Stream Bank Repair

Stream Bank Repair is the action taken by a landowner or manager to address stream bank erosion and degradation. Actions include establishing a 3:1 or 4:1 bank slope and installing native vegetation in the riparian area , with the overall purpose of protecting water quality.

Riparian refers to the land adjacent to the stream. This is an ecotone, or transitional area, between the aquatic and terrestrial environment. It is important for bank stabilizing and also prevents pollutants such as fertilizers, herbicides, and bacteria from entering the stream.

Streams and rivers are constantly changing through the natural movement of water and deposition and erosion of sediment. Although they are changing, their overall form and stability is maintained, which is called dynamic equilibrium. However, these changes can be exacerbated when the velocity and volume of water increases, or surrounding land use is altered in a way that increases runoff. Increased velocity and force of water can degrade stream banks and cause sediment and property loss, bank slumping, stream widening, and disconnection from the floodplain. Additionally, an increase in sediment can harm aquatic organisms.

When native riparian vegetation is removed, a stream bank is more likely to erode and possibly fail. You can prevent this by leaving a “no mow” zone along stream banks and planting native streamside species. Thinking about upstream impacts can also help protect water quality. Increases in impervious surfaces cause water to move off of land into waterways faster, resulting in higher velocities and possible stream bank issues.

No! Stream restoration involves work inside the stream channel. This requires a permit from the Army Corps of Engineers, the South Carolina Department of Health and Environmental Control, and local governments. Stream Bank Repair is intended to be a more cost-effective and simpler approach. Most notably, Stream Bank Repair works above what is called the Ordinary High Water Mark.

The Ordinary High Water Mark (OHWM) defines the boundaries of aquatic features for a variety of federal, state, and local regulatory purposes. The OHWM is created from the regular flow of water and can be identified by a wrack line of debris (twigs, logs, etc.) and changes in soil or vegetation. For more specifics on the identification of OHWM, please view  Field Identification of Ordinary High Water Mark in Relationship to the Field Identification of Bankfull Stage for the Galveston District’s Tiered Stream Condition Assessment Standard Operating Procedure .

Stream Bank Repair workshops are offered October – March. One important step in the process of stream bank repair is using live cuttings called livestakes from dormant species such as elderberry, black willow, and tag alder. These live stakes must be harvested and installed during the plant's dormant season (October-March).