1. Home
  2. All Calculators
  3. Hydrology Calculators
  4. Composite Curve Number With An Unconnected Impervious Area

Composite Curve Number With An Unconnected Impervious Area

This calculation is to be used for calculating the composite CN for area with an unconnected impervious area and a total impervious area of less than 30%.

Result

images
CNp - Pervious runoff curve number
Pimp - Percent imperviousness
R - Ratio of unconnected impervious area to total impervious area
CNc - Composite runoff curve number