A blackwater river is a type of

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end 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 semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

s. 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 tributary, 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 ...

and the

Southern United States The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, Dixieland, or simply the South) is List of regions of the United States, census regions defined by the United States Cens ...

. The term is used in

fluvial A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...

studies,

geology Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...

geography Geography (from Ancient Greek ; combining 'Earth' and 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding o ...

ecology Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...

, and

biology Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, History of life, origin, evolution, and ...

. 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 environm ...

. 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 an English naturalist, explorer, geographer, anthropologist, biologist and illustrator. He independently conceived the theory of evolution through natural selection; his 1858 pap ...

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 White Waters is a 2007 Nigerian slice of life drama film directed by Izu Ojukwu. The film received 12 nominations and won four awards at the 4th Africa Movie Academy Awards including winning Best Director, Best Cinematography, Best Sound and Bes ...

differ significantly in their ionic composition, as shown in

Table 1 Table may refer to: * Table (database), how the table data arrangement is used within the databases * Table (furniture), a piece of furniture with a flat surface and one or more legs * Table (information), a data arrangement with rows and column ...

. Black waters are more

acid An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...

ic, resulting in an

aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

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

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

magnesium Magnesium is a chemical element; it has Symbol (chemistry), 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 ...

calcium Calcium is a chemical element; it has 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 to it ...

, and

potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

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

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 that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

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 Latin 'wheel' and 'bearing'), sometimes called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic Coelom#Pseudocoelomates, pseudocoelomate animals. They were first describ ...

s but fewer

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s and

mite Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as eac ...

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 (biology), class of the crustacean, Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 33,000 species (only 13,000 of which are extant taxon, extant) have been identified,Brandão, S.N.; Antoni ...

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 In chemistry, a solution is defined by IUPAC as "A liquid or solid phase containing more than one substance, when for convenience one (or more) substance, which is called the solvent, is treated differently from the other substances, which are ...

, 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 The Brazilian Highlands or Brazilian Plateau () is an extensive geographical region covering most of the eastern, southern and central portions of Brazil, in all some 4,500,000 km2 (1,930,511 sq mi) or approximately half of the country's la ...

(such as

Tapajós The 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. Prior to a drastic increase in illegal gold mi ...

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 2014 ...

, Xingu and some right tributaries of the

Madeira Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

), but some originate in the

Guiana Shield The Guiana Shield (; ; ; ) is one of the three cratons of the South American Plate. It is a 1.7 billion-year-old Precambrian geological formation in northeast South America that forms a portion of the northern coast. The higher elevations on ...

(such as Nhamundá, Paru, and

Araguari Araguari is a municipality in western Minas Gerais state, Brazil. It is in the northern Triângulo Mineiro region, on the Jordão River, a tributary of the Paranaíba River, at an elevation between . The municipality of Araguari has an area of , w ...

Blackwater rivers of the world

Amazonia

Apaporis River The Apaporis River is a river of the Vaupés Department, Colombia. It is a tributary of the Japurá River (Caquetá River). In the last stretch, before the river joins the Caquetá River, it forms part of the boundary between Colombia and Brazi ...

: a tributary of the

Japurá River The Japurá River or Caquetá River is a long river 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. The Caqu ...

Arapiuns River The Arapiuns River is a river in Pará state in north-central Brazil, which 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 ...

: a tributary of the

Tapajós River The 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. Prior to a drastic increase in illegal gold mi ...

Coari River Coari River is a tributary of the Amazon River ( Solimões section) in the Amazonas state in north-western Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of count ...

Mazaruni River The Mazaruni River is a tributary of the Essequibo River in northern Guyana. Its source is in the remote western forests of the Pakaraima Mountains and its confluence with the Cuyuni River is near Bartica. As it descends from the Guiana Highland ...

* Mirití-Paraná River * Piorini River *

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 Ni ...

: a tributary of the

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

Tefé River The Tefé River (Teffé River in early accounts; ) is a tributary of the Amazon River ( Solimões section) in Amazonas state in north-western Brazil. The Tefé River flows through the Juruá-Purus moist forests ecoregion. It forms the eastern ...

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 ...

* Urubu River *

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

Orinoco basin

Morichal Largo River Morichal Largo River is a river in the North eastern part of Venezuela. It is part of the Orinoco River basin. See also *List of rivers of Venezuela References

*Rand McNally, The New International Atlas, 1993. Rivers of Venezuela {{Vene ...

