$10-$A concrete box culvert will be constructed under a highway to convey flow from a small tributary. The design storm produces a peak flow of $120cfs,$ and the design criterion is that the road cannot be flooded for the design event. The maximum height the box can be is $4\mathrm{.}0$ feet, which provides $1\mathrm{.}0$ foot of cover to the top of pavement. Assuming the maximum box height and $45-$degree wingwalls, what is the minimum width of box that will convey the design flow, in feet? Use the nomograph.