Nickajack Reservoir

Ecological health rating
Swimming advisories
Fish consumption advisories

Ecological health rating

As in previous years, Nickajack Reservoir rated good in 2007. The ecological health score for Nickajack has consistently been among the highest of all the reservoirs monitored by TVA. Nickajack is a small, narrow reservoir with a short retention time. It usually takes only three or four days for water to flow through the reservoir, which helps keep the water mixed, preventing it from stratifying (separating into layers of different temperatures) during the summer. This allows oxygen in the lower water column to be replenished and limits algal growth, which causes elevated chlorophyll concentrations.

TVA monitors two locations on Nickajack Reservoir—the deep, still water near the dam, called the forebay, and the riverlike area at the extreme upper end of the reservoir, called the inflow—usually on a two-year cycle.

Nickajack Reservoir Ecological Health Ratings, 1994-2007

Click chart for raw data.  

 

The table below shows the ratings for individual ecological health indicators at Nickajack in 2007. These ratings are briefly explained in the paragraphs that follow.

Ecological Health Indicators at Nickajack Reservoir, 2007 Monitoring locations Dissolved oxygen Chlorophyll Fish Bottom life Sediment Forebay Good Poor Fair Fair Good Inflow     Good Good   Dissolved oxygen As in previous years, dissolved oxygen rated good at the forebay. Even with the low flows in 2007, the retention time within the reservoir was relatively short, helping to maintain oxygen concentrations throughout the water column. Chlorophyll Chlorophyll rated poor for the first time in 2007. Chlorophyll rated good in previous years, but the extremely dry conditions and resultant low flows through the reservoir in 2007 allowed more time for algae to grow. Fish As in previous years, the fish community rated fair at the forebay monitoring location and good at the inflow location. Fewer fish and fish species were collected at the forebay than expected, and a greater proportion of those were tolerant individuals. Bottom life Bottom life rated at the upper end of the fair range at the forebay and good at the inflow location. Bottom life has rated good at both monitoring locations in previous years. A wide variety of organisms was found, including long-lived and sensitive organisms—such as snails and mayflies—which is indicative of good water quality and conditions that allow for long-term survival. Sediment Sediment quality rated good. No pesticides or PCBs were detected, and concentrations of metals were within the expected background levels. Sediment quality has rated good since 2001, compared to fair in 1995, 1997, and 1999 when low levels of PCBs were detected and in 1993 when low levels of chlordane were detected.   See definitions of ecological health indicators and monitoring locations.

Swimming advisories

TVA has not issued any swimming advisories for Nickajack Reservoir.

E. coli bacteria levels in samples collected in 2007 were within the state of Tennessee’s guidelines for water contact. 

The sites sampled in 2007 are:

Site Name	Location	County	State
Maple View Beach	Tennessee River Mile 425.3L	Marion	TN
Shellmound Day Use Area Beach	Tennessee River Mile 425.4R	Marion	TN
Camp-on-Lake Beach	Tennessee River Mile 429.6L	Marion	TN
Marion County Park Beach	Tennessee River Mile 429.6R	Marion	TN

 

The state of Tennessee has bacteriological advisories on three tributary streams that flow into Nickajack Reservoir: Chattanooga Creek (mouth to Ga. line 7.7 miles), Stringer’s Branch (mile 0.0 to 5.4), and Citico Creek (mouth to headwaters 7.3 miles). More information about state advisories can be obtained at this site: Tennessee Department of Environment and Conservation Fishing and Bacteriological Advisories.

Fish consumption advisories

The state of Tennessee has issued a precautionary fish consumption advisory for channel catfish from Nickajack Reservoir because of PCB contamination. A precautionary advisory means that pregnant women, nursing mothers, and children should not eat the contaminated fish. All others should limit their consumption of the named species to no more than one meal per month. Additionally, the state has issued an advisory that fish from Chattanooga Creek, a tributary stream of Nickajack, should not be eaten because of elevated PCB and chlordane levels.

TVA collected channel catfish, striped bass, and largemouth bass from Nickajack Reservoir for tissue analysis in fall 2005. The results, which were similar to those of previous years, will be provided to state agencies in Tennessee. TVA will analyze fish from Nickajack Reservoir again in autumn 2007.

 

 

Nickajack Reservoir is located on the Tennessee River below Chattanooga in southeastern Tennessee.

 

More about Nickajack

Sport fishing ratings

Spring sportfish survey results

General information

To see monitoring results for other TVA reservoirs, choose from the list below.

Reservoirs Apalachia Bear Creek Beech Blue Ridge Boone Cedar Creek Chatuge Cherokee Chickamauga Douglas Fontana Fort Loudoun Fort Patrick Henry Guntersville Hiwassee Kentucky Little Bear Creek Melton Hill Nickajack Normandy Norris Nottely Parksville Pickwick South Holston Tellico Tims Ford Watauga Watts Bar Wheeler Wilson