* Atabapo River: from the

Guiana highlands The Guianas, also spelled Guyanas or Guayanas, are a geographical region in north-eastern South America. Strictly, the term refers to the three Guianas: Guyana, Suriname, and French Guiana, formerly British, Dutch, and French Guiana respectiv ...

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

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 approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

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 confluenc ...

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

Inírida River The Inírida (, Spanish: Río Inírida) is a river in the north-west of South America, in the territory of Colombia, the largest tributary of the Guaviare (the Orinoco River basin). The length of the river is , of which are navigable for small v ...

: from

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

northeast into the

Guaviare River The Guaviare is a tributary of the Orinoco in Colombia. It flows together with the upper Orinoco (until here also called Río Parágua), which it clearly surpasses in length (altogether about 1,760 km) and water flow. Thus, the Guaviare is hydrol ...

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 The Vichada River (, ) is a blackwater river in Colombia, South America. It flows into the Orinoco River. The eastward course of the Vichada is offset by an Impact crater, impact structure, called the Vichada Structure. The structure is most li ...

: 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 The 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 ...

: along with the Edisto and the

Combahee River The Combahee River ( ) is a short blackwater river in the southern Lowcountry region of South Carolina formed at the confluence of the Salkehatchie and Little Salkehatchie rivers near the Islandton community of Colleton County, South Carolin ...

s in South Carolina makes up the

ACE Basin National Wildlife Refuge The Ernest F. Hollings ACE Basin National Wildlife Refuge is a portion of the larger ACE Basin area, and the only portions that are federally protected. The wildlife refuge is divided into two units: the Edisto River unit and the Combahee Riv ...

. * Big Cypress, Black Cypress, and Little Cypress and the small rivers in the watershed of

Caddo Lake Caddo Lake () is a lake and bayou (wetland) on the border between Texas and Louisiana, in northern Harrison County and southern Marion County in Texas and western Caddo Parish in Louisiana. The lake is named after the Caddoans or Caddo, ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

and

Louisiana Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...

Blackwater River A blackwater river is a type of River#Classification, river with a slow-moving channel flowing through forested swamps or wetlands. Most major blackwater rivers are in the Amazon Basin and the Southern United States. The term is used in fluvial ...

: a tributary of the

Chowan River The Chowan River (cho-WAHHN)
, from the North Carolina Collection's website at the

: a major river in the western

Florida panhandle The Florida panhandle (also known as West Florida and Northwest Florida) is the northwestern part of the U.S. state of Florida. It is a Salient (geography), salient roughly long, bordered by Alabama on the west and north, Georgia (U.S. state ...

, 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 a ...

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 (geometry), direction or geography. Etymology T ...

and South Carolina *

Cape Fear River The Cape Fear River is a 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 in the town of ...

, 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 Riv ...

, 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 River, Chowan and Roanoke River, Roanoke. It is separated from the Atlantic Ocean b ...

. *

Caloosahatchee River The Caloosahatchee River is a river on the southwest Gulf Coast of the United States, Gulf Coast of Florida in the United States, approximately long.U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National ...

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

: flows west from

Lake Okeechobee Lake Okeechobee ( ) is the largest freshwater lake in the U.S. state of Florida. It is the List of largest lakes of the United States by area, eighth-largest natural freshwater lake among the 50 states of the United States and the second-largest ...

to the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

. *

Chowan River The Chowan River (cho-WAHHN)
, from the North Carolina Collection's website at the

. *

Edisto River The Edisto River is one of the longest free-flowing blackwater rivers in North America, flowing over 250 meandering miles from its sources in Saluda and Edgefield counties, to its Atlantic Ocean mouth at Edisto Beach, South Carolina. It rises ...

, South Carolina: flows into the Atlantic Ocean. *

Econlockhatchee River The Econlockhatchee River (Econ River for short) is an U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed April 21, 2011 north-flowing blackwater tributary of the St. Johns River. The E ...

, a

tributary A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''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 into which they ...

of the

St. Johns River The St. Johns River () is the longest river in the U.S. state of Florida and is the most significant one for commercial and recreational use. At long, it flows north and winds through or borders 12 counties. The drop in elevation from River s ...

in Central Florida. *

Forked Deer River The Forked Deer River system is the main drainage of the central portion of West Tennessee. Locals pronounce the first word of the river's name with two syllables, as in “Forkéd” (). The Forked Deer consists of various streams designated ...

: located in West Tennessee *

Four Hole Swamp Four Hole Swamp is a small blackwater river that is a tributary to the Edisto River in South Carolina. The swamp rises in Calhoun County and flows to the confluence. The river is noteworthy for its unusual braided pattern; it has no well-defined ...

