Drought impacts river's water flow
by Richard Simms
posted September 9, 2007
Throughout the summer TVA has been sending out news releases explaining how the drought impacts lake water levels. But those of us who live on the main river around Chattanooga haven't really been able to appreciate the concern. In spite of the low rainfall, TVA has maintained a consistent summer level on mainstream reservoirs.
Many tributary reservoirs never came close to normal summertime water levels.
However folks who live on what are called "tributary reservoirs" to the north and east understand the impact full well. On lakes like Watauga, Douglas, Cherokee, Fontana and others... summertime water levels barely made it above typical wintertime levels. And the impact is dramatic!
On Chickamauga Lake TVA drops the water about six feet in the winter. On those tributary reservoirs the lake levels typically fall 20, 30 or even 40 feet during the winter. This year they stayed nearly that low all summer. Launching ramp and marina operators on those lakes have been seriously impacted.
Now however, the folks on the mainstream are starting to "feel the heat," especially fishermen.
There's very little water "flowing" through the system right now. With TVA dams, the flow of the river is controlled by hydroelectric generators. They are sort of like "faucets" at each TVA dam and TVA turns those faucets on or off depending upon flood control needs and electricity needs.
This is the time of year when TVA would typically turn the faucets "on" more frequently to start lowering the lake levels for the routine winter drawdown. At Chickamauga Dam, when the hydroelectric faucets are on full blast, there is about 45,000 cubic feet of water per SECOND (cfs) flowing through the dam.
However right now there's only an average of 8,300 cfs each day. And the Chickamauga Lake level is still falling... and it is well below the levels the same time last year.
This is the "Operating Guide" for Chickamauga Reservoir as of September 9, 2007. The gray bar represents the normal water levels throughout the year. The thin black line represents last year's water level and the thin red line represents the 2007 water levels.
Chickamauga Dam is somewhat special and may actually release more water than other TVA dams. That's because TVA has an agreement with the city of Chattanooga that guarantees a minimum amount of daily flow regardless of other needs. That is to insure proper effectiveness of the Moccasin Bend Sewage Treatment Plant. Remember, dilution is the solution to pollution.
Meanwhile anglers are missing the additional water flow. They all know that fish react positively to more flowing water. Nobody really knows why... perhaps more flowing water is more highly oxygenated, pehaps it is cooler, perhaps it carries more food downstream... or a combination of all of the above. Regardless, anglers know more flow usually means more fish.
Based upon the current generation schedules, and the weather forecast, it's going to be a long, dry Fall.
It's been a very long time since the Tennessee Valley has seen enough rainfall to force TVA to open the flood gates at Chickamauga Dam. This photo was taken Sept. 19, 2004.
You can monitor TVA lake levels HERE.
| Dining Out | Business | Movies | Focus | About Us |
| Church | Living Well | Memories | Outdoors | Real Estate | Student Scene | Travel |