Q$1.$An accommodation area $3$ km$^2,$ the building covered about $40\%$ from this area, the roads and paths covered about $35\%$ from this area and the remaining area covered green plants$($green area$)$in sand soil and the rain intensity$($i$)=110$ mm$/$hr$.$ Also given: The different values of runoff coefficients are as follows: C$=(0\mathrm{.}95$ to $0\mathrm{.}70)0\mathrm{.}83$ for the upper surface of the building in the total area. C$2=(0\mathrm{.}85$ to $0\mathrm{.}75)0\mathrm{.}80$ for the roads and paths in the total area.C$3=(0\mathrm{.}10$ to $0\mathrm{.}05)0\mathrm{.}075-$for the green area $($plants$)$ in total area.$(1)$ Estimate the average value of runoff coefficient of the total area $($Cavg$.).(2)$ Calculate the amount of drained water$($runoff$)$ or peak discharge from this area