The thermal layering that sometimes occurs in dams has the potential to trigger two serious problems, outbreaks of blue green algae and leaching of metal salts from sediments into the water body.

Many efforts to counter the problem use industrial air compressors in an energy-intensive and often inefficient attempt to raise the cold, deoxygenated water and mix it through the warmer top layer of water. 

The mechanical aeration system developed by Qld-based Water Engineering and Research Solutions (WEARS) uses an axial flow pump, or impeller, to push down the warm layer of water at the top of a dam and draw up the cold water trapped underneath.

The method uses up to one-twentieth the energy of compressor systems and is more effective.