A blackwater river is a type of

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of ...

with a slow-moving channel flowing through forested

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

s or

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes prevailing, especially in t ...

s. As vegetation decays,

tannin Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids. The term ''tannin'' (from Anglo-Norman ''tanner'' ...

s leach into the water, making a transparent, acidic water that is darkly stained, resembling

black tea Black tea, also translated to red tea in various East Asian languages, is a type of tea that is more oxidized than oolong, yellow, white and green teas. Black tea is generally stronger in flavour than other teas. All five types are made from ...

. Most major blackwater rivers are in the

Amazon Basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Boli ...

and the

Southern United States The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, or simply the South) is a geographic and cultural region of the United States of America. It is between the Atlantic Ocean ...

. The term is used in

fluvial In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviog ...

studies,

geology Geology () is a branch of natural science concerned with Earth and other Astronomical object, astronomical objects, the features or rock (geology), rocks of which it is composed, and the processes by which they change over time. Modern geology ...

geography Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, an ...

ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overl ...

, and

biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary ...

. Not all dark rivers are blackwater in that technical sense. Some rivers in temperate regions, which drain or flow through areas of dark black

loam Loam (in geology and soil science) is soil composed mostly of sand ( particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–si ...

, are simply black due to the color of the soil; these rivers are ''black mud rivers''. There are also black mud

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environme ...

. Blackwater rivers are lower in nutrients than whitewater rivers and have ionic concentrations higher than rainwater. The unique conditions lead to flora and fauna that differ from both whitewater and clearwater rivers. The classification of Amazonian rivers into black, clear, and whitewater was first proposed by

Alfred Russel Wallace Alfred Russel Wallace (8 January 1823 – 7 November 1913) was a British natural history, naturalist, explorer, geographer, anthropologist, biologist and illustrator. He is best known for independently conceiving the theory of evolution thro ...

in 1853 based on water colour, but the types were more clearly defined by chemistry and physics by from the 1950s to the 1980s. Although many Amazonian rivers fall clearly into one of these categories, others show a mix of characteristics and may vary depending on season and flood levels.

Comparison between white and black waters

Black and white waters differ significantly in their ionic composition, as shown in Table 1. Black waters are more

acid In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a se ...

ic, resulting in an

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...

concentration greater than that of the more neutral white waters. The major difference is the concentrations of

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar ...

, and

potassium Potassium is the chemical element with the symbol K (from Neo-Latin '' kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmos ...

; these are very low in black waters. This has ecological implications. Some animals need more calcium than is available in blackwaters, so for example,

snail A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class ...

s, which need much calcium to build shells, are not abundant in blackwaters. The lack of dissolved ions in black waters results in a low conductivity, similar to that of rainwater. Black and white waters differ in their

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cruc ...

ic fauna and flora. Tables 2 and 3 compare the number of planktonic animals caught in black and white water localities only a few meters apart. The black water was not as extreme an example as the Rio Negro system. However, it can be seen that the black water held greater numbers of

rotifer The rotifers (, from the Latin , "wheel", and , "bearing"), commonly called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John H ...

s but fewer

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapoda, decapods, ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, krill, remipedes, isopoda, isopods, barnacles, copepods, ...

s and

mite Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear e ...

s. These crustaceans are important foods for larval fish. The zones where the two waters mix are attractive to

ostracod Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 70,000 species (only 13,000 of which are extant) have been identified, grouped into several orders. They are small crustaceans, typic ...

s and young fish. These mixing zones tend to have many animals. The abundance is shown in Table3, which compares animals in of water.

Comparison between clear and black waters

Blackwater rivers resemble clearwater rivers in having a low conductivity and relatively low levels of dissolved solids, but clearwater rivers have water that often only is somewhat acidic (typical pH ~6.5) and very clear with a greenish color. The main Amazonian clearwater rivers have their source in the Brazilian Plateau (such as Tapajós,

Tocantins Tocantins () is one of the 26 states of Brazil. It is the newest state, formed in 1988 and encompassing what had formerly been the northern two-fifths of the state of Goiás. Tocantins covers and had an estimated population of 1,496,880 in 20 ...

