A Yazoo stream (also called a Yazoo tributary) is a geologic and hydrologic term for any

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 drainag ...

stream that runs parallel to, and within the

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

of a larger river for considerable distance, before eventually joining it. This is especially the characteristic when such a stream is forced to flow along the base of the main river's natural levee. Where the two meet is known as a "belated

confluence In geography, a confluence (also: ''conflux'') occurs where two or more flowing bodies of water join to form a single channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river ( main stem); ...

" or a "deferred junction". The name is derived from an exterminated Native American tribe, the Yazoo Indians. The Choctaw word is translated to "River of Death" because of the strong flows under its bank full stage.

Examples

Yazoo River

Yazoo River runs parallel to the

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it ...

for before converging, being constrained from doing so upstream by the river's natural and man-made

levee 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 coastl ...

Mossy Creek

Moesian stream/flow is a parallel derivative remnant of paleoriver. Many Yazoo streams are actually paleo-remnants of just one original river. The good examples of moesian flow are Mossy Creek,

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

and Jezava, Morava.

Montana and Jordan creeks

Important salmonoid fish habitat and large spruce forests inhabit these streams which flow into the Mendenhall River in Alaska.

Tributaries of the Wakarusa River

Yazoo streams here drain the back swamps of the Wakarusa River Valley.

Formation

Natural levees

Over time, the main river flows through the landscape, widening a valley and creating a

Sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sa ...

accumulates and creates a natural

. Tributaries that want to enter the main channel are not allowed because of this levee. Instead, the water then enters the back swamps, or form a yazoo stream. Because yazoo streams are separated from the main river by natural levees, they flow and meander (streams and rivers rarely flow in straight lines) parallel to the main stream channel or river on the

for a considerable distance. These series of smooth bends or curves flows with a slight gradient, and is normally blocked from entering by a natural levee along the larger stream. A yazoo stream will join the major river where it will eventually break through the natural levees and flow into the larger waterway at its belated confluence. Montanaseries2

Yazoo stream formation can also be influenced by glacial processes. An example is the formation of the Montana Creek valley during the recent

Little Ice Age The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region. It was not a true ice age of global extent. The term was introduced into scientific literature by François E. Matthes in 1939. Ma ...

. The Mendenhall Glacier carved out a wide

that is domed in the center. High valley walls due to tectonic uplift and glacial outwash (the natural levee) create two yazoo streams that parallel the Mendenhall River.

Flooding and human influence

Floods are a major driving force for yazoo streams. In the Yazoo Basin,

settler A settler is a person who has migrated to an area and established a permanent residence there, often to colonize the area. A settler who migrates to an area previously uninhabited or sparsely inhabited may be described as a pioneer. Settl ...

s were faced with high waters for most of the year, making it hard for building homes and maintaining agriculture. A few man-made

s were built to improve conditions. In 1927, large floods ravaged the area, allowing Congress to take action into building dams and more levees to reduce the risk of floods. Human alteration within

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) processes prevailing, especially in the soils. The ...

s and streams have resulted in a decrease in ecological functions and associated benefits to society. Miles of streams are in poor condition with high

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seve ...

and

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ea ...

concentrations. Yazoo streams have been altered through intense agricultural activities and flood control measures. Low water, excessive sedimentation, and the accumulation of pesticides such as DDT are the consequences of human disturbances.

References

{{Reflist Geomorphology Floodplains Fluvial landforms Physical geography Riparian zone Rivers Water streams