United States Supreme Court
264 U.S. 146 (1924)
Where property is physically invaded by water, earth, sand, or other material, so as to effectually destroy or diminish the property’s usefulness, a taking has occurred, and compensation is owed.
It is necessary that the invasion be the direct result of a public structure or other improvement, and that the invasion be actual and permanent, amounting to an appropriation of the land and not merely an injury.
