Here is a graphical view of the nonlinear runoff processes in InfoSWMM and SWMM5:

1. Three runoff surfaces

a. Impervious with Depression Storage

b. Pervious

c. Impervious without Depression Storage

2. Slope (same for all runoff surfaces)

3. Width or the Dimension of the Subcatchment (same for all runoff surfaces)… Read the rest