The Big Sioux River is 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 drainage ...

of the Missouri River in eastern

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota people, Lakota and Dakota peo ...

and northwestern

Iowa Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to the ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. It flows generally southwardly for ,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data
The National Map
, accessed March 30, 2011 and its watershed is . The

United States Board on Geographic Names The United States Board on Geographic Names (BGN) is a federal body operating under the United States Secretary of the Interior. The purpose of the board is to establish and maintain uniform usage of geographic names throughout the federal governm ...

settled on "Big Sioux River" as the stream's name in 1931. The river was named after the Lakota people (Sioux Natives) which was known by them as Tehankasandata, or Thick Wooded River. The Big Sioux River rises in

Roberts County, South Dakota Roberts County is a county in the U.S. state of South Dakota. As of the 2020 United States Census, the population was 10,280. Its county seat is Sisseton. The county was named either for S. G. Roberts of Fargo, North Dakota, or for Solomon Robar ...

on a low plateau known as the

Coteau des Prairies The Coteau des Prairies is a plateau approximately 200 miles in length and 100 miles in width (320 by 160 km), rising from the prairie flatlands in eastern South Dakota, southwestern Minnesota, and northwestern Iowa in the United States. ...

and flows generally southwardly through

Grant Grant or Grants may refer to: Places *Grant County (disambiguation) Australia * Grant, Queensland, a locality in the Barcaldine Region, Queensland, Australia United Kingdom *Castle Grant United States * Grant, Alabama *Grant, Inyo County, C ...

, Codington,

Hamlin Hamlin may refer to: Places * Hamlin, Iowa, a city * Hamlin, Kansas, a city * Hamlin, Kentucky, a town * Hamlin, Maine, a town * Hamlin, Michigan, a former community * Hamlin, New York, a town ** Hamlin (CDP), New York, a census-designated pl ...

, Brookings, Moody, and

Minnehaha Minnehaha is a Native American woman documented in Henry Wadsworth Longfellow's 1855 epic poem ''The Song of Hiawatha''. She is the lover of the titular protagonist Hiawatha and comes to a tragic end. The name, often said to mean "laughing wat ...

counties, past the communities of

Watertown Watertown may refer to: Places in China In China, a water town is a type of ancient scenic town known for its waterways. Places in the United States *Watertown, Connecticut, a New England town **Watertown (CDP), Connecticut, the central village ...

, Castlewood,

Bruce The English language name Bruce arrived in Scotland with the Normans, from the place name Brix, Manche in Normandy, France, meaning "the willowlands". Initially promulgated via the descendants of king Robert the Bruce (1274−1329), it has been a ...

, Flandreau,

Egan Egan may refer to: People * Egan (surname) * Egan (given name) Places in the United States * Egan, Illinois, an unincorporated community * Egan, Louisiana, an unincorporated community and census-designated place * Egan, South Dakota, a city * Eg ...

Trent Trent may refer to: Places Italy * Trento in northern Italy, site of the Council of Trent United Kingdom * Trent, Dorset, England, United Kingdom Germany * Trent, Germany, a municipality on the island of Rügen United States * Trent, California, ...

, Dell Rapids, and

Baltic Baltic may refer to: Peoples and languages * Baltic languages, a subfamily of Indo-European languages, including Lithuanian, Latvian and extinct Old Prussian *Balts (or Baltic peoples), ethnic groups speaking the Baltic languages and/or originati ...

Sioux Falls Sioux Falls () is the most populous city in the U.S. state of South Dakota and the 130th-most populous city in the United States. It is the county seat of Minnehaha County and also extends into Lincoln County to the south, which continues up t ...

, where it passes over a

waterfall A waterfall is a point in a river or stream where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf. Waterfalls can be formed in several wa ...

Falls Park Falls Park is a public park in north central Sioux Falls, South Dakota, surrounding the city's falls. The Big Sioux River The Big Sioux River is a tributary of the Missouri River in eastern South Dakota and northwestern Iowa in the United S ...

, which gives that city its name. Downstream of Sioux Falls and the community of

Brandon Brandon may refer to: Names and people *Brandon (given name), a male given name *Brandon (surname), a surname with several different origins Places Australia *Brandon, a farm and 19th century homestead in Seaham, New South Wales *Brandon, Q ...

