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Pickwick Reservoir

Ecological health rating

The overall ecological health condition of Pickwick Reservoir rated fair in 2012, with a score of 63. Pickwick has scored lower the past three years sampled compared to other years due primarily to three indicators (dissolved oxygen chlorophyll, and bottom life) concurrently rating near the low end of their historic ranges at several monitoring locations. Lower ratings (fair) for sediment quality also reduced the overall score in 2012. Conversely, the higher score (84) in 2004 resulted from all indicators rating near the upper end their historic ranges. Pickwick, however, typically scores near (slightly above or slightly below) the break point between a good and fair rating, with year-to-year variation primarily dependent on chlorophyll concentrations (which are affected by reservoir flows), and conditions in the Bear Creek embayment, which generally rates lower than at other monitoring locations on the reservoir.

Pickwick Reservoir Ecological Health Ratings, 1994-2012

reservoir ratings chart

Click chart for raw data.  

 

The table below shows the ratings for individual ecological health indicators at Pickwick in 2012. These ratings are briefly explained in the paragraphs that follow.

Ecological Health Indicators for
Pickwick Reservoir, 2012

Monitoring locations

Dissolved oxygen

Chlorophyll

Fish

Bottom life

Sediment

Forebay
Mid-reservoir
Bear Creek embayment
Inflow (near Wilson Dam)      

Dissolved oxygen

Dissolved oxygen rated fair at the forebay and embayment monitoring locations and good at the mid-reservoir. The fair ratings were the result of low dissolved oxygen concentrations (less than two milligrams per liter) in the lower water column during some sample periods. This indicator usually rates good at the mid-reservoir, but ratings have varied between good and fair at the forebay and embayment locations, generally in response to reservoir flow conditions.

Chlorophyll

Chlorophyll rated poor at the three locations monitored. Chlorophyll typically rates poor at the forebay and embayment locations and has fluctuated between good, fair, and poor at the mid-reservoir. As with dissolved oxygen, reservoir flows have played a part in the year-to-year fluctuations as low-flow conditions tend to allow more time for algal populations to become established.

Fish

The fish community rated good at the forebay and Bear Creek embayment locations and fair at the mid-reservoir and inflow locations. Fish community ratings generally have fluctuated between good and "high fair" ratings at all locations.

Bottom life

Bottom life rated good at the inflow and fair at the other three monitoring locations. However, bottom life scored at the low end of the fair range at the forebay and Bear Creek embayment because of higher proportions of tolerant organisms and reduced overall diversity. The lower scores likely were the result of the low dissolved oxygen conditions that developed along the reservoir bottom in 2012.

Sediment

Sediment quality rated fair at the three locations monitored. Low levels of PCBs were detected in samples from each location. Sediment quality has rated good in Pickwick Reservoir most years. Exceptions were fair ratings at the mid-reservoir in 1993, the forebay in 1996, and all monitoring locations in 1998 due to the detection of low levels of pesticides (DDT/DDD or chlordane) in the sediments.

 

See definitions of ecological health indicators and monitoring locations.

 

Fish consumption advisories

Pickwick 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 Pickwick Reservoir, visit the Water Quality
Division of Tennessee Department of Environment & Conservation’s
web page. http://www.tn.gov/environment/water.shtml ; the
Epidemiology Division of Alabama Department of Public Health’s web page. http://www.adph.org/tox/index.asp?ID=1360  and the Mississippi
Department of Environmental Quality’s web page. http://www.deq.state.ms.us/MDEQ.nsf/page/FS_Mississippi_Fish_
Advisories?OpenDocument
  

 

lake photo

Pickwick Reservoir is located on the Tennessee River in southwest Tennessee and northwest Alabama.

 

More about Pickwick

Sport fishing ratings

Spring sportfish survey results

General information

To see monitoring results for other TVA reservoirs, choose from the list below.

 

 

           
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