The Design of Temporary Sediment Controls for Soil Losses from Highway Cut Slopes

About the report:

This manual describes a computer program which estimates the soil loss from a highway cut slope. Input into the program consists of a basic description of the slope (location, soil erodibility, slope length and gradient) and duration of construction. The output consists of an estimated annual soil loss and a peak loss assuming a 2-year, 6-hour storm event. The preventive measures required to prevent this peak soil loss from getting into streams are in terms of the number of straw flow barriers required.

Several studies suggest that soil loss from highway construction can be estimated by use of the Universal Soil Loss Equation. This soil loss prediction equation was developed by the U. S. Soil Conservation Service for soil losses from agricultural areas of low and uniform steepness. Two difficulties arise in its application to highway construction. These are that the typical highway slope is commonly irregularly shaped in cross section and that at least part of the slope is usually very steep. Recently, a modification of the equation by Foster and Wischmeier allows for the prediction of soil loss from irregular slopes. The program described here is intended to be used for new construction and scheduled erosion control maintenance of existing projects.

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