, the Big Sioux defines the boundary between South Dakota and Iowa, flowing along the eastern borders of

Lincoln Lincoln most commonly refers to: * Abraham Lincoln (1809–1865), the sixteenth president of the United States * Lincoln, England, cathedral city and county town of Lincolnshire, England * Lincoln, Nebraska, the capital of Nebraska, U.S. * Lincol ...

and

Union Union commonly refers to: * Trade union, an organization of workers * Union (set theory), in mathematics, a fundamental operation on sets Union may also refer to: Arts and entertainment Music * Union (band), an American rock group ** ''Un ...

counties in South Dakota, and the western borders of

Lyon Lyon,, ; Occitan: ''Lion'', hist. ''Lionés'' also spelled in English as Lyons, is the third-largest city and second-largest metropolitan area of France. It is located at the confluence of the rivers Rhône and Saône, to the northwest of t ...

Sioux The Sioux or Oceti Sakowin (; Dakota language, Dakota: Help:IPA, /otʃʰeːtʰi ʃakoːwĩ/) are groups of Native Americans in the United States, Native American tribes and First Nations in Canada, First Nations peoples in North America. The ...

and

Plymouth Plymouth () is a port city and unitary authority in South West England. It is located on the south coast of Devon, approximately south-west of Exeter and south-west of London. It is bordered by Cornwall to the west and south-west. Plymouth ...

counties in Iowa, past the communities of Canton, Fairview,

Hudson Hudson may refer to: People * Hudson (given name) * Hudson (surname) * Henry Hudson, English explorer * Hudson (footballer, born 1986), Hudson Fernando Tobias de Carvalho, Brazilian football right-back * Hudson (footballer, born 1988), Hudso ...

Hawarden Hawarden (; cy, Penarlâg) is a village, community (Wales), community and Wards and electoral divisions of the United Kingdom, electoral ward in Flintshire, Wales. It is part of the Deeside conurbation on the Wales-England border and is home ...

, North Sioux City, and Dakota Dunes in South Dakota and Beloit,

and

Akron Akron () is the fifth-largest city in the U.S. state of Ohio and is the county seat of Summit County. It is located on the western edge of the Glaciated Allegheny Plateau, about south of downtown Cleveland. As of the 2020 Census, the city prop ...

in Iowa. It joins the Missouri River from the north at

Sioux City, Iowa Sioux City () is a city in Woodbury and Plymouth counties in the northwestern part of the U.S. state of Iowa. The population was 85,797 in the 2020 census, making it the fourth-largest city in Iowa. The bulk of the city is in Woodbury County, ...

DeLorme DeLorme is the producer of personal satellite tracking, messaging, and navigation technology. The company’s main product, ''inReach'', integrates GPS and satellite technologies. ''inReach'' provides the ability to send and receive text messages ...

(1998). ''Iowa Atlas & Gazetteer''. Yarmouth, Maine: DeLorme.

(2001). ''South Dakota Atlas & Gazetteer''. Yarmouth, Maine: DeLorme. The Big Sioux River, at the

USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...

station in

, has a mean annual discharge of approximately 3,793 cubic feet per second.

Tributaries

The Big Sioux River collects the Rock River from the northeast in Sioux County, Iowa. A minor

headwaters The headwaters of a river or stream is the farthest place in that river or stream from its estuary or downstream confluence with another river, as measured along the course of the river. It is also known as a river's source. Definition The ...

tributary of the Big Sioux in Grant County, South Dakota, is known as the Indian River. Broken Kettle Creek has its confluence with the Big Sioux in Plymouth County, Iowa.

Pollution

The Big Sioux is South Dakota's most populated river basin. Agriculture is the primary use of land along most of the river's course. To comply with the

Clean Water Act The Clean Water Act (CWA) is the primary federal law in the United States governing water pollution. Its objective is to restore and maintain the chemical, physical, and biological integrity of the nation's waters; recognizing the responsibiliti ...

