Determine the minimum diameter $($in$)$ for the culvert above.

You will first determine the minimum diameter for inlet control.

You will then use that diameter as the starting $($minimum$)$ diameter for outlet control and determine if it will pass the flow or if you need to increase the diameter.

Minimum diameter is $18$ inches increasing by $6$ inches $($i$.$e$.,24$ inch, $30$ inch, $36$ inch, etc.$).$

Inlet Control: Orifice $-Q=C^{**}{A}^{**}(2gH{)}^{0\mathrm{.}5}(C=0\mathrm{.}6$;$A={3\mathrm{.}14}^{**}\frac{D^2}{4}$;$g=32\mathrm{.}2f\frac{t}{s^2}$;$H$ is water surface to centerline$)$

butlet Control: $HW+$SOL$=H+TW$

$H=Q^2[\frac{0\mathrm{.}025204(1+K_e)}{D^4}+\frac{4\mathrm{.}6618N^{2}L}{D^{\frac{16}{3}}}]$

$Q(cfs),L(ft),D(ft)$