When grade control or other structures are installed in a stream channel, banks need to be engineered to hold the banks in place until they have enough vegetation and root stability to allow for natural channel migration. In other places, such as the banks along a riffle or run, planted vegetation is sufficient to stabilize the channel because there is less erosive force. But even in these places, the vegetation is often combined with a matrix, such as coconut fiber to provide short-term stability as roots establish.
All streambank bioengineering uses plant materials, and dormant willow cuttings are the most common material used because willows have the ability to root from the stem. When needed, benches are constructed at the bankfull level of the stream channel. These benches are then planted with sod, containerized plants, and/or cuttings, all of which speeds the reestablishment of vegetation and reduces bank erosion.