Streambank erosion in agricultural areas normally occurs as a result of one of three factors: change in stream flow, water flowing over or through the streambank, or the discharge of concentrated runoff from other sources. Streams are subject to wide fluctuations in both flow depth and velocity over a period of years. This is due to normal seasonal changes in rainfall and large single-storm events. As flow depths and velocities increase, the force of the water flowing against the streambank removes soil particles from the banks, and in many cases, erosion causes banks to slump and fall into the flowing water. In extreme situations where high flows persist over long periods, banks can erode several feet annually. Rain falling on streambanks—or runoff from adjacent fields that enters by flowing over the streambanks—can also erode soil, particularly if banks are inadequately protected. Finally, water discharged into a stream from tributary drainage systems (such as waterways or tile lines) can also erode streambanks, particularly if the water is discharged in an area where the bank is unstable and highly erodible.
For more information including case studies on agricultural ditches see agditches.osu.edu
Example of bank erosion taken 3/17 Hardin Co. LaBarge | Example of bank erosion taken 3/17 Hardin Co. LaBarge |
Cleaned ditch taken 10/14 Henry Co. LaBarge | Same cleaned ditch taken 4/17 Henry Co LaBarge |