CIV E 530 - OPEN-CHANNEL HYDRAULICS FALL 2008 HOMEWORK No. 13 Design a circular concrete culvert with the following data:   Q = 220 cfs; inlet invert elevation = 100 ft; stream bed slope = 0.02; culvert length = 200 ft; tailwater depth above outlet invert = 4 ft; and roadway shoulder elevation = 112 ft. Assume f = 0.015, Manning's n = 0.013, entrance type is square edge with headwalls, and upstream freeboard = 2 ft.