, Xingu and some right tributaries of the

Madeira ) , anthem = ( en, "Anthem of the Autonomous Region of Madeira") , song_type = Regional anthem , image_map=EU-Portugal_with_Madeira_circled.svg , map_alt=Location of Madeira , map_caption=Location of Madeira , subdivision_type=Sovereign st ...

), but some originate in the

Guiana Shield The Guiana Shield (french: Plateau des Guyanes, Bouclier guyanais; nl, Hoogland van Guyana, Guianaschild; pt, Planalto das Guianas, Escudo das Guianas; es, Escudo guayanés) is one of the three cratons of the South American Plate. It is a ...

(such as Nhamundá, Paru, and Araguari).

Blackwater rivers of the world

Amazonia

* Apaporis River: a tributary of the

Japurá River The Japurá River or Caquetá River is a river about long in the Amazon basin. It rises in Colombia and flows eastward through Brazil to join the Amazon River. Course The river rises as the Caquetá River in the Andes in southwest Colombia. ...

Arapiuns River The Arapiuns River is a river in Pará state in north-central Brazil. It is a tributary of the Tapajós, and merges into the latter river about before Tapajós merges into the Amazon River. Arapiuns is a blackwater river. See also *List of river ...

: a tributary of the

Tapajós River The Tapajós ( pt, Rio Tapajós ) is a river in Brazil. It runs through the Amazon Rainforest and is a major tributary of the Amazon River. When combined with the Juruena River, the Tapajós is approximately long. It is one of the largest clea ...

Coari River Coari River is a tributary of the Amazon River The Amazon River (, ; es, Río Amazonas, pt, Rio Amazonas) in South America is the largest river by discharge volume of water in the world, and the disputed longest river system in the world ...

* Mazaruni River * Mirití-Paraná River *

Piorini River The Piorini River ( pt, Rio Piorini) is a river in Amazonas state in north-western Brazil. It ends in the Badajos River. See also * List of rivers of Amazonas ReferencesBrazilian Ministry of Transport Rivers of Amazonas (Brazilian state) Tr ...

Potaro River The Potaro River is a river in Guyana that runs from Mount Ayanganna area of the Pakaraima Mountains for approximately before flowing into the Essequibo River, Guyana's largest river. The renowned Kaieteur Falls is on the Potaro. Features Nine ...

: a tributary of the Mazaruni River * Rio Negro: The largest blackwater river in the world; one of the largest Amazonian tributaries. * Tahuayo River * Tefé River *

Uatumã River The Uatumã River (sometimes spelled Uatamã) is a river flowing through the state of Amazonas in Brazil. It is a northern tributary of the Amazon River, and known for its extensive peacock bass population. It is a blackwater river. The river f ...

* Urubu River *

Vaupés River Vaupés River (Uaupés River) is a tributary of the Rio Negro in South America. It rises in the Guaviare Department of Colombia, flowing east through Guaviare and Vaupés Departments. It forms part of the international border between the Vaupés ...

Orinoco basin

Morichal Largo River Morichal Largo River is a river of Venezuela. It is part of the Orinoco River basin. See also *List of rivers of Venezuela This is a list of rivers in Venezuela. By drainage basin This list is arranged by drainage basin, with respective tribu ...

* Atabapo River: from the

Guiana highlands The Guianas, sometimes called by the Spanish loan-word ''Guayanas'' (''Las Guayanas''), is a region in north-eastern South America which includes the following three territories: * French Guiana, an overseas department and region of France * ...

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

west into the

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers , with 76.3 percent of it in Venezuela and the remainder in Colombia. It is the fourth largest river in the wor ...

Caroní River The Caroní River is the second most important river of Venezuela, the second in flow, and one of the longest, from the Kukenan tepui through to its confluence with the Orinoco River. The name "Caroní" is applied starting from the confluence ...

