Hydro-terms visualized
A picture can be worth a thousand words, so we’ll let the pictures help us do the talking:
Cubic foot: instantaneous streamflow is often report in cubic feet per second. For reference, a cubic foot is about 7.5 gallons, so you can picture that many imaginary milk jugs flowing across a point in a second.
Acre-foot: when describing how much water flows past a streamgage during a day or month or year, it is easier to describe in terms of acre feet. An acre-foot is the amount of water that would cover a football field in one foot of water. If a hypothetical stream consistently flowed 1 cubic foot per second (cfs) for an entire year, that would be equal to about 724 acre-feet.
Related
Get the whole picture:
From Gage to Page: A Look Into How USGS Helps You Know the Flow
Measuring Streamflow
Related
Get the whole picture:
From Gage to Page: A Look Into How USGS Helps You Know the Flow