A modeling framework for evaluating streambank stabilization practices for reach-scale sediment reduction

Authors: ENLOW, HOLLY - Oklahoma State University; FOX, GAREY - North Carolina State University; BOYER, TRACEY - Oklahoma State University; STOECKER, ART - Oklahoma State University; STORM, DANIEL - Oklahoma State University; Starks, Patrick; GUERTAULT, LUCIE - North Carolina State University

Submitted to: Journal of Environmental Modeling and Software
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/8/2017
Publication Date: 11/28/2017
Citation: Enlow, H., Fox, G., Boyer, T., Stoecker, A., Storm, D., Starks, P.J., Guertault, L. 2017. A modeling framework for evaluating streambank stabilization practices for reach-scale sediment reduction. Journal of Environmental Modeling and Software. Available at: https://doi.org/10.1016/j.envsoft.2017.11.010.

Interpretive Summary: Streambanks in many parts of the country are unstable and contribute large amounts of sediment to stream waters. Streambank stabilization techniques (conservation practices) are often implemented to reduce sediment loads from these unstable streambanks. Models can be used to evaluate or predict potential sediment yields for various stabilization techniques prior to actual implementation. However, a framework does not exist on how to effectively use these models to evaluate stabilization measures; instead, many projects rely on approaches that fail to quantify impacts up and downstream the stream stabilization site. The objective of this study was to develop a framework to evaluate streambank stabilization practices using physics-based hydraulic/sediment transport models, public and landowner perception, construction costs, and effectiveness. This framework produces a set of sediment reduction graphs to determine the length of streambank actually stabilized and a second set of graphs to determine the cost stabilization. The methodology was applied to Fivemile Creek (a tributary to Fort Cobb Reservoir), located in western Oklahoma. CONservational Channel Evolution and Pollutant Transport System (CONCEPTS) model simulations were developed for a 10.25-km reach from which several stabilization techniques (grade control, riprap toe, and vegetation) were simulated. Vegetation with 2:1 bank slopes was determined to be the most cost-effective stabilization practice.

Technical Abstract: Streambank stabilization techniques are often implemented to reduce sediment loads from unstable streambanks. Process-based models can predict sediment yields with stabilization scenarios prior to implementation. However, a framework does not exist on how to effectively utilize these models to evaluate stabilization measures; instead, many projects rely on empirical approaches that fail to quantify stream-scale impacts. The objective was to develop a framework to evaluate streambank stabilization practices using process-based hydraulic/sediment transport models, public and landowner perception, construction costs, and effectiveness. This framework produces a set of sediment reduction graphs to determine the stabilization length and a second set of graphs to determine the cost. The methodology was applied to Fivemile Creek, located in western Oklahoma. A CONCEPTS simulation was developed for a 10.25-km reach and several stabilization techniques (grade control, riprap toe, and vegetation) were simulated. Vegetation with 2:1 bank slopes was determined to be the most cost-effective stabilization practice.