Wilson Reservoir

Ecological health rating

TVA monitored Wilson Reservoir annually from 1991 through 1994 to establish baseline data on the reservoir’s ecological health under a range of weather and flow conditions. Wilson is now evaluated every other year.

The overall ecological health condition in Wilson Reservoir was fair in 2006. The reservoir ratings for Wilson have fluctuated in a pattern that generally follows reservoir flow conditions, primarily due to the influence of flows of 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, and 2006).

Wilson Reservoir Ecological Health Ratings, 1994-2006

Click chart for raw data.

The table below shows the ratings for individual ecological health indicators at Wilson in 2006. 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, 2006
Forebay	Poor	Poor	Good	Fair	Good
Inflow			Fair	Good
Dissolved oxygen Dissolved oxygen levels near Wilson Dam rated poor in 2006 due to the presence of low dissolved oxygen (<2 mg/L) in the lower water column during May through August. Dissolved oxygen typically rates fair in years with more normal flows and poor in dryer, low-flow years such as 2000, 2002, and 2006. 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 in 2006. The fish community rated fair at the inflow location because of a fair diversity of fish and a high composition of tolerant individuals. The fish assemblage has scored consistently "high fair" to good at the forebay and fair at the inflow location except for a poor rating in 2000. Bottom life Bottom life rated fair at the forebay monitoring location, probably due to low oxygen levels near the reservoir bottom and lack of good habitat. Conversely, this indicator rated good at the inflow location. Sediment Sediment quality rated good because no PCBs or pesticides were detected and all metal concentrations were within the expected range. 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. Sediment quality typically rates good in Wilson. 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.