Floodplain

For other uses, see Floodplain (disambiguation).

Paraná River floodplain, at its confluence with the headstream of the Paranaíba (on the right) and the Verde River, near Panorama, Brazil

A floodplain after a one-in-10-year flood on the Isle of Wight

Gravel floodplain of a glacial river near the Snow Mountains in Alaska, 1902

The Laramie River meanders across its floodplain in Albany County, Wyoming, 1949

This aggradational floodplain of a small meandering stream in La Plata County, Colorado, is underlain by silt deposited above a dam formed by a terminal moraine left by the Wisconsin Glacier.

Riparian vegetation on the floodplain of the Lynches River, close to Johnsonville, South Carolina. These tupelo and cypress trees show the high-water mark of flooding.

A floodplain or flood plain or bottomlands is an area of land adjacent to a river that stretches from the banks of the river channel to the base of the enclosing valley and experiences flooding during periods of high discharge. The soils usually consist of clays, silts, sands, and gravels deposited during floods.

Because of regular flooding, floodplains frequently have high soil fertility since nutrients are deposited with the flood waters. This can encourage farming; some important agricultural regions, such as the Nile and Mississippi river basins, heavily exploit floodplains. Agricultural and urban regions have developed near or on floodplains to take advantage of the rich soil and freshwater. However, the risk of inundation has led to increasing efforts to control flooding.