Cubic foot per second (CFS)

The rate of discharge representing a volume of one cubic foot passing a given point during 1 second. This rate is equivalent to approximately 7.48 gallons per second, or 1.98 acre-feet per day


Source: Corrosion-Doctors.org

Wikipedia:  https://en.wikipedia.org/wiki/Cubic_foot#Cubic_foot_per_second_and_related_flow_rates