Pondage usually refers to the comparably small water storage behind the weir of a run-of-the-river hydroelectric power plant.
Such a power plant has considerably less storage than the reservoirs of large dams and conventional hydroelectric stations which can store water for long periods such as a dry season or year.
[2][3] As a daily hydropeaking cycle of a hydro power plant with pondage results in fast rising river levels downstream, environmental regulations often restrict the full use of the dispatchability as a peaker.
Because of the possibility of limited pondage, calculating its effect on power generation is important in determining how often the plant can be operated.
This gives an estimation and guide that for twelve hours of pondage, there must be as much storage available in the pond as cubic feet per section received.