Run-of-the-river hydroelectricity (
ROR) is a type of
hydroelectric generation plant whereby little or no water storage is provided. Run-of-the-river power plants may have no water storage at all or a limited amount of storage, in which case the storage reservoir is referred to as
pondage. A plant without pondage has no water storage and is, therefore, subject to seasonal river flows. Thus, the plant will operate as an
intermittent energy source while a plant with pondage can regulate the water flow at all times and can serve as a
peaking power plant or
base load power plant.