Apalachia
Reservoir
Ecological
health rating
Apalachia Reservoir received a good rating in 2008, with the highest score (84) to date. This was the result of three indicators (chlorophyll, bottom life, and sediment) concurrently scoring at the upper end of their historical range rather than of a substantial change in any indicator. The reservoir’s score has fluctuated between fair and good since monitoring began.
TVA monitors one location on Apalachia Reservoir — the forebay, near the dam — usually on a two-year cycle.
Apalachia
Reservoir Ecological Health Ratings, 1997-2008
Click chart for raw data.
The table below
shows the ratings for individual ecological health indicators
at Apalachia
in 2008. These ratings are briefly explained in the paragraphs that follow.
|
Ecological
Health Indicators for
Apalachia Reservoir, 2008
|
|
Monitoring
location
|
Dissolved
oxygen
|
Chlorophyll
|
Fish
|
Bottom
life
|
Sediment
|
| Forebay |
|
|
|
|
|
Dissolved oxygen
Dissolved oxygen rated fair at Apalachia because levels were low in a small area along the bottom in late summer. TVA has found low levels of dissolved oxygen in this same area each year of sampling.
Chlorophyll
Chlorophyll concentrations were within the expected range and rated good. Chlorophyll ratings have fluctuated between poor, fair, and good, with no specific trend over time.
Fish
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 fish communities, particularly fish density and diversity. This indicator has rated fair in all previous years.
Bottom life
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
Sediment quality rated good. No PCBs or pesticides were detected, and the 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.
See definitions of
ecological health indicators and monitoring locations.
|
|
Fish consumption advisories
There is a statewide fish consumption advisory due to mercury concentrations. TVA collected channel catfish and largemouth bass from Apalachia reservoir for tissue analysis in autumn 2006. Contaminant concentrations, other than mercury, were either below detectable levels or below the levels used by the state of North Carolina to issue fish consumption advisories. TVA will collect fish from Apalachia again in autumn 2008.
Tennessee Valley Authority
