A surface infiltration basin will be constructed to manage $1$ in $(25$mm$)$ of runoff over $1-$ha drainage area.

The surrounding soils are classified as loamy sand with an infiltration rate of $1\mathrm{.}6$ in$/$h$.$ The basin filling

time is designed as $2$ h and the maximum holding time is $24$ h$.$ Assume that sediment and biogrowth

clogging factor is $0\mathrm{.}49.$

A$.$ For side slopes of $3$:$1$ and a bottom length$-$to$-$width ratio of $4$:$1,$ find the dimensions of the infiltration

basin.

B$.$ Find the volume of sand necessary for the bottom fill of the infiltration basin.