Floodplain soils are often poorly drained, due to the nearness of the water table to the surface. Floodplains result from the continuous process of deposition of material and later cutting away of the surface material over time by the river's meandering. The floodplain may be not much wider than the river's channel where banks are steep. It may extend for many hundreds of feet from the ordinary high water line in low-lying areas. Because of the deposited sediments and high water table, floodplains contain a high diversity of plants and animals.
Flooding is a natural process.
Floodplains dissipate the energy of spring torrents, reducing flood damage downstream and providing recharge areas for adjacent streams. However, runoff from a watershed can be greatly influenced by the kinds of plants and soils in the watershed. Vegetated stream banks reduce the likelihood of flooding. Where overgrazing, timbering, or homesite development removes vegetation, flood events occur more often and with greater severity. Healthy floodplains are those where the activities occurring within the floodplain are benefited by or can adapt to occasional flooding, such as agriculture, recreation, and wildlife.