From the Tennessee Valley Authority (TVA):
In May 2004, the TVA Board of Directors approved a new policy that regulates the operations of the Tennessee River and reservoir system. In this new policy, there are specifications for the flow requirements no only for individual reservoirs, but the system as a whole. These requirements will help keep the riverbed below the reservoir dam from drying out. These system wide requirements will ensure that enough water will flow through the river system to meed downstream needs.
This new policy will help enhance the recreation opportunities on tributary storage reservoirs while also meeting the needs for protecting water quality and aquatic resources. This will ensure year-round navigation as well as provide water for power production and municipal and industrial use.
During the summer, from June1 through Labor day, the down-draw of tributary storage will be restricted. Just enough water will be released to meet downstream flow requirements as well as allowing the needed storage space 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 draw-down 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.
Please note! Water release schedules often change without notice due to unanticipated changes in weather conditions and power system requirements.
Use caution near dams. A large amount of water may be discharged without warning at any time. Your safety depends on obeying all posted safety regulations and warnings.
TVA Tailwater Generation Resources