Exploratory tests were conducted to observe the effects of incoming Large Wood Debris (LWD) on Engineered Log Jams (ELJ) groynes’ stability and permeability and the capacity of an ELJ groyne field, built on the outer bank of a river meander, to trap LWD and establish new habitat. An existing experimental facility, where a 4.2 km curved section of the Amazonian river was modeled at a 1/60 scale, was used to simulate transport and retention patterns of LWD. Bed material was sand, slope was 0.022 per one thousandth and flow was subcritical in all tests. Radius of curvature to width ratio was approximately 2. Wood dowels of different sizes were incorporated into the flow using a manual conveyor belt and trajectories were recorded with video cameras mounted on a drone and on both sides of the testing flume. When ELJ groynes were fully submerged at peak flows, no simulated logs were captured...

In woody areas where traditional construction materials are not available engineered log jams (ELJ) may constitute a potential solution for controlling riverbank erosion. Two ELJ groyne fields formed by four structures were placed in a 12 m long rectangular flume. In the first setup, groynes had a 46% permeability whereas in the second setup, groynes had a 26% permeability. Sediment in suspension was incorporated at a constant rate after flow was stabilized. Tests showed that when groyne permeability has higher, maximum scour depth at the inner end of the groyne diminished while sediment deposition between groynes increased. This result indicates that use of the main resource for building ELJ groynes can be optimized. As the configuration of the groynes was basically idealized as a frame of cylindrical elements, results of this experimental program may also be used to design groynes made...