Norris Reservoir

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Ecological health rating

Norris Reservoir rated fair in 2005 monitoring by TVA.

Swimming advisories

The state of Tennessee has not issued any advisories against swimming in Norris Reservoir.

Fish consumption advisories

The state of Tennessee has not issued any advisories against consuming fish from Norris Reservoir.  

Related Links

More about Norris Reservoir

Sport fishing ratings

Get the facts on the availability of important sport species.

General information

Monitoring river conditions

Find out how TVA evaluates the river system’s ecological health and suitability for human use.

Ecological health rating

TVA monitored Norris Reservoir annually from 1991 through 1995 to establish baseline data on the reservoir’s ecological health under a range of weather and flow conditions. Norris is now monitored every other year.

As in previous years, the ecological health of Norris Reservoir was rated fair in 2005.

Norris Reservoir Ecological Health Ratings, 1994-2005

Click chart for raw data.  

 

The table below shows the ratings for individual ecological health indicators at Norris in 2005. These ratings are briefly explained in the paragraphs that follow.

Ecological Health Indicators at Norris Reservoir, 2005 Monitoring locations Dissolved oxygen Chlorophyll Fish Bottom life Sediment Forebay Poor Good Fair Poor Fair Mid-reservoir, Clinch River Poor Good Good Fair Fair Mid-reservoir, Powell River Poor Good Good Good Fair See definitions of the five ecological health indicators and locations of monitoring sites.

Dissolved oxygen

The most significant ecological health issue on Norris is low dissolved oxygen levels. Dissolved oxygen rated poor at all three monitoring locations because the lower half of the water column contained little oxygen (less than two milligrams per liter) from late summer through early autumn.

This issue is mostly the result of the reservoir’s basic characteristics. Norris is a deep tributary storage reservoir with a long summer retention time; that is, it can take more than 200 days for water to move through the reservoir. As the summer sun beats down on the surface of the reservoir, a warmer layer of water forms on top of a cooler layer. The layers do not mix, so the bottom layer becomes devoid of oxygen as it is used up by decaying plants and other materials that settle to the bottom.

TVA has installed equipment to add oxygen to the water as it is flows through Norris Dam. Learn more about these improvements.

Chlorophyll

Chlorophyll rated good at all three monitoring locations. Chlorophyll typically rates good on Norris.

Fish

The fish community received good ratings at both mid-reservoir monitoring locations due to good species diversity and population characteristics. Fewer fish and fish species were collected at the forebay monitoring location, resulting in a fair rating.

Bottom life

Bottom life ratings varied by location: poor at the forebay, fair at the Clinch mid-reservoir, and good at the Powell mid-reservoir. Bottom life typically rates good or “high fair” at the mid-reservoir sites, but there is greater variability in scores for the forebay, which has rated fair or poor in recent years. The poor ratings for the forebay, as in 2005, have resulted from collecting fewer organisms and fewer species.

Sediment quality

Sediment quality rated fair at all three monitoring locations. As in past years, forebay sediments had elevated concentrations of arsenic and lead. Lows levels of chlordane, a pesticide previously used to control termites and crop pests, were present in the sediments at both mid-reservoir locations.

 

Swimming advisories

TVA has not issued any swimming advisories for Norris Reservoir.   

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

The following locations were sampled in 2007:

Site Name	Location	County	State
Lakeview Boat Ramp	Clinch River Mile 118.0, Hunting Creek	Union	TN
Loyston Point Beach	Clinch River Mile 96L, Mill Creek Mile 1.4	Union	TN
Big Ridge State Park Beach	Clinch River Mile 98L, Big Ridge Lake	Union	TN
Anderson County Park Swim Site	Clinch River Mile 87.6L	Union	TN
Miller Island Clinch River Canoe Access	Clinch River Mile 77.2	Campbell	TN
Cedar Grove Marina Boat Ramp	Clinch River Mile 124.0R	Union	TN
Union County Marina Boat Ramp	Powell River Mile 30.0R	Union	TN

Fish consumption advisories

There are no fish consumption advisories for Norris Reservoir. TVA collected channel catfish and largemouth bass from the 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. These species will be collected for analysis again in fall 2009.

Norris Reservoir is located in east Tennessee north of Knoxville on the Clinch and Powell Rivers.

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

 

View general information on Norris Reservoir.