Levee

A levee ( or ), dike (American English), dyke (Commonwealth English), embankment, floodbank, or stop bank is a structure used to keep the course of rivers from changing and to protect against flooding of the area adjoining the river or coast. It is usually earthen and often runs parallel to the course of a river in its floodplain or along low-lying coastlines.

Levees can be naturally occurring ridge structures that form next to the bank of a river or be an artificially constructed fill or wall that regulates water levels. However, levees can be bad for the environment. Floodwalls are a more confined alternative.

Ancient civilizations in the Indus Valley, ancient Egypt, Mesopotamia and China all built levees. Today, levees can be found around the world, and failures of levees due to erosion or other causes can be major disasters, such as the catastrophic 2005 levee failures in Greater New Orleans that occurred as a result of Hurricane Katrina. Provided by Wikipedia