Wilson Reservoir

Ecological health rating

The overall ecological health condition in Wilson Reservoir was poor in 2008. The reservoir ratings for Wilson have fluctuated in a pattern that generally follows reservoir flow conditions, primarily due to the influence of flows on dissolved oxygen in the forebay. Like most Tennessee River main-stem reservoirs, Wilson tends to rate better in years with higher flows (1994, 1996, 1998, and 2004) and worse in dry, low-flow years (2000, 2002, 2006, and 2008).

Wilson Reservoir Ecological Health Ratings, 1994-2008

Click chart for raw data.

The table below shows the ratings for individual ecological health indicators at Wilson in 2008. These ratings are briefly explained in the paragraphs that follow.

Monitoring locations	Dissolved oxygen	Chlorophyll	Fish	Bottom life	Sediment
Ecological Health Indicators for Wilson Reservoir, 2008
Forebay	Poor	Poor	Good	Poor	Good
Inflow			Fair	Fair
Dissolved oxygen Dissolved oxygen levels near Wilson Dam rated poor due to the presence of low concentrations in the lower water column from May through September. Dissolved oxygen typically rates fair in years with more normal flows and poor in dryer, low-flow years such as 2000, 2002, 2006, and 2008. Chlorophyll Similar to most previous years, chlorophyll rated poor because concentrations were elevated throughout most of the summer. Fish The fish community rated good at the forebay and fair at the inflow. A good variety of fish were collected at both monitoring locations, but the high composition of tolerant individuals at the inflow resulted in a lower rating. The fish assemblage has scored consistently at the upper end of the fair range to good at the forebay and fair at the inflow location except for a poor rating in 2000. Bottom life Bottom life rated poor at the forebay monitoring location, probably due to low oxygen levels near the reservoir bottom and lack of good habitat. This indicator rated fair at the inflow location. Sediment Sediment quality rated good. No PCBs or pesticides were detected, and all metals concentrations were within the expected range. Sediment quality typically rates good, but chlordane, a pesticide previously used to control termites and crop pests, was detected in the sediment sample from the forebay in 1998 and 2004, resulting in fair ratings. See definitions of ecological health indicators and monitoring locations.

Fish consumption advisories

There are no fish consumption advisories on Wilson Reservoir. TVA collected channel catfish and largemouth bass from the reservoir for tissue analysis in the autumn of 2006. All contaminant levels were either below detectable levels or below the levels used by the state of Alabama to issue fish consumption advisories. TVA will analyze fish from Wilson again in the autumn of 2010.