, a tributary of the Edisto River in South Carolina. *

Little Manatee River The Little Manatee River flows , from east of Fort Lonesome, Florida South of Hwy 674 and Earl Reynolds Rd In Hillsborough County through southern Hillsborough County, Florida including towns such as Sun City, Florida, and Gulf City, Florid ...

, 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 i ...

. *

Great Coharie Creek Great may refer to: Descriptions or measurements * Great, a relative measurement in physical space, see Size * Greatness, being divine, majestic, superior, majestic, or transcendent People * List of people known as "the Great" * Artel Great (bo ...

, North Carolina: flows into the Black River. * Little Pee Dee River, South Carolina: flows into the

. *

Lynches River Lynches River, named for Thomas Lynch, Jr., signer of the United States Declaration of Independence, Declaration of Independence, rises in North Carolina near Waxhaw, North Carolina, at about elevation, flowing only a short distance to the So ...

, South Carolina: flows into the

. *

Lumber Lumber is wood that has been processed into uniform and useful sizes (dimensional lumber), including beams and planks or boards. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, window frames). ...

Drowning Creek The Lumber River, sometimes referred to as the Lumbee River, is a river in south-central North Carolina in the flat Coastal Plain. European settlers first called the river Drowning Creek, which is still used as the name of its headwater. The w ...

: located in North and South Carolina. Part of Lumber River State Park *

Myakka River The Myakka River is a river in southwestern Florida. It arises near the Hardee County, Florida, Hardee-Manatee County, Florida, Manatee county line and flows southwest and then southeast through Manatee, Sarasota County, Florida, Sarasota and Cha ...

: 66 mile-long river with its headwaters in

Manatee County, Florida Manatee County is a county in the U.S. state of Florida. As of the 2020 United States census, 2020 U.S. Census, the population was 399,710. Manatee County is part of the Bradenton-Sarasota-Venice, Florida Metropolitan Statistical Area, North Por ...

. The Myakka River discharges into Charlotte Harbor. *

Obion River The Obion River system is the primary surface water drainage system of northwestern Tennessee, United States. Description The Obion has four major forks, the North Fork, Middle Fork, South Fork and Rutherford Fork (which is named after Hen ...

: 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 wor ...

: 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 South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

that passes to the south of the city of

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

and enters the Atlantic Ocean at Ossabaw Sound. *

Ohoopee River The Ohoopee River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 21, 2011 river in east-central Georgia in the United States. It is a tributary of the Altamaha River, which ...

: 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 (U.S. state), Georgia. It flows generally eastward for from its Source (river or stream), origin at the confluence of the Oconee River and Ocmulgee River towards the Atlantic Oce ...

, which flows to the Atlantic Ocean. *

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

: a river in Northeastern

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

. 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, United States. As of the 2020 census, it had a population of 18,629. Elizabeth City is the county seat and most populous city of Pasquotank County. It is the cultural, economic and educational h ...

. *

Peace River The Peace River () 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 the Peace-Athabasca Delta to form the ...

: located in central Florida, flows into Charlotte Harbor. *

Pithlachascotee River The Pithlachascotee River, often called the Cotee or "Cootie" River, is a blackwater river in Pasco County, Florida. Originating near Crews Lake Wilderness Park, Crews Lake, the river flows for over U.S. Geological Survey. National Hydrography ...

: 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 i ...

: a river in southern

Delaware Delaware ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic and South Atlantic states, South Atlantic regions of the United States. It borders Maryland to its south and west, Pennsylvania to its north, New Jersey ...

and southeastern

Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...

on the

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

. 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 (United States), Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula, including parts of the Ea ...

. * 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 hi ...

: 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 most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

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. *

: The largest river in Florida. Flows north through

Jacksonville Jacksonville ( ) is the most populous city proper in the U.S. state of Florida, located on the Atlantic coast of North Florida, northeastern Florida. It is the county seat of Duval County, Florida, Duval County, with which the City of Jacksonv ...

and into the Atlantic. * St. Sebastian River, Indian River County, Florida. *

Suwannee River The Suwannee River (also spelled Suwanee River or Swanee 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 Hydrog ...

: 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 or " Piney Woods" of the Southeast US. The Nat ...

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 pla ...

, 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 Onsl ...

, 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 (state), a state in the northeastern United States * New York City, the most populous city in the United States, located in the state of New York New York may also refer to: Places United Kingdom * ...

