Apalachia Reservoir received a good rating in 2012, the sixth consecutive monitoring year it did so. The reservoir has scored either good or fair since monitoring began. Apalachia received its lowest scores in 1998 and 1999. This was the result of three indicators (chlorophyll, bottom life, and sediment) concurrently scoring at the lower end of their historical range rather than of a substantial change in any indicator. TVA monitors one location on Apalachia Reservoir — the forebay, near the dam — usually on a two-year cycle.
Ecological Health Indicators for Apalachia Reservoir, 2012
Dissolved oxygen rated fair at Apalachia because concentrations were low in a small area along the bottom in late summer. TVA has found low dissolved oxygen concentrations in this same area each year of sampling.
Chlorophyll concentrations were within the expected range and rated good. Chlorophyll ratings have fluctuated between good, fair and poor with no specific trend through time.
The fish community in Apalachia rated fair because relatively few fish were collected. That meant lower ratings for several of the characteristics used to evaluate the fish community, particularly fish density and diversity. This indicator has rated fair in all previous years.
Bottom life has rated good since 2000. This compares to poor and fair ratings in earlier years. The improvement resulted from an increase in the density and diversity of organisms in the samples collected from the reservoir bottom.
Sediment quality rated fair because low levels of PCBs were detected in the sediment samples. No pesticides were detected, and concentrations of metals were within expected background levels. Sediment quality typically rates good, although it rated fair in 2000 due to slightly elevated concentrations of copper, probably related to the area’s geology.
Fish consumption advisories
Apalachia—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 Apalachia Reservoir, visit the Epidemiology Division of North Carolina Department of Health and Human Services’ Web page.