The reason that it became necessary at Lake Ogallala is because historically this lake derived it's water source from The upper third of Lake McConaughy, which was well oxygenated. About twenty years ago the overflow structure was altered so that the water that came from Lake McConaughy was derived from the lower third which was anoxic. The water was plenty cold, but even spraying it into Lake Ogallala did not impart enough O2 to support what was once a world class trout fishery. Hypolimnetic aeration systems were installed, and I believe have been a pretty good success. I have queried the forum at Nebraska Game and Parks Commission to see what the consensus is as to the success of the system.
