Fort Patrick Henry Reservoir

Fort Patrick Henry Reservoir rated poor in 2011. Fort Patrick Henry has received a fair or poor rating every year except 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.

Ecological Health Indicators at Fort Patrick Henry Reservoir — 2011

Monitoring locationDissolved
oxygen
ChlorophyllFishBottom
life

Sediment
Forebay Good Poor Fair Fair Fair

Dissolved oxygen

Dissolved oxygen rated good, as in previous years. The reservoir’s small size and short residence time (the length of time the water sits in the reservoir) inhibits it from becoming thermally stratified and from developing low dissolved oxygen levels (less than two milligrams per liter) during the summer.

Chlorophyll

As in previous years, chlorophyll concentrations were elevated throughout most of 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 lower-than-expected number of species and a high proportion of tolerant individuals, such as gizzard shad.

Bottom life

Bottom life rated fair because a low variety of animals were found in samples collected from the reservoir bottom and most were species able to tolerate poor conditions. Bottom life typically rates within the fair range or at the upper end of the poor range.

Sediment

Sediment quality rated fair because samples contained PCBs and the concentration of arsenic was slightly above suggested background levels. Sediment quality typically rates fair due to low levels of chlordane, a pesticide previously used to control termites and crop pests, and/or copper exceeding suggested background levels. PCBs were last detected in 1994.

Fish consumption advisories

Fort Patrick Henry 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 Fort Patrick Henry Reservoir, visit the Tennessee Wildlife Resource Agency's Web page.