Live Staking: An Opportunity to Engage the Community in Environmental Management
Find New Ways to Volunteer This Earth Day and All-Year Loong
Earth Day is marked by volunteerism — typically communities will host volunteering events, such as stream and roadway cleanups or garden plantings. This Earth Day, broaden your horizons by volunteering in new ways. One such way is to assist with stream restoration. McGill, the communities we work with, and local non-profits that work to restore streambanks, can use live staking during the winter and early spring — as long as the trees are dormant — to prevent soil erosion. Catawba Riverkeeper Foundation, a local non-profit, recently advertised the ability to host live staking volunteer events on an as funded basis. With adequate guidance and assistance from landowners, live staking can be a great way to promote volunteerism and a low-cost way to rehabilitate streambanks.
What is Live Staking?
Live staking involves the insertion of prepared cuttings (live stakes) from dormant woody plants (trees and shrubs) into the ground, so they root and grow. Stem cuttings are taken from certain trees during their dormant season and are directly inserted into the streambank to help prevent further soil loss. McGill uses this technique, coupled with the addition of biodegradable erosion control matting and a native seed mix, to protect streambanks from soil erosion. Although live stakes may not provide much initial soil reinforcement, the stakes take root over time and the roots aid to bind the soil together. Above-ground growth also provides surface protection and adds roughness to the streambank, which in turn reduces the velocity of stream flow.
How to Make it Low Cost
By enlisting volunteers to assist with the harvesting and planting of stakes, live staking can be a low-cost option for streambank repair. Live stakes can be obtained from nurseries, but they can also be gathered directly from surrounding trees and shrubs. Willows, Dogwoods, American Sycamore, Elderberry, Smother / Speckled Alder, Ninebark, Buttonbush, and Spicebush are examples of woody riparian plant species that can be used for live staking. You may get hundreds of live stakes in just a matter of hours if you work hard and have a few helpers.
When Do You Need the Assistance of an Environmental Scientist or Engineer?
For landowners that use live staking to revegetate bare areas on otherwise stable streambanks — computations are often not required. However, before committing to a live staking project, the effects of the water current on the stability of the streambank protection treatment should be considered. You may also want to consult an engineer or environmental scientist with streambank repair experience in the following cases:
- The project is larger than 100 linear feet
- Multiple property owners are involved
- Utilities are located near the stream
- The project requires working below the normal water level of the stream (i.e. sediment removal, large debris removal)
- The project is located within a FEMA regulated floodplain / floodway
- The project requires more than the use of small hand tools to complete
McGill staff members are certified in streambank repair from North Carolina State University and have received training on live staking, in addition to other streambank repair practices.
Is Live Staking the Most Appropriate Protection Treatment for your Project?
Hydraulic analysis may be required to determine where the live stakes should be placed on the slope or to better understand how the above-ground growth will disperse energy at various flow states. For a large project with a sizable investment —McGill would use a computer model, such as the United States Army Corps of Engineers (USACE) HEC-RAS computer program to assess the hydraulic conditions.
For projects where a normal depth approximation is applicable, a simple equation may be used to estimate the velocity.
Average Boundary Shear Stress (lb/ft²) = 62.4 lb/ft³ * Hydraulic Radius * Friction Slope
Live staking can be used when the shear stress is between 0.5 to 2 lb/ft² and the velocity is less than 2.5 ft/s at initial planting and greater than 2 lb/ft² and 10 ft/s once established. Live staking can be used when the shear stress is up to 2.5 lb/ft² if the live stakes are placed in woven coir or even greater levels of shear stress and velocity when inserted into rip rap (joint planting) depending on the riprap stability.
- Stream Protection Practice Standards and Specifications (North Carolina Department of Environmental Quality)
- Riparian and Wetland Tree Planting Pocket Guide for North Carolina (North Carolina Forest Service)
- River Restoration Toolbox Practice Guide 2: Vegetation Restoration (Iowa Department of Natural Resources)