Nottely Reservoir

The ecological health of Nottely Reservoir rated poor in 2011. Nottely typically rates poor due to low ratings for dissolved oxygen, chlorophyll and bottom life. Ratings for these indicators improved in 2001, rating at the upper end of their historic range and resulting in a higher overall health rating of fair. However, subsequent monitoring indicates that the improvements were only a temporary result of the unusual rainfall and reservoir flow patterns in 2001.

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

Ecological Health Indicators at Nottely Reservoir — 2011

Monitoring location Dissolved
Chlorophyll Fish Bottom

Forebay Poor Poor Fair Fair Fair
Mid-reservoir Poor Poor Fair Poor Poor

Dissolved oxygen

Dissolved oxygen rated poor at both the forebay and mid-reservoir monitoring locations. A large proportion of the water column contained low dissolved oxygen concentrations during mid-to- late summer at these locations. This is similar to all previous years, except 2001 when oxygen concentrations were significantly higher at the forebay and rated good, and 2005 when significant rain events in late summer helped replenish oxygen in the upper reaches of the reservoir, resulting in a fair rating at the mid-reservoir location. Although dissolved oxygen typically rates poor at both locations, the extent and duration of low dissolved oxygen has varied in response to the timing and amount of rainfall.


Chlorophyll rated poor at the forebay and mid-reservoir monitoring locations. A poor rating is typical at the mid-reservoir location, but ratings at the forebay have varied between good, fair and poor. As with dissolved oxygen, chlorophyll concentrations have varied in response to the timing and amount of rainfall.


Consistent with previous years, the fish community rated fair at both monitoring locations because the number and variety of fish sampled were slightly less than expected.

Bottom life

Bottom life rated fair at the forebay and poor at the mid-reservoir location. Slightly higher density and diversity of animals were found at the forebay, but the animals collected at both locations were those tolerant of poor conditions. Bottom life typically rates poor or fair at the forebay and fair or good at the mid-reservoir location. Because there are so few bottom-dwelling animals, the ratings are easily influenced by the presence or absence of a few species.


Sediment quality rated fair at the forebay and poor at the mid-reservoir location. Arsenic concentrations were slightly above suggested background levels at the forebay. At the mid-reservoir, the concentrations of arsenic and copper were slightly elevated and PCBs were detected. A good rating is typical for sediment quality at both locations, although naturally occurring metals such as arsenic and copper are generally near—slightly above or below—suggested background concentrations. In addition, sediment quality rated fair at the mid-reservoir in 1995 because low levels of DDE were detected. DDE is a breakdown product of DDT. DDT entered the environment when it was used as a pesticide.

Fish consumption advisories

Nottely 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 Nottely Reservoir, visit the Environmental Protection Division of Georgia Department of Natural Resources’ Web page.