.skip-nav {position:absolute;left:-10000px;top:auto;width:1px;height:1px;overflow:hidden;} Skip to main content
Skip to main content

Fort Patrick Henry Reservoir

Fort Patrick Henry Reservoir rated “fair” in 2022.  Fort Patrick Henry has received a “fair” or “poor” rating every year except 2003, when it rated “good” due primarily to improved chlorophyll concentrations (see discussion below). 

The ecological health of Fort Patrick Henry Reservoir has been monitored using the same methodology since 1994. Ecological health evaluations focus on five indicators: dissolved oxygen, chlorophyll, sediment quality, benthic macroinvertebrate community (bottom life), and the fish assemblage. TVA monitors one location on Fort Patrick Henry Reservoir — the deep, still water near the dam, called the forebay (South Fork Holston River Mile (SFHRM 8.7). 

Fort Patrick Henry Reservoir Ecological Health Ratings, 1994-2022

 

To view or export the data, click on the menu in the top-right corner of the chart.

Ecological Health Score Ranges:
 

 >72 = Good

 

 59-72 = Fair

 

 <59 = Poor

Ecological Health Indicators for Fort Patrick Henry Reservoir ‒ 2022

Monitoring locationDissolved
oxygen
ChlorophyllFishBottom
life

Sediment
ForebayGoodPoorFairGoodGood

Dissolved oxygen

Dissolved oxygen rated “good” in 2022, consistent with ratings of previous years. The reservoir’s small size and short residence time (the length of time the water remains in the reservoir) inhibit it from becoming thermally stratified for extended periods and from developing low dissolved oxygen levels (less than two milligrams per liter) during the summer.

Chlorophyll

Similar to most previous years, chlorophyll in 2022 rated “poor”, as concentrations were elevated throughout most of the summer and autumn. The main exception to this trend was in 2003, when shorter residence times limited algae growth, resulting in the only “good” rating for this indicator.

Fish

The fish community rated “fair” in 2022. Historically, this indicator has rated “fair” or at the upper end of the “poor” range, as monitoring consistently reveals a moderate number of species and a high proportion of a few prolific, tolerant species, such as gizzard shad and spotfin shiner. A total of twenty-one species of fish was collected in 2022, and fish health was assessed a “good” rating with low incidences of disease and parasites.

Bottom life

Bottom life in 2022 scored at the low end of the “good” range. Bottom life scored within the “fair” range in all previous years except 1995, 1997, and 2007, when it rated “poor”. Benthic organisms have consisted mostly of tolerant midges and worms, with limited occurrences of other taxa. The “good” rating in 2022 is attributed to a subtle improvement in composition of the taxa comprising the benthic community.

Sediment

Sediment quality rated “good” in 2022, consistent with ratings since 2016. No PCBs or pesticides were detected in the samples and concentrations of metals were within suggested background concentrations. Prior to 2016, sediment quality often rated “fair” due to one or more of the following contaminants: copper, PCBs, and/or chlordane.

Fish consumption advisories

TVA maintains a program to examine contaminants in fillets of fish collected from TVA reservoirs and their major tributary streams on a rotational basis. The data collected from this program are 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 Department of Environment and Conservation web page.