: from the Guiana Highlands of Venezuela north into the Orinoco. * Caura River: from the Guiana Highlands of Venezuela north into the Orinoco * Inírida River: from

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the ...

northeast into the Guaviare River which flows into the Orinoco *

Ventuari River The Ventuari River is the largest tributary of the Orinoco in southern Venezuela. The Ventuari flows from south-central Venezuela in the Guiana Highlands southwest into the Orinoco River. It is long and its major tributary is the Manapiare River ...

: from eastern Venezuela southwest into the Orinoco * Vichada River: from Colombia east into the Orinoco * Tomo River: from Colombia east into the Orinoco * Tuparro River: from Colombia east into the Orinoco

Southern United States

Ashepoo River Ashepoo River is a short blackwater river in South Carolina, United States. It rises in a confluence of swamps south of Walterboro, flows in a southeast direction and empties into Saint Helena Sound at . The entire course of the river lies wit ...

: along with the Edisto and the Combahee Rivers in South Carolina makes up the ACE Basin National Wildlife Refuge. * Big Cypress, Black Cypress, and Little Cypress and the small rivers in the watershed of Caddo Lake in

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

and

Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is bord ...

Blackwater River A blackwater river is a type of river with a slow-moving channel flowing through forested swamps or wetlands. As vegetation decays, tannins leach into the water, making a transparent, acidic water that is darkly stained, resembling black tea ...

: a tributary of the

Chowan River The Chowan River (cho-WAHHN)
, from the North Carolina Collection's website at the Blackwater River A blackwater river is a type of river with a slow-moving channel flowing through forested swamps or wetlands. As vegetation decays, tannins leach into the water, making a transparent, acidic water that is darkly stained, resembling black tea ...

: a major river in the western

Florida panhandle The Florida Panhandle (also West Florida and Northwest Florida) is the northwestern part of the U.S. state of Florida; it is a salient roughly long and wide, lying between Alabama on the north and the west, Georgia on the north, and the ...

, West Virginia: Located in the Blackwater Canyon in Tucker County. Blackwater Falls, a five-story waterfall, is located along this river with rapids ranging from ClassIII-V+. * Black River: a tributary of the

Pee Dee River The Pee Dee River, also known as the Great Pee Dee River, is a river in the Carolinas of the United States. It originates in the Appalachian Mountains in North Carolina, where its upper course, above the mouth of the Uwharrie River, is known as ...

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north ...

and South Carolina *

Cape Fear River The Cape Fear River is a long blackwater river in east central North Carolina. It flows into the Atlantic Ocean near Cape Fear, from which it takes its name. The river is formed at the confluence of the Haw River and the Deep River (North Caro ...

, North Carolina: flows into the Atlantic Ocean. *

Cashie River This is a list of rivers in the U.S. state of North Carolina. By drainage basin This list is arranged by drainage basin, with respective tributaries alphabetically indented under each larger stream's name. Atlantic Ocean * North Landing R ...

, North Carolina: flows into

Albemarle Sound Albemarle Sound () is a large estuary on the coast of North Carolina in the United States located at the confluence of a group of rivers, including the Chowan and Roanoke. It is separated from the Atlantic Ocean by the Currituck Banks, a bar ...

. * Caloosahatchee River,

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and ...

: flows west from

Lake Okeechobee Lake Okeechobee (), also known as Florida's Inland Sea, is the largest freshwater lake in the U.S. state of Florida. It is the tenth largest natural freshwater lake among the 50 states of the United States and the second-largest natural freshwa ...

to the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United ...

. *

Chowan River The Chowan River (cho-WAHHN)
, from the North Carolina Collection's website at the Albemarle Sound Albemarle Sound () is a large estuary on the coast of North Carolina in the United States located at the confluence of a group of rivers, including the Chowan and Roanoke. It is separated from the Atlantic Ocean by the Currituck Banks, a bar ...

