Adaptation and Application of a Surface Erosion Model for New Mexico Forest Roadways

The most significant source of sediment in forest environments is poorly planned, constructed or maintained roadways. Roadways change drainage patterns, expose the soil, disturb vegetation, and alter existing slope gradients. If improperly maintained, roadways can be subjected to accelerated erosion, which can cause signficant onsite and offsite impacts.

One important aspect of sediment control measures for roadways is the cost of installation and maintenance. These costs vary from year to year and roadway to roadway. The type of control measure should be selected by effectiveness in reducing erosion and associated cost.

This study was conducted to compare effectiveness of measures and associated costs. Data collected from forest roadways on four national forests in New Mexico were used to derive parameters for an existing computer based erosion and sediment yield model. The model was used to estimate sediment yields for different control measures. Yields were compared with costs of measures which were provided through a survey of forest engineers in Arizona and New Mexico. Results show the different costs of using various methods for reducing a unit of sediment yield from forest roadways, and can be used to help determine a best management method.