Natural Stream Processes

Stream systems drain the land as a key part of the nature’s water cycle.  When it rains, some rainwater evaporates directly back into the atmosphere, some is taken up by vegetation.  Some percolates deep into the ground and replenishes the groundwater supply.  The remainder collects and flows down the watershed through drainage ways, ditches, streams and rivers to lakes and the sea.  There it evaporates and begins to cycle again.  Every stream is a dynamic hydrological system that is continually altered by the changing character of the watershed.  Streams reflect land use by changing course, overflowing, eroding their beds, and depositing sediment.  Modification of a stream channel causes channel adjustments such as bank erosion, channel deepening, or sediment deposition, for some distance both upstream and downstream.  Streams are also dynamic biological systems comprised of plants and animals.  The components of this system are interdependent and are fundamentally linked to habitat in and around the stream.

Information obtained from ODNR Ohio Stream Management Guide

As described above, streams are dynamic systems, which constantly move and change in their pursuit to reach equilibrium.  In their natural state, streams and their associated floodplains provide a variety of important functions including the movement of water and sediment, storage of flood waters, recharge of groundwater, treatment of pollutants, dynamic stability, and habitat diversity.  Disturbances to this system, either natural or human-induced, places stress on the system and has the potential to alter structure and/or impair the ability of the stream to perform ecological functions. 

Relatated Resources:
Headwater Stream Fact Sheet  
Natural Stream Processes