Workshop: Application of the Use of Large Woody Material in Stream Restoration and Streambank Protection
Dr. Frank Reckendorf, Fluvial Geomorphologist and Engineering Geologist, Reckendorf and Associates, 950 Market St. NE., Salem, OR, 97301; frecken [at] mac [dot] com
Dr. Barry Southerland, Fluvial Geomorphologist, WQQT, West National Technology Support Center, USDA, Natural Resources Conservation Service, 1201NE Lloyd Blvd. Suite 1000, Portland, OR 97232; Barry [dot] Southerland [at] por [dot] usda [dot] gov
Russell Lawrence, Fluvial Geomorphologist, and Professional Engineer, StreamFix, 19478 S. Starview Ln. Oregon City, OR 97045 russ [at] streamfix [dot] com
Richard Dyrland, Supervisory Hydrologist, Fish First, 27511 NE 29th. Ave. Ridgefield, WA 98642 toppacific2 [at] msn [dot] com
Length: Half Day
This workshop will examine the range of large woody material structures and applications which have been used in stream restoration efforts, and what the outcomes have been over both the short and long term. Large woody material (LWM), and other size class wood material, has been used for streambank protection and in stream restoration measures and attempts for over 100 years. There was extensive use of large woody material with soil bioengineering by the Civilian Conservation Corps in the 1930’s. As early as the 1970’s the Soil Conservation Service did field trials on the application of large woody materials in streambank erosion. In the 1980’s and 1990’S The California Department of Fish and Game modified applications of LWM in streambank protection by adding buttress and toe protection. In the last 30 years LWM has been installed as:
- just logs of various size and orientation,
- just rootwads,
- rootwad and boulder structures of various sizes and orientation,
- log vanes,
- enhanced log vane with J tip for aquatic habitat,
- rootwad roughness structures,
- trash racks
- engineered log jams of various types.
This workshop will examine LWM structures impacts on pools and riffle development, streambank and streambed scour, as well as wood buoyancy and LWM downstream effects. Types of LWM tie downs, buttressing, and anchoring will be discussed. The cost effectiveness of using various sizes of wood material will also be examined.
In addition, enhancement of side channel habitat using LWM will be covered, including the option of deepening side channels prior to placement of LWM as a method to enhance habitat benefits.
Finally, the workshop will examine post project appraisals of many engineered log jams in terms of effectiveness and longevity.