Slide show - Large Woody Debris

  • wood in stream Streams in natural settings generally contain large amounts of downed wood, often in log jams. Wood in streams provides sediment retention, food for invertebrates, and important habitat for many aquatic species.
  • in-channel wood reduction Past timber harvest adjacent to many streams within the Cedar River Municipal Watershed has led to significant reductions in in-channel wood. While riparian forests have since reestablished, tree recruitment into streams lags behind.
  • natural stream complexity In smaller streams, natural tree recruitment processes have already started to recover, contributing to natural stream complexity, aiding in the formation of steps, storage of sediment, and creation and maintenance of pools.
  • little current habitat complexity In low gradient reaches of many streams, however, historic timber harvest has resulted in little current habitat complexity reflected by shallow and uniform water depths, few pools, and little variation in channel widths or little cover.
  • LWD project To improve habitat in reaches where past management activities have had the greatest and most long-lasting impacts, active restoration is occurring. To minimize disturbance to sensitive floodplain soils, logs were placed using a helicopter in this LWD replacement project.
  • Shotgun Creek As a result of this restoration, logs felled directly into this stream from a densely stocked riparian forest change the way water flows. Small wood-formed steps help to create plunge pools used by fish.
  • LWD Rock Creek In a third project, we experimented with hand-built techniques using cable and winches to place smaller wood into a channel by hand.
  • placed logs In most of our projects, we allow for and anticipate a reorganization and positioning of wood debris during large flood events. With time, some of this wood forms jams upon which other naturally recruited debris accumulates, forming larger log jams, deep pools, and areas with good cover for fish.
  • aquatic monitoring All of these projects included pre and post project monitoring efforts so that we can learn which techniques were most successful at achieving project objectives.