A spraybed is a structure designed to oxidize and correct the PH water to make it more suitable for domestic use.
The above photo is of a spraybed operated by Bundaberg Regional Council. In this particular case the spraybed is a concrete structure containing approximately 75mm diameter limestone rubble. Undergound (Bore) water is pumped through Tomago spray nozzles onto the spraybed. The fence in the background of the photo acts as a windbreak reducing the amount of water that drifts beyond the extent of the limestone bed surrounding the spray nozzles.
The rectangular area near the centre of the Google Map below is another Bundaberg Regional Council operated spraybed.