Caltrans New Riprap Classes Caltrans Riprap Sizes Circular Pipe Alternate Depth Circular Pipe: Manning's n FHWA Riprap Size HDS-5 Inlet Control Equations HEC 14: Riprap Apron HEC-15: Permissible Shear Stress HEC-15: Riprap and Gravel Lining Design HEC-15: Vegetative Lining Design HEC-22 PAVEMENT DRAINAGE HY-8 Polynomial Coefficients Is Q=CiA Dimensionally Consistent? Manning's Equation Manning's n For Riprap-Lined Channels Nominal Pipe Diameters Shear Stress & Permissible Velocity Side Slopes & Clear Recovery Zone Trapezoidal Channel: Manning's n