Floodplains are those areas of land adjacent to rivers which periodically flood; they are naturally capable of supporting a wide range of habitats. In the past, their use by humans was limited to management practices compatible with the natural flooding regime of the river. With both terrestrial and freshwater components, floodplains are complex systems.

Where natural flooding still occurs, floodplains may be managed as pasture (used for livestock grazing) or as meadows (cut for hay or silage then grazed). There is little natural floodplain woodland left in the UK.

Most floodplains have been greatly altered by drainage and the creation of flood defences, and where flooding is prevented, floodplains are often used for arable crops or have even been developed.

Floodplains cover over 1.6 million hectares in England and Wales but just 3000 ha is occupied by species-rich floodplain grassland.

Floodplain meadows are thought to have been widespread wherever suitable substrate, topography, hydrological regime and land-use practices coincided. However, the flat terrain and fertile soils of floodplains made floodplain meadows more likely to be agriculturally improved than other lowland grassland types, losses exacerbated by sand and gravel extraction, urban and industrial development and hydrological changes to river floodplains.