
19908-708: The park between 1965 and 1968. These plants were paid for by the National Park Service, the Society for a More Beautiful National Capital and the 1965 Presidential Inaugural Committee. Columbia Island was renamed Lady Bird Johnson Park by the United States Department of the Interior on November 12, 1968 in honor of her work on the beautification campaign. After the 1976 dedication of the Lyndon Baines Johnson Memorial Grove within Lady Bird Johnson Park,
20066-544: The pillars be eliminated. Three days later, the Board of Trade also contacted Hoover directly to lobby against the columns' erection. Faced with overwhelming opposition, the AMBC voted to eliminate the columns in December 1931, and asked Kendall for yet another new design for Columbia Island. In the wake of the AMBC's decision, proposals came from the public and architects outside the project to add either high-spouting fountains or towers which would retract whenever planes took off from
20224-412: The plaza. Design issues surrounding the Columbia Island great plaza were resolved in late 1931 not by the CFA, but by President Herbert Hoover . Two airfields, Hoover Field and Washington Airport , existed in Virginia just south of Columbia Island. In the spring of 1931, AMBC executive officer Ulysses S. Grant III (then a lieutenant colonel with the Corps of Engineers) advised the AMBC and CFA that
20382-478: 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. A variety of fish inhabit
20540-449: The rebellious Batavi pierced dikes to flood their land and to protect their retreat (70 CE ). The word dijk originally indicated both the trench and the bank . It closely parallels the English verb to dig . In Anglo-Saxon , the word dic already existed and was pronounced as dick in northern England and as ditch in the south. Similar to Dutch, the English origins of
20698-547: The rest of the District, leading to Theodore Roosevelt Island in one direction and Ronald Reagan Washington National Airport on the other. The Pentagon is visible from the western side of the island near the marina at the southern tip. Lady Bird Johnson Park is a popular location which authors like to include in their fiction novels, sometimes using the old name Columbia Island. It is mentioned in Anthony S. Policastro's Dark End of
20856-541: 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 source of the North Branch Potomac River is at the Fairfax Stone located at
21014-647: 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 the use of the Potomac. However, in 1996 the MDE denied a permit submitted by the Fairfax County Water Authority to build
21172-413: The river floodplains immediately adjacent to the cut banks. Like artificial levees, they act to reduce the likelihood of floodplain inundation. Deposition of levees is a natural consequence of the flooding of meandering rivers which carry high proportions of suspended sediment in the form of fine sands, silts, and muds. Because the carrying capacity of a river depends in part on its depth, the sediment in
21330-491: The river has improved with a reduction in nutrient runoff, return of fish populations, and land protection along the river. As a result, the same group issued a grade of "B" for 2017 and 2018. In March 2019, the Potomac Riverkeeper Network launched a laboratory boat dubbed the "Sea Dog", which will be monitoring water quality in the Potomac and providing reports to the public on a weekly basis; in that same month,
21488-622: The river in Charles County , Maryland, as the Mallows Bay–Potomac River National Marine Sanctuary in 2019. The river has significant historical and political significance, as the nation's capital of Washington, D.C. is located on its banks, as is Mount Vernon , the home of "Father of his Country" George Washington . During the American Civil War, the river became the boundary between the Union and
21646-440: The river to form a wider channel, and flood valley basins are divided by multiple levees to prevent a single breach from flooding a large area. A levee made from stones laid in horizontal rows with a bed of thin turf between each of them is known as a spetchel . Artificial levees require substantial engineering. Their surface must be protected from erosion, so they are planted with vegetation such as Bermuda grass in order to bind
21804-430: The river turns southeast. 103 miles (166 km) downstream from its source, the North Branch is joined by the South Branch between Green Spring and South Branch Depot , West Virginia from whence it flows past Hancock , Maryland and turns southeast once more on its way toward Washington, D.C. , and the Chesapeake Bay . The exact location of the South Branch's source is northwest of Hightown along U.S. Route 250 on
21962-497: The river 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
22120-561: The riverbed, even up to a point where the riverbed is higher than the adjacent ground surface behind the levees, are found for the Yellow River in China and the Mississippi in the United States. Levees are very common on the marshlands bordering the Bay of Fundy in New Brunswick and Nova Scotia , Canada . The Acadians who settled the area can be credited with the original construction of many of
22278-414: The road across Columbia Island connecting Arlington Memorial Bridge with Boundary Channel Bridge was finished in December. The CFA continued to wrestle with Columbia Island's great plaza design in 1931. The commission again discussed the columns in January, and eliminated a granite balustrade around the great plaza (saving $ 400,000). But by September, the agency still had come to no resolution on redesigning
22436-408: The roads on Columbia Island was also needed. These roads were staked out in January 1934, and the CFA and NCPC began discussing whether a new, large traffic circle should be added to the center of the island to replace the bottleneck that a simple cross-axis would be. The engineering and architectural design for the northern bridge was approved in October 1936. The CFA further discussed what to do with
22594-430: The significant pollution control projects at the time was the expansion of the Blue Plains Advanced Wastewater Treatment Plant , which serves Washington and several surrounding communities. Enactment of the 1972 Clean Water Act led to construction or expansion of additional sewage treatment plants in the Potomac watershed. Controls on phosphorus , one of the principal contributors to eutrophication, were implemented in
