The ecological health of Watauga Reservoir scored at the upper end of the fair range in 2012. Watauga has scored within the mid-fair to good range most years. The score of 60 in 1998 was the lowest recorded for Watauga. This was the result of several indicators concurrently scoring at the lower end of their historical ranges, rather than of a substantial change in any indicator. However, sediment quality has exhibited an overall improvement over the years.
TVA monitors two locations on Watauga Reservoir — the deep still water near the dam called the forebay, and the middle part of the reservoir.
Dissolved oxygen rated fair at the forebay and poor at the mid-reservoir. Ratings were reduced at both locations because oxygen concentrations were low (<2 mg/L) along the reservoir bottom during some sample periods. Dissolved oxygen has consistently rated good or “high fair” at the forebay, whereas ratings at the mid-reservoir typically have been poor. However, dissolved oxygen rated good at the mid-reservoir in 2004 and 2010. Although low dissolved oxygen was present in the lower water column those years, only a small area was affected.
Chlorophyll levels were within the expected range at both monitoring locations and rated good, consistent with most previous years.
The fish community rated fair at the forebay and good at the mid-reservoir. The fish assemblage in Watauga Reservoir is characterized by moderate to good species diversity and abundance. In previous years, the fish community has rated at the upper end of the fair range or good at the mid-reservoir and fair at the forebay except in 2010, when it rated good.
Bottom life rated fair at the forebay and poor at the mid-reservoir. Historically, bottom life has rated fair or poor at both locations because relatively few organisms are found in samples collected from the reservoir bottom, and most are species capable of tolerating poor conditions. Improved ratings (fair) generally result from an increase in the number of organisms collected rather than an improvement in the variety of organisms.
Sediment quality rated good at both monitoring locations because no PCBs or pesticides were detected, and concentrations of metals were within expected background levels. The forebay has received a good rating most years; however, the mid-reservoir first received a good rating in 2006. In prior years, the mid-reservoir site rated fair because sediment samples contained low levels of chlordane, a pesticide previously used to control termites and crop pests. Chlordane also was detected in the sediments at the forebay in 1993 and 1998.
TVA maintains a program to examine contaminants in fish fillets from TVA reservoirs and their major tributary streams on a rotational basis. The data collected from this program is distributed to the state officials who are responsible for placing or removing fish tissue consumption advisories on those bodies of water. For information on advisories currently in effect for Watauga Reservoir, visit the Tennessee Wildlife Resource Agency.