SILTspread: Performance-Based Approach for the Design and Installation of Silt Fence Sediment Barriers

Abstract

Construction operations are susceptible to high rates of rainfall-induced soil erosion due to the earth-disturbing nature of land-grading activities. Silt fence sediment barriers are a temporary sediment control practice comprising geotextile material supported by posts. Silt fence sediment barriers create containment systems to remove suspended soil particles by intercepting stormwater runoff and forming temporary impoundments. Most existing silt fence sediment barrier design guidance primarily relies on state design standards based on rules of thumb that lack scientific justification. Proper design and implementation of silt fence sediment barriers is critical and must consider site-specific factors such as topography, precipitation, soil type, and other site parameters. This technical paper describes a silt fence sediment barrier design and installation standard developed through a literature review of current state agency guidance and performance-based research. This study proposes a hydrologic design approach using local site conditions while accounting for detention volumes provided by silt fence sediment barrier installations. A streamlined hydrologic design approach and volumetric storage relationships were developed for three standard silt fence sediment barrier installation configurations (linear, J-hook, and C-shape). In addition, a user-friendly spreadsheet-based tool was developed to assist designers in calculating hydrologic and volumetric parameters, properly sizing silt fence sediment barrier segments, and estimating maintenance needs. A case study and recommendations for state agency implementation are included to demonstrate the application of the developed design approach.