. * Edisto River, South Carolina: flows into the Atlantic Ocean. * Econlockhatchee River, a

tributary A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drai ...

of the St. Johns River in Central Florida. * Forked Deer River: located in West Tennessee *

Four Hole Swamp Four Hole Swamp is a small blackwater river A blackwater river is a type of river with a slow-moving channel flowing through forested swamps or wetlands. As vegetation decays, tannins leach into the water, making a transparent, acidic water ...

, a tributary of the Edisto River in South Carolina. * Little Manatee River, Florida: flows into

Tampa Bay Tampa Bay is a large natural harbor and shallow estuary connected to the Gulf of Mexico on the west-central coast of Florida, comprising Hillsborough Bay, McKay Bay, Old Tampa Bay, Middle Tampa Bay, and Lower Tampa Bay. The largest freshwater ...

. *

Great Coharie Creek Great Coharie Creek is a long 5th order tributary to the Black River in Sampson County, North Carolina. Variant names According to the Geographic Names Information System, it has also been known historically as: *Cohary Swamp Course Great Co ...

, North Carolina: flows into the Black River. *

Little Pee Dee River The Little Pee Dee River is a tributary of the Pee Dee River (which originates in the Appalachian Mountains where it is known as the Yadkin River). The Little Pee Dee technically arises near Laurinburg, North Carolina as Gum Swamp, which flows so ...

, South Carolina: flows into the

. *

Lynches River Lynches River, named for Thomas Lynch, Jr., signer of the Declaration of Independence, rises in North Carolina near Waxhaw, North Carolina, at about 700 feet (210 m) elevation, flowing only a short distance to the South Carolina border, and th ...

, South Carolina: flows into the

. *

Lumber Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, w ...

/ Drowning Creek: located in North and South Carolina. Part of Lumber River State Park * Myakka River: 66 mile-long river with its headwaters in

Manatee County, Florida Manatee County is a county in the Central Florida portion of the U.S. state of Florida. As of the 2020 US Census, the population was 399,710. Manatee County is part of the North Port- Sarasota- Bradenton Metropolitan Statistical Area. Its count ...

. The Myakka River discharges into Charlotte Harbor. * Obion River: located in Northwest Tennessee *

Ochlockonee River The Ochlockonee River ( ) is a fast running river, except where it has been dammed to form Lake Talquin in Florida, originating in Georgia and flowing for before terminating in Florida. Background The name is from the Hitchiti language words ...

: a river in northern Florida *

Ogeechee River The Ogeechee River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 26, 2011 blackwater river in the U.S. state of Georgia. It heads at the confluence of its North and Sout ...

: a 245-mile river in eastern

Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...

that passes to the south of the city of

Savannah A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

and enters the Atlantic Ocean at Ossabaw Sound. * Ohoopee River: a 119-mile-long (192 km) river in east-central

. It is a tributary of the

Altamaha River The Altamaha River is a major river in the U.S. state of Georgia. It flows generally eastward for 137 miles (220 km) from its origin at the confluence of the Oconee River and Ocmulgee River towards the Atlantic Ocean, where it empties ...

, which flows to the Atlantic Ocean. *

Pasquotank River The Pasquotank River
, from the North Carolina Collection's website at the

North Carolina North Carolina () is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. The state is the List of U.S. states and territories by area, 28th largest and List of states and territories of the United ...

. Located between Camden and Pasquotank counties, the Pasquotank connects directly to the

and is part of the Intracoastal Waterway via

Elizabeth City Elizabeth City is a city in Pasquotank County, North Carolina, United States. As of the 2020 census, it had a population of 18,629. Elizabeth City is the county seat and largest city of Pasquotank County. It is the cultural, economic and educ ...

. *

Peace River The Peace River (french: links=no, rivière de la Paix) is a river in Canada that originates in the Rocky Mountains of northern British Columbia and flows to the northeast through northern Alberta. The Peace River joins the Athabasca River in ...

