Tellico Reservoir

Tellico Reservoir rated poor in 2011. Tellico has rated either poor or at the low end of the fair range, except in 1994 when it scored slightly higher due primarily to improved chlorophyll concentrations.

TVA monitors two locations on Tellico Reservoir, the deep, still water near the dam and the middle part of the reservoir, usually on a two-year cycle.

Ecological Health Indicators at Tellico Reservoir — 2011

Monitoring locationDissolved
oxygen
ChlorophyllFishBottom
life

Sediment
Forebay Poor Poor Good Poor Fair
Mid-reservoir Good Fair Good Poor Fair

Dissolved oxygen

Dissolved oxygen rated good at the mid-reservoir location and poor at the forebay due to low concentrations (<2 mg/L) in the lower water column throughout summer. Historically, dissolved oxygen ratings at the forebay have fluctuated between good, fair and poor. Weather conditions and related changes in reservoir flows are a major factor in the differences that arise from year to year. Dissolved oxygen has consistently rated good at the mid-reservoir location.

Chlorophyll

Chlorophyll rated poor at the forebay and fair at the mid-reservoir location. Higher chlorophyll levels can be expected at the forebay monitoring location because of the exchange of water from the chlorophyll-rich forebay of Fort Loudoun Reservoir via the canal connecting the two reservoirs. However, concentrations were higher than expected at the mid-reservoir location given the nutrient-poor soils in the upstream watershed. Chlorophyll typically rates poor at the forebay and fair or poor at the mid-reservoir location.

Fish

The fish community rated good at both monitoring locations. This indicator typically rates fair in Tellico Reservoir, but it has occasionally rated good. Monitoring usually shows moderate to good species diversity, but the number of fish collected each year has been lower than expected.

Bottom life

As in previous years, bottom life rated poor at both monitoring locations because few animals were found and most were capable of tolerating poor conditions. Low dissolved oxygen levels and cold bottom water are likely contributing factors.

Sediment

Sediment quality rated fair at both monitoring locations because PCBs were detected and arsenic concentrations were slightly above suggested background levels. Sediment quality rated good in most previous years, but the detection of pesticides (chlordane and aldrin) and/or elevated levels of arsenic have resulted in some fair ratings. Arsenic naturally occurs in the soils and concentrations in sediments deposited in the reservoir are generally near—slightly above or below—suggested background concentrations. The pesticides that were detected in Tellico Reservoir were banned from use in the 1970s and 1980s. However, they continue to be detected sporadically in sediments because of their persistence in the environment.

Fish consumption advisories

Tellico Reservoir—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 Tellico Reservoir, visit the Tennessee Wildlife Resource Agency's Web page.