Dennis A . Lyn , John F . Newton Approaches to the Design of Biotechnical Streambank Stabilization Volume I — A Guide to the Literature

The Joint Transportation Research Program serves as a vehicle for INDOT collaboration with higher education institutions and industry in Indiana to facilitate innovation that results in continuous improvement in the planning, design, construction, operation, management and economic efficiency of the Indiana transportation infrastructure. NOTICE The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views and policies of the Indiana Department of Transportation or the Federal Highway Administration. The report does not constitute a standard, specification, or regulation. Abstract Streambank stabilization has traditionally been performed with riprap for which reliable design and installation procedures are available. Due to concerns about the environmental impact of riprap, there has been increasing interest in more natural biotechnical (or bioengineering) alternatives. A review of the litera‐ture on biotechnical approaches to streambank stabilization has been per‐formed, with a focus on those works that might be particularly useful in developing design guidelines or standards for the Indiana Department of Transportation. Works that synthesized the literature (up to about the year 2000) and so covered a broad range of topics, were examined, including monographs and manuals published by federal and state agencies. More recent publications were also found on narrower more specific topics, including the ecological effects of riprap and bio‐technical approaches, advances in the geotechnical modeling of vegetation effects on bank stability, the effectiveness of biotechnical measures, and screening methods for selecting appropriate measures. Implications of the reviewed work for the development of design guidelines are discussed. Introduction Streambank stabilization has traditionally been performed with riprap or other hard-armor techniques for which reliable design and installation procedures are available. Due to concerns about the environmental impact of riprap and the consequent regulatory pressures, the Indiana Department of Transportation (INDOT) is interested in finding softer, more environmentally sensitive alternatives to the pure hard-armor approaches. This report examines the literature on biotechnical approaches, which emphasizes the use of vegetative elements, possibly in combination with hard-armor elements. Documents of particular interest would be those helpful in formulating detailed design guidelines for the application of biotechnical techniques to Indiana conditions, and, specifically, INDOT projects. Findings The review found a large body of literature related to biotechnical engineering of slopes and/or streambanks. These were divided into (i) works of synthesis, frequently monographs or federal and state agency reports …