$(8$ pt$)$ You've been tasked to assess runoff rates due to construction of an aircraft parking

ramp at a base near Tallahasee, Florida. The area under consideration is $250$ acres of open

pasture and you intend to pave $30\%$ with reinforced concrete. You determine that the time

of concentration for this area will decrease from $3$ hours to $40$ minutes after the ramp is in

place. Currently a grass$-$lined drainage ditch carries the runoff for the $250$ acres. For

runoff coefficients, use the highest published range value in the approriate category.

a$)$ If you design for a $50-$ yr storm, how much will the peak runoff flow rate change? Report

the answer as a $\%$ increase in flowrate.

b$)$ Determine if the drainage ditch will still be capable of carrying the runoff once the

paving is complete.

c$)$ What happens if the drainage ditch is paved with float finished concrete? How deep is

the flow?

$n=0\mathrm{.}025$

$s=1\%$

$y_{\text{m}\text{a}\text{x}}=3ft$