The Curve Number model uses the approach adopted from the Natural Resources Conservation Service (formerly known as the Soil Conservation Service or SCS) Curve Number method for estimating runoff.
A full description of this method can be found in the SWMM5 Reference Manual (Hydrology), which can be downloaded from the EPA website.
To use the this infiltration model in a SWMM network, ensure that the Infiltration model in the Model parameters is set to Curve_number and that the following parameters are set for each subcatchment include in the SWMM network, which is to be modelled using this method of infiltration: