Streambank Erosion

What is it:

Streambank stabilization practices protect banks of streams or constructed channels, and shorelines of lakes, reservoirs, or estuaries to reduce erosion. Methods used include soil bioengineering and structural measures. Most measures are primarily used in streams and rivers, and for shoreline protection. Streambank stabilization is considered an in-channel practice.

Where is it used:

Streambank stabilization can be used where channel or impoundment banks are vulnerable due to instability. It can also be used where relatively simple erosion and stability control measures will solve the problem. Care should be taken so that the failure of these measures will not create a hazard that can result in serious damage to property or loss of life.

This standard does not apply to more complex bank erosion problems on major bodies of water such as Lake Erie and its major bays.

Why install it:

Benefits of streambank stabilization include:

  • Reducing loss of land, and reducing damage to land uses or other facilities adjacent to the banks.

  • Maintaining the flow or storage capacity of the channel or impoundment.

  • Reducing the downstream effects of sediment resulting from bank erosion.

  • Maintaining or restoring channel meanders that enhance stream conditions.

  • Improving or enhancing the stream corridor for fish and wildlife habitat, aesthetics, and recreation.

How does it work:

  • The root mass of living plants stabilizes the soil. Also, transpiration by the living plants reduces the soil moisture.

  • Measures such as rock riprap harden the banks and prevent scour.

  • Rock structures such as barbs deflect flow away from the banks.

  • Flattening side slopes reduces bank instability.

  • Floodplain establishment reduces shear stresses on the bed and banks.

Who do I contact in Ohio:

Extension: https://extension.osu.edu/lao#county

SWCD: https://agri.ohio.gov/wps/portal/gov/oda/divisions/soil-and-water-conservation/find-a-local-swcd

NRCS: https://www.nrcs.usda.gov/wps/portal/nrcs/oh/contact/local/

Design:

Extensive design details are available at Ohio NRCS Standard 580: Streambank and Shoreline Stabilization

Information found on the Ohio State University Extension AgBMPs website.

Backyard Streams

Information/article found on the Green City Blue Lake: The Cleveland Museum of Natural History

Creeks and streams can suffer from erosion problems leading to homeowner troubles. Depending on the severity of the problem, there are numerous ways to reduce the erosion.


Historically, creek and stream erosion solutions have involved conventional measures such as dumping specifically sized stones (rip rap) and building walls of wire baskets filled with stones (gabion baskets).


Long term monitoring of creeks and streams using these erosion control methods shows that instead of solving the problem, they aggravate it.


While placing stone rip rap, railroad ties, or concrete on an eroding stream bank may appear to solve the problem, these practices often fail because they do not stabilize the bank properly. Water flowing near the rip-rap generally moves fast and there is often turbulence near the bank. As water hits and deflects off the rip rap it gains velocity and is more likely to erode adjacent unprotected areas. Rip rap also tends to require ongoing maintenance to correct instances where the rock is being undermined and either peeling away from the bank, or slumping into the stream. These methods transfer and sometimes amplify this energy to the next section of unprotected stream bank, creating a new set of problems, and usually causes increased erosion around and downstream of the hard materials. These structures, if installed incorrectly, may narrow the creek or stream, which increases the speed of the flow, further increasing erosion. Inappropriate solutions may cause more long-term damage than doing nothing at all. Any in-stream work to install these hard structures requires US Army Corp of Engineers and Ohio EPA permits.


Hard structures such a gabion baskets are typically used when infrastructure, such as utility lines, roads or buildings are endangered by the eroding stream. Use the Ohio Department of Natural Resources, Stream Management Guide – Gabion Baskets for design and installation guidelines. In addition, contact your community and US Army Corp of Engineers and Ohio EPA about necessary permits.

Use a vegetative bank instead

Vegetation is the best resource for protecting eroding stream banks. A creek or stream with limited damage may be stabilized with select plantings. The banks are planted with deep rooted plants that can hold soil in place and can withstand flooding and high-velocity water. Vegetation planted along the creek or stream can be extremely useful in controlling soil erosion, providing wildlife habitat and improving water quality. One way to establish vegetation is through the use of dormant, woody stakes and posts to stabilize the banks and bare-root or transplanted trees can be used on top of the banks.


The upper section of the bank should also be planted with deep-rooted vegetation to prevent erosion. Plants may include native shade trees, shrubs, tall grasses or green herbaceous plants. For a more formal look, plant a strip of medium height native grass (2-3 feet) between the creek bank and lawn. When mowing the lawn add a design by mowing a curve along the lawn and planted area. Add color to the edge of the planted area with flowering plants. To view the stream, cut or mow view corridors, and/or make a pathway corridor to the stream. Use wood chips other soft materials that will soak up rain.


For directions on how and what dormant shrubs and vegetation to plant, see the following resources. It is recommended that you consult with your local soil and water conservation district, stormwater utility, or watershed organization before starting a stream bank stabilization project.