4ft (w) x 3 ft (d) box concrete culverts (n=0.013, entrance has 90° and 15° wingwall flares) carry 150 cfs along a 31-m length of pipe constructed at 1.0 % slope. the tailwater depth is 2 ft.
a) what is the headwater depth?
b) are the culverts flowing under inlet or outlet control conditions?
c) what would the headwater depth and flow regime for a flow rate of 190 cfs