What distinguishes modified natural streams from ditches?

Modified natural streams and ditches are fundamentally different in their formation and characteristics. The correct answer highlights that ditches are typically constructed by humans and often found in drier upland areas, whereas modified natural streams retain their stream-like nature, even if altered.

Understanding this distinction is crucial because it impacts how water flows, how ecosystems function, and the types of vegetation that can thrive in these environments. In contrast, many modified natural streams may feature natural elements but have undergone alterations, such as channelization or changes in flow to accommodate surrounding land uses.

By recognizing that ditches are constructed, it becomes clear that they do not naturally arise from the geography of the landscape as modified streams do. This insight helps differentiate between engineered systems and those that retain some degree of their natural characteristics despite modifications.