Abstract: An overflow-siphoning device to control the water level of swimming pools or other like pools of water that have peripherally-disposed coping and decking, said device preventing the water level from rising to the joint between the coping-bond beam and the coping. The device, comprising a tubular conduit positioned and fixedly received in a transverse channel formed in the bond beam, has a substantially-flat, elongated mouth defining the inlet therein, followed by an uninterrupted throat portion having an inclined lower wall and a horizontal upper wall, with side walls tapering inwardly to a point of juncture wherein the continuity of the four walls integrally form a circumferential outlet duct, whereby various well-known piping components can be readily attached for diverting the overflow water away from the pool area.