Abstract: A method and apparatus for controlling water temperature in a man-made pond includes means defining a closed loop raceway within the pond with at least a pump mounted to circulate the water in the raceway. At least a portion of the raceway is covered by a cover which will absorb heat and release a portion thereof into the water as it passes along the raceway below the cover. The pump is preferably arranged to draw cool water from the bottom of the raceway and eject it under the cover at the surface of the pond thereby assuring more uniform water temperature.