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The SCS Runoff Method is described in the SCS National Engineering Handbook - Section 4 (NEH-4), with the input attributes described below.

This method may not be available for your region. For more information, refer to the Regionalisation topic.

Pervious Curve Number - The runoff curve number for the pervious fraction of the Catchment, as described in NEH-4 Chapter 9. Typical values vary from 20 for regions with high infiltration and interception capacities to 98 for impervious areas. It is a dimensionless number depending on hydrologic soil group, cover type, treatment, hydrological condition, and antecedent moisture conditions. This number has a valid range from 0 to 100 with typical values from 60 to 90 and 98 for impervious surfaces.