Consider a conceptual urban drainage design presented below for three urbanized subcatchments $($A$,$ B$,$ and C$)$ with areas varying between $1\mathrm{.}5$ and $3$ acres, as shown in the figure below.

Compute the stormwater runoff peak flow using the Rational Method, assuming a rainfall intensity of $5\mathrm{.}95$ inches$/$hour$.$

Each of these subcatchments will drain their stormwater runoff to sewers $S1,S2,$ and $S3,$ as shown in the figure below. The commercially available sewer diameter options are $1,2,3,4,5$ and $6-$ft diameters. Using the diagram Q$/$Qf on this page, design the sewer'size option that yields a flow depth in each sewer that is nearest to $70\%$ of the diameter.

Considering all the runoff contributions from areas A$,$ B$,$ and C$,$ calculate the anticipated water depth in the triangular grassed swale that receives the inflows from all the sewers.