APPLICATION OF GIS IN WATERSHED CONDITION ASSESSMENT: LITTLE RIVER CANYON NATIONAL PRESERVE, ALABAMA

Little River Canyon National Preserve, a park unit of the National Park Service (NPS), occupies approximately 14,000 acres on Lookout Mountain, a synclinal structure whose eastern escarpment marks the eastern boundary of the Cumberland Plateau Region of Alabama. The Little River and its tributaries flow almost their entire length on top of Lookout Mountain and have deeply incised valleys developed along zones of weakness such as joints and faults in the bedrock. Over a distance of 27 miles the Little River falls 1250 feet to the mouth of Weiss Lake creating a scenic gorge, waterfalls, and a public swimming area at Little River Canyon Mouth Park. Little River is designated as an Outstanding National Resource Water (ONRW) in Alabama.

This study assesses watershed characteristics of Little River and adjoining tributaries within the National Preserve and current water quality conditions relative to federal and state standards. Data were gathered from a number of sources including the EPA STORET and the NPS Cumberland Piedmont Network Vital Signs Monitoring Plan. Water quality parameters used in this study include acid neutralizing capacity, dissolved oxygen, E. coli, nitrate, pH, phosphate, specific conductance, sulfate, water temperature, and turbidity. Results at selected sampling points are displayed graphically using a “stoplight” approach, which indicates widespread, limited, or no exceedances of water quality standards.

Temporal data are sporadic and some parameters have brief sampling histories resulting in low confidence in determined current condition. Although water conditions where the Little River flows out of the Preserve generally meet state water quality standards, some upstream sub-watersheds demonstrate varying water quality. Level of confidence, current condition, trends, and potential stressors on water quality provide valuable input in developing a resource management plan and articulating the desired future condition of water resources at Little River Canyon National Preserve.