A measure of the rate of the flow, as a unit volume, in streams, rivers, canals etc. It is equal to a volume of water one foot high and one foot wide flowing a distance of one foot in one second. One cubic foot is equal to 7.48 gallons. As an example, a child’s paddling pool, 4 foot x 4 foot x 1 foot deep (16 cubic feet), would be filled in 8 seconds by water flowing at a rate of 2cfs.