When not flowing, the water may remain in isolated pools, or surface water may be absent. The substrate consists of organic deposits, sand, gravel, cobble, rubble, bedrock, or pioneering plants. There are generally no named soils in this community, although some areas may be listed as mixed alluvial land.
Vegetation is dependent on the length of inundation, as well as the substrate type.
Many small drainage ditches are included with this type.