We live next to a beautiful amenity – Tellico Lake. Yet it wasn’t always this way. The lake is only 40 years old, having been created once TVA completed the Tellico Dam in 1979. TVA likes to call it a “reservoir”, because it’s an artificial lake. Regardless, today it provides 33 miles of recreation and economic development opportunity along its 361 miles of shoreline (at full pool level).
Now that we have this wonderful resource, we need to take care of it, which is the purpose of this month’s advocacy article.
TVA routinely measures the ecological health of all of its reservoirs. In the case of Tellico, it has provided health ratings every 2 years since 1994. Two areas are sampled: the area in front of Tellico Dam (at Little TN River Mile 1.0) and at a mid-reservoir area (at Little TN River Mile 15.0, which is the roughly at the mid-point of Rarity Bay). The last measurement period was 2017, when Tellico earned an overall rating of “poor”. The lake has been rated on the borderline between “poor” and “fair” for every year except 1994, when higher chlorophyll counts improved the overall rating a small amount.
From the TVA 2017 report, the overall scores for Tellico Lake are:
Ecological Health Score Ranges: >72 = Good; 59-72 = Fair; <59 = Poor
So, why doesn’t TVA think our lake is very healthy? To understand that you have to look at how their measurement system works. TVA health evaluations focus on five measurements:
- Dissolved Oxygen. The amount of dissolved oxygen in the water is important for maintaining healthy fish populations.
- Chlorophyll. The concentration of chlorophyll in the water is directly related to the amount of algae living in the water. Algae is important because it adds oxygen to the water (as a by-product of photosynthesis) and is at the base of the food web for many aquatic species. On the other hand, excessive concentrations of algae give lakes an undesirable “pea soup” appearance, producing a foul odor and is unpleasant for swimming.
- Fish. Fish are an important part of the overall aquatic food chain and provide important aesthetic and recreational benefits.
- Bottom Life. This includes lake bottom-dwelling, readily visible aquatic worms, snails, crayfish, and mussels. They are an important part of the aquatic food chain and a good indicator of overall lake health since they have limited capability of movement, which prevents them from avoiding undesirable conditions.
- Sediment Quality. Sediment quality is an important aspect of the overall aquatic ecosystem because it can influence the quality of the water above and also supports creatures living on the bottom of the lake. Identifying changes in sediment quality can be an indication of environmental change and chemical inputs from point or non-point sources.
The TVA 2017 Report gave the following scores for each of the Ecological Health Indicators in Tellico Lake:
| Monitoring location | Dissolved Oxygen | Chlorophyll | Fish | Bottom Life | Sediment |
| Tellico Dam | Poor | Poor | Fair | Poor | Good |
| Mid-reservoir | Fair | Fair | Good | Poor | Good |
Dissolved oxygen. According to the 2017 TVA report, dissolved oxygen ratings have fluctuated between “good”, “fair”, and “poor” through the years. In general, the ratings at the dam have been lower than at mid-reservoir. “Prevailing weather patterns and the related changes in reservoir flows are major factors in differing dissolved oxygen conditions from year-to-year. Poorer dissolved oxygen conditions typically occur as a result of reduced flows through the reservoir during periods of low rainfall and runoff.”
Chlorophyll. The 2017 TVA report states that “higher chlorophyll concentrations can be expected at the…. [Tellico Dam] …. because of the exchange of water from the nutrient-rich …. Fort Loudoun Reservoir via the canal connecting the two reservoirs. However, concentrations were higher than expected at the mid-reservoir location given the nutrient-poor soils in the upstream watershed.”
“It should be noted that chlorophyll concentrations in Tellico Reservoir are assessed relative to expectations for the Blue Ridge Ecoregion, which has naturally low nutrient concentrations. Therefore, chlorophyll concentrations are expected to be much lower in Tellico than in other Tennessee Valley reservoirs located outside the Blue Ridge Ecoregion, such as Fort Loudoun Reservoir.”
Fish. When compared to other reservoirs in the TVA system, Tellico Lake is a cool water impoundment due to the cold water inflows from Chilhowee Lake and the Tellico River. As a result the reservoir is relatively infertile and does not support high densities of fish.
