Yazoo stream

A Yazoo stream is a geologic and hydrologic term for any tributary stream that runs parallel to, and within the floodplain 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 or a 'deferred' junction. The name is derived from a now vanished 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.

Runs parallel to the Mississippi River for 280 km (170 mi) before converging, being constrained from doing so upstream by the river's natural and man-made levees.

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

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

Over time, the main river flows through the landscape, widening a valley and creating a floodplain. Sediment accumulates and creates a natural levee. 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 floodplain for a considerable distance. These series of smooth bends or curves flows with a slight gradient, usually south, 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.

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 Mendenhall Glacier carved out a wide floodplain 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.

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