The various types of environmental variations which occur in sufficient quantity to provide habitat diversity to support a wide range of species in the stream.
Channelization is a process by which people change the course of a river's channel, typically by dredging it and straightening it out.
The stream has not been altered from its original state.
The stream has been channelized in the past, but it has recovered most of its natural channel characteristics.
The stream has been channelized, but the change was long enough in the past that it is in the process of regaining its former natural characteristics. However, the stream shows sufficient impact from the channelization that its habitats are still degraded.
The streams has been channelized recently, or at least recently enough to show no significant recovery of habitats. Such streams may include drainage ditches, grass lined or rock rip-rap banks, etc.
