NCHRP 24-19 [Completed]
Environmentally Sensitive Channel- and Bank-Protection Measures
| Project Data
||Salix Applied Earthcare|
||John McCullah |
||NCHRP Report 544 Environmentally Sensitive Channel- and Bank-Protection Measures|
The findings of research conducted under this project are presented in NCHRP Report 544, "Environmentally Sensitive Channel- and Bank-Protection Measures" and accompanying CRP-CD-58. NCHRP Report 544 presents a description of useful environmentally sensitive channel- and bank-protection measures, design guidelines for their application, and a selection system for determining the most appropriate channel- and bank- protection measure. The selection system is presented as an interactive software program entitled "Greenbank," which can be found on the accompanying CD-ROM (CRP-CD-58).
Environmentally sensitive channel- and bank-protection measures, such as bioengineering, root wads, large woody debris, riparian vegetation, bendway weirs, and energy dissipaters, are being called for more frequently to protect transportation facilities from erosion, scour, and lateral migration. However, relatively little guidance has been developed to help practitioners apply environmentally sensitive channel- and bank-protection measures with confidence that their designs are adequate. Traditional channel- and bank-protection techniques rely on countermeasures such as riprap, gabions, cable-tied blocks, or grout-filled bags, which may not offer sufficient in-stream functions, such as habitat diversity, fish passage, water quality, and energy dissipation. Definitive selection criteria and guidelines are needed to allow practitioners the option for greater use of environmentally sensitive channel- and bank-protection measures.
The research conducted under this project resulted in the development of selection criteria, design guidelines, and a compilation of techniques used for environmentally sensitive channel- and bank-protection measures. While the NCHRP Project 24-19 research oversight panel approved the research results for publication they felt it important to emphasize that the panel's approval of the research for publication does not constitute endorsement of the research results, specific implementation methods, or specific products by the members of the panel or their respective agencies or companies.
In general, for transportation projects, licensed staff in specialty subjects are usually required. For environmentally sensitive, "bioengineering", projects, the inclusion of licensed staff on an interdisciplinary design team is currently a significant issue in several states. Many bioengineering practitioners, as well-qualified as they may be, are generally not licensed and often are not degreed or trained geologists or engineers. The California Boards of Registration for Engineers and Geologists investigated the unlicensed practice of engineering and geology in river restoration projects. In early 2005, a decision was not yet made, but it appeared likely that the California Boards would determine that much of the restoration or rehabilitation work currently being done in the river corridor does constitute the practice of geology and/or engineering, and thus must be done under the direction of an appropriately licensed specialist. This is a significant issue for resource management agencies and departments of transportation involved in the application of environmentally sensitive channel- and bank-protection techniques in transportation projects.
NCHRP Report 544 recommends a team comprised of members from different areas of expertise pertinent to the project should be selected for the development and application of environmentally sensitive channel- and bank-protection measures. However, Report 544 does not specifically identify the team composition. The NCHRP Project 24-19 research oversight panel feels that such a team should include a riparian ecologist or aquatic biologist, a licensed geologist with a practical knowledge and experience in fluvial geomorphology, a licensed civil engineer with practical knowledge and experience in hydrology and hydraulics, a licensed landscape architect with practical knowledge and experience in natural settings, and a structural engineer, for projects in the vicinity of bridges or other structures.
Status: Research is complete.
Product Availability: NCHRP Report 544, "Environmentally Sensitive Channel- and Bank-Protection Measures" and accompanying CRP-CD-58 are available through the TRB website at:http://trb.org/news/blurb_detail.asp?id=5617.