Field evaluation of sediment retention devices under concentrated flow conditions

Purpose: Sediments are the leading cause of water quality deterioration around the world. A number of sediment retention devices, including ditch checks, have been developed in the last few decades to improve water quality. Differences between methodologies used to evaluate product performance in the past have led to difficulties in comparing evaluations from various studies. Materials and methods: A new testing protocol for evaluating ditch check products was developed at the Erosion Control Research and Training Center (ECRTC) of the University of Illinois at Urbana-Champaign to provide a reliable and easily replicable testing procedure to evaluate product performance under standardized testing conditions. As per the field-scale protocol, three different flow conditions (5, 7.5, and 10 l s⁻¹) were used to evaluate performance both in terms of water quality (turbidity and sediment concentration) and channel disturbance prior to permanent stabilization, while simulating the conditions typically found during construction activities. The flow conditions can be reproduced in the field setting using commercially available pumps and were selected based on the peak flow-generated construction site of varying size in central Illinois, and the 5, 7.5, and 10 l s⁻¹ flows corresponded to peak flow generated from 5, 7.5, and 10 acre construction area from 10-year rainfall event. The three products tested were GeoRidge, Sediment Log, and Triangular Silt Dike. Results and discussion: In terms of sediment concentration, Triangular Silt Dike performed better under all flow conditions, while GeoRidge and Sediment Log performed similarly. GeoRidge was able to retain more sediment upstream compared to Triangular Silt Dike and Sediment Log. Conclusions: This study provides a reliable and easily replicable testing procedure to evaluate ditch check product performance under standardized testing conditions. This study can also help in future product development and proper product selection for erosion and sediment control plans based on the product performance.