$(20$ pts$)$ A rectangular weir is needed to measure and control flow for an irrigation project. The

flow range is $3-5f\frac{t^3}{s}$ and the height of water above the weir $(H)$ should remain between $0\mathrm{.}5$

and $0\mathrm{.}8$ ft $.$ If the weir height, $Y=1ft,$ what weir crest length, $b,$ do you recommend?

$Q$~~$(0\mathrm{.}564+0\mathrm{.}0846\frac{H}{Y})b{g}^{\frac{1}{2}}{H}^{\frac{3}{2}}$

$($a$)$ ruil$-$wium setaangic.