Water quality impacts from an ORV trail stream crossing in the Talladega National Forest, Alabama, USA
Off-Road Vehicles (ORVs) are one of the most damaging forms of recreation utilized in our National Forests. Erosion from ORV trails can be a major source of water quality impact. In 2003, a study was initiated in the Talladega National Forest to quantifjl water quality impacts of an ORV trail crossing a local stream. Automated samplers were installed upstream and downstream from an ORV trail stream crossing to collect suspended sediment (SS) samples. Storm-event SS samples were collected over a 9-month period and trail conditions were monitored. Three different operational conditions - closed, maintenance, and open - were observed during the sampling period. During the trail closed condition, four storm events, which included a 49 mm storm, contributed a total of 109.3 kg of SS load. Subsequent to this, two storm events during the trail maintenance period contributed a total of 4. lkg of SS to the stream. The trail was then opened to ORV traffic. During the trail open period, eight storms contributed a SS load of 6.5 kg. Since most of the observed storms had return periods of less than one year, the SS loads contributed by the ORV stream crossing were small. The measured data and the observations, however, suggest that the ORV stream crossing can contribute large SS loads during storm events with return periods of one year or more.