Boosting Oxygen in the Water

Infusing deep waters with life-giving oxygen preserves cold-water species.

  • In summer, a natural process called thermal stratification occurs in deep tributary waters where warm oxygen-rich water floats to the top.
  • The bottom layer can become starved for oxygen as it is used by organic materials or swept into the reservoir.
  • This stresses cold-water wildlife.
  • TVA has developed some ingenious solutions for aerating this cold water, which it deploys on a dam-by-dam basis.

Our Solutions

To help cold-water species continue to thrive, TVA has developed some ingenious solutions, which it employs on a dam-by-dam basis. There are five key technologies:

Aerating Turbines

At some dams, TVA uses aerating turbines to draw air into the water as power is being generated; at other dams, turbines add water after generation.

Surface Water Pumps

At other dams, such as Douglas, surface-water pumps (which look a bit like big ceiling fans) are positioned just above the dam’s intakes and push oxygen-rich water downward during generation.

Oxygen Injection Systems

At some reservoirs, oxygen is injected into the water before it enters the dam’s intake. The system consists of an oxygen tank and evaporators on the bank that are connected to perforated hosing suspended above the reservoir floor upstream of the dam. (It’s the same kind of hosing used in gardens for irrigation.) Gaseous oxygen is pumped through the hosing, creating oxygen bubbles that can be delivered straight to the cold bottom layer.

Aerating Weirs

These are small dams designed to mimic a natural waterfall, adding oxygen to the water as it plunges over the weir walls. Larger infuser weirs are also used, like the one pictured above, which resides at Chatuge Dam.

Low-Pressure Blowers

As advertised, these aerators blow air into the water as it flows through the dam.

With more oxygen in the reservoirs, TVA is able to fulfill its mission of being a good environmental steward, providing the right conditions for cold water species not only to survive but thrive.