Problem $3$ Unit Hydrograph Application $(15$ pts$).$

The annual CEAE student softball game is to occur soon, but a vicious $3-$hour long rainstorm is being forecast! You have

been told a typical pattern of how that event will occur $($the synthetic hyetograph$),$ and you know how your watershed

responds $($unit hydrograph$),$ but you don't know the actual depth of precipitation that is forecast. A makeshift flood

protection device has been installed on the field, but it can only prevent flooding up to $10$ cfs of flow.

$3\mathrm{.}1(10$ pt$)$: Choose a rainfall value and apply the synthetic hyetograph and unit hydrograph to create the runoff

timeseries $($assume no baseflow$).$ Via trial and error, find how large would the total amount of excess precipitation have

to be$,$ in order to cause a peak flow that is larger than $10$ cfs$?$

$3\mathrm{.}2(3pt$ Report the difference in time between when the peak precipitation amount and the peak runoff rate occur.

$3\mathrm{.}3(2$ pt$)$: At what point does the watershed stop responding to the rainfall event?