Chickamauga
Reservoir
Ecological
health rating
The ecological health of Chickamauga Reservoir rated good in 2009, the same as in previous years except 2007 when Chickamauga rated fair. In 2007, three indicators (dissolved oxygen, chlorophyll, and bottom life) either rated at the low end of their historic range or lower than in previous years. The lower ratings were largely due to low reservoir flows in 2007, which was the driest year in 118 years of record.
TVA monitors four locations on Chickamauga Reservoir—the deep, still water near the dam, called the forebay; the middle part of the reservoir; the Hiwassee River embayment; and the riverlike area at the extreme upper end of a reservoir, called the inflow—usually on a two-year cycle.
Chickamauga
Reservoir Ecological Health Ratings, 1994-2009
Click chart for raw
data.
The table below
shows the ratings for individual ecological health indicators at Chickamauga
in 2009. These ratings are briefly explained in the paragraphs that follow.
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Ecological
Health Indicators at
Chickamauga Reservoir, 2009
|
|
Monitoring
locations
|
Dissolved
oxygen
|
Chlorophyll
|
Fish
|
Bottom
life
|
Sediment
|
| Forebay |
|
|
|
|
|
| Mid-reservoir |
|
|
|
|
|
| Hiwassee
River embayment |
|
|
|
|
|
| Inflow |
|
|
|
|
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Dissolved oxygen
Dissolved oxygen rated good at all locations monitored. Dissolved oxygen typically rates good, except during extremely dry, low flow years such as 2007, which can result in the development of low dissolved oxygen conditions near bottom and fair ratings.
Chlorophyll
Chlorophyll rated poor at the forebay and mid-reservoir locations because concentrations were elevated in a majority of the samples collected. Chlorophyll rated good at the Hiwassee location. Ratings have fluctuated between good, fair, and poor at each location, generally in response to reservoir flow conditions, but annual average concentrations indicate a trend of increasing at the forebay and mid-reservoir.
Fish
The fish community rated at the high end of the fair range at all monitoring locations. The fish community typically rates good or at the high end of the fair range.
Bottom life
Bottom life rated fair at the forebay and Hiwassee embayment locations and good at the two other locations. Ratings typically vary between good and fair at each location. However, bottom life rated at the low end of the fair range at the forebay in 2007 — lower than in previous years — and poor at the embayment location because overall abundance and diversity of animals were lower. The lower ratings likely were the result of the low dissolved oxygen conditions that developed along the reservoir bottom in 2007.
Sediment
Sediment quality rated good at all monitoring locations. No PCBs or pesticides were detected, and all metal concentrations were within the expected range. Elevated concentrations of PCBs and selected metals—generally zinc and copper—have been detected in sediment samples from the forebay and Hiwassee embayment monitoring locations in some previous years.
See definitions of
ecological health indicators and monitoring locations.
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Fish
consumption advisories
Chickamauga 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 Chickamauga Reservoir, visit the Water Quality Division of Tennessee Department of Environment & Conservation’s web page. http://www.tn.gov/environment/water.shtml
Tennessee Valley Authority