: located in central Florida, flows into Charlotte Harbor. * Pithlachascotee River: a small river in central

Pocomoke River The Pocomoke River stretches approximately U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 1, 2011 from southern Delaware through southeastern Maryland in the United States. At it ...

: a river in southern

Delaware Delaware ( ) is a state in the Mid-Atlantic region of the United States, bordering Maryland to its south and west; Pennsylvania to its north; and New Jersey and the Atlantic Ocean to its east. The state takes its name from the adjacent ...

and southeastern

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean t ...

on the

Delmarva Peninsula The Delmarva Peninsula, or simply Delmarva, is a large peninsula and proposed state on the East Coast of the United States, occupied by the vast majority of the state of Delaware and parts of the Eastern Shore regions of Maryland and Virginia. ...

. The river is a tributary to the

Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the Eastern Shore of Maryland / ...

. * Santa Fe River: a river in northern Florida *

Satilla River The Satilla River rises in Ben Hill County, Georgia, United States, near the town of Fitzgerald, and flows in a mostly easterly direction to the Atlantic Ocean. Along its approximately U.S. Geological Survey. National Hydrography Dataset hig ...

: a river in southeast

that flows through the city of Waycross and empties into the Atlantic Ocean near

Cumberland Island Cumberland Island, in the southeastern United States, is the largest of the Sea Islands of Georgia. The long-staple Sea Island cotton was first grown here by a local family, the Millers, who helped Eli Whitney develop the cotton gin. With its ...

. * Scuppernong River: a small river in

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

and Tyrrell Counties in eastern

Pettigrew State Park Pettigrew State Park is a North Carolina State Park in Tyrrell and Washington Counties, North Carolina in the United States. It covers around the shore lines of Lake Phelps and the Scuppernong River. The park's developed facilities are sou ...

Sopchoppy River The Sopchoppy River is a minor river in the Florida Big Bend. A tributary of the Ochlockonee River, it is approximately in lengthBoning, Charles R. 2007. ''Florida's Rivers''. Sarasota, Florida: Pineapple Press, Inc. and nearly entirely within ...

: a river in northern Florida * St. Mary's River (Florida–Georgia): a 130-mile river located in southeast Georgia and is bordered by the Satilla River Basin to the north and the Suwannee River Basin to the west. * St. Johns River: The largest river in Florida. Flows north through

Jacksonville Jacksonville is a city located on the Atlantic coast of northeast Florida, the most populous city proper in the state and is the List of United States cities by area, largest city by area in the contiguous United States as of 2020. It is the co ...

and into the Atlantic. *

St. Sebastian River The Saint Sebastian River is a river in the U.S. state of Florida, a tributary of the Indian River west and north of the city of Sebastian. Dredging Dredging Dredging is the excavation of material from a water environment. Possible ...

, Indian River County, Florida. *

Suwannee River The Suwannee River (also spelled Suwanee River) is a river that runs through south Georgia southward into Florida in the southern United States. It is a wild blackwater river, about long.U.S. Geological Survey. National Hydrography Dataset h ...

: a large river in southern

and northern Florida flowing into the Gulf of Mexico * Upper Little River, North Carolina: flows into the

. * Upper Nanticoke River, Delaware and Maryland: flows into the Chesapeake Bay. * Village Creek, a 63 Mile long stream in the

Big Thicket The Big Thicket is the name given to a somewhat imprecise region of a heavily-forested area of Southeast Texas in the United States. This area represents a portion of the mixed pine-hardwood forests of southeast US. The National Park Service esta ...

region of southeast Texas: flows into the

Neches River The Neches River () begins in Van Zandt County west of Rhine Lake and flows for through the piney woods of east Texas, defining the boundaries of 14 counties on its way to its mouth on Sabine Lake near the Rainbow Bridge. Two major reservoirs, ...

. *

Waccamaw River The Waccamaw River is a river, approximately 140 miles (225 km) long, in southeastern North Carolina and eastern South Carolina in the United States. It drains an area of approximately 1,110 square miles (2886 km²) in the coastal plai ...

