online_culvert:   Hydraulic design of highway culverts by FHWA method Reference Hydraulic Design of Highway Culverts, HDS 5, Federal Highway Administration, September 1985. SAMPLE INPUT: [HW/D table]       [Main page]       [Description] SAMPLE INPUT: Units: U.S. Customary The design discharge Q:   200   [cfs] The inlet invert elevation z1:   100   [ft] Manning's n:   0.013 The natural streambed slope So:   0.01 The tailwater depth above the outlet invert y2:   3.5   [ft] The culvert length L:   200   [ft] The roadway shoulder elevation Es:   110   [ft] Freeboard Fb:   2   [ft] SAMPLE OUTPUT: Culvert diameter D:   5 ft Critical depth yc:   4.037 ft Normal depth yn:   3.284 ft Thank you for running online_culvert   [130301]