Modeling the Effectiveness of the FAEST Silt Fence Technology

Background information, example computer model predictions, and field validation results are given for a new silt fence technology known as FAEST. Developed at Oklahoma State University, FAEST has the potential to dramatically improve sediment trapping efficiency at construction sites by eliminating typical failure mechanisms. In field studies, more than 90 percent of sediment was trapped. A model of the process has been developed, validated, and incorporated into the IDEAL watershed hydrology-water quality model. The model algorithms for the silt fence objects are based on fundamental theory and widely accepted empirical relationships. The user can predict the performance of FAEST for varying land conditions, terrain slopes, slopes along the fence, soil types, and rainfall patterns. The principal intended application of the model is for construction sites. Hydrographs, sedigraphs, and trapping efficiency are generated for flow through the fence along with predictions of effluent particle size distribution. Failure by means of overtopping of the fence can be identified. The model was validated using field studies conducted to evaluate the performance of the new silt fence technology.