Given: A narrow bridge over a river with $600$ cfs discharge, width of $45$ ft$,$ banks of $8$ ft$,$

sand bottom $($d$50=0\mathrm{.}9$ mm$),$ slope of $0\mathrm{.}0003.$ The bridge has a pier of width of $4$ ft with

a bottom located $30$ ft below the riverbed. Distance between abutments is $40$ ft$.$

Find: $($a$)$ If the bridge causes flooding

$($b$)$ If bridge will fail due to scour

solve it referring to hydraulic structures $4$th edition