Bank Stabilization and River Training Devices

Bank stabilization and river training devices are intended to inhibit the erosion and movement of stream banks. They may be needed either to defend against actions of the stream that threaten the highway crossing or to protect the stream banks and the highway from an anticipated response to highway construction.
Various materials and devices designers use include the following:
  • stone protection
  • concrete lining
  • wood, steel, or rock jetties
  • steel or concrete jack fields
  • wire fences
  • timber bulkheads
  • articulated concrete mattresses
  • guide banks, dikes, and spurs (usually constructed of earth and rock).
The choice of the appropriate device or devices for use depends on the geomorphology of the river. Futile attempts at localized control can be avoided where the river is in the midst of changes by studying long reaches. Regardless of the size of the stream and the control measures used, stream response to the measure must be considered. For instance, bank stabilization at a crossing may cause scour in the bed of the channel or redirect the current toward an otherwise stable bank downstream.
Bank stabilization and river training is a specialized field requiring familiarity with the stream and its propensity to change, knowledge of the bed load and debris carrying characteristics of the stream, and experience and experimentation at similar sites on the same or a similar stream.
The following are general principles for the design and construction of bank protection and training works:
  • The cost of the protective measures should not exceed the cost of the consequences of the anticipated stream action.
  • Base designs on studies of channel morphology and processes and on experience with compatible situations. Consider the ultimate effects of the work on the natural channel (both upstream and downstream).
  • Inspect the work periodically after construction with the aid of surveys to check results and to modify the design, if necessary.
  • Understand that the objective of installing bank stabilization and river training measures is to protect the highway. The protective measures themselves are expendable.
Refer to
the FHWA publication Stream Stability at Highway Structures
 (
HEC 20
) for more detailed information regarding bank stabilization and stream training facilities.
The effectiveness of protective and training measures in many alluvial streams and the need for the measures may be short-term because of the dynamic nature of streams. The stream will move to attack another location or outflank the installation.
A cost comparison of viable options should be made. Alternatives to stream protection measures include the following:
  • a continuing effort to protect the highway by successive installations intended to counter the most recent actions of the stream
  • relocation of the roadway away from the river hazard
  • a larger opening designed to accommodate the hazard
  • abutment foundations designed sufficiently to allow them to become interior bents at a later date.