Fort
Loudoun Reservoir
Ecological
health rating
Fort Loudoun Reservoir rated poor in 2007 monitoring. Conditions were similar to most previous years. Low ratings for two indicators—chlorophyll and bottom life—consistently reduce the reservoir’s overall health score. In addition, dissolved oxygen concentrations rate lower during years with low flows such as 2007. One indicator—sediment quality—improved in 2007.
TVA monitors three locations on Fort Loudoun Reservoir—the deep, still water near the dam, called the forebay; the middle part of the reservoir; and the riverlike area at the extreme upper end of a reservoir, called the inflow. Fort Loudoun is monitored annually because it is the first reservoir on the main channel of the Tennessee River and because a number of water-quality issues have been identified in past years. (Most TVA reservoirs are monitored every other year.)
Fort
Loudoun Reservoir Ecological Health Ratings, 1994-2007
Click chart for raw
data.
The table below
shows the ratings for individual ecological health indicators at Fort
Loudoun in 2007. These ratings are briefly explained in the paragraphs
that follow.
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Ecological
Health Indicators at
Fort Loudoun Reservoir, 2007
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|
Monitoring
locations
|
Dissolved
oxygen
|
Chlorophyll
|
Fish
|
Bottom
life
|
Sediment
|
| Forebay |
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|
|
|
|
| Mid-reservoir |
|
|
|
|
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| Inflow |
|
|
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Dissolved oxygen
Dissolved oxygen rated poor at the forebay and good at the mid-reservoir monitoring location. This indicator usually rates good, except during years with exceptionally low flows such as in 1999, 2001, 2002, and 2007, when dissolved oxygen rated poor at the forebay. TVA has installed aeration equipment to add oxygen to the deep water above Fort Loudoun Dam and to improve conditions immediately downstream. Learn
more about these improvements.
Chlorophyll
Chlorophyll concentrations were high at both monitoring locations, resulting in poor ratings. High chlorophyll concentrations are a consistent issue on Fort Loudoun, rating poor at both sites in 12 of the last 14 years of monitoring.
Fish
The fish assemblage rated good at the forebay and fair at the mid-reservoir and inflow monitoring locations. The variety of fish collected at all three locations was good, but catch rates were slightly lower than desired.
Bottom life
Similar to previous years, bottom life rated poor at the forebay and inflow monitoring locations. It also rated poor at the mid-reservoir location where it typically rates fair. Relatively few organisms are usually collected from the forebay and inflow locations, and those collected are primarily species capable of tolerating poor conditions. Bottom life at the mid-reservoir location typically rates fair due to greater diversity, which includes a better representation of intolerant species such as mayflies.
Sediment
Sediment quality rated good at both the forebay and mid-reservoir monitoring locations. Sediment quality typically rates fair at both locations due to chlordane, PCBs, and/or zinc exceeding suggested limits.
See definitions of
ecological health indicators and monitoring locations.
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Fish
consumption advisories
The state of Tennessee advises
against eating catfish or largemouth bass over two pounds from Fort
Loudoun Reservoir because of PCB contamination. The state has also
issued a fish
consumption advisory against eating any largemouth bass caught in the
Little River embayment.
TVA collected channel catfish and largemouth bass from the reservoir for tissue analysis in the autumn of 2006. The results, which will be provided to state agencies in Tennessee, were similar to those of previous years. TVA plans to collect and analyze channel catfish from the mid-reservoir site in autumn 2007 for selected pesticides and PCBs.
Tennessee Valley Authority
