The intensity$-$duration$-$frequency $($IDF$)$ relation for a $0\mathrm{.}15m{i}^2$ watershed is given by: $i=\frac{a{T}_r^d}{t_d^b+c}$ where $T_r$ is the return period in years, $t_d$ is the rainfall duration in minutes, $i$ is the rainfall intensity in in$/$hr$,$ and $a,b,c,$ and $d$ are empirical constants $21\mathrm{.}5,d=0\mathrm{.}23.$ The watershed is single$-$family residential