The overall ecological health condition of Wilson Reservoir rated poor in 2012. Ratings for Wilson Reservoir 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 flow and worse in dry years that result in extended periods of low flow.
Dissolved oxygen levels near Wilson Dam rated poor due to the presence of low concentrations in the lower water column from May through August. Dissolved oxygen typically rates fair in years with more normal flows and poor in dryer, low-flow years.
Similar to most previous years, chlorophyll rated poor because concentrations were elevated throughout most of the summer.
The fish community rated good at the forebay and fair at the inflow monitoring location. The fish assemblage has consistently scored at the upper end of the fair range to good at the forebay whereas scores at the inflow have fluctuated within the fair range except for a poor rating in 2000.
Bottom life rated poor at the forebay and good at the inflow. Bottom life has rated poor or at the low end of the fair range each year at the forebay, probably due to low oxygen levels near the reservoir bottom and lack of good habitat. This indicator typically rates good or "high fair" at the inflow location.
Sediment quality rated fair because low levels of PCBs were detected in samples collected at the forebay. No 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.
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 Wilson Reservoir, visit the Epidemiology Division of Alabama Department of Public Health.