$5.(15$ pt$)$ Stormwater Design $-$ Given the image posted as Stormwater.pdf$,$ answer the following questions regarding approach and methods for stormwater design. Flow from subbasin $1$ is collected at location A is piped to location B where more flow is collected from subbasin $2$ and then it is all piped to $\backslash ($ C $\backslash )$ and then $\backslash ($ D $\backslash ).$ At location $\backslash ($ D $\backslash ),$ flow from subbasin $3$ is collected. All of this flow is then transported to the outfall where it enters the natural environment. There is another subbasin at the top where runoff drains to a vegetated open channel $($labeled X$-$Y$-$Z$).$

$($a$)$ Describe your approach to design the underground stormwater pipe conveyance system to the outfall location. Include as much detail as possible from start to finish. Site the methods that you would use and how you would obtain the necessary information to use these methods.

$($b$)$ If the $\backslash ($ Q $\backslash )$ p at location $\backslash ($ A $\backslash )$ is $8$ cfs and the slope of the pipe from $\backslash ($ A $\backslash )$ to $\backslash ($ B $\backslash )$ is $0\mathrm{.}003,$ what standard pipe size should be specified to convey flow from $\backslash ($ A $\backslash )$ to $\backslash ($ B $\backslash )?$

$($c$)$ If Qp in the $820$ ft long open channel is $38$ cfs $,$ the Manning roughness coefficient is $0\mathrm{.}035,$ the bottom width of the trapezoidal cross section is $6$ ft and the side slopes are $\backslash (3\backslash$mathrm$\{$H$\}$: $1\backslash$mathrm$\{$~V$\}\backslash ),$ what is the normal depth?