A raised bank of alluvium flanking a river. The bank is built up when the river dumps much of its load during flooding. New Orleans was founded on a natural levée; elevations as high as 19 feet above sea level provided the driest land for settlement. French colonists created their own levées, and ever since permanent settlement began, residents have been expanding the levées. See Turner (2007) Tech. in Soc. 29, 2 on the repetitive disasters resulting from levée failure around, and within, New Orleans.