Riparian Buffers

It is commonly recognized that the roots of trees and other vegetation tend to bind soil particles and contribute to channel-bank stability.  With this understanding, best management practices encourage a healthy riparian corridor, or vegetated buffer strips, that include a diversity of plant species of various sizes and age classes.  As a first step to identifying locations of expected channel-bank instability, one can identify those locations where vegetation has been removed, or is otherwise absent, from areas adjacent to a stream channel.

An example of this is illustrated by the two photos below. The image on the left shows a meandering reach of White Lick Creek near Plainfield, Indiana. The image shows that this entire channel reach is lined with trees. One can assume that the roots of the trees add some level of stability to the local channel banks. In contrast, the image on the right shows another reach of White Lick Creek where, in some locations, fluvial erosion processes have completely undermined and consumed the channel-side trees. In the locations where channel-side trees and roots have been lost, it is common to see accelerated rates of bank erosion and channel migration.

Where the protective buffer of channel-side trees is lost in close proximity to man-made infrastructure, landowners and communities must be mindful of the potential consequences that continued erosion may bring.

A reach of White Lick Creek near Brooklyn, Ind. where, without stabilizing tree roots, the channel bank is rapidly eroding. (Click image to enlarge)
A reach of White Lick near Plainfield, Indiana where riparian buffers adjacent to the stream aid in adding stability to the channel banks (Click image to enlarge)

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