Bridges and other crossings can also lead to erosion and sedimentation. Other forestry activities affect floodplain conditions. Logging in riparian zones has led to increased bank erosion, loss of in-channel islands, increased size and frequency of sediment wedges, and altered stream shape. Logging camps, storage areas, and dumps are commonly located in floodplain areas because of the relative ease of access and construction and the readily available source of drinking water. These facilities have caused stream pollution problems, as well as changes to the stream channel itself.
Streams are watercourses formed when water flows between continuous definable channel boundaries.
Streams range in size from very small in headwater areas to very large in downstream areas of a watershed. Streams commonly flow through floodplain materials previously deposited by the stream itself. Forestry activities influence some, but not all, factors that control channel conditions. Changes in sediment supply to the channel can have a major influence on in-stream biological conditions. The influence of logging will also vary depending on stream size.