Problem $5.(15$ points$)$ A suburban watershed can be divided into ${?}^3$ Bub$=$

catchments, with $40\%$ of area covered by paved surface $(CN=98),15\%$ of area

covered by business districts $(CN=88),$ and the remaining area covered by lawns

and parks $($GN $61).$ The total area of this watershed is $5$ ml $,$ and assume an

average slope of $2\mathrm{.}5\%$ and a hydraulic length of $1\mathrm{.}6$ mi $.$ Use the equations for

developing the triangular SCS Unit Hydrograph to determine:

$(1)$ The time to peak $(C_p,hr).$

$(2)$ Peak discharge $(q$ p$,$ in efs$).$

$($hint: $(1)$ ealculate the area weighted CN first: $(2)$ the peak flow is based on the total

runoff $Q=1$ inch of rainfall exeess$)$