Abstract: A floating reservoir cover tensioning system that eliminates unsightly towers that are mounted on the upper surface of the surrounding containing walls of a reservoir. A plurality of tensioning assemblies are mounted in cases supported on the top surface of the surrounding containing wall of the reservoir at predetermined spaced intervals to assure that the tension forces are equally distributed. Each of the tensioning assemblies has a combined structure of a cable drum and a storage drum journaled on a bearing extending up from a mounting plate. A pair of laterally spaced spring motor drums are also journaled on their respective bearings extending up from the mounting plate. One end of a first coiled-band spring is secured to one of the spring motor drums and its opposite end is secured to the storage drum. A second coiled-band spring has its one end secured to the second motor drum and its other end secured to the storage drum.