Riprap

a name commonly applied to a wall of broken stones laid up loosely for protective purposes. Railroad embankments are faced with a loose, slanting wall of this description to prevent their being washed away by encroaching streams. In Europe where labor is cheap and bottom land is valuable, the shores of rivers are not infrequently riprapped to prevent the carrying away of rich soil. The Swiss banks of the Rhone and other streams are protected in this way. Riprap on a shore with little dip is practically a sort of paving. The term is applied also to heaps of broken stone dumped in a river just above piers and abutments to break the force of the current. See Galveston