, the state monitors water quality of its rivers. Most of the Big Sioux north of Sioux Falls was scored well in 2012. Portions near

Lake Kampeska Lake Kampeska is a inland glacial lake A glacial lake is a body of water with origins from glacier activity. They are formed when a glacier erodes the land and then melts, filling the depression created by the glacier. Formation Near the end ...

and between Willow and Stray Horse Creeks ( Codington and

counties) exceeded federally allowable levels of ''

E. coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...

'' and

fecal coliform A fecal coliform (British: faecal coliform) is a facultatively anaerobic, rod-shaped, gram-negative, non-sporulating bacterium. Coliform bacteria generally originate in the intestines of warm-blooded animals. Fecal coliforms are capable of growth ...

bacteria. However, the Big Sioux south of Sioux Falls is much more polluted with ''E. coli'', fecal coliform, and

suspended solids Suspended solids refers to small solid particles which remain in suspension in water as a colloid or due to motion of the water. Suspended solids can be removed by sedimentation if their size or density is comparatively large, or by filtration. It ...

. Several portions heavily restrict fishing or human contact, and swimming is banned.

Flood control

Between 1955 and 1961, an extensive

flood control Flood control methods are used to reduce or prevent the detrimental effects of flood waters."Flood Control", MSN Encarta, 2008 (see below: Further reading). Flood relief methods are used to reduce the effects of flood waters or high water level ...

system was constructed by the

U.S. Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

along the Big Sioux and some of its tributaries in Sioux Falls to protect the city from a

100-year flood A 100-year flood is a flood event that has a 1 in 100 chance (1% probability) of being equaled or exceeded in any given year. The 100-year flood is also referred to as the 1% flood, since its annual exceedance probability is 1%.Holmes, R.R., Jr. ...

event. Features of the system include of

levees A levee (), dike (American English), dyke (Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually earthen and that often runs parallel to the course of a river in its floodplain or along low-lying coastlin ...

, a

floodwall A flood wall (or floodwall) is a primarily vertical artificial barrier designed to temporarily contain the waters of a river or other waterway which may rise to unusual levels during seasonal or extreme weather events. Flood walls are mainly u ...

in downtown, and a diversion channel with a dam at one end and a spillway at the other. The diversion channel connects two ends of the Big Sioux's natural loop around central Sioux Falls in an effort to channel floodwater away from the city. The levees then act to contain any floodwater either remaining in the natural channel or originating from Skunk Creek (whose mouth is downriver of the diversion dam).Jorgensen, Don. ''Sioux Falls diverts water to ease flooding'

KELO-TV KELO-TV (channel 11) is a television station in Sioux Falls, South Dakota, United States, affiliated with CBS and MyNetworkTV. The station is owned by Nexstar Media Group, and maintains studios on Phillips Avenue in downtown Sioux Falls; its tran ...

. March 15, 2010. (accessed April 19, 2010). Additionally, a greenway covers much of the river's floodplain in southern and eastern Sioux Falls, further mitigating any property damage from high water.

Flooding

The Big Sioux River experienced record-breaking flooding during the 2019 Midwestern U.S. floods. The Big Sioux River Flood Information System was used to model flooding during the March 2019 bomb cyclone event. The river overflowed its banks between September 12–15, 2019, flooding three blocks of

Dell Rapids, South Dakota Dell Rapids is a city in Minnehaha County, South Dakota, Minnehaha County, South Dakota, United States. The population was 3,996 at the 2020 United States Census, 2020 census. It is known as "The Little City with the Big Attractions." The city to ...

, and damaging up to a dozen homes.

Interstate 90 Interstate 90 (I-90) is an east–west transcontinental freeway and the longest Interstate Highway in the United States at . It begins in Seattle, Washington, and travels through the Pacific Northwest, Mountain West, Great Plains, Midwest, and ...

was shut down between

Mitchell Mitchell may refer to: People *Mitchell (surname) *Mitchell (given name) Places Australia * Mitchell, Australian Capital Territory, a light-industrial estate * Mitchell, New South Wales, a suburb of Bathurst * Mitchell, Northern Territo ...

and Sioux Falls.

Tributaries

Pollution

Flood control

Flooding

See also

References

Further reading