Hydrologic Soil Group C consists mainly of soils characterized by what feature?

Hydrologic Soil Group C is primarily characterized by soils that have a layer impeding water movement. This classification includes soils with moderate infiltration rates when saturated and containing a significant layer of material that restricts water movement, which can often lead to a higher tendency for surface runoff compared to soils in Groups A or B.

The presence of this restrictive layer affects how water is absorbed by the soil and influences various aspects of stormwater management practices. It is important to understand this feature as it plays a critical role in assessing the potential for erosion and managing sediment transport in these areas.

While other features such as high infiltration rates, excessive drainage capabilities, and sandy texture may describe different soil types classified in Groups A or D, they do not accurately represent the characteristics of Hydrologic Soil Group C. Thus, the defining feature of having a layer that impedes water movement is essential for understanding the soil's behavior under wet conditions and its contribution to hydrologic processes.