Land disturbing construction activities can become nonpoint sources of pollution, particularly due to suspended sediment, if erosion and sediment control measures are ineffective. Wattles have become popular practices among many governing agencies and contractors because of the variety of wattle materials available and their vast array of applications, such as ditch checks, inlet protection practices, and perimeter controls. As technologies continue to emerge, quantifying wattle performance can be a difficult and daunting task. To better understand hydraulic performance, flume experiments were conducted on eight manufactured wattles using a testing regime that used four inflow rates of 0.007, 0.021, 0.035, and $0.057{\mathrm{m}}^3/\mathrm{s}$ (0.25, 0.75, 1.25, and $2.00{\mathrm{ft}}^3/\mathrm{s}$ ) and three longitudinal channel slopes of 3.50%, 4.25%, and 5.00%. Hydraulic measurements to assess wattle performance were taken for each trial after flow stabilization. Six different fill materials (excelsior wood fiber, wheat straw, coconut coir, recycled synthetic fiber, chipped wood, and miscanthus fiber) and four containment systems (natural netting, synthetic netting, synthetic socking, and polyester socking) were evaluated. Test results indicated that wattles fall into one of four developed classes based on correlations between hydraulic depth ratios and subcritical length ratios identified in the study. Class 1 wattles are considered the least hydraulically favorable, and Class 4 wattles are considered the most favorable at reducing supercritical flows when compared to the performance of an impervious weir control test. Two-way (flow rate and channel slope) ANOVA analyses were conducted to evaluate the degree of wattle performance variations for each wattle type, and a multiple linear regression model was developed to quantify performance characteristics based on fill material, slope, and flow rate from a base case (i.e., impervious weir) scenario. The ANOVA analyses indicated that synthetic fiber and miscanthus filled wattles had superior hydraulic performance capabilities when subjected to various flow rates and longitudinal slopes based on no statistical difference across flow rates and slopes. The multiple linear regression model suggested that excelsior fiber was the least effective fill material for establishing flow velocities favorable for soil particle settlement, while miscanthus fiber created the most favorable conditions. Lastly, water absorption evaluations suggest that saturated wattle density, as opposed to dry density, can be used to link the wattle fill type to hydraulic performance.

Construction-related ground-disturbing activities leave exposed land susceptible to soil loss and increase the risk of polluting adjacent waterbodies with sediment-laden discharge. State and federal regulations require stormwater pollution prevention plans to be implemented during construction to mitigate the impact of stormwater runoff. Areas prone to soil loss can be identified early in site planning using soil loss modeling. Identification of these critical areas could influence the design and placement of erosion and sediment control practices. The Revised Universal Soil Loss Equation (RUSLE) can be applied to estimate the soil loss on construction sites in tonnes per Ha per year (tons/acre/year) by considering factors of rainfall erosivity, soil erodibility, length of slope, erosion control, and sediment control. This study integrates geographic information system (GIS) with RUSLE to create soil loss models for residential, commercial, and highway construction scenarios in the contiguous U.S.A. These three construction types were modeled in various locations throughout the country to assess erosive risk. Soil loss outputs were categorized into five risk tiers ranging from very low to very high. Southeastern states had the highest estimated soil loss during residential, commercial, and highway construction, reaching rates of 1,464, 706, and 1,302 tonnes per Ha per year (653, 315, and 581 tons/acre/year), respectively. This study provides a customizable model for any site-specific slope-length factor outside of the three construction scenarios modeled. Integration of GIS provides a unique opportunity to apply RUSLE across a larger landscape. The presented macro-scale data can be used for the design of erosion and sediment control practices.

Stormwater regulations require erosion and sediment control practices to be implemented during construction to prevent discharging polluted water offsite and mitigate downstream effects. Sediment basins are a common practice used to detain suspended sediment from stormwater runoff by providing residence time and storage to promote gravitational settling. Sediment basin design, and thus pollutant removal efficiency, vary regionally due to local design standards and preferences. This manuscript presents the results of a case study from Highway U.S. 30 construction in Tama County, Iowa, USA where two sediment basin systems were created within a conveyance channel by constructing an earthen berm across the channel to detain sediment-laden stormwater. A dewatering riser pipe was routed through the earthen berm to provide primary dewatering. The in-channel sediment basin was constructed with a 3% slope and a 10 ft. bottom width. The first system consisted of one basin created by a single earthen berm damming sediment-laden runoff, whereas the second system included two earthen berms, creating two in-channel sediment basins in series. Field monitoring was conducted on in-situ basins by deploying a rain gauge and automated water samplers positioned at the inflow and discharge points of a (a) single basin and (b) two basins in series within a roadside channel. During the monitoring period, no maintenance or dredging was recorded. Water samples were taken from the monitored basins at regular time intervals and analyzed for turbidity. Inflow turbidities often reached magnitudes up to the 10³ NTU and discharge samples indicated negligible turbidity reduction after residence. On several occasions, the in-channel sediment basins acted as a sediment source, with discharge turbidities measuring higher than inflow. Despite their initial performance, there was interest in improving the in-channel basin design due to the potential to maximize length-to-width flow ratios, and use of existing infrastructure, which reduced the amount of right of way needed for basin construction, installation time and cost. As a result, several potential design improvements and techniques were recommended to enhance in-channel sediment basin performance.

Sediment remains one of the most commonly occurring pollutants affecting the U.S.’s water bodies, as identified by the United States Environmental Protection Agency (USEPA) ( 1). Construction activities largely accelerate soil erosion and subsequent sediment deposition. The National Pollutant Discharge Elimination System Construction General Permit requires construction operators to implement erosion and sediment control (E&SC) plans to minimize downstream implications from sediment-laden discharge. However, E&SC practices are often designed from “rules of thumb” and lack scientific, performance-based evidence in their design and implementation. The Auburn University Stormwater Research Facility (AU-SRF), previously the Auburn University Erosion and Sediment Control Testing Facility (AU-ESCTF), is an outdoor research center dedicated to evaluating E&SC practices and products commonly used on highway construction projects. Large-scale test apparatuses and methods at AU-SRF are designed to mimic construction site conditions, including rainfall, flow rates, topography, and soil characteristics, to evaluate existing and novel E&SC practices. Since its inception in 2008, AU-SRF has provided small-, medium-, and large-scale testing evaluations for numerous Departments of Transportation and product manufacturers. Findings from controlled testing have continued to inform the selection, design, implementation, and maintenance of E&SC practices used on construction sites and protect downstream waters and infrastructure. In the first decade, AU-SRF has directed 13 research projects and produced more than 30 peer-reviewed publications and 100 professional presentations. As AU-SRF grows into its second decade and efforts reach outside of the southeastern region, the mission to advance knowledge through E&SC research and development, product evaluation, and training remains constant. This review synthesizes the research produced from large-scale testing at AU-SRF to date and presents ongoing projects.