: a river starting in the western

Adirondacks The Adirondack Mountains ( ) are a massif of mountains in Northeastern New York (state), New York which form a circular dome approximately wide and covering about . The region contains more than 100 peaks, including Mount Marcy, which is the hi ...

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 (state), New York. The Canada–United Sta ...

. *

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 Michigan, Upper Peninsula of the U.S. state of Michigan, flowing mostly ...

Michigan Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...

: a river in the far western

Upper Peninsula The Upper Peninsula of Michigan—also known as Upper Michigan or colloquially the U.P. or Yoop—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 b ...

that flows into

Lake Superior Lake Superior is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. Lake Michigan–Huron has a larger combined surface area than Superior, but is normally considered tw ...

. 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-f ...

. *

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 H ...

and its tributaries from the

Pine Barrens Pine barrens, pine plains, sand plains, or pineland areas occur throughout the U.S. from Florida to Maine (see Atlantic coastal pine barrens) as well as the Midwest, West, and Canada and parts of Eurasia. Perhaps the most well known pine-barre ...

New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...

, where the dark water is called cedar water * Gooseberry River: a river in northern Minnesota that leaches from peat bogs and pine forests * Ocqueoc River, 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. It is shared on the north and east by the Canadian province of Ontario and on the south and west by the U.S. state of Michigan. The name of the lake is derived from early French ex ...

Tahquamenon River The Tahquamenon River ( ) is an U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed January 3, 2012 blackwater river in the Upper Peninsula of the U.S. state of Michigan. The river flows ...

: 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 th ...

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 The Niger Delta is the delta of the Niger River sitting directly on the Gulf of Guinea on the Atlantic Ocean in Nigeria. It is located within nine coastal southern Nigerian states, which include: all six states from the South South geopolitic ...

) are blackwater.

Australia

Gordon River The Gordon River is a major perennial river located in the central highlands, south-west, and western regions of Tasmania, Australia. Course and features The Gordon River rises below Mount Hobhouse in the Franklin-Gordon Wild Rivers Nation ...

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

: a river rising in the center of the island and flowing westward, emptying into

Macquarie Harbour Macquarie Harbour is a shallow fjord in the West Coast region of Tasmania, Australia. It is approximately , and has an average depth of , with deeper places up to . It is navigable by shallow-draft vessels. The main channel is kept clear by th ...

on the West Coast *

Pieman River The Pieman River is a major perennial river located in the west coast region of Tasmania, Australia. Course and features Formed by the confluence of the Mackintosh River and Murchison River, the Pieman River rises in what is now known as La ...

, 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 thr ...

, 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 o ...

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

: a small section of the Noosa River running between Lake Cootharaba and Lake Cooroibah * Searys Creek, Queensland: a small river running from the Great Sandy National Park to Tin Can Bay stained with tea-tree tannin.

Intermittent blackwater events

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 language, Ngarrindjeri: ''Millewa'', Yorta Yorta language, Yorta Yorta: ''Dhungala'' or ''Tongala'') is a river in Southeastern Australia. It is List of rivers of Australia, Aust ...

Edward River Edward River, or Kolety is 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, as a r ...

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 th ...

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 *

Kapuas River The Kapuas River ( Old Indonesian spelling: Kapoeas River) is a river in the Indonesian part of Borneo island, at the geographic center of Maritime Southeast Asia. At in length, it is the longest river on the island of Borneo, the longest ri ...

Gallery

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

bald cypress ''Taxodium distichum'' (baldcypress, bald-cypress, bald cypress, swamp cypress; ; ''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 w ...

trees in

Trap Pond State Park Trap Pond State Park is a Delaware state park located near Laurel, Delaware, United States. It preserves one of the largest surviving fragments of what was once an extensive wetland in what is now southwestern Sussex County. The state park f ...

in Southern

Manaus-Amazon-NASA.jpg,

Manaus Manaus () is the List of capitals of subdivisions of Brazil, capital and largest city of the States of Brazil, Brazilian state of Amazonas (Brazilian state), Amazonas. It is the List of largest cities in Brazil, seventh-largest city in Brazil, w ...

, the largest city on the Amazon River, from a

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

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 Mitú () is the capital town of the department of Vaupés in Colombia. It is a small town located in South eastern Colombia in the Amazon Basin. Founded in 1936, Mitú lies next to the Vaupés River at 180 meters above sea level. It is where th ...

, Colombia

References

{{Wetlands Aquatic ecology Rivers