Fort
Patrick Henry Reservoir
Ecological
health rating
Fort Patrick Henry Reservoir rated fair in 2007. Fort Patrick Henry has received a fair or poor rating every year, except for 2003 when it rated good due primarily to improved chlorophyll levels (see discussion below).
TVA monitors one location on Fort Patrick Henry Reservoir—the deep, still water near the dam, called the forebay—usually on a two-year cycle.
Fort Patrick
Henry Reservoir Ecological Health Ratings, 1994-2007
Click chart for raw
data.
The table below
shows the ratings for individual ecological health indicators at Fort
Patrick Henry in 2007. These ratings are briefly explained in the paragraphs
that follow.
|
Ecological
Health Indicators at
Fort Patrick Henry Reservoir, 2007
|
|
Monitoring
location
|
Dissolved
oxygen
|
Chlorophyll
|
Fish
|
Bottom
life
|
Sediment
|
| Forebay |
|
|
|
|
|
Dissolved oxygen
Dissolved oxygen rated good. The reservoir’s small size and short residence time (the length of time the water sits in the reservoir) prevent it from becoming thermally stratified during the summer.
Chlorophyll
As in previous years, chlorophyll concentrations were elevated throughout the summer and autumn and rated poor. The exception was in 2003 when a shorter average residence time limited algae growth, resulting in the only good rating for this indicator.
Fish
The fish community rated fair. This indicator typically rates poor or fair. Monitoring consistently reveals a higher-than-expected proportion of species able to tolerate pollution or habitat degradation, such as gizzard shad.
Bottom life
Bottom life rated poor because of the low variety of animals found in samples collected from the reservoir bottom.
Sediment
Sediment quality rated good. No pesticides or PCBs were detected, and concentrations of metals were within the expected background levels. Sediment quality typically rates fair due to low levels of chlordane, a pesticide previously used to control termites and crop pests.
See definitions of
ecological health indicators and monitoring locations.
|
|
Fish
consumption advisories
There are no fish
consumption advisories for Fort Patrick Henry Reservoir. TVA collected channel catfish and largemouth bass from the reservoir for tissue analysis in fall 2005. The results, which were similar to those of previous years, will be provided to state agencies in Tennessee. TVA will analyze fish from Fort Patrick Henry again in the autumn of 2009.
Tennessee Valley Authority