22752-404: The soil to better resist instability. Artificial levees can lead to an elevation of the natural riverbed over time; whether this happens or not and how fast, depends on different factors, one of them being the amount and type of the bed load of a river. Alluvial rivers with intense accumulations of sediment tend to this behavior. Examples of rivers where artificial levees led to an elevation of
22910-441: The trait of the levee's ridges being raised higher than both the channel and the surrounding floodplains. The modern word dike or dyke most likely derives from the Dutch word dijk , with the construction of dikes well attested as early as the 11th century. The 126-kilometer-long (78 mi) Westfriese Omringdijk , completed by 1250, was formed by connecting existing older dikes. The Roman chronicler Tacitus mentions that
23068-494: The water which is over the flooded banks of the channel is no longer capable of keeping the same number of fine sediments in suspension as the main thalweg . The extra fine sediments thus settle out quickly on the parts of the floodplain nearest to the channel. Over a significant number of floods, this will eventually result in the building up of ridges in these positions and reducing the likelihood of further floods and episodes of levee building. If aggradation continues to occur in
23226-482: 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 First United States Congress by act of July 16, 1790 stated that
23384-501: The wavy green granite steps, creating a concrete plaza around the memorial, installing two flagstone walks to lead to the memorial, and landscaping the area. During the latter part of the 1960s and the early part of the 1970s, the National Park Service relandscaped Columbia Island extensively as part of a nationwide, urban-beautification campaign sponsored by then– First Lady Lady Bird Johnson between 1964 and 1968. More than one million daffodils and 2,700 dogwood trees were planted on
23542-415: The word lie in digging a trench and forming the upcast soil into a bank alongside it. This practice has meant that the name may be given to either the excavation or to the bank. Thus Offa's Dyke is a combined structure and Car Dyke is a trench – though it once had raised banks as well. In the English Midlands and East Anglia , and in the United States, a dike is what a ditch is in the south of England,
23700-407: Was Jennings Randolph Lake on the North Branch. The Corps built a supplementary water intake for the Washington Aqueduct at Little Falls in 1959. In 1940 Congress passed a law authorizing the creation of an interstate compact to coordinate water quality management among states in the Potomac basin. Maryland, West Virginia, Pennsylvania, Virginia, and the District of Columbia agreed to establish
23858-453: Was broken by Secretary of the Navy Charles Francis Adams , Secretary of the Treasury Andrew W. Mellon , Marine Corps Major General Ben H. Fuller , Coast Guard Commandant Rear Admiral Frederick C. Billard , and Assistant Secretary of Commerce David Sinton Ingalls on December 2, 1930. Work on the memorial stopped for nearly three years. The statue itself was finally emplaced in 1934. However, lack of funds meant that instead of
24016-422: Was built by the Qin as a water conservation and flood control project. The system's infrastructure is located on the Min River , which is the longest tributary of the Yangtze River , in Sichuan , China . The Mississippi levee system represents one of the largest such systems found anywhere in the world. It comprises over 5,600 km (3,500 mi) of levees extending some 1,000 km (620 mi) along
24174-451: Was complete in the spring of 1924. The new island received its name in about 1918 from an unnamed engineer working for the District of Columbia and the first use of this name in The Washington Post was in April 1922, the same year it was transferred to the National Park Service. In 1922, Congress authorized the Arlington Memorial Bridge Commission (AMBC) to hold a design competition for the proposed Arlington Memorial Bridge . It awarded
24332-431: Was constructed during the early 1400s, under the supervision of the tlahtoani of the altepetl Texcoco, Nezahualcoyotl. Its function was to separate the brackish waters of Lake Texcoco (ideal for the agricultural technique Chināmitls ) from the fresh potable water supplied to the settlements. However, after the Europeans destroyed Tenochtitlan, the levee was also destroyed and flooding became a major problem, which resulted in
24490-430: Was finished and the light removed in September 1964. A year later, in September 1965, a new bridge just west of the South Washington Boulevard bridge opened. The George Washington Memorial Parkway was expanding north of its old terminus at Arlington Memorial Bridge, but this necessitated moving the parkway's southbound lanes onto the Virginia shoreline and off the northern part of Columbia Island. The new bridge connected
24648-440: Was immediately established to disburse the funds appropriated by the act. On July 13, just a month after the PWA was formed, the agency announced a $ 3 million grant to finish work on Columbia Island and other parts of the Arlington Memorial Bridge project. The CFA and NCPC met in November to decide how to proceed on Columbia Island, which had only one link to Virginia – and that led only to Arlington National Cemetery. On December 4,
24806-487: Was in March 1936 when it reached 426,000 cubic feet (12,100 m ) /s. The lowest average daily flow ever recorded at the same location was 601.0 cubic feet (17.02 m ) /s in September 1966 The highest crest of the Potomac ever registered at Little Falls was 28.10 ft, on March 19, 1936; however, the most damaging flood to affect Washington, DC and its metropolitan area was that of October 1942. For 400 years Maryland and Virginia have disputed control of
24964-400: Was widened to six lanes from four. The northern bridge carrying the George Washington Memorial Parkway over Boundary Channel was realigned in late 1962 as part of a larger road realignment allowing Arlington Boulevard to link to the new Theodore Roosevelt Bridge. A traffic light, the only one anywhere on the parkway, was installed to control traffic during the realignment process. The new bridge
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