The total loss from a subcatchment pervious area is the sum of the evaporation + infiltration loss. Typically the evaporation rate is much less than the infiltration rate. SWMM 5 now has two options – evaporation during only dry periods or evaporation during both wet and dry periods.
Figure 1: An example network that shows the relationship between the rainfall, total losses from the previous area, evaporation and infiltration only rate.
Figure 2: The same model with the Evaporation during only Dry Periods turned on