Natural Drainage Classes Natural Drainage Classes Soil Water Natural drainage class refers to the frequency and duration of wet periods for the water regime assumed to be present under relatively undisturbed conditions similar to those under which the soil developed. Alteration of the water regime by man, either through drainage or irrigation, is not a consideration.
Water is removed very rapidly.
The soils are commonly very-coarse textured or rocky. All are free of the mottling that is related to wetness. Somewhat excessively drained. Water is removed from the soil rapidly. The soils are commonly sandy and rapidly pervious.