, North and South Carolina: flows into the Atlantic Ocean. *

White Oak River The White Oak River is a blackwater river, close to 48 mi (77 km) long, on the coastal plain of southeast North Carolina in the United States. It empties in the Atlantic Ocean. Course It rises in the White Oak Pocosin in northern Onslo ...

, North Carolina: flows into the Atlantic Ocean. * Wolf River: arises in Northern Mississippi and runs through southwest Tennessee/Memphis into Mississippi River

Northern United States

* Black River,

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

: a river starting in the western

Adirondacks The Adirondack Mountains (; a-də-RÄN-dak) form a massif in northeastern New York with boundaries that correspond roughly to those of Adirondack Park. They cover about 5,000 square miles (13,000 km2). The mountains form a roughly circular d ...

that flows into

Lake Ontario Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the U.S. state of New York. The Canada–United States border sp ...

. *

Black River (Gogebic County) The Black River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed May 1, 2012 river on the Upper Peninsula of the U.S. state of Michigan, flowing mostly in Gogebic County into Lake ...

Michigan Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and t ...

: a river in the far western

Upper Peninsula The Upper Peninsula of Michigan – also known as Upper Michigan or colloquially the U.P. – is the northern and more elevated of the two major landmasses that make up the U.S. state of Michigan; it is separated from the Lower Peninsula by ...

that flows into

Lake Superior Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh wa ...

. The northern section of the river is listed as a

National Wild and Scenic River The National Wild and Scenic Rivers System was created by the Wild and Scenic Rivers Act of 1968 (Public Law 90-542), enacted by the U.S. Congress to preserve certain rivers with outstanding natural, cultural, and recreational values in a free- ...

. *

Mullica River The Mullica River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 1, 2011 river in southern New Jersey in the United States. The Mullica was once known as the ''Little Egg Ha ...

and its tributaries from the Pine Barrens,

New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delawa ...

, where the dark water is called cedar water *

Gooseberry River Gooseberry River is a 23-mile stream in Lake County, Minnesota, USA, draining into Lake Superior. It is known for its waterfalls, near its mouth in Gooseberry Falls State Park. The Gooseberry, like many of its neighboring streams, has an irregul ...

: a river in northern Minnesota that leaches from peat bogs and pine forests *

Ocqueoc River The Ocqueoc River ( ') is stream in Presque Isle County in the northeastern part of the lower peninsula in the U.S. state of Michigan. It is longU.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map ac ...

, Michigan: a river in the northern Lower Peninsula that flows in

Lake Huron Lake Huron ( ) is one of the five Great Lakes of North America. Hydrologically, it comprises the easterly portion of Lake Michigan–Huron, having the same surface elevation as Lake Michigan, to which it is connected by the , Straits of Mack ...

* Tahquamenon River,

: a river in the

that flows into

* Tuckahoe River,

: a short river in southern New Jersey that flows into

Great Egg Harbor Great Egg Harbor Bay (or Great Egg Harbor) is a bay between Atlantic and Cape May counties along the southern New Jersey coast. The name derives from Dutch explorer Cornelius Jacobsen May's description of the plentiful birds laying eggs, naming t ...

Africa

* Most Congo and Lower Guinean rivers that flow through rainforests are blackwater. * The Congo basin lakes Mai-Ndombe and Tumba are blackwater. * The New Calabar and Sombreiro Rivers (both exiting in the Niger River Delta) are blackwater.

Australia

* Gordon River,

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

: a river rising in the center of the island and flowing westward, emptying into Macquarie Harbour on the West Coast *

Pieman River The Pieman River is a major perennial river located in the West Coast, Tasmania, west coast region of Tasmania, Australia. Course and features Formed by the confluence of the Mackintosh River and Murchison River (Tasmania), Murchison River, the ...