Historically, the amounts and types of Tellico Lake fish have varied through the years. TVA reported that in 2017 “the number and variety of fish observed at each location were consistent with long-term averages, and fish health was assessed a “good” rating with low incidences of disease and parasites. A total of thirty-eight different species was observed reservoir-wide. Bluegill, spotfin shiners and brook silversides accounted for a significant portion of the fish observed.”
TDEC (TN Department of Environment & Conservation) has issued a “precautionary advisory for catfish” that covers all of Tellico Lake due to the presence of PCBs. “Children, pregnant women, and nursing mothers should not consume the fish species named. All other persons should limit consumption of the named species to one meal per month.”
Bottom life. Not a lot seems to be known as to why the bottom life is so limited in Tellico Lake. It is thought that the cause is due to the cold, nutrient poor, low mineral content discharges from Chillihowee Dam. All of these conditions limit the ability to establish a diverse, abundant aquatic community on the bottom of the lake. In part this is because few organisms are capable of tolerating these environmental conditions. Low dissolved oxygen concentrations in the water is also a likely factor.
Sediment. The 2017 TVA report stated that “no PCBs or pesticides were detected and concentrations of metals were within suggested background levels. Sediment quality rated “good” in most years prior to 2017, but the detection of PCBs or pesticides (chlordane and aldrin) and/or elevated levels of arsenic has resulted in some “fair” ratings. Arsenic occurs naturally in the soils and concentrations in sediments deposited in the reservoir are generally near – slightly above or below – suggested background concentrations. The pesticides chlordane and aldrin were detected in sediment samples collected from Tellico Reservoir in the early 1990’s. These pesticides were banned from use in the 1970s and 1980s. However, they continue to be detected sporadically in sediments because of their persistence in the environment. Similarly, PCBs were banned from commercial production in 1979, though they may be present in products and materials produced before the ban. PCB concentrations have, however, declined in fish samples collected from Tellico Reservoir. “
So, what should we make of all this? Is Tellico Lake really unhealthy? I think we can draw a few conclusions from the information that is available:
- Our lake is relatively young. How it develops in the future is an opportunity largely up to us. I think Tellico Village needs to consider itself a steward of the lake and be actively working to keep it great.
- The waters feeding the lake are cold, nutrient poor, and have low mineral content. We should not expect the same level of biodiversity from Tellico Lake as is seen on the TN River.
- PCB and other pollutions appear to be declining over time due to sediment build up on the bottom (covering it up) and/or washing out of the system. It is critical that we continue to monitor and prevent pollution to the lake in the future to avoid creating new problems. The greatest current threat appears to be from us as our fertilizers and pesticides get washed into the lake.
- TVA’s idea of “good”, “fair”, and “poor” is a perspective based on creating a healthy, biodiverse environment. That may mean more algae in the water than we’re comfortable seeing. Getting the balance right (not pea soup, but not starving the marine life) is key in this and what is right for Tellico Lake may not be the same answer as in other reservoirs.
What should we all do to help?
- Limit the amount of fertilizer and pesticide you use in your yard. Regardless of where you live in Tellico Village, your yard drains into the lake and so has an impact.
- Join WATeR (Watershed Association of the Tellico Reservoir), which is an all-volunteer organization that works to protect and improve the quality of water in the Tellico Reservoir. tellicowater.org
- Encourage Tellico Village to install “Riparian Buffer Zones” at all drainage outfalls that go into the lake. WATeR has already targeted the lakeside homeowners with this idea: Riparian Buffer Zones
Much of the material for this article was taken from the 2017 TVA Ecological Health Ratings for Tellico Reservoir. Here is the link to their document: Tellico Reservoir
While our ability to see each other at HOA Social gatherings is currently limited, please feel free to send me a note if you have any issues or concerns that I might be able to help with.
Thank you. I look forward to hearing from you.
Mark Pantley
HOA VP of Advocacy
mark.pantley@gmail.com
(832) 654-1272