|Shields jr, Fletcher|
Submitted to: Government Publication/Report
Publication Type: Other
Publication Acceptance Date: 9/15/2005
Publication Date: 8/31/2007
Citation: Fripp, J., Copeland, R., Shields Jr, F.D., Bernard, J., McComas, D., Jonas, A., Goertz, L. 2007. Sediment impact assessments. Chapter 13 in Stream Restoration Design, National Engineering Handbook Part 654, USDA-NRCS Washington, D. C., CD-ROM. Interpretive Summary:
Technical Abstract: The Stream Design Guide provides guidance for multidisciplinary teams who are planning and designing projects that are intended to control floods or sediment sources, hasten drainage, stabilize banks, improve fish habitat, or restore ecological functions and processes. Sedimentation analysis is a key aspect of design since many projects fail due to excessive erosion or deposition. The chapter in the Stream Design Guide concerning "Sediment Impact Assessments" provides a brief overview of several types of assessments along with their rigor and level of uncertainty. The focus of this chapter is primarily on techniques which are appropriate for alluvial channels, but threshold channels are also discussed. Major categories of analytical techniques include visual geomorphic assessments, equilibrium slope calculations, sediment rating curves, sediment budgets, and non-equilibrium sediment transport. Guidance for technique selection is also presented. Guidelines for sampling stream bed material are presented in an appendix. This chapter is important because the complexity of sedimentation issues often leads to serious errors in planning and design that contribute to poor project performance or failure.