Riprap — also known as rip rap, rubble, revetment, shot rock or rock armour — is rock or other material used to armor shorelines and streambeds against water erosion. Use Riprap reduces water erosion by resisting the hydraulic attack and dissipating the energy of flowing water or waves. The shape of rock is important. Coarse, angular rock, usually made by crushing or blasting, or from scree, is more effective at ground reinforcement than round river rock. A correct mixture of aggr… (More on Riprap)