Using Stabilization Techniques
To control erosion and protect property
If your streambank or shoreline is severely eroded, you’ll need to stabilize the soil to promote plant growth. There are three general approaches you might consider: live planting, bioengineering, and hard armoring. The best technique will depend on your situation — the size and location of your stream or shoreline, and the cause and severity of the erosion. In many cases, the best approach is to use a combination of techniques. Before attempting any shoreline stabilization activity, you should obtain applicable TVA shoreline construction permits.
You may be able to stabilize shorelines or prevent erosion problems by planting appropriate types of vegetation, then allowing nature to heal itself. Costs of this approach are relatively low, and homeowners can implement this approach on their own. A small investment of time and money can prevent a serious erosion problem in the future that could be very expensive to correct.
Bioengineering relies on a combination of structural components and plant material to produce a dense stand of vegetation that serves as a “living system” to protect streambanks and shorelines. This technique works to stabilize many, but not all, erosion problems. One challenge in bioengineering is protecting the bank from erosion until the vegetation becomes established. This could take one to two years. There are a number of structural components available to provide temporary protection while the plant growth becomes established. One example is the use of coconut fiber rolls (flexible “logs” made from coconut hull fibers). These can be effective in providing the structural component which protects the “toe,” or base of the streambank or shoreline most vulnerable to erosion. Another example is erosion control blankets, useful for protecting the slope of the bank above the toe. Bioengineering may require bank shaping to reduce the slope of the bank.
Hard armoring includes a variety of techniques, including rock riprap (large stones placed along the slope of a streambank or shoreline) and gabions (rock-filled wire baskets placed along a streambank or shoreline). Hard armoring typically involves grading the bank to a gentler slope. If done properly, these techniques provide very good protection and will work in more severe situations where bioengineering will not. However, hard armoring techniques can be relatively expensive, and may require professional assistance. These techniques are often used in situations where less expensive, more environmentally friendly and aesthetically pleasing alternatives would have been successful.
The following table presents a few examples of the many techniques being used as bank treatments for streams and reservoirs. These illustrations are conceptual only; seek professional advice to determine the best solution for your property.
Illustrations were adapted with permission from “Stream Corridor Restoration: Principles, Processes, and Practices,” by the Federal Interagency Stream Restoration Working Group
Stabilization projects in progress