Log Rollers
Potential permits required: CWA 404, Threatened & Endangered Species, FloodplainOUTSIDE HELP:
Log rollers are large, crisscrossed dead trees spanning across the channel to create fish habitat and control erosion. The trees are anchored into the streambanks. Benefits of installing log rollers include:
• Increased channel complexity
• Controls flows
• Controls erosion
• Improved fish habitat
• Fish habitat
Installed Log Rollers
Log rollers are created by burying large dead trees into the streambank. The trunk of the tree goes out into the stream and overlaps with other dead trees in a criss-cross pattern. The trees have to be anchored in place very securely so that they don’t become dislodged in flood events. Often, boulders will be placed on top of the logs to help secure them. The logs will usually angle down towards the stream’s center, creating a low-flow channel.
Log rollers mimic what happens naturally in stream systems; when floods leave large woody material behind, it is often partially buried by sediment. These dead trees create shelter areas for fish, breeding areas for insects and help to stabilize streambanks. They also add to the complexity of the channel, in turn, making a more stable stream system that can support more types of life.
Log rollers are complex structures that require engineering and planning to account for the impacts to the upstream and downstream areas, the floodplain and the surrounding ecosystems. Engineers, landscape architects and/or environmental consultants will need to help you by designing the structure and guiding you through the permitting processes. When it comes time to build the structure, a qualified river constructor should be hired.
Log rollers are less common than other stream restoration methods. It will be helpful if you can work with outside consultants who have experience designing and building similar structures. This will also help to expedite the permitting process as they will know the best ways of applying for the permits. Before contacting the outside help, consider if you have large woody material and/or boulders that can be used for the project on your property.
Photo courtesy of: Ben Swigle, CPW