National Engineering Handbook: Chapter 9 - Hydrologic Soil-Cover Complexes
From ASDSO Dam Safety Toolbox
Natural Resources Conservation Service, 2004
A combination of a hydrologic soil group (soil) and a land use and treatment class (cover) is a hydrologic soil-cover complex. This chapter gives tables and graphs of runoff curve numbers (CNs) assigned to such complexes. This CN indicates the runoff potential of a complex during periods when the soil is not frozen. A higher CN indicates a higher runoff potential and specifies which runoff curve of appendix A or figure 10–2 in National Engineering Handbook, part 630 (NEH 630), chapter 10, is to be used in estimating runoff for the complex. Applications and further description of CNs are given in NEH 630, chapters 10 and 12.
Revision ID: 5890
Revision Date: 12/16/2022