Bank Assessments

A drainage pipe exposed by recent bank erosion. (Click image to enlarge)

Assessments of channel-bank stability may be completed for a variety of reasons. In some cases, a community may know that their streams and fisheries are being degraded by excessive loads of sediment or may have identified locations where local infrastructure components are currently threatened, or have been undermined, by channel-bank erosion. In other cases, the effort to assess channel-bank stability may be initiated by a desire to learn if and where there are bank-stability concerns so that avoidance strategies or corrective actions can be applied. In any case, the level of effort and the methods employed will be somewhat constrained by the time frame and financial resources available for the effort.

To the benefit of all those tasked with completing bank-stability assessments, there are a variety of techniques that may be employed. In those cases where the level of effort is substantially restricted by time and/or budget constraints, a simple analysis of online satellite and aerial-photo imagery may be sufficient to identify the locations where perennial stream channels are experiencing significant bank erosion and/or channel migration. If resources are available to permit some limited field activities, reconnaissance level mapping of bank and vegetation characteristics on a watershed scale can be completed to document relative bank stability within the watershed. If resources are available to complete even more detailed bank-stability analysis, there are established field protocols that one may follow.

Bhowmik/Robinson              Bank Erosion Hazard Index (BEHI)

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