An aeration apparatus for aerating water discharged from a hydraulic turbine includes: a manifold disposed within a crown of a runner of the hydraulic turbine; a plurality of radial pipes extending radially from an outer perimeter of the manifold and in fluid communication with the manifold; and one or more air injectors having a first end disposed within an aeration pipe, each of the one or more air injectors having a second end extending into a nozzle at a first end of one of the radial pipes. Rotation of the aeration apparatus resulting from rotation of the runner causes pumping of water from the manifold through the radial pipes past the one or more air injectors, and water flowing past the one or more air injectors causes air to become entrained in the water. The radial pipes discharge the water and entrained air from the aeration apparatus.