Big Sioux River facts for kids
The Big Sioux River is a long river, about 419 miles (674 km) in length. It flows through eastern South Dakota and northwestern Iowa in the United States. This river is a branch of the mighty Missouri River.
The name "Big Sioux River" was officially chosen in 1931. The river was named after the Lakota people, also known as the Sioux Natives. They called it "Tehankasandata," which means "Thick Wooded River."
The Big Sioux River starts in Roberts County, South Dakota, on a low, flat area called the Coteau des Prairies. It generally flows south through several counties in South Dakota. These include Grant, Codington, Hamlin, Brookings, Moody, and Minnehaha counties.
Along its path, the river passes by many towns. Some of these are Watertown, Flandreau, and Dell Rapids. It then reaches Sioux Falls. Here, the river flows over a beautiful waterfall in Falls Park. This waterfall is actually how the city of Sioux Falls got its name!
After Sioux Falls, the Big Sioux River forms the border between South Dakota and Iowa. It flows along the eastern edge of Lincoln and Union counties in South Dakota. On the Iowa side, it borders Lyon, Sioux, and Plymouth counties.
More towns are found along this part of the river. These include Canton and North Sioux City in South Dakota. In Iowa, towns like Hawarden and Akron are by the river. Finally, the Big Sioux River joins the Missouri River from the north at Sioux City, Iowa.
At Sioux City, about 3,793 cubic feet of water flow through the Big Sioux River every second. This is how much water moves through the river on average each year.
River Branches
The Big Sioux River collects water from other rivers that flow into it. One important river is the Rock River. It joins the Big Sioux from the northeast in Sioux County, Iowa.
Near where the Big Sioux River begins in Grant County, South Dakota, there's a smaller branch called the Indian River. Another stream, Broken Kettle Creek, also flows into the Big Sioux in Plymouth County, Iowa.
River Health
The Big Sioux River basin is home to many people in South Dakota. Most of the land along the river is used for farming. To keep the water clean, the state checks the river's water quality. This is part of the Clean Water Act.
In 2012, most of the Big Sioux River north of Sioux Falls had good water quality. However, some parts near Lake Kampeska and between Willow and Stray Horse Creeks had too much bacteria like E. coli.
The Big Sioux River south of Sioux Falls has more pollution. It has higher levels of bacteria and also more mud and other particles floating in the water. Because of this, fishing is limited in some areas. Also, it's not safe to swim or have direct contact with the water in many parts.
Controlling Floods
Between 1955 and 1961, a big system was built to control floods. The United States Army Corps of Engineers created this system. It protects Sioux Falls from very large floods.
This system includes about 29 miles (47 km) of levees, which are like walls built along the river. There's also a floodwall in downtown Sioux Falls. A special channel, about 15,000 feet (4,572 m) long, helps move floodwater away from the city. This channel connects two parts of the river's natural path.
The levees help hold back any floodwater that stays in the main river channel. They also manage water from Skunk Creek. A greenway, which is a natural area, also covers much of the river's flood plain. This helps reduce damage to buildings during high water.
Recent Floods
The Big Sioux River has experienced some very big floods. In 2019, the river had record-breaking floods during the 2019 Midwestern U.S. floods.
A special system called the Big Sioux River Flood Information System helped model the flooding. This was used during the March 2019 bomb cyclone event.
From September 12 to 15, 2019, the river overflowed its banks. This caused flooding in three blocks of Dell Rapids, South Dakota. It also damaged about a dozen homes. Interstate 90 was even closed between Mitchell and Sioux Falls because of the high water.
See also
In Spanish: Río Big Sioux para niños