, Tasmania: a river on the West Coast which leaches from rainforests and heathlands *

Davey River The Davey River is a perennial river located in the south-west region of Tasmania, Australia. Course and features The Davey River rises on the western slopes of the Frankland Range, below Coronation Peak, and flows generally south by west th ...

, Tasmania: a relatively small river in the southwest corner of the island which runs through extensive heathlands, peat bogs and button grass plains *

Noosa River The Noosa River is a river situated in South East Queensland. The catchment starts in the Como Escarpment near Mount Elliott in the coastal Great Sandy National Park and meanders south through a lakes district around Tewantin. Lakes situated on ...

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

: a small section of the Noosa River running between Lake Cootharaba and Lake Cooroibah Other rivers in Australia may experience infrequent 'blackwater events' associated with flood waters connecting to forested floodplains and these events may be associated with hypoxic waters ow oxygen Examples include the

Murray River The Murray River (in South Australia: River Murray) (Ngarrindjeri: ''Millewa'', Yorta Yorta: ''Tongala'') is a river in Southeastern Australia. It is Australia's longest river at extent. Its tributaries include five of the next six longest ...

Edward River Edward River, or Kyalite River, an anabranch of the Murray River and part of the Murray–Darling basin, is located in the western Riverina region of south western New South Wales, Australia. The river rises at Picnic Point east of Mathoura, ...

Wakool River Wakool River, an anabranch of the Edward River that is part of the Murray River catchment within the Murray–Darling basin, is located in the western Riverina region of south western New South Wales, Australia. The Wakool River splits from t ...

and

Murrumbidgee River The Murrumbidgee River () is a major tributary of the Murray River within the Murray–Darling basin and the second longest river in Australia. It flows through the Australian state of New South Wales and the Australian Capital Territory, desce ...

Indonesia

Sabangau River Sabangau National Park (sometimes spelled Sebangau) is a national park in Central Kalimantan, a province of Indonesia in Kalimantan, the Indonesian part of the island of Borneo established in 2004. Between 1980 and 1995 the site was a massive l ...

Images of blackwater rivers

Amazon blackwater.JPG, Amazon tributary classified as blackwater Bald Cypress.JPG, Cluster of

bald cypress ''Taxodium distichum'' (bald cypress, swamp cypress; french: cyprès chauve; ''cipre'' in Louisiana) is a deciduous conifer in the family Cupressaceae. It is native to the southeastern United States. Hardy and tough, this tree adapts to a wide ...

trees in Trap Pond State Park in Southern

Manaus-Amazon-NASA.jpg,

Manaus Manaus () is the capital and largest city of the Brazilian state of Amazonas. It is the seventh-largest city in Brazil, with an estimated 2020 population of 2,219,580 distributed over a land area of about . Located at the east center of the s ...

, the largest city on the

Amazon River The Amazon River (, ; es, Río Amazonas, pt, Rio Amazonas) in South America is the largest river by discharge volume of water in the world, and the disputed longest river system in the world in comparison to the Nile. The headwaters of t ...

, from a

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...

satellite image, surrounded by the muddy Amazon river and the blackwater Rio Negro File:Blackwater and muddy water, Big Thicket NP. Jack Gore Baygall Unit, Hardin Co. TX; 3 Apr 2020.jpg, A cypress slough where

baygall A bayhead or baygall is a specific type of wetland or swamp habitat.Watson, Geraldine Ellis (2006) Big Thicket Plant Ecology: An Introduction, Third Edition (Temple Big Thicket Series #5). University of North Texas Press. 152 pp. Natural Communi ...

blackwater (left) mixes with the more typical muddy waters (right) of the region.

National Preserve, Jack Gore Baygall Unit, Hardin Co. Texas; 3 April 2020 File:Caño Ceima Cachivera, Mitú, Vaupés.jpg, Caño Ceima Cachivera, Mitú, Vaupés: one of the most visited waterfalls and indigenous communities In Mitú, Colombia

References

{{Wetlands Aquatic ecology Rivers