Tims Ford Reservoir

Ecological health rating

TVA monitored Tims Ford Reservoir annually from 1992 through 1996 to establish baseline data on the reservoir’s ecological health under a range of weather and flow conditions. Tims Ford is now evaluated every other year.

Tims Ford Reservoir rated poor in 2006, similar to previous years. Consistent issues are low dissolved oxygen levels in the lower water column and poor ratings for bottom life. Lower ratings for chlorophyll at the mid-reservoir location have been an issue in recent years.

Tims Ford Reservoir Ecological Health Ratings, 1994-2006

Click chart for raw data.

The table below shows the ratings for individual ecological health indicators at Tims Ford 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 Tims Ford Reservoir, 2006
Forebay	Poor	Good	Fair	Poor	Fair
Mid-reservoir	Poor	Fair	Fair	Poor	Good
Dissolved oxygen As in previous years, dissolved oxygen rated poor at both monitoring locations. Oxygen levels were below two milligrams per liter throughout much of the lower water column during the summer and at or near zero on the bottom from July through October. Chlorophyll Chlorophyll concentrations were within the expected range at the forebay and rated good, while slightly elevated concentrations in the spring at the mid-reservoir resulted in a fair rating. At the mid-reservoir, chlorophyll concentrations indicate a trend of increasing. Chlorophyll rated good at the mid-reservoir site during the early 1990s, followed by fair and poor ratings since 1996. Fish The fish assemblage rated fair at both monitoring locations. The fish assemblage has scored fair or a “low good” at both locations all years monitored. Typically, a good variety of fish are collected, but a large number of them are species that are more tolerant of degraded water quality. Bottom life As in previous years, bottom life rated poor at both monitoring locations because few animals were found and most were species able to tolerate poor conditions. Low dissolved oxygen levels near the reservoir bottom are a likely contributing factor. Sediment Sediment quality rated good at the mid-reservoir but fair at the forebay due to elevated levels of nickel. Nickel has exceeded the expected background levels at forebay location in all previous years of monitoring, while arsenic exceeded those levels in 2002. Low levels of chlordane were detected at the mid-reservoir location in 1996, 1998, and 2002. See definitions of ecological health indicators and monitoring locations.

Fish consumption advisories

There are no fish consumption advisories on Tims Ford 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 Tennessee to issue fish consumption advisories. TVA will collect fish from Tims Ford again in the autumn of 2010.