Wheeler Reservoir

Ecological health rating

The ecological health of Wheeler Reservoir rated fair in 2009. Wheeler Reservoir has rated either good or fair in all previous years except 2007 when it rated poor. Generally, lower ecological health scores occur during years with lower flows when, typically, chlorophyll concentrations are higher and dissolved oxygen concentrations are lower. The lowest score occurred in 2007, which was the driest in 121 years of record.

TVA monitors four locations on Wheeler Reservoir—the deep, still water near the dam, called the forebay; the middle part of the reservoir; the Elk River embayment; and the riverlike area at the extreme upper end of a reservoir, called the inflow—usually on a two-year cycle.

Wheeler Reservoir Ecological Health Ratings, 1994-2009

Click chart for raw data.

The table below shows the ratings for individual ecological health indicators at Wheeler in 2009. These ratings are briefly explained in the paragraphs that follow.

Monitoring locations	Dissolved oxygen	Chlorophyll	Fish	Bottom life	Sediment
Ecological Health Indicators at Wheeler Reservoir, 2007
Forebay	Poor	Poor	Good	Poor	Good
Mid-reservoir	Good	Good	Fair	Good	Good
Elk River embayment	Poor	Poor	Fair	Poor	Good
Inflow			Fair	Good
Dissolved oxygen Dissolved oxygen rated good at the mid-reservoir location and poor at both the forebay and Elk River embayment due to low concentrations (less than two milligrams per liter of oxygen) in the lower water column during the summer. Dissolved oxygen has rated good at the mid-reservoir location in all previous years, but ratings have varied between good, fair and poor at the forebay and embayment locations, primarily in response to reservoir flows. Chlorophyll Chlorophyll rated good at the mid-reservoir location and poor at the forebay and Elk River embayment because concentrations were elevated in most of the samples collected. Chlorophyll typically rates poor at the forebay and Elk River embayment, but ratings have varied between good, fair and poor at the mid-reservoir location. Fish The fish community rated good at the forebay and fair at the other three locations monitored. Ratings have fluctuated between good and fair at each location. 2005 was the only year the fish community rated good at all locations. Bottom life Bottom life rated poor at the forebay and Elk River embayment and good at the mid-reservoir and inflow monitoring locations. The lower ratings were due to relatively sparse populations, predominantly composed of animals able to tolerate poor water quality. Sediment Sediment quality rated good at all locations monitored. No pesticides or PCBs were detected, and the concentrations of metals were within expected background levels. Sediment quality typically rates good, although it rated fair at the mid-reservoir location in 2003 due to the presence of low levels of chlordane (a pesticide previously used to control termites and crop pests). See definitions of ecological health indicators and monitoring locations.

Fish consumption advisories

Wheeler 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 Wheeler Reservoir, visit the Epidemiology Division of Alabama Department of Public Health’s web page. http://www.adph.org/tox/index.asp?ID=1360

Wheeler Reservoir is located on the Tennessee River in north central Alabama.