The overall ecological health condition of Beech Reservoir rated fair in 2012. Historically, ecological health ratings have fluctuated within the poor range. Consistent problems have been high chlorophyll concentrations and low dissolved oxygen levels near the bottom. In addition, one or more contaminants often are present in the sediments. The higher score (64) in 2012 was primarily the result of improved chlorophyll concentrations. The score of 42 in 2000 was the lowest recorded for Beech Reservoir. This was the result of several indicators concurrently scoring at the low end of their historical range rather than a substantial change in any one indicator.
TVA monitors one location on Beech Reservoir — the deep, still water near the dam — usually on a two-year cycle.
As in previous years, dissolved oxygen rated poor. Dissolved oxygen concentrations were low near the reservoir bottom from April through September, with extended periods of time when the bottom water was completely devoid of oxygen.
Chlorophyll concentrations were quite variable throughout the 2012 sampling period, but the average concentration was within the expected range, resulting in a good rating for this indicator. High chlorophyll levels have been a problem in Beech Reservoir, typically resulting in poor ratings.
The fish community rated fair. As in previous years, lack of species diversity — particularly the absence or low numbers of intolerant species — lowered the overall fish community score.
Bottom life rated good. Bottom life in Beech usually rates good compared to other reservoirs in the Tennessee Valley’s interior plateau ecoregion.
Sediment quality rated poor because samples contained detectable levels of PCBs and DDE—a breakdown product of the pesticide DDT — and slightly more arsenic than would be expected to occur naturally. Sediment quality has rated fair most years due to chlordane, DDE or arsenic; however, it rated good in 1994, 1996 and 2002, when no problems were detected.
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 Beech Reservoir, visit the Tennessee Wildlife Resource Agency.