Problem $2$

$($a$)$ Draw the graph of rainfall intensity relationship with duration at $10$ minutes interval for a catchment is having total area of $80$ hectares with rainfall intensity given by $I=\frac{100}{t+15}$ where I is in $c\frac{m}{h}$ and $t$ is duration of rain in minutes.

$($b$)$ What will be the storm runoff from this catchment if the average imperviousness factor is $0\mathrm{.}63$ and time to concentration is $35$ minutes?

$($c$)$ If the population density of the area is $350$ persons per hectare and water consumption is $170$ LPCD$,$ what will be the design discharge for separate and combined system?

Comment on each of your answers in $($a$),($b$)$ and$($c$)$ above