Land drainage refers to deliberate removal of surface water and lowering of the water table in order to drain wetlands, typically for land uses such as agriculture. Drainage of floodplains began soon after European settlement of the contiguous United States: George Washington’s personal library included a manual on land drainage, for example.

Land drainage can employ artificial levees to limit overbank flooding, drainage canals to convey water from a floodplain, tile drains that are subsurface pipes designed to collect and carry away water beneath the surface, or some combination of these techniques. During the 20th century, scientists systematically documented the vital role that floodplain wetlands play in providing habitat for diverse organisms, attenuating floods, enhancing nutrient uptake, and storing organic carbon in soil, but people living in regions historically rich in wetlands have understood for more than a century how loss of this ecosystem impoverished their world (see the story map for the Illinois River). Floodplain drainage does facilitate agricultural and urban access to formerly flood-prone, wet areas, but also substantially reduces habitat, biodiversity, flood attenuation, nutrient uptake, and carbon storage. 

Mitsch, W.J., L. Zhang, D.F. Fink, M.E. Hernandez, A.E. Altor, C.L. Tuttle, and A.M. Nahlik. 2008. Ecological engineering of floodplains. Ecohydrology and Hydrobiology, 8, 139-147.

Vileisis, A. 1997. Discovering the Unknown Landscape: A History of America’s Wetlands. Island Press, Washington, DC.

Wohl, E. 2013. Wide Rivers Crossed: The South Platte and the Illinois of the American Prairie. University Press of Colorado, Boulder, CO.

Wohl, E., J. Castro, B. Cluer, D. Merritts, P. Powers, B. Staab, and C. Thorne. 2021. Rediscovering, reevaluating, and restoring lost river-wetland corridors. Frontiers in Earth Science, 9, 653623.