Problem $1$: A $65-$acre forest$/$timber land is to be converted into residential multiunit$/$paved drainage path. Find the pre$-$ and post$-$development peak runoff from the area based on the rational method. The design rainfall has a $25-$year return period. The IDF curve is given by $\backslash ($ i$=198/\backslash$left$($t$\_\{$c$\}+10\backslash$right$)\backslash ),$ where $\backslash ($ i $\backslash )$ is rainfall intensity in inches $\backslash (/\backslash$mathrm$\{$hr$\}\backslash )$ and $\backslash ($ t$\_\{$c$\}\backslash )$ is the time of concentration in minutes. Point $\text{'}$ C $\text{'}$ represents the outlet of the area. AC is the path that takes the longest time for the runoff to reach the outlet. Segment AB has a length of $950$ ft and average slope of $\backslash (3\mathrm{.}5\backslash \%\backslash ),$ while segment BC has a length of $1100$ ft and average slope of $\backslash (2\mathrm{.}3\backslash \%\backslash ).[10]$

Hint: Find velocity from the graph for segments AB and BC and the corresponding travel times. Find the time of concentration by adding the two travel times. Use the IDF equation to find the rainfall intensity and then use the rational method to find peak discharge. Make sure to use the proper values for frequency factor. Must repeat the process for post$-$development.