Douglas Lake Water Levels
In May 2004, the TVA (Tennessee Valley Authority) Board of Directors approved a new policy for operating the Tennessee River and reservoir system. This policy shifts the focus of TVA reservoir operations from achieving specific summer pool elevations on TVA-managed reservoirs to managing the flow of water through the river system.
The new policy specifies flow requirements for individual reservoirs and for the system as a whole. Reservoir-specific flow requirements keep the riverbed below that reservoir's dam from drying out. System-wide flow requirements ensure that enough water flows through the river system to meet downstream needs.
These flow requirements help to enhance recreation opportunities on tributary storage reservoirs while meeting other needs: protecting water quality and aquatic resources, ensuring year-round navigation, and providing water for power production and municipal and industrial use.
TVA enhances recreational opportunities by restricting the drawdown of tributary storage reservoirs during the summer from June 1 through Labor Day. During this period, under normal operations, just enough water is released from these reservoirs to meet downstream flow requirements. TVA works to keep the water levels in these reservoirs as close as possible to each reservoir's flood guide level a guideline that reflects how much storage space each reservoir needs to hold back potential flood waters. When water must be released to meet downstream flow requirements, a fair share of water is drawn from each reservoir.
System-wide flows are measured at Chickamauga Dam, located near Chattanooga, Tennessee, because this location provides the best indication of the flow for the upper half of the Tennessee River system.
If the total volume of water flowing into Chickamauga Reservoir is less than needed to meet system-wide flow requirements, additional water must be released from upstream reservoirs to augment the natural inflows (a function of rainfall and runoff), resulting in some drawdown of these projects. How much water is released depends on the time period and the total volume of water in storage in 10 tributary reservoirs: Blue Ridge, Chatuge, Cherokee, Douglas, Fontana, Nottely, Hiwassee, Norris, South Holston, and Watauga.