1853 NC Hwy 141, Murphy, NC 28906  •  Phone/Fax: (828) 837-5414

LAKE STUDIES

HISTORY & STATISTICS

Nottely and Chatuge Reservoirs were impounded by the Tennessee Valley Authority (TVA) in 1942 for the purpose of storing flood waters for TVA’s Hiwassee and Apalachia Reservoirs downstream on the Hiwassee River, as well as mainstream dams further downstream on the Tennessee River. In the mid-1950s, single-unit powerhouses were installed at both dams. Today, both reservoirs are operated for many purposes, including flood control, augmentation of flows for navigation, hydropower production, water quality, recreation and aquatic ecology. Vital statistics for the reservoirs are:

WATER QUALITY CONCERNS

Because the north Georgia/western North Carolina region offers a vast array of natural resources, the area is a popular vacation destination for recreational and environmental enthusiasts. The area is also experiencing tremendous growth as more people choose to live away from large urban centers. The latest census data indicate that the growth rate in the area is twice the normal growth rates for North Carolina and Georgia. This growth is apparent upon evaluation of the land conversions along the shoreline.

In 2003, development along the shorelines of Nottely and Chatuge encompassed at least 25 and 42 percent of the total shoreline miles respectively.  As a result of this growth, critical shoreline buffers are being lost. Shoreline buffers are the last line of defense in preventing nonpoint source pollution. Combined with  discharges from municipal waste treatment facilities, the potential exists for a deterioration of water quality in both of these lakes.

TVA reservoir monitoring programs indicate that both reservoirs are showing signs of accelerated eutrophication. Natural eutrophication is a process by which lakes gradually age, filling with sediment and becoming more nutrient-rich. This process normally takes hundreds of years. However, humans, through various watershed activities, have greatly accelerated this process for lakes and reservoirs around the globe.

The influx of large concentrations of sediment (making the water more shallow and therefore allowing more light penetration) and nutrients (plant food) into a lake stimulates the growth of algae. Excessive algae growth (often called "algae blooms") leads first to super-saturation of the water column with oxygen. Then, when populations of algae get too high, there are large die-offs and oxygen depletion occurs. Low concentrations of oxygen often result in fish kills, particularly if fish populations were weakened by previously supersaturated conditions.

For more information about TVA's reservoir monitoring programs and reservoir ecological health ratings, visit http://www.tva.gov/environment/water/index.htm.

For more information about water quality conditions in streams and lakes in North Carolina, visit http://h2o.enr.state.nc.us/basinwide/.

ECONOMIC BENEFITS OF LAKES

During the early 1990s, representatives from Kennesaw State College and the University of Florida conducted a study on the economic value of north Georgia reservoirs. Although the values are somewhat dated, they are presented here so that the reader may gain a general understanding of the importance of good water quality in reservoirs in the upper Hiwassee River watershed in terms of the benefit to the regional economy.

                                                           1990 Economic Study Dollars

As is demonstrated by the values above, these two reservoirs bring millions of dollars into the regional economy of north Georgia and western North Carolina. The loss of all or part of this financial base would likely devastate the region. Because of the combined potential impacts to water quality, ecological health, the regional economy, and property values, the Hiwassee River Watershed Coalition, Inc. (HRWC) decided proactive measures were necessary to better understand and prevent degradation of the reservoirs.

OUTLINE OF HRWC STUDIES

In 2001, HRWC received an appropriation from the Georgia legislature of $216,000 (83 percent of the original request) to determine the causes of water quality deterioration in the watersheds of Nottely and Chatuge Reservoirs and to develop an action plan for improving water quality conditions.

More specifically, HRWC committed to:

• Collect and analyze water quality data from the lakes and tributaries both by professionals and volunteers;

• Determine what factors actually "drive" water quality concerns in each reservoir;

• Identify tributaries contributing the highest levels of nutrients and sediment;

• Identify activities within the watersheds which are the most likely sources of nutrients and sediment;

• Develop actions to reduce nutrients and sediment or which will positively affect the water quality "drivers" for each reservoir; and

• Implement and/or encourage implementation of the actions.

STUDY METHODS

Eighteen months of physical/chemical water quality data were collected professionally in 2002 (Nottely) and 2003 (Chatuge) from 11 sites in each watershed, half of which were stations within the lakes and half were sites on major tributary streams flowing into the lake.  The Monitoring Plan for the Lake Chatuge Eutrophication Study (pdf) contains details about sample collection and analysis, including quality assurance and quality control procedures.

In addition to the professional monitoring, HRWC established volunteer monitoring teams to monitor even more sites on tributaries throughout the two watersheds.  [These teams continue to monitor 14 parameters monthly at 21 locations.  Our volunteer monitoring web pages contain more information about this program.] Over the same period, TVA conducted a detailed land use analysis based on low-altitude, color infrared, aerial photography for each watershed.

In 2004, all of the physical/chemical data that’s been collected, the land use information, flow data from gaging stations throughout the watersheds, and data from wastewater treatment plant discharges (there are actually two discharges into Lake Chatuge) were used to calibrate computer models for each watershed.

Once the models were calibrated, different scenarios were evaluated (2005) by HRWC and TVA staff to determine how various activities in the watershed affect the ecological health of Lake Chatuge and Lake Nottely.  The results will show what types of improvements we as communities should pursue over the next five years to actually improve water quality in these lakes!

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